US2553999A - Press for rubber footwear - Google Patents

Description

Patented May 2 2, 1951 PRES Si. FOR. RUBBER FOOTWEAR Alois Banovskfizlin, Czechoslovakia, assignor to Bata, narodni' podnik, Zli'ng. Czechoslovakia.

ApplicationgAprili28, 1947;.Serial'N0. 744,284 In Germany ctober19;.19.44

7 Claims. 1.

In the known processv for the pressing of a shoe. sole and simultaneously. vulcanizing it on to a. prepared upper (as distinct from ordinary pressing. when the pressure of the press on the workpiece acts in a single direction. only) the sole. and'the upper, and if desired also the heel, aref exposed simultaneously to pressure in two directionsv at right angles to one another.

The, presses employed hitherto for carrying outv this process have. been either purely hydraulic, i. e. equipped with two plungers arranged at right angles to one another, or mechanical with a system of levers driven hydraulically or pneumatically or by an electric motor.

With the known mechanical presses the two pressures acting at right angles to one another are produced by a complicated system of transmissions and levers. On the other, hand the purely hydraulic presses have the disadvantage of ;heavy weight and of depending upon a source of liquidunderpressure. Similarly the mechanical presses, if driven hydraulically or pneumatically, are dependent upon. asource of pressure fluid. Mechanical. presses driven by electric motors are prone tobreak-downs inoperation very frequently dueto the complication of the transmission.

An objectof the present. invention is to eliminate these disadvantages of the known presses for the pressing of shoe soles made. of rubber and thelike and the simultaneous vulcanization ofthe soles to the finished uppers.

To -the attainment of. this objectthe. inven-.- tion, provides a novel arrangement allowing the use, of much lighter and simpler press components and characterized in, that the. pressures necessary for the pressing. operation acting in two directions at right angles. with. respect to one. another are produced by means. of a loop orrigid'frame equipped with arms pivotedthereon.v The two pressures acting at right angles with,respect to one, another are. then produced simply. by shiftingthe loopor rigid frame relatively to the. workpiece during which shitting movement the said. arms are made to act one against, the other, the shoe sole moulding por tion being brought. into position for pressing at the same time.

The, foregoing and further advantageous featuresof the invention willbecome clear. from the.,following description of. one exemplifiedembddiment. illustrated on the. accompanying. draw-'- ings... whereon- Fig. I shows diagrammatically, in perspective 2. and; partly insection, oneembodiment of a pressing device according to. the invention;

Fig...2 shows adetailof Fig-.lon a larger scale, namely, the. ballv joint of the mould core; and

Eig. 3 shows. another detail of Fig. 1, on a larger. scale, namely, the attachment of the switch;

The wholeof. the. stresses occurring in the course: of the pressing processare carried bya loop or rigid frame I-, the threaded spindles 2, 2, the base plate 3, and the linked arms 4, 4'. The threaded. spindles 2 movethe loop orrigid frame I; in; a. downward direction when pressing, i. e. when. closing thepress, and in an upward direction when opening the press. Heated holding pieces 5, 5. are pivoted to the arms 4, 4' and supported-from the base plate 3 by pivotally connected'rods. 6, 6 on opposite sides. of the workpiecesupport II and last I0. Each of the heated holding pieces 5. 5 forms, together with the rods 6., 6., a. parallelogram link system which carries the lateral, moulding jaws 7, 1' and transmitsto them the heat required for the operation. The. moulding jaws I, I, together with the press plunger 8ipenetrating between them from above, constitute the. operative components proper of the. press, in place of a box-shaped pressing mould, asv hitherto used.

When the arms 4', 4" that arepivoted on the loop I' are lowered. and raised, respectively, they cause the 'approachmentand separation, respectively, of. the holding, pieces 5, 5' together with themouldingjaws 1, T, vthe'press plunger 8 being alternatively interposed between and withdrawn from. the said mouldinglaws.

The press plunger 8 is attachedv to a heating plate 9 which. is.carried. by the loop or rigid frame l and takes part in its movements describedjabovei. e. downward when pressing, and upward when opening the .press.

Theshoe last I0 formingv the. core of the mould isarranged at the upper end of a support column I] whose lower reduced" end I3 is equipped with aballllfwhich forms a ball joint with the componentsl3; l4, l5. See also Fig. 2. The reduced ehdil3fofcolumn has such a clearance in the hole of "component 14 that the last ll] remains in an;er'ect position, the clearance being very small, that'jis,jof the order of approximately 0.3 mm. The purpose of the balljoint is to, permit, when thepress is closed, correct location of the last in themould. The last has substantially a correct shape according to the jaws I and l but during assembly and by action. of heat certain inaccuracies; though small; arise in' the location of the last and these inaccuracies have an unfavorable elfect on the product when anchoring the last. The mentioned ball joint is pushed into the guide groove (preferably of T-shaped cross section) of a support component I6 of the device and admits an independent adjustment of the last 10 between the jaws 1, I. The component I5 constitutes a slide which is displaceable in proportion to the orbital movement of last ID on the upper end of the workpiece support or column II to operate electric switch 24 when the last is adjusted to the proper position between the jaws I, 1' to initiate operation of the electric motor which drives the shaft, gear and pinion system for revolving the spindles 2, 2 for displacing the frame I. In order to properly center the last 10 with respect to the jaws I, 1', the workpiece support or column II is grasped and adjusted in a substantially orbital path until last I is correctly centered with respect to jaws l, I, at which time the motor is activated through the proper position of the lever 25 to actuate electric switch 24.

Advantageously the drive of the pressing device is effected by means of the two threaded spindles 2, 2' through helical gears IT, [8 and bevel gearing I9, 29 from a motor (not shown) driving the shaft 2| of the bevel pinion 20.

The course of operations is as follows:

The last H), which has been prepared for pressing and which forms a unit with the ball joint components !2 to I5, is pushed into the guide of the component It of the machine, together with the uppers of the shoe fitted to it and with the required rubber plates put on at the sole portion. In the correct position of the last the supply of electric current is switched on by means of an electric switch 24 (see Fig. 3) of known design, and thereby the starting of the driving motor, i. e. the initiation of the pressing operation, is made possible. The electric switch is actuated by lever 25 when the support 15 is in the correct position. The motor then turns the shaft 22 by means of the shaft 2|, through the bevel gearing 19, 2d, and sets the two threaded spindles 2, 2' in rotary motion through the worm gears ll, 18. These threaded spindles 2, 2, by means of the threads in the eyes 23, 23 of the loop or rigid frame 1, draw the latter down towards the moulding last 10, the linked arms 4, 4 being thereby turned from the oblique position shown in Fig. 1 into a substantially horizontal position, i. e., until they are approximately parallel to the loop or rigid frame I in which position the maximum pressing force is produced by the lever action. The holding pieces 5, 5' of the lateral moulding jaws I, I follow the aforesaid movement of the arms 4, 4; they remain, however, constantly in a horizontal position through the action of the rods 6, 6, and press the mould jaws I, 5' against the last I0. Simultaneously with the lowering of the loop or rigid frame I the plunger 8, equipped with a (negative) impression of the sole, approaches the last [0 from above. This plunger 8 is fixed in known manner on a spring-supported heating plate 9. As soon as the jaws 1, 7' reach abutting position and simultaneously with the insertion of the plunger 8 between them, the loop or rigid frame I which has reached in the meantime its lowest position causes by its action the switching-off of the current, preferably automatically by means of an electric switch, whereby the pressing device comes to a standstill in the closed position. After the lapse of a the period required for the vulcanizing of the rubber the device is set in motion again automatically in known manner, and the press is opened. After taking out the last, pulling-off the finished shoe and fitting-on a new prepared upper, the process is repeated as described.

It is, of course, possible to arrange the loop or rigid frame I in which all stresses converge, in a special guide, or to use an alternative driving mechanism instead of the threaded spindles 2, 2'. Further, it is within the scope of the invention to have the loop or rigid frame I remain stationary when closing the press and move the base plate 3 together with the mould last I!) and the other components with respect thereto.

I claim:

1. A device for pressing and vulcanizing on workpieces consisting of soles and heels of rubber-like footwear, comprising a base, a pair of vertically extending spindles mounted in spaced positions on said base, screw-threads formed on the upper ends of said spindles, a rigid frame having screw-threaded apertures adjacent opposite ends thereof engaged by the screw-threads on said spindles, said frame being bodily displaceable on said spindles, arms pivotally mounted between the sides of said frame adjacent opposite ends thereof, a workpiece engaging member pivotally connected with each arm, means supporting said workpiece engaging members from said base, a workpiece support extending from said base, and a last carried by said workpiece support in a position between said workpiece engaging members whereby the workpieces on said last may be subjected to pressure by displacement of said workpiece engaging members against the workpieces.

2. A device as set forth in claim 1 in which said arms are so dimensioned that bodily displacement of said rigid frame on said spindles automatically efiects pivotal displacement of said arms through a suflicient distance to move said workpiece engaging members into a position for automatically engaging or disengaging the workpiece with respect to said last.

3. A device as set forth in claim 1 in which said workpiece engaging members comprise heated holders and wherein said means supporting said workpiece engaging members are constituted by pivoted parallelogram links pivotally connected with said base at their lower ends and pivotally connected with said workpiece engaging members at their upper ends.

4. A device as set forth in claim 1 in which said workpiece support is adjustably mounted on said base by a ball joint which permits orbital adjustment of said last with respect to said workpiece engaging members.

5. A device as set forth in claim 1 in which said workpiece engaging members comprise heated holders and wherein a shaped jaw is interposed between each heated holder andone side of the last, the means supporting said workpiece engaging members on said base com- 5 facilitating the operation of said jaws against workpieces positioned on said last.

6. A device as set forth in claim 1 in which said spindles are connected through gearing with drive means carried by said base, and means for controlling the operation of said drive means when the workpiece support is adjusted to a position centering said last with respect to the workpiece engaging members.

7. A device as set forth in claim 1 which includes an orbital joint between the lower end of said workpiece support and said base, said orbital joint being seated in a displaceable slide. a control switch operative by displacement of tion in which said last is centered with respect REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 841,121 Cavanagh Jan. 15, 1907 2,029,060 Co zzo Jan. 28, 1936 2,221,742 Hofza Nov. 12, 1940 2,310,674 B'glstwick Feb. 9, 1943 2,338,280 Brundage Jan. 4, 1944

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