US999464A - Guard for machinery. - Google Patents

Description

B." W. PINKERTON.

GUARD FOR MACHINERY.

APPLICATION FILED APR. I 1911.

999 464 Patented Aug. 1, 1911.

' eoaaca.

urn earns arr FFTQ .ERVIN W. PINKERTON, OF ROCHESTER, NEW YQRK.

GUARD ron MACHINERY.

Specification of Letters Patent.

Paton-ted Aug. 1, 1911.

Application filed April 1, 1911. Serial No. $18,485.

new and useful Improvements in Guards for lllachinery, of which the following is a specification.

This invention relatesto a guard adapted to prevent injury to the hand of an operator in feeding material to the operative instrumentalities of a machine.

' In machines of certain types, particularly in a die-press, it is impracticable to provide guards by which the operator can be abso- Jfitely prevented from accidentally inserting the hand between the dies, or other operative instrument-alities, when the machine is running, since guards for this purpose would interfere with the proper presentation of the bers which interfere in any way with the convenient operationof the machine. this end I propose to employ an electric current in such'a manner that, in case the operator allows his hand to approach into dangerous proximity with the operative instrumentalities', the hand is subjected to a shock. This shock not only gives the operator unmistakable warning of danger, but it is also possible, by the use of a current of a power- 111, but not dangerous, character, to cause an involuntary movement of the hand by which it is immediately and inevitably with drawn out of danger.

It has been previously proposed to employ electricity to guard at punching-press in the manner stated, by means of apparatus which is automatically thrown into operation when the dies of the punching-press move together. and which is thrown out of operation again automatically when the dies move apart. Such a construction is effective,

however, only in machines provided withoperative instrumentalities which, like dies,

moveintermittently toward and from each other. In the present invention, however, I arrange the electrical apparatus tobe thrown into, and out of, operation by the treadle, or other manually-operable device bp vhichthe machine as a whole is thrown into or out of operation. Accordingly, my novel arrangement. is applicable to machines of all kinds having dangerous operative instrumentalities, whether these operate intermittently, as in a press, or constantly, as in the case of a sawing or molding-machine, or the like, the electric apparatus being operative so long as the operator retains the t'readle in depressed position to continue the operation of the machine.

A. further feature of the invention consists in the use of the treadle, or other manually-operable device, as one electrode for conducting the current to the body of the operator, whereby I simplify the construc tion of the device and avoid the necessity of an independent electrode for the purpose.

- The accompanyingdrawing is a side-elevation'of a die-press provided with a guard embodying the present invention.

The machine of the drawing is a die-press of ordinary form, having the usual upper and lower dies 1 and 2. The lower die rests upon a metal plate or bed 3-supported on the frame of the machine, and this plate serves as a conductor for the electric current. The front-portion of the frame of the machine is covered by insulating material 4,50 that the operator may touch this partwithout receiving a shock, butif, in feeding the material between the dies, he inadvertently permits his hand to approach into dangerous proximity to the dies, the contact between his hand and the plate 3 subjects the hand to a powerful shock, causing the hand to be immediately and involuntarily withdrawn.

To complete the electric circuit through the operator I make use of the treadle 5 of the machine as an electric contact in such circuit. This treadle is insluated'from the pivoted arm 11 on which it is supported, and is connected with one terminal of the source of electricity. The source of electricity maybe an ordinary induction-coil 6.

- of which the primary, winding is connected tor depresses the treadle 5 to start the machine in the usual manner, the arm 11 draws down the rod 10, thus throwing the clutchmechanism into operation and at the same machine, the switch 9 breaks the primary circuit of the coil, and there is no further consumption of current.

My invention is applicable to machines of various types, and obviously various sources of electric current may be employed. Where the machine is not provided with any member conveniently located to serve as a contact to engage the hand of the operator it will be obvious that a special part may be applied to the machine for this purpose.

1. In combination with a machine having operative instrumentalities and driving mechanism therefor, including a normally inoperative clutch, means for generating high-tension electricity, a conductor located adjacentsaid instrumentalities and in the path of movementof the operators hand when feeding work to the machine. a man ually-operable member for throwing and holding said clutch into operation, connections between said generating-means, said conductor and said manually-operable member, whereby a circuit may be produced 2. In combination with a machine having 4.5

operative instrumentalities and a treadlecontrolled driving mechanism therefor, means for generating high-tension electricity adapted to produce a powerful, but not dangerous, shock, a conductor located adjacent said instrumentalities and in the path of movement of the operators hand when feeding work. to the machine, and connections between said generating-means, said conductor and the treadle of the machine, whereby 'a circuit may be produced through the operators body in case the hand is brought into contact with said conductor.

3. In combination with a machine having operative instrumentalities and a treadlecontrolled drivingmechanism therefor, means for generating high-tension electricity adapted to produce a powerful, but not dangerous, shock, a conductor located ad-- jacent said instrumentalities and in the pat of movement of the operators hand when feeding work to the machine, connections between said generating-means, said conductor and the treadle of the machine, whereby a circuit may be produced through the operators body in case the hand is brought into contact with said conductor, and a circuit-breaker operated by the treadle and connected with said generatingmeans to throw the latter into operation when the treadle is depressed to start the machine.

ERVIN IV. PINKERTON. Witnesses:

D. Gmuvnn, C. W. CARROLL.

Copies of this patent may be obtained for five centseach, by addressing the Commissioner of Patents, Washington, D..C.

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