US2328524A - Safety device - Google Patents

Description

Aug. 31, 1943. R. BECKER SAFETY DEVICE Filed March 25, 1942 Patented Aug. 31, 1943 Rudolph Becker, North Plainfield, N. J., assignor to The Singer Manufacturing Company, Elizabeth, N. J a corporation of N ew Jersey Application March 25, 1942, Serial No. 436,088

1 Claim.

This invention relates to safety devices for machines which are controlled by an operator and particularly to devices adapted to prevent the repetition of the machine cycle in the event the operator inadvertently maintains the machine control means depressed.

The primary object of this invention is to provide a simple and compact safety device which is particularly designed so that i-t'may be readily applied to any appropriate type of machine having an operative mechanism and a manipulative means for initiating the action of the operative mechanism. e n

The present invention is an improvement over that type of safety device disclosed in the U. S. Patent No. 1,244,458, to Barron et al., dated October 30, 1917. Furthermore, the present device is primarily adapted to be used on the type of machine disclosed in this patent.

With the above and other objects in view as will hereinafter appear. the invention comprises the devices, combinations and'arrangements of parts hereinafter set forth and illustrated in the accompanying drawing of a preferred embodiment of the invention, from which the several features of the invention and the advantages.

attained thereby will be readily understood by those skilled in the art.

The several features of the present invention will be clearly understood from the following description and accompanying drawing which- Fig. 1 is a front elevation of the present device in starting position and with its cover plate removed.

Fig. 2'is a front elevation of the present device showing in solid lines the relative positions of its component parts when the parallel arms have moved downward to the position assumed by the parts the moment before the latching means is opened. The broken lines illustrate the positions of the parts when the latching are'parallel to and in sliding contact with each other. Furthermore, it may be seen that one end of each arm extends beyond an end portion of the housing. IG. Each of the arms l2 and I3 has a recess M formed in one side thereof for the purpose of receiving a compression spring I5 the upper ,end of which engages a shoulder I6 of the recess I4. The springs I5 are disposed within the housing I!) in parallelism with each other and the lower portion of. each spring engages a respective one of two ward movements thereof in a similar manner.

A pin 2| carried by the first arm I2 functions as a pivotal mounting for a couplinglatch device comprising a first finger 22 and a second finger 23 both of which extend outwardly from a hub portion 24. A tension spring 2:a one end of means has been opened and the actuating arm has reached its lowest position.

Fig. 3 is a horizontal section taken substantially along line 3-3 of Fig. 1 but showing the cover plate in its proper position.

Fig. 4 is a disassembled perspective view of the major parts of the safety device.

Referring to the drawing I0 represents a housing member provided with the bearing channel II which is adapted to slidably receive a first or actuating arm l2 and a second arm I3. As may be seen in Fig. 1 these two arms are mounted within the bearing channel I I so that they which is secured by means of the hook .26 to arm I2 and theother end of which is secured to finger 23 by means of a hook 2i, constantly urges the latch in a counter-clockwise direction about the pin 2|. This movement of the latch however, is limited by an abutment member 28 carried by the arm l3 and engaged by the finger 22.

As may be best shown in Fig. 2, a downward movementof arm I2 will bring the curved outer end of finger 22 in engagement with curved shoulder 29, and therefore, the arms I2 and I3 will move downwardly in unison against the combined actions of springs I5. When the arms have moved downwardly a predetermined distance the outer portion of finger 23 will engage the upper end of a trip-member 30 which is secured to the housing ID by means of a screw 3|. Further downward movement of the arms will cause the latch to pivot about .pin 2| and slide the end of finger 22 off of the abutment shoulder 29 to thus open the latch and release the arm I 3 so that it will be forced upwardly i response to the action of its compression spring IS. The solid lines of Fig. 2 illustrate the mechanism the moment before the latch is opened and the broken lines represent the relative positions of the mechanism when the arm |2 is in its lowest position and the arm I3 has risen to its upper or starting position. Upon release of the arm I2 its spring I5 will force it upwardly and the tension or latch spring will again force the latch into engagement with the abutment member.

It is to be understood that arm I3 is adapted to be connected to a machine operative or starting and stopping means and the arm I2 to a manipulative means. Therefore, a downward movement of the manipulative means will, as above described, also move the arm I3 downwardly to thus actuate the operative means and thereby initiate the action of the machine cycle. If the operator then inadvertently maintains the manipulative means depressed the machine cannot repeat its cycle of operation. Upon the release of the manipulative means the safety device is again ready to initiate the starting of the machine cycle.

The trip-member is provided with an elongated aperture 32 for the purpose of receiving the screw El and permitting the trip member to be adjusted relative to the housing member ID. Adjustment of this trip-member will lengthen or shorten the length of stroke required of the arm I 2 before the latch memberis opened.

Plates 33 and 34 are each secured to the housing II! by means of screws 35 for the purpose of retaining the arms I2 and I3 and the springs I5 in their proper respective places whenever a cover-plate 35 is removed from the housing. Screws 3'! secure the cover-plate 35 to the housing thereby to enclose all of the moving parts of the safety device with the exception of the extended portions of the arms I2 and i3. These plates 33 and 34, however, may be omitted from the present safety device without impairing the action or the efficiency thereof.

Provided in the cover-plate 36 is an aperture 38 which permits entry of a screw driver into the cover-plate so that the trip-rnember may be adjusted relative to the housing without removing the cover-plate from the unit. Furthermore, a shoulder portion 39 is formed on the inner face of the cover-plate 36 for engaging the trip-member 30 and preventing thesame from pivoting about the screw 3! when the latter is loosened for adjusting purposes. In order to provide proper clearance space within the device for the latch, latch-spring and the abutment member, a recess 43 is formed in the inner face of the coverplate.

Each of the arms I2 and I3 is provided with an aperture in the outer end portion thereof for receiving a chain 4| or a like element for con-' necting the arms of the safety device to the appropriate parts of a machine and its control pedal.

From the above description it is to be understood that the simple and compact construction of the present safety device permits the same to be readily applied to any appropriate type of machine. The apertured lugs 42 are provided on the housing It to function as mounting means for the device, as for example, when the device is used in conjunction with a sewing machine the housing is adapted to be received within an aperture formed in the sewing machine table top so that the lugs 42 rest upon the table top to be secured thereto by means of screws. It will be understood however, that the housing may be greatly modified Within the scope of .the invention to adopt the same for the specific use to which the device is to be applied.

Having thus set forth the nature of the invention what I claim herein is:

A safety device of the class described comprising a rectangular housing having a single bearing channel disposed longitudinally thereof, a pair of parallel reciprocatory members mounted in'sliding contact with each other within said bearing channel, each of'said reciprocatory members projecting beyond an end portion of said housing and being provided with a recess Within the side of the member opposite to that side which is in contact with the other member, a pair of parallel coil springs each mounted within the recess of and engaging one of said reciprocatory members, a latching means having two extending fingers and being pivotally mounted on one of said reciprocatory members, a latch spring engaging said latching means to force the same about its pivotal point, an abutment memher in the form of a curved shoulder mounted on the other of said reciprocatory members and being adapted to be engaged by one of said extending fingers so that said reciprocating members may be moved in unison during a portion of their reciprocatory movements in opposition to theaction of said springs, a trip-member having an elongated aperture formed longitudinally therein, a screw received within said aperture and a threaded into said housing to adjustably secure said trip-member thereto, said trip-member being adapted for engaging said latch means at a predetermined point thereby to disengage the same from said abutment member, and a coverplate removably secured to said housing and disposed so as to confine said reciprocatory members within said channel and said coil springs within the respective recesses.

RUDOLPH BECKER.

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