DESCRIPTION

MATERIAL SUPPLY DEVICE FOR FROZEN-DESSERT MAKING MACHINE, AND FROZEN-DESSERT MAKING MACHINE INCLUDING

THE SAME

TECHNICAL FIELD

The present invention relates to a material supply device for a frozen-dessert making machine and a frozen-dessert making machine including the same. More specifically, the present invention relates to a material supply device for a frozen-dessert making machine which makes frozen desserts such as soft ice creams or shakes.

BACKGROUND ART

Fig. 19 is a schematically cross- sectional view illustrating a conventional frozen-dessert making machine, from a side surface thereof. Fig. 20 is a cross-sectional view explaining the structure of a material supply valve used in the conventional frozen-dessert making machine. Fig. 21 is a lateral cross-sectional view of the material supply valve used in the conventional frozen-dessert making machine. As a conventional frozen-dessert making machine for making frozen desserts such as soft ice creams and shakes, there is a machine described in JP-A No. 2002-65171. As illustrated in Fig. 19, the frozen-dessert making machine includes a material tank 1 for storing a liquid-type frozen-dessert material M, a cylinder portion 2 for agitating and cooling the frozen-dessert material M together with air into a frozen

dessert S, a cooling portion for cooling the material tank 1 and the cylinder portion 2, and a material supply valve 3 which is provided in the material tank 1 and is capable of supplying the material M to the cylinder portion 2. In this field, such a "liquid-type frozen-dessert material" is called

"Mix", and such a "material supply valve" is called "Mix Valve".

The material tank 1 has a material introducing path Ia at its bottom portion. The material introducing path Ia is connected to the cylinder portion 2, and a material supply valve 3 is mounted to the material introducing path Ia. Further, on the bottom surface of the bottom portion of the material tank 1 , there is provided an impeller, not illustrated, which is rotated by a motor for agitating the material M in the material tank 1.

Further, the cylinder portion 2 includes a spiral-shaped dasher 2a for agitating and mixing the material M and air supplied to the inside of the cylinder portion 2, a motor 2 c for rotating and driving the dasher 2a, and an extracting portion 2b for extracting the frozen dessert S made in the cylinder portion 2. The frozen dessert S in the cylinder portion 2 is extracted by opening the extraction path in the extracting portion 2b and by dasher rotation.

The cooling portion is a refrigeration cycle mechanism including an evaporator, a compressor, a condenser, an expansion valve and the like which are connected to one another in the mentioned order in a loop shape through pipe paths. The material supply valve 3 has a double structure constituted

by an outer cylinder 4 and an inner cylinder 5, as illustrated in Fig. 19 to Fig. 21.

The outer cylinder 4 is connected to the material introducing path Ia in the material tank 1 and has a through hole 4a near the bottom of the material tank 1.

The inner cylinder 5, which is inserted into the outer cylinder 4 from the upper opening thereof, has, in its lower portion, a plurality of (two, in the figure) through holes 5a and 5b with different sizes which can communicate with the through hole 4a in the outer cylinder 4. The through hole 4a and the through hole 5a or 5b form a communication hole.

Further, the outer cylinder 4 has positioning cutout slots 4b and 4c at its upper end and, also, the inner cylinder 5 has, at its upper end, a protruding piece 5c to be engaged with the aforementioned cutout slot 4b or 4c. Further, the material supply valve 3 is opened at its upper end and also serves as an air introducing pipe for introducing air from its opening together with the material M into the cylinder portion 2.

The material supply valve 3 having the aforementioned structure is capable of changing the positional relationship between the outer cylinder 4 and the inner cylinder 5. By causing the through holes 4a, 5a and 5b, which intercommunicate the insides and outsides of the respective cylinders to be overlapped or displaced with or from each other, in position, it is possible to open or close the communication hole. Further, one of the smaller through hole 5a and the larger

through hole 5b in the inner cylinder 5 can be selected and the selected through hole can be overlapped with the through hole 4a in the outer cylinder 4, which enables adjusting the size of the communication hole which communicates the material tank 1 and the cylinder portion 2 to each other. By adjusting the size of the communication hole, the flow rate of the material M flowing into the cylinder portion 2 can be adjusted to within a predetermined range, thereby adjusting the mixing ratio between the material M and air in the cylinder portion 2 to within a predetermined ratio, even when the height of the liquid level L of the material M in the material tank 1 is changed.

When the frozen dessert S is extracted from the cylinder portion 2, air and the material M from the material tank 1 are supplied to the cylinder portion 2 through the material supply valve 3.

That is, when the size of the communication hole is maintained at a constant value, as the liquid level L of the material M in the material tank 1 is descended, the pressure by the material M exerted on the communication hole is decreased. As a result, the flow rate of the material M flowing into the cylinder portion 2 through the communication hole is decreased. In addition thereto, the amount of the material M in the material supply valve 3 which is introduced into the cylinder portion 2 is decreased, which makes the mixing ratio of air to the material M in the cylinder portion 2 to be higher than the predetermined ratio, thereby deviating the quality of the frozen dessert S from a permissible range. Therefore, as the material liquid level L descends, the size of the communication hole can be adjusted such that

it is gradually increased, which can adjust the amount of the material M supplied to the cylinder portion 2 such that it is prevented from largely changing. This can maintain the mixing ratio between the material M and air in the cylinder portion 2 within the predetermined range.

DISCLOSURE OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

However, the conventional frozen-dessert making machine has required an operator to monitor the height of the liquid level of the material as required, then select a communication hole with a proper size in the inner cylinder according to the liquid level L of the material M and operate the inner cylinder manually. That is, the operator is required to adjust the amount of the material supplied from the material tank 1 to the cylinder portion 2. Accordingly, there has been a need for such complicated operations and, also, there have been concerns about hygienic aspects since the operator accesses the material with his or her hand.

Further, as described above, the size of the communication hole is increased in a stepwise manner as the material liquid level L is descended, in order to maintain the mixing ratio between the material M and air in the cylinder 2 within a predetermined ratio. However, there is a problem as follows.

As illustrated in Fig. 22, until the size of the communication hole is changed to the next size, the flow rate of the material M flowing into the material supply valve 3 is decreased with descending liquid level L of

the material M in the material tank 1. This gradually increases the mixing ratio of air to the material M supplied to the cylinder portion 2. Further, the timing of changing the size of the communication hole is varied depending on the operator. Therefore, as illustrated by a broken line in Fig. 22, there are cases where the mixing ratio between the material M and air is deviated from the predetermined ratio, if the timing is largely varied.

As described above, the conventional frozen-dessert making machine has had the problem that the mixing ratio between the material M and air supplied to the cylinder portion 2 is not stabilized, since the size of the communication hole is changed in a stepwise manner and, also, the size of the communication hole is manually changed by an operator.

MEANS FOR SOLVING THE PROBLEM

The present invention was made in view of the aforementioned problem and aims at providing a material supply device for a frozen-dessert making machine which can eliminate the necessity of operator's valve operations according to the height of the liquid level of the material, simplify the operations and improve hygienic aspects and also providing a frozen-dessert making machine including the same.

Therefore, according to the present invention, there is provided a material supply device for a frozen-dessert making machine, the material supply device being provided in the frozen-dessert making machine including a material tank for storing a liquid-type

frozen-dessert material, a cylinder portion for agitating and cooling the frozen-dessert material together with air into a frozen dessert, and a cooling portion for cooling the material tank and the cylinder portion, and the material supply device being adapted to adjust the amount of the frozen-dessert material supplied from the material tank to the cylinder portion, the material supply device including: a liquid level detection means for automatically detecting a liquid level of the frozen-dessert material in the material tank; an amount supplied adjustment means for adjusting an amount of the frozen-dessert material supplied to the cylinder portion in conjunction with the height of the detected liquid level; and an air introducing means for introducing air into the cylinder portion; wherein the liquid level detection means is a floating member which floats on the liquid level of the frozen-dessert material in the material tank, and the amount supplied adjustment means includes a double cylinder portion including an outer cylinder portion having a first through hole and an inner cylinder portion having a second through hole communicable to the first through hole and rotate relatively to the outer cylinder portion, and a displacement transfer means for transferring the upward and downward displacement of the floating member to the double cylinder portion to rotate the outer cylinder portion and the inner cylinder portion with respect to each other for changing the size of a communication hole formed by the portions of the first through hole and the second through hole which are overlaid on each other, thereby adjusting the amount of the material supplied to the cylinder portion.

Further, according to another aspect of the present invention, there is provided a frozen-dessert making machine including a material tank for storing a liquid-type frozen-dessert material, a cylinder portion for agitating and cooling the frozen-dessert material together with air into a frozen dessert, a cooling portion for cooling the material tank and the cylinder portion, and the material supply device for a frozen-dessert making machine.

EFFECTS OF THE INVENTION According to the present invention, the height of the liquid level of the material in the material tank is detected by the liquid level detection means, and the amount of the material supplied to the cylinder portion can be adjusted in conjunction with the height of the detected liquid level by the amount supplied adjustment means, which enables automatically adjusting the mixing ratio between the material and air in the cylinder portion to within a predetermined range, thereby making a desired frozen dessert. This can eliminate the necessity of operator's complicated operations for monitoring the height of the liquid level of the material and adjusting, through a valve, the amount of the material supplied to the cylinder portion according to the height of the liquid level. Further, the operator is not required to insert his or her hand into the material tank for operating the valve, thereby improving hygienic aspects.

Further, the liquid level detection means is a floating member which floats on the material liquid level in the material tank and can be

fabricated with a simple structure and lower cost without using electric means.

Further, the amount supplied adjustment means can form a mechanism for mechanically transferring the displacement of the floating member in the material tank to the double cylinder portion through the displacement transfer means to rotate the outer cylinder portion and the inner cylinder portion with respect to each other. That is, without using a power source such as a motor for rotating the outer cylinder portion and the inner cylinder portion with respect to each other, the movement of the floating member which moves along with the change of the height of the material liquid level in the material tank can be utilized as power. This enables fabricating the amount supplied adjustment means with a lower cost.

The liquid level detection means and the amount supplied adjustment means can be employed in various types of embodiments which will be described later.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a cross- sectional view illustrating the schematic structure of a first embodiment of a frozen-dessert making machine of the present invention, from a side surface thereof.

Fig. 2 is a side view illustrating a material supply device formed by assembling and unitizing a liquid level detection means, an amount supplied adjustment means and an air introduction means of the first embodiment.

Fig. 3 is an exploded view illustrating the material supply device according to the first embodiment at an exploded state.

Fig. 4(a) and 4(b) are an explanation view illustrating a state where a communication hole according to the first embodiment has a smaller size.

Fig. 5 (a) and 5(b) are an explanation view illustrating a state where the communication hole according to the first embodiment has a larger size.

Fig. 6 is a side view illustrating a state where a floating member according to the first embodiment has descended.

Fig. 7(a) and 7(b) are an explanation view illustrating a state where a material is supplied to a cylinder portion according to the first embodiment.

Fig. 8 (a) and 8(b) are an explanation view illustrating a state where the material and air are supplied to the cylinder portion according to the first embodiment.

Fig. 9 is a view explaining the relationship between the descend of the liquid level of the material in the material tank and the mixing ratio between the amount of air and the material supplied to the cylinder portion.

Figs. 10 (a) to 10(f) are views illustrating a first modification example of the first embodiment.

Fig. 11 is a view illustrating a second modification example of the first embodiment. Fig. 12 is a view illustrating a third modification example of the

first embodiment.

Fig. 13 is a side view illustrating a material supply device according to the third modification example of the first embodiment.

Fig. 14 is an explanation view illustrating a material supply device according to a second embodiment.

Fig. 15 is a concept view explaining the fact that, if a pin is descended, this causes a first through hole to rotate, thereby gradually increasing the size of a communication hole in the second embodiment.

Fig. 16 is an explanation view illustrating a material supply device according to a third embodiment.

Fig. 17 is an explanation view illustrating a material supply device according to a fifth embodiment.

Fig. 18 is a concept view explaining the fact that, when a pin is descended, this causes an outer cylinder portion to rotate, thereby gradually increasing the size of a communication hole in the fifth embodiment.

Fig. 19 is a cross-sectional view illustrating the schematic structure of a conventional frozen-dessert making machine, from a side surface thereof. Fig. 20 is a cross-sectional view explaining the structure of a material supply valve of Fig. 19.

Fig. 21 is a lateral cross-sectional view of the material supply valve of Fig. 19.

Fig. 22 is a view explaining the relationship between the descend of the liquid level of the material in the material tank and the mixing

ratio of air with respect to the amount of the material and air supplied to the cylinder portion.

PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION A material supply device for a frozen-dessert making machine according to the present invention is a material supply device being provided in the frozen-dessert making machine including a material tank for storing a liquid-type frozen-dessert material, a cylinder portion for agitating and cooling the frozen-dessert material together with air into a frozen dessert, and a cooling portion for cooling the material tank and the cylinder portion, and also being adapted to adjust the amount of the frozen-dessert material supplied from the material tank to the cylinder portion, the material supply device including: a liquid level detection means for automatically detecting a liquid level of the frozen-dessert material in the material tank; an amount supplied adjustment means for adjusting an amount of the frozen-dessert material supplied to the cylinder portion in conjunction with the height of the detected liquid level; and an air introducing means for introducing air into the cylinder portion; wherein the liquid level detection means is a floating member which floats on the liquid level of the frozen-dessert material in the material tank, and the amount supplied adjustment means includes a double cylinder portion including an outer cylinder portion having a first through hole and an inner cylinder portion having a second through hole communicable to the first through hole and rotate relatively to the outer cylinder portion,

and a displacement transfer means for transferring the upward and downward displacement of the floating member to the double cylinder portion to rotate the outer cylinder portion and the inner cylinder portion with respect to each other for changing the size of a communication hole formed by the portions of the aforementioned first through hole and the second through hole which are overlaid on each other, thereby adjusting the amount of the material supplied to the cylinder portion.

The frozen-dessert making machine according to the present invention is a frozen-dessert making machine which agitates and mixes a material and air at a mixing ratio within a predetermined ratio under a cooling state for making a fine bubble dispersed frozen desserts such as soft ice creams and drinks called shakes.

Hereinafter, there will be described embodiments of a material supply device for a frozen-dessert making machine according to the present invention and a frozen-dessert making machine including the same, with reference to the drawings. However, the present invention is not intended to be limited to the following embodiments.

(First Embodiment)

Fig. 1 is a cross-sectional view illustrating the schematic structure of a first embodiment of a material supply device according to the present invention and a frozen-dessert making machine using the same, from a side surface thereof. The frozen-dessert making machine includes a material tank 10

which stores a liquid frozen-dessert material M, a cylinder portion 20 which agitates and cools the frozen-dessert material M together with air into a frozen dessert, a cooling portion which cools the material tank 10 and the cylinder portion 20, and a material supply device Fl which adjusts the amount of frozen-dessert material M which is supplied to the cylinder portion 20 from the material tank 10.

The material tank 10 has an upper opening portion which is opened and closed by a lid member 10a and also has a material introduction path 1 1 at its bottom portion, and the material introduction path 11 is connected to the cylinder portion 20. Further, on the bottom surface of the bottom portion of the material tank 10, there is provided an impeller, not illustrated, which is rotated by a motor for agitating the material M in the material tank 10.

Further, the cylinder portion 20 has a dasher 21 having spiral-shaped agitation blades for agitating and mixing the material M and air supplied to the inside thereof, a motor 22 for rotating and driving the dasher 21, and an extraction portion 23 for extracting the frozen dessert S made therein. The frozen dessert S in the cylinder portion 20 is extracted by opening the extraction path of the extraction portion 23 at a state where the dasher 21 is rotated.

In the present embodiment, the cooling portion is not limited to a particular structure and is a refrigeration-cycle mechanism constituted by, for example, an evaporator, a compressor, a condenser, an expansion valve and the like which are placed around the material tank 10 and the cylinder portion 20.

Further, the material tank 10, the cylinder 20 and the cooling portion can have the same structures as those of the conventional frozen-dessert making machine described with reference to Fig. 19.

The material supply device Fl placed in the material tank 10 includes a liquid level detection means 40 for automatically detecting the liquid level L of the material M in the material tank 10, an amount supplied adjustment means 50 for adjusting the amount of the material M which is supplied to the cylinder portion 20 in conjunction with the height of the detected liquid level, and an air introduction means 60 for introducing air into the cylinder portion 20.

Fig. 2 is a side view illustrating the material supply device Fl formed by assembling and unitizing the liquid level detection means 40, the amount supplied adjustment means 50 and the air introduction means 60. Fig. 3 is an exploded view illustrating the material supply device Fl at an exploded state.

As illustrated in Fig. 1 to Fig. 3, the air introduction means 60 is a vertical pipe 61 which has an external-air introducing port 61a at its upper portion and extends from the external-air introducing port 61a through the material tank 10 to communicate with the inside of the cylinder portion 20. This vertical pipe 61 is inserted at its lower end to the material introduction path 1 1 of the material tank 10. The vertical pipe 61 has a concave peripheral slot 61b for fitting an O ring 9 thereto and also has an outer flange 61c to be contacted with the bottom portion of the material tank 10 slightly above the concave peripheral slot 61b. The O ring 9 prevents the material M in the material tank 10

from being supplied to the cylinder portion 20 through portions other than a communication hole which will be described later.

The liquid level detection means 40 is a floating member 41 which floats on the material liquid level L in the material tank 10. The floating member 41 has a ring shape with a hole through which the vertical pipe 61 is inserted and is constituted by a floating- member main body 42 with a circular container shape, and a lid member 43 which is fitted in the floating-member main body 42 to cover the upper opening portion thereof. Further, the floating- member main body 42 has a cylinder portion 42a for inserting the vertical pipe 61 therethrough at its center portion and also has, at is bottom portion, a concave portion 42b formed in the direction across the cylinder portion 42a.

Further, there is provided a pair of first horizontal shafts 156a at positions on the outer peripheral surface of the floating- member main body 42 above the concave portion 42b, along the same axis. The pair of first horizontal shafts 156a are shafts for mounting a first arm 157 of a link mechanism 155 which will be described later to the floating member 41 such that it can sway. Further, the lid member 43 has a short cylinder portion 43a and an outer peripheral wall portion 43b. The short cylinder portion 43a enables inserting the vertical pipe 61 through the center of the lid member 43 and is fitted to the cylinder portion 42a. The outer peripheral wall portion 43b is provided vertically along the outer peripheral edge of the lid member 43 and is fitted to the outer peripheral

upper edge of the floating- member main body 42.

The amount supplied adjustment means 50 is structured to include a double cylinder portion 51 and a link mechanism 155 as a displacement transfer means, as illustrated in Fig. 1 and Fig. 2. As illustrated in Fig. 1 to Fig. 3, the double cylinder portion 51 has an inner cylinder portion 53 having a second through hole 53a and an outer cylinder portion 52 having a first through hole 52a which can communicate with the second through hole 53a. The outer cylinder portion 52 is fitted in the inner cylinder portion 53 such that the outer cylinder portion 52 is rotatable with respect to the inner cylinder portion 53.

This double cylinder portion 51 is opened at its one end and is communicated to the vertical pipe 61 and is extended horizontally near the bottom portion of the material tank 10. Further, the double cylinder portion 51 is closed at the other end thereof.

More specifically, the inner cylinder portion 53 is communicated and coupled to the vertical pipe 61 at its one end and also is opened at the other end thereof. Further, the inner cylinder portion 53 is provided with the second through hole 53a at its lower portion and also is provided with a protrusion 53b in its axial direction on the outer peripheral surface of its upper portion.

On the other hand, the outer cylinder portion 52 is fitted in the inner cylinder portion 53 from its opened end and is closed at the other end thereof, and a second horizontal shaft 156b is provided integrally with the closed end portion of the outer cylinder portion 52.

The second horizontal shaft 156b is a shaft for mounting a second arm 158 of the link mechanism 155, which will be described later, to the outer cylinder portion 52 and also for transferring the force transferred from the link mechanism 155 to the outer cylinder portion 52. Therefore, the second horizontal shaft 156b is not a circular shaft and is formed to have, for example, an isosceles-triangular-column shape.

Further, the outer cylinder portion 52 has, in its lower portion, the first through hole 52a which can communicate with the second through hole 53a in the inner cylinder portion 53 and also has a concave portion 52b in its inner peripheral surface opposite from the first through hole 52a. The concave portion 52b is for receiving the aforementioned protrusion 53b on the inner cylinder portion 53 and is formed over a predetermined range in the circumferential direction. In the double cylinder portion 51 having the aforementioned structure, the outer cylinder portion 52 is fitted to the outer side of the inner cylinder portion 53 such that the outer cylinder portion 52 is rotatable with respect to the inner cylinder portion 53 with substantially no gap interposed therebetween. Further, at the side of the vertical pipe 61 opposite from the second horizontal shaft 156b, a supporting rod 159 is extended horizontally from the outer peripheral surface of the vertical pipe 61. Further, at the end portion of the supporting rod 159, there is provided a sub-second horizontal shaft 1 156b having an axis coincident with the axis of the second horizontal shaft 156b. This sub-second horizontal

shaft 1156b is a shaft for supporting the second arm 158 of the link mechanism 155 such that it can sway.

Fig. 4 is an explanation view illustrating a state where the communication hole according to the present embodiment has a smaller size, and Fig. 5 is an explanation view illustrating a state where the communication hole according to the present embodiment has a larger size.

As illustrated in Fig. 4, the second through hole 53a in the inner cylinder portion 53 is formed to have a longer-hole shape extending in the axial direction, while the first through hole 52a in the outer cylinder portion 52 is formed to have substantially a triangular shape. The double cylinder portion 51 having the aforementioned structure has a communication hole 51a constituted by the first through hole 52a in the outer cylinder portion 52 and the second through hole 53a in the inner cylinder portion 53 which are overlapped with each other.

With this double cylinder portion 51 , the outer cylinder portion 52 is rotated from the state of Fig. 4 in the direction of an arrow A, which moves the position of the first through hole 52a, thereby changing the size of the aforementioned communication hole 51a, as illustrated in Fig. 5. At this time, the movement of the first through hole 52a with respect to the second through hole 53a is restricted by the end surfaces of the concave portion 52b of the outer cylinder portion 52 in the circumferential direction against the protrusion 53b on the inner cylinder portion 53. At a state where the liquid level L of the material M in the

material tank 10 is at a higher position as illustrated in Fig. 1, the positional relationship between the first through hole 52a and the second through hole 53a is such that the size of the communication hole 51a is smaller as illustrated in Fig. 4. On the other hand, at a state where the liquid level has been descended to the vicinity of the bottom portion of the material tank, the communication hole 51a has a larger size, as illustrated in Fig. 5.

Accordingly, considerations are made for the shape and size of the second through hole 53a and the width of the protrusion 53b in the inner cylinder portion 53, the position at which the first through hole 52a is formed, the shape and size of the first through hole 52a and the size of the concave portion 52b in the outer cylinder portion 52, and the like, such that the positional relationship between the first through hole 52a and the second through hole 53a and the size of the communication hole 51a according to the height of the material liquid level L become those described above.

As illustrated in Fig. 1 to Fig. 3, in the amount supplied adjustment means 50, the link mechanism 155 as the displacement transfer means converts the upward or downward movement of the floating member 1 according to the height of the material liquid level L into rotational movement of the outer cylinder portion 52 and the inner cylinder portion 53 with respect to each other about a horizontal axis, which changes the size of the communication hole 51a in the double cylinder portion 51 (Fig. 4 and Fig. 5), as described above. That is, the link mechanism 155 is structured to change the size of the

communication hole 51a, as described above, for adjusting the amount of the material M which is supplied to the cylinder portion 20.

As illustrated in Fig. 3, the link mechanism 155 includes the first arm 157 having pivo tally-coupling portions at its opposite ends, and the second arm 158 having pivo tally-coupling portions at its opposite ends. The pivo tally-coupling portion of the first arm 157 at its one end and the pivo tally-coupling portion of the second arm 158 at its one end are pivotally coupled to each other such that they can sway. The pivotally-coupling portion of the first arm 157 at the other end thereof is coupled to the first horizontal shaft 156a such that the first arm 157 can sway. The pivotally-coupling portion of the second arm 158 at the other end thereof is coupled to the second horizontal shaft 156b such that the outer cylinder portion 52 is rotatable.

The first arm 157 is formed to have substantially a Y shape having a bifurcated portion 157a at its one end and also having a bent portion 157b which is bent orthogonally at the other end portion thereof. At the opposite ends of the bifurcated portion 157a, there are formed axial holes 157c as pivotally-coupling portions which enable rotatably inserting the pair of first horizontal shafts 156a therethrough. At the end portion of the bent portion 157b, a shaft-shaped pivotally-coupling portion 156c is formed integrally therewith.

The second arm 158 is also formed to have substantially a Y shape having a bifurcated portion 158a at its one end, similarly to the first arm 157, and also has a pair of parallel linear portions 158b at its portion opposite from the bifurcated portion 158a.

At one end portion of the bifurcated portion 158a, there is formed a triangular hole 158c as a pivo tally-coupling portion to be fitted to the second horizontal shaft 156b having an isosceles-triangle-column shape and, also, at the other end portion of the bifurcated portion 158a, there is formed an axial hole 158d as a pivotally-coupling portion which enables inserting the sub-second horizontal shaft 1156b therethrough such that the sub-second horizontal shaft 1156b is rotatable with respect to the other end portion of the bifurcated portion 158a. The bifurcated portion 158a prevents the outer cylinder portion 52 from being pulled out from the inner cylinder portion 53.

Further, at end portions of the pair of parallel linear portion 158b, there are formed hole-shaped pivotally-coupling portions 158e which enable inserting the shaft-shaped pivotally-coupling portion 156c therethrough such that the shaft- shaped pivotally-coupling portion 156c is rotatable with respect to the end portions of the parallel linear portions 158b, so that the pair of parallel linear portions 158b sandwich the pivotally-coupling portion 156c of the first arm 157 in such a way as to pivotally support it. Further, in the opposing surfaces of the end portions of the pair of parallel linear portions 158b which are provided with the pivotally-coupling portions 158e, there are formed a pair of tapered slots 158f having a depth gradually increasing with increasing distance from the pivotally-coupling portions 158e in the upward direction perpendicular to the parallel linear portion 158b. In mounting the pivotally-coupling portions 156c to the pivotally-coupling portions 158e, when the shaft tip ends of the pivotally-coupling portions

156c are moved along the respective tapered slots 158f, the gap between the pair of parallel linear portions 158b is increased due to the elastic deformation thereof, which enables inserting easily the pivotally-coupling portions 156c into the pivotally-coupling portions 158e.

In the link mechanism 155 having the aforementioned structure, at a state where the material tank 10 is filled with a material M up to its upper portion and, thus, the floating member 41 exists at an upper position as illustrated in Fig. 1 and Fig. 2, the first and second arms 157 and 158 take such an attitude that they are bent in an L shape while being coupled to each other.

When the material M in the material tank 10 is supplied to the cylinder portion 20, the liquid level L is gradually descended. Along therewith, the floating member 41 is gradually descended as illustrated in Fig. 6, which causes the second arm 158 to sway downwardly (in the direction of an arrow A) with respect to the second horizontal shaft 156b, thereby causing the first arm 157 and the second arm 158 to approach each other.

Since the second arm 158 sways downwardly, the outer cylinder portion 52 of the double cylinder portion 51 which is coupled to the second arm 158 is rotated in the direction of the arrow A, which causes the first through hole 52a to be moved with respect to the second through hole 53a from the state of Fig. 4 to the state of Fig. 5, thereby gradually increasing the size of the communication hole 51a. Further, Fig. 6 is a side view illustrating a state where the floating member has

descended in the present embodiment.

Further, as illustrated in Fig. 6, the bent portion 157b of the link mechanism 155 prevents the first arm 157 and the second arm 158 from interfering with each other and, further, the concave portion 42b provides a clearance for preventing the bottom portion of the floating member 41 from coming into contact with the double cylinder portion 51 , which allows the floating member 41 to descend to the vicinity of the bottom portion of the material tank 10 or to the bottom portion thereof. Accordingly, with the present embodiment, the stroke of the sway of the second arm 158 can be increased, which increases the range in which the outer cylinder portion 52 can rotate, in comparison with cases where the floating member 41 has a flat bottom surface. As a result, with the present embodiment, it is possible to ensure a longer stroke of the movement of the first through hole 52a with respect to the second through hole 53a, thereby causing the size of the communication hole 51a to change moderately, not abruptly, along with the descend of the liquid level.

Further, since the floating member 41 can descend to the vicinity of the bottom portion of the material tank 10 or to the bottom surface thereof and, further, the communication hole 51a is placed in the lower portion of the double cylinder portion 51, it is possible to supply the material to the cylinder portion 20 even if the liquid level L of the material in the material tank 10 descends to the vicinity of the bottom portion. The material supply device Fl having the aforementioned

structure can be fabricated from a plastic such as polyacetal or a metal such as a stainless steel.

Hereinafter, a state where a material is supplied to the cylinder portion 20 from the material tank 10 in the frozen-dessert making machine according to the first embodiment will be described.

Fig. 7 is an explanation view illustrating a state where a material is supplied to the cylinder portion according to the first embodiment, and Fig. 8 is an explanation view illustrating a state where the material and air are supplied to the cylinder portion according to the first embodiment.

In the frozen-dessert making machine illustrated in Fig. 1 , the cylinder 20 stores a frozen dessert S made by agitating and mixing a material and air at a mixing ratio within a predetermined range, for example, a material and air at a volume ratio of about 7 : 3 in the case of a soft ice cream, under a cooling condition. Further, in the frozen-dessert making machine illustrated in Fig. 1 , at a state where the material tank 10 stores a material M up to the vicinity of the upper- limit height thereof, the material M has been flowed into the vertical pipe 61 up to the same height as the height of the liquid level L in the material tank 10, as illustrated in Fig. 7(a). At this time, the communication hole 51a constituted by the first through hole 52a in the outer cylinder portion 52 and the second through hole 53a in the inner cylinder portion 53, which are overlapped with each other in the double cylinder portion 51, has a smaller size, as illustrated in Fig. 4. A predetermined amount of the frozen dessert S is extracted by

opening the extraction path in the extracting portion 23 and by dasher rotation in the cylinder portion 20. At this time, as shown in Fig. 7(b), a negative pressure is generated in the cylinder portion 20, which causes the material M in the vertical pipe 61 to flow into the cylinder portion 20 at first, due to the suction effect of the negative pressure in the cylinder portion 20. Along therewith, the liquid level Ll of the material M in the vertical pipe 61 is descended.

As the liquid level Ll of the material M in the vertical pipe 61 is descended, the pressure exerted on the communication hole 51a by the material M in the material tank 10 gradually becomes greater than the pressure exerted on the communication hole 51a by the material M in the double cylinder portion 51 , due to the relationship with the difference between the height of the liquid level L of the material M in the material tank 10 and the height of the liquid level Ll of the material M in the vertical pipe 61 and the specific gravity of the material M and the like. As a result, the material M in the material tank 10 is gradually flowed into the communication hole 51a of the double cylinder portion 61 (see Fig. 8(a)).

When the frozen dessert S is further extracted, the liquid level Ll of the material M in the vertical pipe 61 is descended to reach the inside of the cylinder portion 20. Along therewith, as illustrated in Fig. 8 (a), the material M flowing from the material tank 10 through the communication hole 51a and air in the vertical pipe 61 flow into the cylinder portion 20 and, then, the material M and the air are agitated and mixed in the cylinder portion 20, under the cooling condition, thus

resulting in formation of a frozen dessert. At this time, the air flowed into the cylinder portion 20 is introduced into the frozen dessert by being mixed with the material M.

Then, after the completion of the extraction of the frozen dessert S, as illustrated in Fig. 8(b), the material M and air are no longer flowed into the cylinder 20, and the material flows into the vertical pipe 61 until its height reaches the liquid level L of the material M in the material tank 10.

During the extraction of the frozen dessert, as the liquid level L of the material M in the material tank 10 is descended, the floating member 41 illustrated in Fig. 1 is also descended. As the floating member 41 is descended, the outer cylinder portion 52 is rotated by an amount corresponding to the amount of the sway of the second arm 158 due to the operation of the aforementioned link mechanism 155, which continuously increases the size of the communication hole 51a.

Accordingly, even when the liquid level L of the material M in the material tank 10 is continuously descended and, accordingly, the pressure exerted on the communication hole 51a by the material M in the material tank 10 is gradually decreased, the flow rate of the material M flowing through the communication hole 51a is prevented from deviating from a predetermined range. As a result, the mixing ratio between the material M and air flowing into the cylinder portion 20 is prevented from deviating from a predetermined range.

As described above, a predetermined amount of the frozen dessert S is extracted from the cylinder portion 20 a plurality of times,

which causes the height of the liquid level L of the material M in the material tank 10 to be gradually descended. During this, at the time when the extraction of the frozen dessert S is stopped, the material flows into the vertical pipe 61 until its height reaches the height of the liquid level L of the material in the material tank 10 as described with reference to Fig. 8(b), but the height of the liquid level Ll of the material in the vertical pipe 61 is decreased every time the frozen dessert S is extracted. That is, every time the frozen dessert S is extracted, the amount of the material M in the vertical pipe 61 which is introduced into the cylinder portion 20 at the time of the extraction of the frozen dessert is decreased.

The material supply device according to the present invention is designed in consideration of the amount of the material M in the vertical pipe 61. That is, in the material supply device, the size of the communication hole 51a and the rate of change thereof are designed such that the mixing ratio between the material M and air falls within a predetermined range, even if, every time the frozen dessert S is started to be extracted, the height of the material liquid level L in the material tank 10 and the height of the material liquid level Ll in the vertical pipe 61 at the time when extraction of the frozen dessert S is not performed are varied. This enables automatically controlling the flow rate of the material M flowing into the double cylinder portion 51 to be a flow rate which causes the material M and air to be supplied to the cylinder portion 20 at a proper ratio. With the material supply device according to the present

invention and the frozen-dessert making machine using the same, the amount of the material M in the material tank 10 is decreased as the frozen dessert S is gradually extracted as described above and, when the material liquid level L is descended to below the communication hole 51a, the material M is no longer supplied to the cylinder portion 20. Accordingly, it is preferable that an operator replenishes the material tank 10 with the material M at a time when the liquid level L is above the communication hole 51a, such as a time when the double cylinder portion 51 is exposed to air above the liquid level L. Further, when the material tank 10 is replenished with the material M, the floating member 41 is ascended and, along therewith, the amount supplied adjustment means 50 performs the opposite operation from that when the floating member 41 is descended, so that the communication hole 51a is restored from the state of Fig. 5 where it has a larger size to the state of Fig. 4 where it has a smaller size.

Further, generally, in the frozen-dessert making machines of this type, the cooling portion can be operated according to the heating cycle, which is the reverse of the refrigeration cycle, for heating the material tank 10 and the cylinder portion 20 at a temperature which causes no deterioration of the material M for thermally pasteurising the material M and the frozen dessert S. At this time, for example, a shielding tube having an outer collar at its upper end can be inserted into the vertical pipe 61 to prevent the communication between the vertical pipe 61 and the double cylinder portion 51. Such shielding is performed in order to prevent the material M in the material tank 10

from flowing into the cylinder portion 20 through the communication hole 51a even if a space is formed in the cylinder portion 20 since the frozen dessert S in the cylinder portion 20 is molten and separated into the material M and air. With the material supply device Fl having the aforementioned structure according to the first embodiment, it is possible to offer advantages as follows.

(Effect 1-1) The height of the liquid level L of the material M in the material tank 10 is detected with the floating member 41, and the link mechanism 155 is operated in conjunction with the detected height of the liquid level L. Further, the outer cylinder portion 52 is rotated with respect to the inner cylinder portion 53 to adjust the size of the communication hole 51a, thereby adjusting the amount of the material M which is supplied to the cylinder portion 20. This enables automatically adjusting the mixing ratio between the material M and air in the cylinder portion 20 to within a predetermined range, thereby enabling making a desired frozen dessert. In addition thereto, there is also offered the advantage of eliminating the necessity of operator's complicated operations for monitoring the height of the liquid level L of the material M and manually adjusting the amount of the material M supplied to the cylinder portion 20 through a valve according to the height of the liquid level L. Furthermore, there is also offered the advantage of improving

the hygienic aspects since the operator is not required to insert his or her hand into the material tank 10 for operating the valve.

Further, as illustrated in Fig. 9, the size of the communication hole is automatically and continuously increased as the liquid level L of the material M in the material tank 10 is descended, which can stabilize the flow rate of the material M flowing into the double cylinder portion 51. This prevents the mixing ratio between the material M and air supplied to the cylinder 20 from deviating from the predetermined range. Further, in Fig. 9, for ease of description, the graph line representing the mixing ratio is designated as a straight line indicative of a constant ratio, it is not problematic that the graph line is not a straight line, provided that it falls within the predetermined range.

(Effect 1-2) Further, the liquid level detection means is the floating member

41 which floats on the material liquid level L in the material tank 10 and can be fabricated with a simple structure and lower cost without using electric means.

Further, the amount supplied adjustment means used herein is a mechanism for mechanically transferring the displacement of the floating member 41 in the material tank 10 to the double cylinder portion 52 through a displacement transfer means to rotate the outer cylinder portion 52 and the inner cylinder portion 53 with respect to each other, and no power source such as a motor for rotating the outer cylinder portion 52 and the inner cylinder portion 53 with respect to

each other is employed. That is, the amount supplied adjustment means can be constituted by a mechanism capable of utilizing, as motive power, the movement of the floating member 41 which moves along with the change of the height of the material liquid level L in the material tank 10. Accordingly, the amount supplied adjustment means can be fabricated with a simple structure and lower cost without using electric means.

(Effect 1-3) Further, the displacement transfer means is the link mechanism

155 and therefore is capable of smoothly converting the upward or downward displacement of the floating member 41 into a rotational force and certainly transferring it to the outer cylinder portion 52.

Further, since the vertical pipe 61 is inserted in the hole of the floating member 41 , the floating member 41 is prevented from freely floating on the material liquid level L, which can maintain the first horizontal shaft 156a at a position substantially just above the second horizontal shaft 156b. This enables operating the link mechanism 155 such that the outer cylinder portion 52 is rotated by an amount corresponding to the upward or downward displacement of the material liquid level L with high accuracy.

(Effect 1-4)

Due to the use of the vertical pipe 61 as an air introducing means, it is possible to eliminate the necessity of providing separate

means for introducing air into the cylinder portion 20, thereby simplifying the structure of the material supply device Fl.

(Effect 1-5) Since the communication hole 51a is placed in the lower portion of the double cylinder portion 51, it is possible to supply stably the material to the cylinder portion even when the liquid level L of the material in the material tank 10 is descended to the vicinity of the bottom portion. The following variations can be made to the present first embodiment.

(First Modification Example of First Embodiment)

Fig. 10 is a view illustrating a first modification example of the first embodiment. The shapes of the first and second through holes in the double cylinder portion according to the first embodiment can be changed to shapes as illustrated in Fig. 10(a) to 10(f), for example.

Fig. 10(a) illustrates a case where the first through hole 152a in the outer cylinder portion 152 and the second through hole 153a in the inner cylinder portion 153 have the same isosceles triangle shape, and the respective triangular shapes are placed in the same orientation.

Also, the shapes of the respective communication holes can be properly changed to regular triangle shapes, right triangle shapes or the like, as well as isosceles triangle shapes. Fig. 10(b) illustrates a case where the first through hole 252a in

the outer cylinder portion 252 and the second through hole 253a in the inner cylinder portion 253 have the same isosceles triangle shape, and the respective triangle shapes are placed in the opposite orientations.

Fig. 10(c) illustrates a case where the first through hole 352a in the outer cylinder portion 352 and the second through hole 353a in the inner cylinder portion 353 have the same oblong shape extending in the circumferential direction. Also, the shapes of the respective through holes can be properly changed to elliptical shapes, droplet shapes or the like, as well as oblong shapes. Fig. 10(d) illustrates a case where the first through hole 452a in the outer cylinder portion 452 and the second through hole 453a in the inner cylinder portion 453 have the same square shape. Also, the shapes of the respective communication holes can be properly changed to rectangular shapes, rhombus shapes, pentagon shapes, hexagon shapes or the like, as well as square shapes.

Fig. 10(e) illustrates a case where the first through hole 552a in the outer cylinder portion 552 and the second through hole 553a in the inner cylinder portion 553 have the same circular shape.

Fig. 10(f) illustrates a case where the first through hole 652a in the outer cylinder portion 652 and the second through hole 653a in the inner cylinder portion 653 are the same two longer holes which are extended in the circumferential direction and arranged in the direction of the cylinder axis. Also, the numbers of the respective through holes can be properly changed to three or more and, also, the sizes of the respective through holes can be made different from each other.

Further, although not illustrated, the first and second through holes can be placed in the end surface of the double cylinder portion. In this case, the end portion of the inner cylinder portion is closed similarly to the outer cylinder portion, and the first and second through holes are formed in the closed end walls of the inner cylinder portion and outer cylinder portion, around the second horizontal shaft. The shapes of the first and second through holes can be arc shapes, as well as triangle shapes, rectangular shapes, circular shapes and the like as described above. Further, the shapes and the combination of the first and second through holes are not limited to those described above, and it is also possible to combine first and second through holes having different shapes and different numbers of first and second through holes.

(Second Modification Example of First Embodiment)

Fig. 1 1 is a view illustrating a second modification example of the first embodiment. The second horizontal shaft 156b in the link mechanism according to the first embodiment can be placed in the inner cylinder portion 753 of the double cylinder portion, as illustrated in Fig. 1 1. In this case, an outer cylinder portion 752 having opened opposite ends is communicated and connected, at its one end, to the vertical pipe. Further, an inner cylinder portion 753 is closed at its one end with an end wall 753a with an outer diameter larger than an inner diameter of the outer cylinder portion 752, and the second horizontal shaft 156b is formed integrally with the end wall 753a. Further, the

opened end portion of the inner cylinder portion 753 is inserted in and mounted to the outer cylinder portion 752. Further, a first through hole 752a and a second through hole 753a are formed in the lower portions of the outer cylinder portion 752 and the inner cylinder portion 753. Further, preferably, a concave portion and a protrusion as those described with reference to Fig. 3 are provided in the outer cylinder portion 752 near its opening portion and on the inner cylinder portion 753 near the end wall 753a, in order to limit the range of the rotation of the inner cylinder portion 753.

(Third Modification Example of First Embodiment)

Fig. 12 is a view illustrating a third modification example of the first embodiment. Fig. 13 is a side view illustrating a material supply device according to the third modification example of the first embodiment.

As illustrated in Fig. 12, the link mechanism can be provided with a plurality of pairs of first horizontal shafts 156a in the vertical direction. By doing this, a pair of first horizontal shafts 156a can be selected from the plurality of pairs of first horizontal shafts 156a at different vertical positions and the first arm 157 can be pivotally coupled thereto as illustrated in Fig. 13, which enables changing the height of the axial holes 157c (see Fig. 3) with respect to the floating member 41 and the mounting angle between the first arm 157 and the second arm 158 in the link mechanism 155. As a result, for the same height position of the floating member

41 , the size of the communication hole in the double cylinder portion 51 can be changed with the position of the selected first horizontal shafts 156a. For example, when the material M used herein has a higher viscosity, it is possible to take a countermeasure of making the size of the communication hole to be slightly larger than that when its viscosity is lower. In addition thereto, with the position of the selected first horizontal shafts 156a, it is possible to change the variation of the size of the communication hole with respect to the amount of descend of the floating member.

(Fourth Modification Example of First Embodiment)

The floating member 41 illustrated in Fig. 1 , Fig. 2 and the like is only required to have the hole enough to prevent the floating member 41 from being horizontally disengaged from the vertical pipe 61. Therefore, the floating member 41 can have a C shape, a horseshoe shape or the like, as well as a ring shape. Also, the floating member 41 can be made of a foamed member, such as a foamed plastic.

Further, the buoyant force applied to the floating member 41 floating on the material liquid level L in the material tank 10 is determined by the weight of the floating member 41 , the amount of air in the floating member 41 and the like. Therefore, it is possible to offer the same effect as that of the aforementioned third modification example, namely the effect of changing the position of the fist horizontal shafts 156a with respect to the material liquid level L, through a method of mounting a buoyant-force adjustment weight to the floating member

41 or introducing water into the floating- member main body 42.

(Fifth Modification Example of First Embodiment)

While there has been described a case where the first arm 157 in the link mechanism 155 is provided with the bent portion 157b with reference to Fig. 1 to Fig. 3 and Fig. 6, such a bent portion can be provided in the second arm 158 or bent portions can be provided in both the first arm 157 and the second arm 158. Also, the bent portion can have a curved shape, as well as a folded shape with a right angle.

(Sixth Modification Example of First Embodiment)

While there has been described a case where the first arm 157 and the second arm 158 are employed as the link mechanism with reference to Fig. 1 to Fig. 3 and Fig. 6, a single arm can be employed. In the case of employing such a single arm, the single arm is provided, at its opposite ends in the longitudinal direction, with axial holes 157c and axial holes 158c and 158d, and the length between these opposite ends is substantially equal to the sum of the distance from the third horizontal shaft 156c to the axial holes 157c and the distance from the axial holes 158c and 158d to the axial holes 158e. In this case, it is necessary that, when the floating member 41 descends, the floating member 41 is separated from the vertical pipe 61 while being prevented from sliding against the vertical pipe 61. Therefore, the floating member 41 is not required to have the cylinder portion 42a and the concave portion 42b.

(Second Embodiment)

The second embodiment is similar to the first embodiment in that the material supply device in the frozen-dessert making machine includes a liquid level detection means, an amount supplied adjustment means and an air introduction means, but is different from the first embodiment in the structures of them. Hereinafter, the second embodiment will be described, mainly regarding differences from the first embodiment. Fig. 14 is an explanation view illustrating the material supply device F2 according to the second embodiment, and Fig. 15 is a concept view for explaining the fact that, if a pin 85 is descended, this causes a first through hole 81a to rotate, thereby gradually increasing the size of a communication hole 86. In the material supply device F2, the liquid level detection means is a ring-shaped floating member 241 which floats on the liquid level of a frozen-dessert material in the material tank 10. The floating member 241 has a flat bottom portion and has no concave portion 42b as that of the floating member 41 according to the first embodiment (see Fig. 1 and Fig. 3).

The amount supplied adjustment means includes a double cylinder portion 80 and a displacement transfer means, as illustrated in Fig. 14 and Fig. 15.

The double cylinder portion 80 is constituted by an outer cylinder portion 81 having a first through hole 81a, and an inner

cylinder portion 82 having a second through hole 82a communicable to the first through hole 81a, wherein the inner cylinder portion 82 can be rotated relatively to the outer cylinder portion 81. The communication hole 86 is formed from the portions of the first through hole 81a and the second through hole 82a which are overlaid on each other.

The displacement transfer means transfers the upward or downward displacement of the floating member 241 to the double cylinder portion 80 to rotate the outer cylinder portion 81 and the inner cylinder portion 82 with respect to each other, which changes the size of the aforementioned communication hole 86, thereby adjusting the amount of the material supplied to the cylinder portion.

Further, Fig. 14 illustrates a state where the outer cylinder portion 81 has been pulled out from the inner cylinder portion 82, wherein the inner cylinder portion 82 is connected at its lower end to a material introduction path in the bottom portion of a material tank 10 at a liquid-tight state.

More specifically, the outer cylinder portion 81 is a vertical pipe extending from the bottom portion of the material tank 10 to the upper portion thereof. The inner cylinder pipe 82 is also a vertical pipe having, at its lower end, an outer flange to be contacted with the bottom portion of the material tank 10 and also having, below the outer flange, a concave peripheral slot for fitting, therein, an O ring for sealing when it is inserted in the material introduction path of the material tank 10.

The double cylinder portion 80, which is assembled by inserting the inner cylinder portion 82 into the outer cylinder portion 81, has an

external-air introducing port at its upper portion and is mounted in the material tank 10 in the vertical direction. In the double cylinder portion 80 mounted in the material tank 10, the external-air introducing port is communicated and connected to the inside of the cylinder portion through the inner cylinder portion 82 and, therefore, the double cylinder portion 80 also serves as an air introducing means.

Further, the displacement transfer means according to the second embodiment is a direction-of-movement conversion mechanism which converts the upward or downward movement of the floating member 241 according to the height of the material liquid level into rotational movement of the outer cylinder portion 81 and the inner cylinder portion 82 relative to each other.

The direction-of-movement conversion mechanism includes different guide slits formed in the respective peripheral walls of the outer cylinder portion 81 and the inner cylinder portion 82, and a pin 85 made of a metal or a hard plastic which is mounted to the floating member 241 and inserted in the respective guide slits.

The guide slit formed in the outer cylinder portion 81 is, for example, a longitudinal guide slit extending in the cylinder longitudinal direction and also serves as the aforementioned first through hole 81a. A guide slit 84 formed in the inner cylinder portion 82 is, for example, a spiral guide slit and also serves as the aforementioned second through hole 82a. Namely, the first through hole 81a and the second through hole 82a also have the function of guiding the direction of the movement of the pin 85.

Mounting of the pin 85 to the floating member 241 can be attained by forming a threaded hole in a mounting portion 87 with an L- shape piece provided on the bottom surface of the floating member 241 and also by screw the pin 85 having a male-threaded to the threaded hole, detachably. By doing this, the pin 85 can be mounted to the mounting portion 87 and inserted into the first and second through holes 81a and 82a for assembling them, after the double cylinder portion 80 is inserted into the hole of the floating member 241. Further, as illustrated in Fig. 14 and Fig. 15, the second through hole 82a has a width gradually increasing in the downward direction. If the pin 85 is descended along with the descend of the floating member 241 along the first through hole 81a and the second through hole 82a, this will rotate the outer cylinder portion 81 and the inner cylinder portion 82 relative to each other. This will gradually increase the size of the communication hole 86, which is constituted by the portions of the first through holes 81a and the second through hole 82a which are overlaid on each other, wherein the pin 85 is inserted into the overlaid portions.

In the second embodiment, as illustrated in Fig. 14 and Fig. 15, the inner cylinder portion 82 is fixed to the material tank 10 and, therefore, the outer cylinder portion 81 is rotated together with the floating member 241 to which the pin 85 is mounted, along with the descend of the floating member 241. Along with the rotation of the outer cylinder portion 81 , the position of the communication hole 86 is descended and, also, the size of the communication hole 86 is gradually

increased.

With reference to Fig. 1, Fig. 14 and Fig. 15 for description, in the second embodiment having the aforementioned structure, the distance from the material liquid level L in the material tank 10 to the communication hole 86 which exists at the position of the pin 85 is maintained at a constant value, even if the height of the material liquid level L is changed. Accordingly, even if the height of the material liquid level L is changed, the communication hole 86 exists at a position which maintains substantially a constant distance from the communication hole 86 to the vicinity of the material liquid level L.

When the frozen dessert S is extracted from the frozen-dessert making machine according to the second embodiment, the material M in the double cylinder portion 80 flows into the space in the cylinder portion 20, at first. Then, when the material liquid level L in the double cylinder portion 80 is descended to the vicinity of the communication hole 86, the material M in the material tank 10 starts flowing into the double cylinder portion 80 through the communication hole 86. When the material liquid level L in the material introducing path 1 1 reaches the inside of the cylinder portion 20, air is also supplied to the inside of the cylinder portion 20, and the material M and air are agitated and cooled therein. Then, when the extraction of the frozen dessert S is completed, the liquid level L of the material M continuously flowing into the double cylinder portion 80 ascends to the same height as the height of the material liquid level L in the material tank 10. During this, along with the descend of the material liquid level L

in the material tank 10, the pin 85 is descended along the spiral second through hole 82a and the straight first through hole 81a while being rotated, which gradually increases the size of the communication hole 86, thereby gradually increasing the flow rate of the material M in the material tank 10 which flows into the double cylinder portion 80.

In the second embodiment, the distance from the material liquid level L in the material tank 10 to the communication hole 86 is hardly changed and, therefore, even when the height of the material liquid level L in the material tank 10 is changed, the pressure exerted on the communication hole 86 by the material M in the material tank 10 is maintained substantially at a constant value. However, the amount of the material M in the double cylinder portion 80 is varied according to the height of the material liquid level L in the material tank 10. Namely, every time the frozen dessert S is extracted and, thus, the height of the material liquid level L in the material tank 10 is descended, the amount of the material M in the double cylinder portion 80 which flows into the cylinder portion 20 is decreased.

In order to compensate for the reduction of the material M in the double cylinder portion 80, in the second embodiment, the width of the second through hole 82a is gradually increased in the downward direction, which increase the flow rate of the material M in the material tank 10 which flows into the double cylinder portion 80, thereby maintaining the mixing ratio between the material M and air supplied to the cylinder portion 20 in a predetermined range. Accordingly, in the second embodiment, the rate of the increase

of the width of the second through hole 82a as a spiral guide slit, the width of the first through hole 81a, the diameter of the pin 85 and the like are designed in consideration of the fact that the mixing ratio between the material M and air supplied to the cylinder portion 20 should be maintained in the predetermined range.

With the second embodiment, it is possible to offer the following effects, in addition to the aforementioned effects 1-1 and 1-2 of the first embodiment.

(Effect 2- 1)

The double cylinder portion 80 works also as an air introducing means. In addition thereto, the displacement transfer means is constituted by the pin 85 mounted to the floating member 241 and the different guide slit formed in the peripheral walls of the outer cylinder portion 81 and the inner cylinder portion 82. Accordingly, the material supply device can be fabricated with a smaller number of components, a simple structure and a lower cost.

The following variations can be made to the present second embodiment.

(First Modification Example of Second Embodiment)

A plurality of threaded holes can be formed vertically in the mounting portion 87 having an L-shape piece for mounting the pin 85 to the floating member 241 , which enables changing the height of the position at which the pin 85 is mounted.

By doing this, for the same height position of the floating member 241, the size of the communication hole 86 in the double cylinder portion 80 can be changed with the height of the selected position at which the pin 85 is mounted. For example, in cases where the material M has a higher viscosity, it is possible to take a countermeasure of making the size of the communication hole 86 to be slightly larger than that when its viscosity is lower.

Also, as in the fourth modification example of the first embodiment, a weight or water can be introduced into the floating member 241 for adjusting the buoyant force, thereby changing the position of the pin 85 with respect to the material liquid level L in the material tank 10.

(Second Modification Example of Second Embodiment) The pin can be formed from a coil spring or an elastic member made of a rubber or an elastic plastic and can be fixed to the floating member 241. By doing this, in assembling and disengaging the floating member 241 to and from the double cylinder portion 80, the pin can be elastically deformed and therefore will not interfere with assembling and disengaging.

Further, in this case, another through hole which is the same as the first through hole 81a can be formed at the opposite position which is deviated by 180 degree from the first through hole 81a in the outer cylinder portion 81 , also another through hole which is the same as the second through hole 82a can be formed at the opposite position which is

deviated by 180 degree from the second through hole 82a in the inner cylinder portion 82 and, further, a pair of pins can be provided at opposite positions which are deviated by 180 degree from each other. By doing this, it is possible to reduce the load exerted on a single pin. Also, instead of adding a through hole to the inner cylinder portion 82, it is possible to employ a non-through pin guiding slot formed in the peripheral wall of the inner cylinder portion 82. Further, this structure can be applied to a pin made of a metal or hard plastic.

(Third Modification Example of Second Embodiment)

The second through hole 82a in the inner cylinder portion 82 can have a constant width, while the first through hole 81a in the outer cylinder portion 81 can have a width gradually increasing in the downward direction. Also, both the second through hole 82a and the first through hole 81a can have a width gradually increasing in the downward direction.

(Third Embodiment) Fig. 16 is an explanation view illustrating a material supply device F3 according to a third embodiment.

The third embodiment is different from the second embodiment in that a spiral- shaped first through hole 181a which also serves as a guide slit is formed in the outer cylinder portion 181 in the double cylinder portion 180, and a straight second through hole 182a which

also serves as a guide slit is formed in the inner cylinder portion 182, but the other structures are substantially similar to those of the second embodiment. Further, in Fig. 16, the same components as those of the second embodiment are designated by the same reference numbers. In this case, as illustrated in Fig. 16, at least one of the first through hole 181a and the second through hole 182a is formed to have a width gradually increasing in the downward direction.

In the material supply device F3 according to the third embodiment, a pin 85 descends straightly along the second through hole 182a in the inner cylinder portion 182, while the edge portion of the first through hole 181a which contacts with and slides against the pin 85 receives a force in the circumferential direction, thereby causing the outer cylinder portion 181 to rotate. Further, the size of the communication hole 86 in which the pin 85 is inserted (see Fig. 15) is gradually increased, thereby gradually increasing the flow rate of the material M flowing from the material tank 10 into the double cylinder portion 180, similarly to in the second embodiment.

With the third embodiment, it is possible to offer the same effects as the aforementioned effects 1-1 and 1-2 of the first embodiment and the aforementioned effect 2- 1 of the second embodiment.

(Modification Example of Third Embodiment)

The first, second and third modification examples of the second embodiment can be applied to the third embodiment.

(Fourth Embodiment)

The fourth embodiment is similar to the second and third embodiments, except that the structure for connecting the double cylinder portion to the material introducing path of the material tank (not illustrated) is different from those of the second and third embodiments illustrated in Fig. 14 and Fig. 16.

Namely, using the second embodiment (similar to the third embodiment) for example for description, in the second embodiment, the inner cylinder portion 82 in the double cylinder portion 80 is connected and fixed to the material introducing path 1 1 in the material tank 10 to rotate the outer cylinder portion 81, but, in the fourth embodiment, the outer cylinder portion 81 is connected and fixed to the material introducing path 1 1 in the material tank 10 to rotate the inner cylinder portion 82. In the present fourth embodiment, there are formed an outer flange to be contacted with the bottom portion of the material tank 10 and a concave peripheral slot for an O ring, in the lower portion of the outer cylinder portion 81. Further, the respective communication holes 81a and 82a formed in the outer cylinder portion and the inner cylinder portion, the structure for mounting the pin 85 to the floating member 241 and the like are similar to those of the second embodiment.

With the fourth embodiment, it is possible to offer the same effects as the aforementioned effects 1- 1 and 1-2 of the first embodiment and the aforementioned effect 2- 1 of the second embodiment.

The first and third modification examples of the second embodiment can be applied to the fourth embodiment.

(Fifth Embodiment) Fig. 17 is an explanation view illustrating a material supply device F5 according to a fifth embodiment.

The fifth embodiment is a structure similar to the second and third embodiments including the floating member 241 and the pin 85, but is different from the second and third embodiments in the direction-of- movement conversion mechanism for converting the upward or downward movement of the floating member 241 along with the height of the material liquid level L into rotational movement of the outer cylinder portion 281 and the inner cylinder portion 282 relative to each other, and the first through hole 281a and the second through hole 282a in the double cylinder portion 280. Further, in Fig. 17, the same components as those of the second and third embodiments are designated by the same reference characters.

Hereinafter, the fifth embodiment will be described mainly with respect to differences from the second and third embodiments. The direction-of-movement conversion mechanism according to the fifth embodiment includes a longitudinal guide slit 283 formed in the axial direction in the peripheral wall of the outer cylinder portion 281 , a diagonal guide slot 285 formed diagonally in the peripheral wall of the inner cylinder portion 282, and a pin 185 mounted detachably to the floating member 241.

The pin 185 is inserted in the longitudinal guide slit 283 and can slide at its tip end along the diagonal guide slot 285.

In the double cylinder portion 280, the circumferential range in which the diagonal guide slit 285 is formed in the inner cylinder portion 282 is the range of the rotation of the outer cylinder portion 281 and the inner cylinder portion 282 with respect to each other.

Further, the first through hole 281a is formed to have, for example, a long-hole shape elongates in the circumferential direction, at a position at which the longitudinal guide slit 283 does not exist, in the lower portion of the peripheral wall of the outer cylinder portion 281. The second through hole 282a is formed to have, for example, a long-hole shape longer in the circumferential direction, at a position at which the diagonal guide slit 285 does not exist, in the lower portion of the peripheral wall of the inner cylinder portion 282. The first through hole 281a and the second through hole 282a are placed at positions which are at the same height and also are overlaid on each other within the range of the rotation of the outer cylinder portion 281 and the inner cylinder portion 282 relative to each other.

Fig. 18 is a concept view explaining the fact that, if the pin 185 is descended, this causes the outer cylinder portion 281 to rotate, thereby gradually increasing the size of the communication hole 286 in the fifth embodiment.

With the fifth embodiment having the aforementioned structure, as illustrated in Fig. 17 and Fig. 18, when the pin 85 descends along the longitudinal guide slit 283 and the diagonal guide slot 285 along with

the descend of the floating member 241, the pin 185 pushes a side edge of the longitudinal guide slit 283 in the circumferential direction, thereby causing the outer cylinder portion 281 to rotate with respect to the inner cylinder portion 282. Consequently, the first through hole 281a is moved in the circumferential direction with respect to the second through hole 282a, thereby gradually increasing the size of the communication hole 286 formed by the first through hole 281a and the second through hole 282a which are overlapped with each other. This increases the flow rate of the material in the material tank which flows into the double cylinder portion 80.

With the fifth embodiment, it is possible to offer the same effects as the aforementioned effects 1- 1 and 1-2 of the first embodiment and the aforementioned effect 2- 1 of the second embodiment.

(Sixth Embodiment)

In the fifth embodiment illustrated in Fig. 17, the inner cylinder portion 282 in the double cylinder portion 280 is connected and fixed to the material introducing path 1 1 in the material tank 10 to rotate the outer cylinder portion 281, but, in the sixth embodiment, the outer cylinder portion 281 is connected and secured to the material introducing path 1 1 in the material tank 10 to rotate the inner cylinder portion 282 (not illustrated).

In the sixth embodiment, there are formed an outer flange to be contacted with the bottom portion of the material tank 10 and a concave

peripheral slot for an O ring, in the lower portion of the outer cylinder portion 281. Further, the guide slit and the guide slot formed, respectively, in the outer cylinder portion 281 and the inner cylinder portion 282, the structure for mounting the pin to the floating member and the like are similar to those of the fifth embodiment.

With the sixth embodiment, it is possible to offer the same effects as the aforementioned effects 1- 1 and 1-2 of the first embodiment and the aforementioned effect 2- 1 of the second embodiment.

(Modification Examples of Fifth and Sixth Embodiments)

The first and second modification examples of the second embodiment can be applied to the fifth and sixth embodiments.

Further, the shapes and the combination of the first through hole and the second through hole according to the fifth and sixth embodiments can be properly changed as in the first modification example of the first embodiment.

Also, in the fifth and sixth embodiments, a diagonal guide slit can be formed in the outer cylinder portion, while a longitudinal guide slot can be formed in the inner cylinder portion.