BACKGROUND OF THE INVENTION

This invention relates to an apparatus for unloading tires for a tire vulcanizing machine.

An unloader in a tire vulcanizing machine is an apparatus for unloading tires after completion of vulcanization from the mold of the tire vulcanizing machine to a predetermined position, for example, to a post-cure inflator (hereinafter referred to as P.C.I.), which is generally located in the rear of the vulcanizing machine.

Among a few conventional types of unloaders for a tire vulcanizing machine, particularly, a swing type unloader disposed centrally on the housing of the vulcanizing machine is worth referring to in connection with the present invention. Realization of this swing type unloader for a tire vulcanizing machine as disclosed in US Pat. No. 4,449,903 partially owes to the development of such a new type of tire vulcanizing machine as the upper half of the mold thereof is to be displaced only in the vertical direction by raising and lowering movement without swing movement in the horizontal direction. A pair of unloading booms in this swing type unloader, as in the loading apparatus disposed on the front of the housing, are slidably and swingably fitted onto a pair of vertical guide rods which are fixedly secured to the center of the housing.

The apparatus for unloading tires for a tire vulcanizing machine according to US Pat. No. 4,449,903, as shown in FIGS. 26 and 27, has a technical construction in which said apparatus essentially comprises a pair of vertically extending guide rods 100 fixedly secured to a housing 101 of the tire vulcanizing machine, a common board 102 slidably fitted onto said guide rods so as to be displaced in the vertical a direction with the aid of driving means, a pair of booms 103 adapted to be displaced in the vertical

direction together with said common board 102, each of said booms being turnable about the guide rod 100, tire grasping means 104 including a plurality of grasping pawls 105 disposed at the one end of each of the booms 103, said grasping pawls being adapted to expand or contract, and πieans 106 for limiting the extent of turning movement of the boom, or, said apparatus essentially comprises a pair of vertically extending guide rods 200 disposed at the predetermined position located between the tire vulcanizing machine 201 and the P.C.I. 202, each of said guide rods 200 being fixedly secured to the tire vulcanizing machine by way of a bracket 203 extending therebetween, a pair of booms 204 slidably fitted onto the guide rods 200 at one end part thereof so as to turn between two positions with the aid of hydraulic cylinders 205 and 206, one of said positions being the center of a mold on the tire vulcanizing machine while the other being the center of P.C.I, rings on the P.C.I., each of said booms being adapted to move up and down along the guide rods 200 and tire grasping means 207 disposed at the other end part thereof for grasping a vulcanized tire at the bead portion, said tire grasping means including a plurality of grasping pawls adapted to expand and contract.

The unloader according to US Pat. o.4, 49,903 has some advantageous features from the viewpoint of cost and maintenance service in comparison with conventional unloading systems in which unloading booms are in general separately arranged on both sides of a housing of the tire vulcanizing machine so as to vulcanize two green tires simultaneously in one cycle of vulcanizing and also actuators for raising and lowering the unloading booms are disposed for each of the unloaders so as to raise up and lower vulcanized tires during the prosecution of unloading.

However, it is found that the unloading system according to US Pat.No.4,449.903 still has a few disadvantageous features as follaws.

(1) The unloading boom assemblies including hydraulic cylinders 205 and 206 for turning the booms about the vertically fixed guide rods 200 must have three stop points respectively during one stroke of turning movement

thereof with the aid of said hydraulic cylinders, one being a center of the vulcanizing mold, another being a waiting position and the third one being a center of P.C.I, rings on the P.C.I., so, it is hard for only one hydraulic cylinder alone to exactly control the position where the booms should stop. Accordingly, at least two hydraulic cylinders 205 and 206 have to be provided for each boom assembly so as to make the booms 204 exactly turn and stop between the mold of the vulcanizing machine and the P.C.I, and, subsequently, this provision results in complicated arrangements and increase in manufacturing cost and maintenance service. (2) A P.C.I, is an appratus for air cooling tires after vulcanization. With the aid of the P.C.I, vulcanized tires can maintain their profiles as intended to be produced in the end. Without this apparatus the profiles of the vulcanized tire might be deformed due to a sudden change of heat under no bolstering of the sidewalls of the tire. However, the strength of sidewalls of low series tires developed lately became much stronger than those of prior high series tires owing to relative shortening of sidewalls compared with broadened width of tread as well as owing to development of reinforcement members embeded in the body plies such as nylon cords that are little influenced with heat, and, subsequently, even though vulcanized tires are subjected to natural air cooling without being treated with the P.C.I., deformation which might be caused to sidewalls are insignificant.

Therefore, in connection with the advance of materials and designs for tires, a new apparatus for unloading tires for a tire vulcanizing machine needs to be developed with the understanding that the P.C.I, is not always essential.

SUMMARY OF THE INVENTION

Thus, the present invention has been made with the foregoing problems in mind and its objects reside in providing an apparatus for unloading tires for a tire vulcanizing machine which is simple in structure and can be manufactured and maintained at lower cost.

Another object of the present invention is to provide an apparatus for

unloading tires for a tire vulcanizing machine which can be maneuvered under condition of P.C.I, as an option.

To accomplish the above objects there is proposed according to the present invention an apparatus for unloading tires for a tire vulcanizing machine which is characterized in that said apparatus essentially comprises*:

(A) a horizontally extending guide rail fixedly secured by means of an attaching plate to a lower center of a housing of a tire vulcanizing machine;

(B) a boom assembly slidably fitted onto said guide rail so as to be linearly displaced in the horizontal direction between the center of a vulcanizing mold of a tire vulcanizing machine and a predetermined position, said boom assembly comprising:

(a) a pair of vertically extending guide rods fixedly secured between plates; (b) a pair of booms slidably fitted onto said guide rods at one end of each of said booms so as to be displaced in the vertical direction but not turned about said guide rods in the horizontal direction, said booms forming a fixed angle therebetween so that the distance between the other ends of said booms facing toward the tire vulcanizing machine is kept ^" equal to the distance between the leftward mold and the rightward mold of a tire vulcanizing machine;

(c) a means for grasping tires which includes a plurality of grasping pawls disposed at the other end of each of said booms, said grasping pawls being adapted to expand or contract; and

(d) a driving means for displacing each of said booms simultaneously along with said tire grasping means in the vertical direction; and (C) a driving means for displacing said boom assembly in the horizontal direction along said guide rail.

The above and other objects, features and advantages of the present invention will be apparent from the following description of the appended claims, taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

FIG.l is a plan view of an unloader according to the first embodiment of the invention.

FIG.2 is a side view of the unloader in FIG.l.

FIG.3 is a plan view of a boom assembly from the view point of A-A line in FIG.2.

FIG.4 is a front view taken from the viewpoint of the arrow B in FIG.2, which shows a horizontally extending guide rail and a driving means for linearly displacing the boom assembly in the horizontal direction. FIG.5 is a side view of a horizontally extending guide rail. FIG.6 is an enlarged front view of the horizontally extending guide rail and the driving means for displacing the boom assembly.

FIG.7 is a front view of a housing of a tire vulcanizing machine which shows a setting position where the apparatus for unloading tires according to the present invention should be disposed. FIG.8 is a plan view of a first base plate.

FIG.9 is a front view of the first base plate in FIG.8. FIGS.10 to 12 are a plan view, a side view and a front view of connecting brackets respectively.

FIG.13 is a plan view of a lower plate which is disposed on the first base plate.

FIG.14 is a front view of the lower plate in FIG.13. FIG.15 is a plan view of an upper plate. FIG.16 is a front view of the upper plate in FIG.15. FIG.17 is a plan view of a second base plate. FIG.18 is a front view of the second base plate in FIG.17. FIG.19 is a plan view and a front view of a blocking plate.

FIG.20 is a plan view of a fixing plate for adjustably fixing the end of a cylinder rod which actuates in the vertical direction. FIG.21 is a front view of the fixing plate in FIG.20. FIG.22 is a plan view of a driving means for linearly displacing the boom assembly in the horizontal direction according to the second embodiment of the present invention.

FIG 23. is a front view of the guide rail and a connecting means taken from the viewpoint of the arrow C in FIG.22.

FIGS.24 and 25 are a plan view and a side view of driving plate assembly including the first base plate, which is applicable to the second embodiment in FIG.23.

FIG.26 is a plan view of an apparatus for loading or unloading tires for a tire vulcanizing machine according to US Pat. NO. 4,449,903.

FIG. 27 is another plan view of an apparatus for unloading tires for a tire vulcanizing machine according to US Pat. NO. 4,449,903. DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION As will be apparent from FIG.l to 7, a housing 1 of a tire vulcanizing machine includes an attaching bracket 2 fixedly secured to the lower center part thereof by means of a plurality of bolts 3. A pair of parallel brackets 4,4 whose sectional shape is of substantially rectangular pipe, are welded to said attaching bracket 2 at one end of each of the brackets 4,4 so that they can form a basic seat for mounting a horizontally extending rail assembly 10 thereon.

The rail assembly 10 includes a linear motion guide rail 5 fixedly mounted on said parallel brackets 4,4 along with a pair of rail seats 7,7 by means of a plurality of bolts 8 and two pairs of bearing blocks 6,6 and 6',6' which are slidably coupled with said guide rail 5. Drawing No. 9 designates reinforcing fillets so as to uphold the rectangular parallel brackets 4,4 which are welded onto the attaching bracket 2. On the bearing blocks 6,6 and 6',6' is fixedly mounted a first base plate 11 by means of a plurality of bolts 12,12,..., whose enlarged plan

view and front view are illustrated in FIGS.8 and 9, respectively.

All the upper structure including a boom assembly to be explained later are mounted on said first base plate 11 and the latter is constructed to be linearly slidable along the guide rail 5 in the horizontal direction with the aid of a hydraulic cylinder 13.

A hydraulic cylinder 13 as a driving means for linearly displacing a boom assembly in the horizontal direction along said guide rail 5 is, as clearly depicted in FIG. 6, pivotably mounted beneath the rectangular brackets 4,4 in the middle part thereof by means of cylinder supporting plates 14,14, whose upper ends are fixedly secured to the brackets 4, 4, and the rod 15 thereof is so connected with said first base plate 11 by means of vertically extending plates 16,16 and a horizontally disposed plεte 17 as shown in FIGS. 2 and 10 to 12 that the first base plate 11 can be linearly displaced in the horizontal direction along the guide rail 5 with the aid of expansion or contraction of the cylinder rod 15.

Reference No. 18 in FIGS.2 and 6 designates a blocking plate welded onto the free ends of the rectangular brackets 4,4, which serves to make the brackets 4,4 united in a body and improve the outward show thereof. Further, Reference No. 19 designates other blocking plates fixedly secured onto both sides of said first base plate 11, which serve to improve the outward show of the apparatus and to prevent the linear motion bearing system from becoming dusty.

Now, a boom assembly will be described with reference to FIGS.1,2, and 13 to 21. A lower plate 20 which is fixedly mounted on said first base plate 11 includes a propping wall 21 and a pair of holes 22,22. Said propping wall 21 serves to support an upper plate 24 on which a hydraulic cylinder 33 depicted in FIG. is mounted. A pair of vertically extending guide rods 30, 30 as shown in FIGS. 1 and 2 are fixedly secured between said lower plate 20 and upper plate 24. The holes 22, 22 and 26,26 formed in each of the plates 20 and 24 make seats for fixedly inserting the upper ends and lower ends of

said vertical guide rods 30,30 respectively. Drawing No. 25 in FIG. 19 represents stoppers which are secured on said upper plate 24 by bolts 27, 27 so as to prevent said vertical guide rods coming out upward through said upper plate 24. A pair of booms 40, 40 are slidably fitted onto said vertical guide rods 30, 30 by means of a pair of sleeves 31, 31 respectively at one end of each of said booms so as to be displaced in the vertical direction. It should be noted that in the present invention each of said booms 40, 40 is so constructed that it is to be displaced only in the vertical direction but not to be turned about said guide rods 30,30 in horizontal direction and, further, said booms form a fixed angle therebetween in the horizontal plane so that the distance between the free ends thereof facing toward the tire vulcanizing machine is always kept equal to the distance between the centers 45,45 of the vulcanizing molds of the tire vulcanizing machine. These features of the present invention make critical differences from the prior art, particularly, from such a swing type unloader as disclosed in US Pat. NO. 4,449,903. Erom these features, the apparatus for unloading tires for a tire vulcanizing machine in accordance with the present invention can eliminate all the four hydraulic cylinders which were indispensable in turning the booms about the vertically extending guide rods during unloading vulcanized tires and, consequently, the unloader according to the present invention can be of great help in saving the manufaturing and maintenance cost that much.

FIGS. 17 and 18 represent a plan view and a front view of a second base plate 35 respectively on which each of said booms 40, 40 and said sleeves 31, 31 is fixedly supported. Since the end of the rod 34 of the hydraulic cylinder 33 is fixedly secured by way of a fixing plate 37 shown in FIG. 20 and 21 to said second base plate 35, each of said booms 40,40 along with said sleeves 31,31 moves up and down in accordance with the expansion or contraction of the rod 34 of said hydraulic cylinder 33.

On said second base plate 35 there are provided with stoppers 50 which

serve to prevent each of said booms turning about said guide rods in the horizontal direction and, thus, to make said booms form a fixed angle a therebetween. Said stoppers 50 comprise a pair of posts 51, 51 fixedly secured onto said second base plate 35 at the bottom ends of each of said posts, and adjusters 52, 52 provided at the upper ends of each of said posts at the same height where each of said booms is secured to the outside of the sleeves 31,31 said adjusters having screwed rods 53,53 whose one end is, as shown in FIG. 3, fixedly secured to the inside surface of the booms respectively and adjusting nuts 54 which are coupled with said screwed rods 53,53 repectively. As will be readily apparent from the above, a range of spreading angle of said booms can be easily but very accurately adjusted as required by changing the position where the nut is locked.

The apparatus for unloading tires for a tire vulcanizing machine is critically different from prior arts including the swing type unloader in that it is possible for the apparatus for unloading tires in accordance with the present invention to unload the vulcanised tires from a mold of tire vulcanizing machine to a predetermined position only by linear movements of said boom assembly in the vertical and in the horizontal directions without turning movements. A means for grasping tires which includes a plurality of grasping pawls

61 are disposed at the free ends of each of said booms 40, 40 respectively, said grasping pawls, as in prior arts, being adapted to expand or contract by means of conventional actuators such as air or hydraulic cylinder 60.

Next, an unloader in accordance with another embodiment of the present invention will be described with reference to FIGS. 22 to 25.

As illustrated in the drawings, a horizontally extending bracket 70 whose sectional shape is of substantially rectangular pipe is welded at said attaching bracket 2 at one end thereof so that it can form a basic seat for mounting a horizontally extending rail assembly 80 thereon. The rail assembly 80 includes a pair of linear motion guide rail 81 fixedly mounted on both sides of said rectangular bracket 70 respectively,

and two pairs of bearing blocks 82, 82 and 82', 82' which are slidably coupled with said guide rail 81. Drawing No. 83 represents a pair of vertically disposed brackets which serve to mount each of said bearing blocks thereon. These brackets 83,83 are fixedly secured to said first base plate 11 at upper edge thereof. Drawing No. 84 designates reinforcing fillets so as to uphold said first base plate 11 and to make said vertical brackets 83,83 and said first base plate 11 united in a body.

The most important technical feature of the unloader in accordance with this embodiment is to provide a double cylinder 90 as an actuator for displacing said boom assembly in the horizontal direction. Said double cylinder is slidably secured beneath said rectangular bracket 70 by means of mounting brackets 91 and 92 and rollers 93,93 --- which serve to make said double cylinder 90 slidable in the horizontal direction in accordance with the operation of expansion and contraction of said cylinder 90. Said double cylinder 90 has two operational rods 94 and 95 which are extending in opposite directions, one of said rods 94 being fixedly secured to said attaching bracket and the other 95 being fixedly secured to a mounting bracket 85 which is disposed at the front end of said vertical brackets 83,83. Said double cylinder 90 makes a contribution to shorten the stroke thereof.

Cylinders 90A, 90B which form said double cylinder 90 can be constructed so as to be communicated with each other through common line of power.not shown), or can be constructed so as to operate separately through dependent lines of power, and particularly, the latter case is useful if when a P.C.I, is to be provided as one of continual processes of an unloading system since dependent double cylinders can serve to achieve correct alignment including three stop points of said boom assembly as mentioned before.

Now, the unloading operation by using the unloader in accordance with the present invention will be described.

On completition of vulcanizing, the upper half of the mold(not shown)

of a tire vulcanizing machine is opened by operation of the depression hydraulic cylinder (not shown). Next, the hydraulic cylinder 13 or 90 is actuated in the horizontal direction so as to transfer the tire grasping means disposed at the free ends of each of said booms 40, 40 to the center of the lower half of the mold and, then, by operation of the hydraulic cylinder 33 said tire grasping means go down so as to let the tire grasping pawls grasp the upper beads of the vulcanized tires with the aid of the cylinder 60. After grasping the vulcanized tires with said pawls, said boom assembly moves up and draws back with the aid of said hydraulic cylinders 33 and 13 successively.

In the present invention, since there is not provided a P.C.I, which is directly associated with the unloading process, the vulcanized tires transfered to a predetermined position P by said hydraulic cylinder 13 are to be put on a conventional transferring device such as a series of rollers on an inclined conveyer and then to be displaced to another predetermined position for the next process.

The unloader in accordance with the embodiments of the present invention has the following advantageous features :

(1) Since the apparatus for unloading tires for a tire vulcanizing machine in accordance with the present invention can be maneuvered by only two hydraulic cylinders 13 and 33, the structure thereof becomes much simpler than before and, accordingly, manufacturing and maintenance cost can be decreased.

(2) If the present apparatus is to adopt a P.C.I, only a double cylinder can meet requirements without any modification of the structure.

(3) The linear movement is superior to turning movement in achieving correct alignment of the system during operation the system.

While the present invention has been described above with respect to the illustrated embodiments, it should be understood that the present invention should not be limited only to them, but various changes or

modifications may be made properly without contradiction of the sprit and scope of the invention.