US1829394A - Head checking means for power operated pressing machines - Google Patents

Description

E. DAVIS Oct. 27, 1931.

HEAD CHECKING MEANS FOR POWER OPERATED PRESSING MACHINES Filed Dec. 12, 1927 Patented Oct. 27, 1931 UNITED STATES PATENT OFFICE-- ERNEST DAVIS, OF SYRACUSE, NEW YORK, ASSIGNOR TO THE PROSPERITY COMPANY, INC., OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK HEAD CHECKING MEANS FOR POWER OPERATED PRESSING- MACHINES Application filed December 12, 1927. Serial No. 239,389.

g This invention relates to machines having an opening and closing movement as pressing machines, and has for its object a particularly simple and efiicient mechanism for retarding the opening and closing movement of the movable element or head, particularly the closing movement as the movable element approaches closed position, and relieving I the retarding action during the final portions ure 1.

Figure 3 is an enlarged longitudinal sec-. tional view of the retarding means.

This invention comprises, generally, means for checking the movement of the movable element or press head of the pressing machine toward the other element or buck as the head approaches closed position, and relieving the checking action during the final portion of the closing movement. The checking means is constructed also to check to some extent the opening movement during an intermediate portion only thereof, and relieve the movable element of the checking action as the movable pressing element or head approaches its wide open position. 1

In power press machines, the power first applied much be sufiicient to overcome the inertia of the press head but once the press head is in motion, it comes down against the stationary pressing element or buck with a jarring or slamming action. Likewise in opening the press, the press head gains momentum on its upward movement and comes to a stop with a more or less violent or jarring action.

By my invention, both the opening and closing movements are checked during the intermediate parts only of such movements, and the movable element is relieved of the checking action at the end of its closing movement when final pressure is being applied and also to a less extent at the end of its opening movement. The checking of the opening movement is not of as much consequence as the checking of the closing movement.

The pressing machine may be of any suitable form, size or construction, that here shown including a head 1 movable toward and from a buck 2 mounted on a suitable bench 3 carried by a suitable frame. The actuating mechanism for the head comprises a motor as a cylinder 4 having a piston therein, the rod 5 of which is connected'to the head 1 through suitable motion transmitting connections. These connections are here shown as including a horizontal lever 6 pivoted at 7 to the frame and having an upwardly extending arm 8 connected to a link 9 which is pivoted at 10 to the rear arm of a lever 11 pivoted between its ends at 12 to the frame. The lever 11 carries the head 1 at its front end. The parts 8 and 9 constitute a toggle. The lever 11 is provided with a suitable counterweight 13 and springs 14 and 15 to open the press, as the cylinder 4: is single acting. However, the cylinder with the piston therein is the prime mover. The control of air or other motor fluid to and from the cylinder is effected by any suitable manually operable means. The manual means here shown includes a push button 16 which operates to open an intake valve in casing 16, and a lever 17 which opens an exhaust valve in said casfhe construction of the parts thus far described forms no part of this invention.

The checking means forming the subject matter of this invention acts to check the closing movement of the press as the head 1 approaches the buck 2 and relieves the head of the checking action when the final pressure is being applied by the air pressure in the cylinder 4 against the piston, and also acts to slightly check the opening movement of the press under the influence of counterweight 13 andsprings 14 and 15, before the head comes to wide open position. The checking means is here shown as a cylinder 18 and a piston 19 in the cylinder, one of these parts, usually the piston, being movable and fits said intermediate portion. The end portions are usually of truncated conical form and taper toward the cylindrical intermediate portion 20. In order that the machine may open quickly, the checking efiect is lessened by providing a by-pass for the fluid from one side of the piston to the other. As here illustrated, the by-pass is provided in the piston, and the piston is shown as formed with passages 23 therethrough which are closed during the down st oke of the piston by a flat valve 24. During the up or return stroke of the piston the flat valve is pressed away from the passages 23 by the fluid. The fiat valve 24 is, in effect, a check valve.

A piston rod 25 slides in a head 26 of the cylinder 18 and is connected to one of the motion transmitting parts here shown as the toggle link 8. The connection between the toggle link 8 and the piston rod 25 comprises a lever 27 pivoted between its ends to the frame at 28, one arm of the lever being connected to the swinging toggle link 8 by a link 29 and the other arm being connected to the piston rod by a swinging link 30 pivoted at 31 to the lever 27 and at 32 to a head 33 on the end of the piston rod.

The cylinder is usually fixed to a suitable part of the frame as the rear leg 34 and is located below the table or bench 3. The piston rod extends through the upper end of the cylinder, and hence the connecting rod'30 extends along one side of the cylinder beyond the lower end thereof where it is pivoted at 31 to the lever 27.

In operation, when motor fluid is permitted to pass into the upper end of the cylinder 4, the piston 19 is in the upper portion 22 of the cylinder 18 and there is practically no checking effect until the head 1 has moved far enough toward the buck 2 to carry the piston 19 in the contractedportion 20 of the cylinder when the closing movement of the head 1 is retarded momentarily until the momentum of the head is overcome or nearly overcome.

The piston 19 then moves into the larger lower end portion 21of the cylinder thus relieving the retarding or checking effect while flillll unchecked final pressure is being ap- 'ed.' p The press is held closed by the air in the cylinder 4 and when this air is released, by operating the lever 7, the head opens under the influence of the counterweight 13 and springs 14 and 15. During the beginning of such opening movement, there is no checking effect while the weight 13 and springs 14 and 15 are overcoming the inertia of the head. Thereafter when the press partly open, the

piston 19 again reaches the contracted portion 20 of the cylinder and the momentum of the head during its upwardmovement is momentarily checked to a slight extent, the checking effect being decreased because the fluid is now free to pass through the passages 23.

WVhat I claim is:

1. In a pressing machine, upper and lower pressing elements, the upper element being movable towardand from the lower element, actuating mechanism for moving the upper element toward and from the lower, and means for checking the operation of the upper element after it has been started in motion, and relieving it of the-checking force as the upper element comes into coaction with the lower element and when it approaches the limit of its upward movement away from the lower element.

2. A pressing machine including co-operating pressing elements, one of which is movable toward and from the other, actuating mechanism for actuating the movable element, and means for retarding the movable .element during intermediate parts only of the opening and closing movements thereof.

3. A pressing machine comprising coopcrating pressing elements, one of which is movable toward and from the other, mechanism for actuating the vmovable element, means for retarding the movable element during intermediate parts of the opening and closing movements thereof, said retarding means including mechanism for causing a greater retarding effect when the movable element moves in one direction than when said movable element moves in the other direction.

4. In a pressing machine, the combination of a fixed pressing element, a movable pressing element, actuating mechanism for said movable element, means cooperating with said actuating mechanism to retard the motion of said movable element during a part of its movement in each direction.

5. In a pressing machine, the combination of a fixed pressing element, a movable pressing element, actuating mechanism for said movable element, means cooperating with said actuating mechanism to retard the inotion of said movable element during a. part of its movement ineach direction, and dis- 'aaaaeea tion, and discontinue the retarding efiect as the movable element approaches its limit of travel ineach direction, and valve mechanism in said fiuid retarding means operable g to decrease retarding action as the movable element is moved in one direction.

In testimony whereof, I have hereunto signed my name, at Syracuse, in the county of .Onondaga, and in the" State of New York, 10 this 8th day of Dec, 1927.

ERNEST DAVIS.

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