US2020839A

US2020839A - Safety control for presses

Info

Publication number: US2020839A
Application number: US565773A
Authority: US
Inventors: Leo M Kahn
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-09-29
Filing date: 1931-09-29
Publication date: 1935-11-12
Anticipated expiration: 1952-11-12

Description

Nov. 12, 1935. I L M KAHN 2,020,839

SAFETY CONTROL FOR PRESSES Filed Sept. 29, 1931 54C Cf 11V VEN 7 'OR Patented Nov. 12, 1 935 UNITED STATES,

PATENT OFFICE 5 Claims.

This invention relates to improvements in pressing machines for various purposes whose operation may involve danger to the operator. It can be used in any power press, but is more particularly related to garment and laundry presses, on which the moving head of a press must be controlled in such a manner as to positively protect the operator against any hazardous actions on her part.

Among the objects of this invention is provision of a simple mechanical device whereby the operator is forced to employ both of her hands for the control of the movable head-of such laundry presses. Another object is to provide for the actuation of the machine by foot means, which is releasable by hand operated means. These are other objects of my invention are attained in the construction hereinafter set forth and claimed.

Reference is had to the accompanying drawing in which like numerals and characters refer to corresponding parts throughout the different views.

Figs. 1 and 2 are respective frontand side elevations of a laundry press. Fig. 3 is an enlarged top view of part of the safety control device. Figs. 4 and 5 are respective front and side views of a modification of a certain element of the safety control device.

My invention is here shown applied to a conventional type of laundry pressing machine consisting of a frame ID, a stationary buck H, a movable head l2, operated by a toggle joint mechanism l3, which is actuated by a pressure cylinder l4, connected with lever l5 to said mechanism l3.

The cylinder is operated through two valves or main control members l6 and ll of which the former is employed to release an air pressure which will cause the piston in said cylinder to press head I 2 against buck ll.

Valve I1 is employed to release an air pressure to cause a reverse motion of said piston and head l2.

Both valves are fed by a source of power through pipe l9, having therein a stopcock 29 to cut off the power.

A bar fastened to the front part of frame It has fulcrumed to both its ends two operating levers 2| and 22. Fastened to their extremes are respective cords or

chains

23, 24 passing over

respective pulleys

25 and 26 held 'to frame l0.

Cords

23 and 24 are fastened to respective slidable rods 21, 28 located on respective bearing blocks 3i, 32 secured to frame H). To each slide rod 21, 28 is fastened a respective

auxiliary control member

33, 34 located in such a manner that a pedal 30, hinged to bearing blocks 3|, 32 is prevented from being operated or pressed in a downward direction.

Springs 35, 36 located on said slide rods between the bearing blocks and the auxiliary control members serve to locate the latter underneath said pedal when the same is not being used.

Extension 31 of pedal carries a spring 38, to retain the pedal in a normal .or inoperative position.

When pedal 30 is pressed down, extension 3! will raise valve member 39 for the release of air pressure to lower the head l2.

After said valve member has been raised it will be prevented from assuming its original position 15 through a pawl 40 hinged to frame I0, engaging an extension 4| of valve member 39.

Lever42 forming a part at pawl 40 is normally located underneath the head of valve member 43 of valve I l.

A push rod 44 slidably mounted to frame l0 resting on a push lever 45 and forming a part v with lever 42 and pawl 40, serves to release the latter from valve member 39 and thereby eliminate the air pressure on piston l8 and head l2. 2 Pushrod 44 also serves to operate valve I! to cause piston l8 to remove head l2 from buck l l to a position as indicated in dotted lines.

The operation of the safety control as illustrated in Figs. 1, 2, and 3 consists in the depression of operating levers 2|, 22 by both hands of the operator, to permit the latter to actuate pedal 30. It is obvious that the depression of only one of the operating levers will not release the pedal, so that in this manner the operator is automatically forced to keep her hands away from the buck while the head of the press is descending. When pedal 30 is depressed and valve I6 is caused to permit air pressure to lower head l2 as shown in Fig. 2, the pressure will remain on buck l l until the operator desires the same to be released. This is done by means of pushrod 44, the function of which has already been described. 45

In the modification of Figs. 4 and 5 pedal 30 has been eliminated and a foot operated valve Ilia is located underneath two

auxiliary control members

53, 54 fastened to respective sliderods 51, 58 which are located by

respective springs

55, 56. These control members, which overlap each other, are moved to left and right in the manner described, hereinabove for the other construction, and will not permit the operator to depress the valve unless both of her hands have removed the control members to enable her to place her foot between the same, and then cause the machine to operate. If it is desired to keep both head 2| and platform 20, in a raised position while the machine is idle, the air pressure in pipe l9 may be shut off through stopcock 29.

I claim:

'1. In a pressing machine, coacting press elements therein, fluid pressure means to actuate said press elements, a valve mechanism to control said fluid pressure means to actuate said press; auxiliary members for obstructing the actuating of said valve mechanism and means requiring the use of both hands for moving said auxiliary obstructing members to permit said valve mechanism to be actuated for controlling the fluid'power to effect the closing of said pressing elements, retaining means for holding said valve actuated to keep said press elements in the position after said valve had been actuated, and separate manually operated means for releasing retaining means to allow said pressure means and valve to separate said coacting elements.

2. A press comprising a stationary buck, a movable head, fluid power means for opening and closing the head on the buck, control valves for said power means, a pedal operated mechanism for actuating one of said control valves, a pair of auxiliary control members normally obstructing access to said pedal adapted to be actuated by both hands to permit access to said pedal, to control said, valve, for admitting fluid to said fluid powermeans to efiect the closing of the head on the buck, and separate valve controlling means to control the fluid power means to effect the opening of the head from the buck.

3. In a pressing machine, coacting press elements, fluid pressure means to effect pressure between said press elements, a pedal to control the flow of fluid to said fluid pressure means, auxiliary members for preventing the actuation of said pedal, and control means requiring use of both hands for rendering said auxiliary members inefiective to prevent the actuation of said pedal to permit said pedal to be actuated, means for maintaining the flow of fluid pressure to said fluid pressure means after said pedal had been actuated, and means independent of the two hand control means for controlling the said fluid 10 pressure means to cause the same to separate said press elements.

4. In a pressing machine, coacting press elements, fluid pressure means to effect pressure between said press elements, a pedal to control the flow of fluid to said fluid pressure means, auxiliary members for preventing the actuation of said pedal, and control means requiring use of both hands for rendering said auxiliary members ineffect ve to prevent the actuation of said pedal to permit said pedal to be actuated, and means independent of the two hand control means for controlling the said fluid pressure means to cause the same to separate said press elements.

5. In a pressing machine, coacting press elements, fluid power means for effecting pressure between and for separating said elements, a pedal, a valve operated by said pedal for admitting fluid to said power means to cause said pressing elements to effect pressure therebetween, barrier means to inhibit access to said pedal, a pair of auxiliary control members adapted to be actuated by both hands to remove said barrier means to allow access to said pedal to permit actuation thereof, and separate valve means for 5 controlling said power means to separate said press elements.

LEO M. KAHN.