AN INSTRUMENT FOR MEASURING DIMENSIONS OF A

CAN SEAM PORTION TECHNICAL FIELD

The present invention relates to an instrument for measuring dimensions of a seam portion between the body and the cap of a can which is used as a canning container of foodstuffs, etc. BACKGROUND ART

A can which is used as a canning container of foodstuffs, etc. is seamed after filling the contents in the can and seaming the cap to the body. A dimensional control of this seam operation is an important measure for judging the can seamability. A process control is necessary to ensure that cans poor in the seaming do not occur by regularly inspecting the seam portion of the cans after the completion of the seaming process.

Figure 4-(a) is a view showing the seamed can body and cap. Figure 4-(b) is a view showing the section of a seam portion formed by seaming. This seam portion is formed by overlapping a body hook BH formed with edge lb of the neck portion of the can body rolled in and a cover hook CH formed with edge portion 2a of the can cap rolled in and pressing the overlap strongly. Usually, the seam portion slants outwardly at a micro- angle of 0 from an extension line of the can body according to the dismantling of a seaming tool, quality of the can, inner pressure of the can, etc.

An inspection is made from many aspects in order to judge about being good or poor in the seaming state of lis seam portion. Usually, respective dimen¬ sions are measured about seaming thickness T, seaming width W, counter sink C, body hook BH, cover hook CH, overlap OL as shown in Figure 4-(b) and can height H as shown in Figure 4-(a). If seaming thickness T and seaming width exceed any defined value among these

measured values, poor seaming is likely t occur. Thus, these seaming thickness T and seaming width W are the most important spots to be measured.

The present invention is directed to an instru- c ment for measuring exactly these seaming thickness T and seaming width W.

Hitherto, at the time of measuring seaming thickness T and seaming width W there has been generally adopted a method in which one takes a can and a micro- _ _Q meter for exclusive use by hand on the table and enters manually the measured value into' a recording paper. However, this method has problems in that any skill is required to measure the seaming thickness T and seaming width by maintaining an accurate measuring angle

• _j c because the seamed portion is circular and slant; an indicator scale of the micrometer for exclusive use is small and difficult to read; and much time is required to record measured values.

While, as an equipment for automatically

20 measuring these seamed portions have been contrived a measuring device of can seam dimensions as disclosed in Japanese Laid-Open Patent Publn. No. 63-108935, a method for inspecting cans as disclosed in Japanese Laid-Open Patent Publn. No. 64-2744, etc. These are excellent

25 devices which are advanced in the labor-saving but have the following disadvantages because of their complex structure, i.e. much time is spent in exchanging a mold in accordance with the kind of cans and in confirming the measuring accuracy after the exchange of a mold; and the

30 device used becomes large and requires a wide area at the time of installation.

The present invention is such as been made by considering the above problems and makes it an object to provide an instrument for measuring dimensions of a can

35 seam which is so designed as to ensure an exact measure¬ ment by a simple operation.

A further object of the present invention is to provide a measuring instrument of a can seam portion which is so designed that an exact measuring accuracy can be reproduced by the quick mold exchange in response to measuring dimensions about different kinds of cans.

Other objects and merits of the present inven¬ tion will be apparent from the following explanation. DISCLOSURE OF INVENTION

According to the present invention, there is provided the following measuring instrument in order to achieve the above objects, i.e. a measuring instrument enabling one to determine dimensions of a spot of the can to be measured through a simple operation by placing the can cap face or the can body face on the supporting block, an object for measurement while the spot of the can to be measured is held between the criterion measur¬ ing pin and measuring spindle of the measuring instru¬ ment.

In accordance with the present invention, the above problem can be dissolved by providing an instrument for measuring dimensions of a can seam portion, said device characterized by comprising a criterion measuring pin, a linear gauge provided with a measuring spindle which is so supported as to be movable along straight line L in the direction of approaching said criterion measuring pin and in the direction of leaving said criterion measuring pin, a can cap supporting block which holds the can such that the direction of measuring can seaming thickness T may be identical with the above straight line L and the inner face of the can seam portion may contact said criterion measuring pin, and a can body supporting block which holds the can such that the direction of measuring can seaming width W may be identical with the above straight line L and the lower face of the can seam portion may contact said criterion measuring pin.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 is a side view of the instrument for measuring dimensions of a can seam portion conformable with any suitable working example of the present 5 invention.

Figure 2 is a perspective view of the instru¬ ment for measuring dimensions of a can seam portion in Figure 1.

Figure 3-(a) and -(b) are each a side view 0 taken when the can seam thickness and can seaming width are measured by the instrument for measuring dimensions of a can seam portion in Figure 1.

Figure 4-(a) is a side view of the seamed can. And Figure 4-(b) is a sectional view taken on line X-X in ₅ Figure 4-(a) .

BEST MODE FOR CARRYING OUT THE INVENTION

Firstly, an explanation will be made of the structure of the instantly claimed measuring instrument of dimensions of a can seam portion on the basis of the o accompanying drawings. Figure 1 is a side view of the entire measuring instrument. Figure 2 is a perspective view of the entire measuring instrument. Figure 3-(a) and 3-(b) are a side view at the time of measuring can seaming thickness T and can seaming width W. 5 In Figs. 1 and 2, 1 denotes a stand having a slant upper face; 2, a measuring stand which is fastened to the base 1 by means of a bolt 3. Said stand 1 and measuring stand 2 construct a supporting stand 20. On the upper face 21 of the groove 4 made in the measuring 0 stand 2 are placed a measuring block 5, a can cap supporting 6 and a body supporting block 7 linearly. The measuring block 5 is fixed onto the measuring stand 2 by means of a bolt 8.

On the measuring block 5 are arranged a 5 criterion measuring pin 9 against which the spot of a can to be measured is held and a linear gauge 10 for

measuring the distance from said criterion measuring pin 9 in the following position. In the criterion measuring pin 9 its criterion face 22 is so fastened as to make a rectangular angle with the upper face 5a of the measuring block 5. And the linear gauge 10 is so fixed as to be in parallel with the upper face 5a of the measuring block 5 and as to be on the straight line of the criterion measuring pin 9 by means of bolt 11.

Further, the measuring spindle 12 of the linear gauge 10 reciprocates along the straight line L and is pressed in the direction of criterion measuring pin 9 by means of a spring 13 of the linear gauge 10 at a measur¬ ing pressure which is always constant. Its edge becomes higher than the criterion face 22 of the criterion measuring pin 9.

The upper face of the cap supporting block 6 constitutes the cap supporting face 6a which places the can with the can cap face (seam portion) downside. Part of the left and right portions of the cap supporting face 6a is provided with guiάe projections 6b circum- ferentially in pluralities conformable with the kind of can diameters. These guide projections 6b guide the can such that the diameter direction of the can cap will be identical with the above straight line L. Further, the center of the upper face is made in the form of groove 6c (Figure 2) to ensure that the can body may not contact at the time of measuring the can seaming width by placing the body lateral.

Further, the cap supporting face 6a is so designed that an angle ΘX (i.e. an angle of the cap supporting face 6a with the upper face 5a of the measur¬ ing part of the measuring block 5) equivalent to a slant angle θ of the seaming thickness T of a can to be measured can be adjusted by means of an adjustment screw 17 and an angle adjustment shim 14 with a intersecting point of the upper face 5a of the measuring block 5 and

the criterion face 22 of the criterion measuring pin 9 as a pivotal center.

The can body supporting block 7 is provided with an upper face 7a which is parallel to an upper face

5 11a of the shoulder of the measuring stand 2 and a V- letter groove 7b which supports the can body.

In the V-letter groove 7b its centerline is parallel to a central axis of the measuring spindle 12.

Moreover, this groove is made in the form of a V-letter

■ _j _0 to insure that the can body face and the upper face 5a of the measuring part of the measuring block 5 become parallel to each together when the can is so placed that a lower face of the neck of the body of a can to be measured may touch the criterion face 22 of the criterion 5 measuring pin 9. The size of the groove is determined by an outer diameter of the can body and an outer diameter of the neck of the can body. Accordingly, the can cap supporting block is exchangeable in response to the kind of cans different in this relation.

20 A wireless transmitter 15 is fastened to the measuring stand 2 and is connected to the linear gauge 10 via cable 16. This wireless transmitter comprises a circuit in which any data measured by the linear gauge 10 is indicated as a digital numerical value on the display

25 10a at the top face of the linear gauge 10 and this is outputted to the wireless transmitter 15 and then is transmitted to a data processor (not shown) with a receiving function by pressing a transmission switch 15a of the transmitter 15. In case of the linear gauge 10

30 and the wireless transmitter 15, a battery system is preferable.

Next, there will be explained a procedure of measurement made through the use of a measuring instru¬ ment of dimensions of a seam portion having the above

35 structure.

First, at the time of measuring dimensions of

can seaming thickness T, a slant angle θ of the seaming thickness T according to the kind of cans is measured and then an angle ΘX of the can cap supporting block 6 is so adjusted by means of the adjustment screw 17 and the angle adjustment shim 14 as to be identical with its angle. This brings the following two directions into agreement, i.e. a direction of measuring can seaming thickness T and a direction of movement (straight line L) of the measuring spindle 12. Successively, the can seam portion to be measured is faced down and the measuring point is held gently against the measuring spindle 12 thereby to force the can open and the measuring point is placed in the center of the guide projection 6b of the can cap supporting block 6 while being held between the measuring spindle and the criterion measuring pin 9. As a result, the seaming thickness T is measured by means of the linear gauge 10. Further, seaming thickness T dimen¬ sions at any optional point can be determined by rotating the can in the above state. Secondly, at the time of measuring dimensions of can seaming width W, the can body supporting block 7 selected according to the kind of cans is disposed in the groove 4 of the measuring stand 2.

Successively, the can is faced lateral and can body is placed on groove 7b of supporting block 7, and then the seam measuring point is held gently against the measuring spindle 12 thereby to force this open and the measuring point is held between the measuring spindle and the criterion measuring pin 9. As a result, the seaming width W is measured by means of the linear gauge 10.

Whereby the seaming width W is determined in such state that a direction of measuring the can seaming width W and a direction of movement (straight line L) of the measuring spindle 12 agree with each other. Further, seaming width dimensions at any optional point can be determined by rotating the can in

the above state. These measuring data are indicated as digital numerical values on the display 10a at the top face of the linear gauge. After confirming its numerical value, the transmission switch 15a of the wireless trans¬ mitter 15 is pressed thereby to transmit its data signal to a data processor.

By repeating the above operation, it is pos¬ sible to measure seaming thickness and width dimensions at any optional point and transmit its data.

As above, the present invention enables one to take a quick and exact measurement by a simple operation without requiring any skill, to save a labor of recording and to sharply reduce a period of time spent in the measurement. Moreover, thanks to a simple structure, the claimed measuring instrument can answer to an exchange of molds for different cans having various sizes quickly and is small in the frequency of trouble. This can reproduce an extremely reliable accuracy of measurement. Shown below is an explanation by arranging the instrument for measuring dimensions of a can seam portion which conforms with appropriate working examples of the present invention.