US2090798A - Driving claw - Google Patents

Description

Aug. 24, 1937. A. LINGG ET AL 2,090,798

DRIVING CLAW Filed Dec. 14, 1934 2 Sheets-Sheet l In ve i fors Aug. 24, 19370 A. LINGG ET AL 2,090,798

DRIVING CLAW Filed Dec. 14, 1934 2 Sheets-Sheet 2 Patented Aug. 24, 1937 UNITED STATES PATENT OFFICE DRIVING CLAW Application December 14, 1934, Serial No. 757,539 In Germany December 14, 1933 Claims.

Our present invention relates to a driving claw device of the type in which the claw is driven through a crank and its motion controlled by a bearing slide.

5 Owing to its simplicity, this type of device is particularly suitable for advancing perforated photographic films. Known devices of this type, however, have not satisfied the stringent requirements of modern practice in reproducing sound or pictures from films, regarding noiseless operation and a short feeding or driving movement.

It is an object of the present invention to provide a crank actuated claw which has properties hitherto possessed only by high-speed claws which are moved over a complex path, for example, in respect to the short length of the feeding path.

It is a further object to provide a crank actuated gripper which runs with very little noise and which is comparatively free from bearing or pivot wear, so that its life is prolonged.

A still further object is to provide a crankactuated claw and its associated actuating mechanism which is more compact than the known arrangements.

Further objects will be seen from the detailed specification following hereafter. Reference is made to the accompanying drawings in which Fig. 1 shows a side elevation of a crank actuated driving claw according to this invention,

Fig. 2 shows a. plan view of the device shown in Fig. 1,

Fig. 3 shows a side elevation of another crank actuated driving claw, and

Fig. 4 shows a plan view of the device shown in Fig. 3.

An advantage is obtained by the present invention in that the motion of a bearing slide which guides the claw-arm is provided by means of an intermediate arm which is driven so that the claw enters into engagement with the member it is to drive in approximately a straight line and the driving stroke of the claw begins after the claw has completely engaged with the driven member and ends before the claw has disengaged therefrom.

By employing an eccentric or the like to control the motion of the bearing slide the further advantage is obtained in that it is possible to reduce the feed angle to 45 or even less. Such a short driving motion was hitherto only possible when the claw moved over complex curves or when one or more idle movements were provided between each driving movement of the claw. The shaft driving such a claw must, therefore, move at a much higher speed than the crank shaft of a claw of the usual type. A high speed of rotation has, among other drawbacks the disadvantage that when used in sound film apparatus it causes undesirable noise.

In the arrangement described in detail below although the crank shaft has a low speed of retation, its angular feed movement is small without it being necessary for the claw to be moved over say a figure 8 or other comparatively complicated curve. Moreover, in consequence of the omission of the previously necessary idle movements, the construction of the present device can be more compact than previously.

The invention will now be described with reference to the accompanying drawings.

Referring to Figs. 1 and 2, the claw arm I, on the outer free end of which are fitted the claws 2, is pivotally mounted about a crank pin 3. A crank disc 4 is actuated by driving mechanism through a shaft 5. On the arm I near to the claws is arranged a bearing slide 6 which guides the arm I. The slide 6 is controlled by an intermediate lever I, which is pivotally connected with an oscillating lever 8 by a pin 9 and with the slide 6 by a pin Ill. The intermediate lever is pivoted about a. bolt II fixed on the frame I2. The lever 1 is slotted at I3.

The oscillating lever 8 rocks about a pivot I4 which is likewise fixed on the frame I2. The oscillating lever 8 is provided with two parallel flanges l5 and I511 which engage the periphery of an eccentric I6 fixed on the crank shaft 5. Thus, when the shaft 5 is rotated the claw arm is moved on the one hand by the crank pin 3 and on the other hand by the eccentric I6, the oscillating lever 8, the intermediate lever I and the pivoting guide 6, in such a manner that the resultant path of a claw is the curve indicated by broken lines in Fig. 1. The other claw describes a similar curve.

In the construction shown in Figs. 3 and 4, the claw arm 26 is provided at one end with the claws 21 and at the other end is pivotally mounted on the crank pin 28. The crank 29 is mounted on the driving shaft 30. By means of the slide 3! the claws 21 are constrained to describe the curve 25 shown in Fig. 3. Fig. 3 shows the path of one claw as will be understood. The slide 3| is arranged to pivot about a pin H on a Z-shaped oscillating lever I8 which is pivotally carried on the shaft 30. The slide 3| is controlled by a connecting rod I9 pivotally carried on the crank pin 28 and which slides to and fro in a guide sleeve 20 mounted in a bore in the spindle 24, so that it rocks a lever 2| fixed to'the spindle 24. This movement of the lever 2| is transmitted to the oscillating lever I8 by a pin 22 which engages between two guide members 23, 23a, carried on the lever l8. The spindle 24 on which the lever 2| is mounted is carried in the wall i2 of the apparatus.

The curve 25 described by the teeth of the claw mechanism results from the following two partial movements: A reciprocating movement of the claw arm 26 is effected by means of the crank pin 28 mounted on the disk 29 which is rotated by the axle 30, and a reciprocating movement on an are perpendicular to the first-named reciprocating movement is caused by the slide 3| which is moved by the Z-shaped lever l8. The lever i8 is rotatably mounted on the axle 30 and is moved by means of the lever 2| and the pin 22. The lever 2| is fixedly mounted on the spindle 24 and is reciprocated by means of the guide sleeve 20 in which slides the rod l9 driven by the crank pin 28 which simultaneously drives the claw arm 26.

What we claim is:

1. A driving claw comprising in combination, a wall, a power driven shaft journalled in said wall, a crank disk mounted on said shaft, a pivot mounted on said crank disk, a claw arm mounted on said pivot, a slide mounted on said claw arm at a substantial distance from said pivot and the free end of said claw arm, an eccentric mounted on said crank disk, a first lever rotatably mounted on said wall, two flanges mounted on said first lever engaging the periphery of said eccentric, a second lever rotatably mounted on said wall with one end pivoted to the free end of said first lever and with its other end rotatably mounted on said slide, a slot provided in said second lever at a substan- 40 tial distance between its two ends, and a pin 2. A driving claw comprising in combination, a wall, a power driven shaft journalled in said wall, a crank disk mounted on said shaft, a pivot mounted on said crank disk, a claw arm mounted on said pivot, a slide mounted on said claw arm at a substantial distance from said pivot and the free end of said claw arm, a first lever rotatably mounted with its one end on said shaft and with its other end rotatably mounted on said slide, a spindle rotatably mounted on said wall, a guide sleeve mounted in the free end of said spindle, a rod rotatably mounted on said pivot and having one end engaging said guide sleeve, two guide members mounted on said first lever, a second lever fixedly mounted on said spindle, and a pin mounted on said second lever and engaging said guide members on said first lever.

3. A driving claw comprising in combination a wall, a power driven shaft journalled in said wall, a crank mounted on said shaft, a pivot mounted on said crank, a claw arm mounted on said pivot, a lever and means mounting the same for angular movement about a fixed axis, guide means carried by one end of said lever for slidably supporting said claw arm at a region between the claw end thereof and said

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