US1454898A - Safety device - Google Patents

Description

Patented May 15, 1923.

,- UNITED STATES BEBNARD SCOTT LEE, 0! BEVERLY, MASSACHUSETTS, ASSIGNOR TO UNITED SHOE I HACHINERY CORPORATION, OF PATERSON, NEW JERSEYA JERSEY.

CORPORATION OF NEW SAFETY DEVICE.

Application filed October 4, 1919. Serial No. 828,528.

To all whom it may concern:

Be it known that I, BERNARD S. LEE, a citizen of the United States, residin at Beverly, in the county of Essex and btate of Massachusetts, have invented certain Imrovements in Safety Devices, of which the chines capable of causing injury to the operator.

It has been found advantageous to provide many machines with individual motor driving means so that each machine is independent-of line shafting and may be installed in any available or desirable space in the factory. As a matter of economy the electrical motor provided with any given machine is selected with reference to the load under regular operating conditions and hence it occasionally happens that with an unusual load, the motor possesses insuflicient power to turn the driven shaft. Under such circumstances, the operator may attempt to turn the shaft by hand to release the work or to adjust the working parts and, in order to do so, the guard which covers the fly wheel is removed or displaced to permit of the introduction of a bar into perforations in the fly wheel so that with the aid of the bar, the shaft may be readily turned. Again, in making adjustments in the work operating parts of machines, as in the illustrative machine wherein dies and cutting blocks are occasionally changed for new parts or for others of a different size, it becomes necessary to turn the shaft over by hand to determine if the newly introduced parts are properly adjusted. A fly wheel provided with a bar for the purpose described would be dangerous to the operator if power were applied to move the fly wheel while the bar is still inserted therein. Hence, means is'provided for rendering the startting mechanism of the machine inoperative so long as the guard is displaced, the construction being such that when'the guard is replaced, which necessitates the withdrawal of the bar, the starting mechanism is again operative.

In one aspect the invention comprises a guard movable along a shaft to cover or uncover a member rotatable with the shaft, the construction and arrangement being such that the starting means cannot be employed tostart themachine in operation while the guard is in inoperative or uncovering position relative to said member.

Other objects and advantages of the invention and other combinations of parts will be described in the following detailed specification and pointed out in the claims.

In the drawings Fig. 1 is a view in side elevation of a machine embodying the invention;

Fig. 2 is a detailview partly in section showing one of the switches for controlling the current to the motor; and

Fig. 3 isjasection on the line 3-3 of F i 2.

or convenience of illustration the invention is shown as applied to the heel liftcutting machine disclosed and claimed in the patent to W. C. Baxter No. 1,291,726, granted January 21, 1919, which comprises a main shaft 4 having fixed thereto a fly wheel 6 provided with perforations 8.

In the illustrative construction the power for rotating the shaft 4 is supplied by an electric motor 10, the armature shaft of which carries a pulley 14. connected by a belt 16 to a pulley 18 securely fixed to shaft 4. It will be clear that upon rotation ofthe motor shaft, power will be communicated to run the shaft 4 of the machine. Mounted in the frame 20 of the machine is areciprocable plunger 22 connected by means of a crank or eccentric with the shaft 4 so as to be operated upon rotation of the latter. The plunger 22 co-operates with a .die (not shown) to cut blanks from sheet mate- 7 rial, as disclosed in said- Letters Patent No. 1,291,726. Occasionally it is necessary, for reasons stated in the foregoing discussion, to turn the shaft 4 over by hand. Ordinarily the operator will make-use of a bar which can be introduced into any one of the perforations 8 in the fly wheel '6 and then the shaft may be easily turned by exerting force upon the bar. It will be understood that if the bar should be inadvertently left inserted in a perforation in the wheel and the machine started in operation, there would'be serious danger of injury to the operator as well as to the machine. In the illustrated embodiment of the invention, a guard 24 is rovided which must be moved to uncover t e perforations and which is 50 connected to a switch that when the guard is moved to inoperative position the said switch is opened, thus making it impossible to run the motor. The construction is such that the guard must be returned to operative position covering the perforations, so that the bar must be removed before the switch is closed. The guard 24 may surround the wheel 6 or may be made in two sections of which the rear portion (not shown) is stationary while the front part is movable as described.

In the construction shown an auxiliary switch 26, shown in detail in Figs. 2 and 3, is enclosed in a casing 28 (Fig. 1) and has one portion 30 of the switch connected to a movable bar 32 which in turn is attached securely to the guard 24. Conveniently a handle 34 is provided at'the front end of the bar so that it may be operated to move the guard to cover or uncover the fly wheel 6. To hold the guard in either its operative or inoperative position a locking means is provided which, in the construction shown, consists of a spring-pressed pin 36 mounted in a bearing 38 which surrounds the bar 32, the

said locking pin being so arranged as to drop into either of two co-operating openin s 40 in the bar 32.

referably the auxiliary switch comprises two plates 42 secured to an insulating block 44 carried by a bracket 46 attached to the bar 32. Mounted upon another bracket 48 extending from the stationary bearing 38 is a second insulat' block 50 which carries two pairs of contacting plates 52 (see Fig. 3) designed to embrace the plates 42 when the latter are moved the full distance toward the right in Fig. 2, thus closing the switch by bringing the co-operating plates into full contact with each other. The wires which bring the electric current from the dynamo are indicated at 54, the said wires being secured to bolts 56 attached to plates 52. Thus, when the co-operating plates are separated the circuit is broken at two oints which is a feature insuring abso utely against any possibility of the current remaining unbroken. The-wires 58 pass from the lower set of bolts or pins 60 and through a conduit 62 to a switch box 64, a switch 66 of the usual commercial type being interposed as indicated in Fig. 1. From the switch box the wires pass through the conduit 68-to the motor 10.

In the operation of the machine it will ordinarily be necessary only to turn the switch 66 when it is desired to commence operations, since upon turning the switch in the proper direction the motor is enered andpower is transmitted therefrom to the main shaft of the machine by the means described. If, however, it becomes necessary to turn the shaft 4 over by hand, the operative must remove the guard 24 before inserting a bar in the perforations in the fly wheel 6 to turn it over. This shifting of the guard to inoperative position at once opens the auxiliary switch as describedv so that upon turning the fly wheel there is no possibility of power being applied to turn it further and thus cause possible injury to the operator. The guard is so arranged that the rod must be removed from the perforations before the guard can be returned sufliciently far to close the switch. Hence, so

long as the bar is in one of the perforations there is no possibility of injury to the operator. To operate the machine the guard must he returned to operative position coverin the perforations in the fly wheel, and it is preferably locked in such position by the means 'described. If the switch 66 is left closed the machine will start to operate as soon as the auxiliary switch is closed by moving the bar 32 to the right by means of the handle 34. While, in t e illustrated construction, the member which may cause inju to the operator is disclosed as a fly whee having a bar inserted therein, my invention contemplates covering any rotatable member capable of causin injury to the operator, by a guard movab e like that shown and so connected to the switch as to open the switch when the guard is displaced so that the guard must be replaced to cover the member before the machine can be started in operation.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is 1. In a machine of the class described, a shaft, a member projecting laterally from the shaft and capable of causing injury to the operator when the member is unguarded, a guard slidably axially of the shaft to vcover and uncover said member, power means for operating said member, a switch in an electric circuit for controlling the power means, and means connected to the guard and so arranged as to prevent electrification of the circuit and the starting of the machine in operation when the guard is in uncovering position with respect to said member.

2. In a, machine of the class described, a

vided with perforations for receiving a bar utilized in turning the shaft over by. hand,

shaft, a fly wheel fixed on the shaft and pro- 1 a guard for the fly wheel, power means for] driving the shaft comprising an electric motor, a switch for controlling the motor,

and means controlled by'the guard for preventing electrification of themotor. circuit when the guard. is in inoperative or uncovering position with respect-to the perforations in the wheel.

3. In a machine of the class described, a shaft, a fl wheel fixed on the shaft and. provided wit perforations for receiving a bar utilized in turning the shaft over by hand, a guard for the fly wheel movable to cover and uncover the perforations in the wheel, power means for operating the machine, and a switch in an electrical circuit for controlling the power means, a portion of the switch'being connected to the movable guard and so arranged that the guard must be in operative position to cover'the perforations 1n the Wheel before the machine can be started. Q

4. In a machine of the class described, a

shaft, a member rotatable with the shaft and capable of causing injury to the operator, a guard slidable axially of the shaft to cover and uncover the member, power means for operating the machine comprising an electric motor, vand a switch for the motor circuit controlled b the guard and so ar- BERNARD SCOTT LEE.

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