IL24980A - Working machines with safety device - Google Patents

Description

PATENTS AND DESIGNS ORDINANCE SPECIFICATION Working machines with safet device T inea tpnn oy ni a'y m uss I (we) Benjamin B1RA , an Israel citizen, of 25 David Pinski Street, Haifa. Israel do hereby declare the nature of this invention and in .what manner the same is to be performed, to be particularly described and ascertained in and by the following s-tatement: The present Invention concerns workin machines in which a working tool is periodically lowered on a working table, and lifted therefrom, which will be referred to hereinafter for shor as "working machines of the kind specified".

A typical example of working machines of the kind speoifled are presses and the invention will be specifically described hereinafter with reference to presses, it bein understood that it is not confined thereto and also covers other working machines such as, for example, drills, saws and the like.

Working machines of the kind specified operate in cycles each of which comprises ah operative and a rest period. During the operativ period the treated object is processed while during the rest period the sam object is handled by the operator, e.g. inserted, extraoted, shifted and the like. As a rule these machines are so designed that the end of the rest period is determined by the operator who by actuation of a lever, handle, button pedal or the like actuation means releases the operative cycle.

During the rest period when the treated object is handled as specified above, the operator has to put his hands on the working table at a location below the working tool and there exists a very substantial danger of an accident due to an untimely release of the operative cycle. It is therefore necessary to provide certain safety means in working machines of the kind specified for protecting the operator from Injury.

Israel Paten Specification No. 12102 describes a combination of a press or a similar machine with a safety device comprising a shutter or grating which i swlngable in front of the working parts of the machine for preventing or permitting, as the case may be, access to these parts* wherein the shutter is meohanioally connected for common movement with a slldable member designed to be temporarily Incorporated in a chain of links connected to an actuating pedal, and can be withdrawn from the chain of links so as to interrupt it and to make it impossible to switch on the machine.

Such a machine cannot be actuated before the slldable member Is incorporated in the chain of links* Consequently, two consecutive operations are required for starting the machine, namely: ( ) to bring the shutter into the operative position, and (2) to depress the actuating pedal* In order to enable the performance of the first of these operations there is provided in accordance with that patent a special lever or handle which has to be held by the operator in the operative position during the full operational cycle* Moreover, if the handle is not released at the proper moment at the end of the cycle, the press wil contin e to operate and perform another cycle.

Another combination of a working machine with safety means of the kind specified is described in Israel Patent Specification o* 6621. The safety means in accordance with that patent is a screen or grating vertically reciproeable between a guarding and non-guarding position, Yet another solution of the problem ia described in Israel Patent Speci ication 1828 · According to that specification there is provided a combination of a working machine of the kind specified with a safety device wherein the safety device is a awingable screen or equivalent member permanently linked to the actuating handle or pedal of the machine and biased into an inoperative position, and a leve connected to a coupling or other member controlling the operation of the machine is made to bear agains the awingable safety device in such a manner;as to engage and arrest the latter in the operative position when by the actuation of the pedal or handle the work of the machine is started, and to release the safety device and allow the latter together with the peda or handl to return into an inoperative position under the action of the biasing force at the end of each operational cycle of the machine.

While this design constitutes an improvement over the previous ones described in specifications 6821 and 2102 referred to above* it has turned out not to be fully satisfactory mainly because its proper operation is dependent on an interplay between various swingable members which has turned out not to be fully reliable and to be liable to break down. It is therefore the object of the present invention to provide an improved combination of a working machine with a safety device of simpler and more reliable design than the one described in Israel Patent Speci ication 8281 · In working machines of the kind specified the release of the operational cycle is brought about by an operation which will be referred to hereinafter as "coupling". Where the machine is hydraulieally or pneumatically operated the coupling will consist in an actuation of the pneumatic or hydraulic system whereas in case of a mechanically operated machine such as, for example, an eccenter press, the coupling will also be of a mechanical nature, e.g. by means of a clutch.

The invention consists in a working machine of the kind specified in combination with a svingable rotating screen or guard (hereinafter "screen"), comprising a vertically reoiprocable rod for coupling and uncoupling so designed that when it is in one extreme position the working tool of the machin is coupled and whe it is in the other extreme position the working tool is uncoupled, which reoiprocable rod is biased into the uncoupling position, means for the actuation of said reoiprocable rod, a tumable horizontal axle, pin or equivalent means (hereinafte "axle") on which Is keyed said swingable screen, which axle is jounalled in proximity of said reoiprocable rod, the rod and the axle comprising complementary interlocking means so designed that the rod is looked by the axle in the uncoupling position of the former in any angula position of the screen except when the latter is completely lowered, and aotuating means for turning the axle thereby to bring about ••'lifting of the screen.

- - The actuation means of the rod and the screen are distinct from each other. In a preferred embodiment of the invention the screen is biased into the lowermost operative position and in order to keep it in the lifted inoperative position in which the rod is locked, it is necessary to actuate continuously the actuation means for the screen. In accordance with this embodiment it is further pre erred that the actuation means for the rod and screen are two separate pedals to be aotuated by the same foot so that when the operator has to press continuously the pedal or th screen he automatically is prevented from actuating the pedal for the coupling rod and vice versa.

I this manner simultaneous actuation of the coupling rod and the screen is inherently made impossible.

The invention is illustrated, by way of example only, in the accompanying drawings in which: Pig. 1 is an elevation of a press according to the invention showin the safety screen and coupling rod in the inoperative position Fig. 2 is an elevation of the same press showing the screen in the lowermost, operative position while the coupling rod is still in the inoperative position} Fig. 3 is an elevation of the same press showing the screen and coupling rod both in operative positions; Fig., 4 is a fragmentary elevation, partly in section of the safety mechanism of the press according to Figs. 1 to 3 showing the axle o the screen and the rod interlocked in the inoperative position corresponding to Fig. 1 ; - - Fig. 5 is a similar view showing the axle and the rod no longer interlocked in th inoperative position corresponding to Fig. 2j and Fig. 6 is a similar view showing the axle and the rod in the operative position corresponding to Fig. 3* The press here illustrated comprises a frame structure generally indicated at 1 fitted with a working table 2, A die or punch 3 is reolprocable inside the uppe portion of frame 1 and is actuated by means of rod 4 leading to mechanical driving means such as, for example, a cam shaf (not shown).

A vertically reolprocable rod 5 serves as coupling rod and is pivotally linked at its upper end to another rod 6 which in turn leads to the actual coupling device (not shown), while at its lower end it is pivotally linked to another rod 7 which In turn ie linked to a pedal 8.

The design in this case is such that when the coupling rod 5 is in its uppermost position the machine is uncoupled while when the rod is in its lowermost position the machine is coupled. Consequently the rod 5 is biased into its uppermost position by means of a spring (not shown).

A screen 9 is mounted on a arm 10 which is keyed on an axle 11. Also keyed on axle is a link 12 which is pivotally connected to a rod 13 which in turn is pivotally connected to a pedal 14. the safety mechanism Is enolosed within a box 5· As is seen In Fig. 1 in the completely inoperative position of the press when screen 9 is lifted and rod 5 is in the uncoupling position pedal 4 ie depressed while operator's foot has to remain rested on the pedal all the time.

The position of Fig. 2 may be termed as a transltionary one. As shown screen 9 is in the lowermost operative position but rod 5 is still in the uncoupling position. In these positions both pedals 14 and 8 are lifted. If from this position rod 5 is to be shifted into the coupling position pedal 8 has to be depressed while pedal 14 remains in its uppermost position. This is shown in Pig. 5.

Pedals 8 and are so positioned that they have to be Operated by the same foot so that when one is depressed the other one cannot be depressed at the same time. Thus when pedal 8 is depressed it is impossible to depress at the same time pedal 14 and thereby to attempt to lift soreen 9. Although the entire mechanism is such (as will be shown below) that even if attempted pedals 8 and 14 could not be depressed simultaneously, an attempt to do so could possibly damage the mechanism.

The mechanism of the safety arrangement of the press according to Figs. 1 to 3 is illustrated in Figs. 4 to 6. In these three figures the cover plate o casing 15 is removed and axle 1 is shown in section. Arm 10 and link 12 which are both above the plane of the figures are shown therein in hyphenated lines for better understanding.

As shown coupling rod 5 is reciprocable inside a matching guiding groove of casing 15· Likewise axle 11 is turnable within a matching cylindrical bore inside casing 5· As further shown in the figures rod 5 comprises a chamferred surface 17· As shown the mutual positions of rod 5 and axle 1 are such that in the uppermost position of the rod shown in Fig. %, which corresponds to t ¾erati position of Pig. 1t a non-ehamferred portion of axle 11 engages the cylindrical cut-out 16 of rod 5· In this position screen 9 is in the inoperative position as symbolized by the angular position of arm 10 shown in Fig. 4 in hyphenated lines. When arm 10 is now turned anticlockwise the cham erred portion 17 of axle 1 gradually comes to face the out-out 16. However, for as long as even only a small non-eham erred portion of axle 11 remains inside cut-out 16 rod 5 remains looked in its uncoupling, uppermost position. When eventually scree 9 is fully lowered into its operative position of Fig. 2 the ohasaferred portion 17 of axle 1 faces cut-out 16 and is parallel to the rod 5 as shown in Fig. 5. In this position rod 5 is no longer locked and can be lowered into the coupling position o Fig. 3 as shown in Fig. 6.

In the position of Figs. 3 and 6 pedal 8 is depressed. As mentioned above rod 5 is biased into the uppermost, uncoupling position. Therefore as soon as » pedal 8 is released rod 5 springs back into its uppermost, uncoupling position, that is the mechanism returns from the position of Figs. 3 and 6 to those of Figs. 2 and · If from this position pedal 14 is depressed the mechanism returns into the position of Figs* 1 and 4 and a new operational cycle can be started.

The manner described hereinbefore for the interlocking of axle 11 and rod 5 was given by way of - coupling rod and a -horizontal, turaable axle hearing the swlagable guard or screen. Thus, for example, axle 11 may be notched or fluted and rod 5 provided with a suitable matching pro^eo^ion. Alternatively, axle 1 may comprise a cam fo cooperation with a suitably shaped cut-out of rod 5» and the like,.

The linkage between either of the pedals and the axle or the rod may also be of a flexible nature, e.g. of the brushes-wire-type. Moreover, the actuation means need not necessarily bo pedals and may.also be in the form of handles, buttons and the like.

Claims (1)

1. HAVING HOW particularly described and ascertained the nature of said invention and in what manner the same is to be X deolare that what X claim working machine of the kind specified combination with a rotating screen or comprising a vertically same to said working tool rod for coupling and uncoupling designed that when it in one extreme position the working tool of the machine is coupled whe it is the other extreme position the working tool is which reoiprooable rod is biased into the uncoupling means for the actuation of said reoiprooable a turnable horizontal pin or equivalent means on which is keyed said swingable which axle is in proximity of said reoiprooable the rod and the axle comprising complementar interlocking means so designed that the rod is locked by the axle in the uncoupling position of the former in any angular position of the screen except when the latter is completely and actuating means for turning axle thereby to brin about of the working machine according to Claim wherein the actuation means are working according to Claim or wherein the axle comprises a ohamferred portion and the rod a matching the circumference o the axle and the axle and rod interlock in any angular position of the screen but the in which lowermost position the ohamferred portion of the axle faces the rod and is working machine according to 1 substantially as described hereinbefore with reference to the Dated this 14th day of Januar insufficientOCRQuality