US3027829A - Press - Google Patents

Description

C. F. BREY April 3, 1962 PRESS 2 Sheets-Sheet 1 Filed July 15, 1960 INVENTOR. awn A 5/ C. F. BREY April 3, 1962 PRESS 2 Sheets-Sheet 2 Filed July 15, 1960 FIG. 2.

INVENTOR. (1484 AT 565% 47roeA/EYS This invention relates to improvements in presses, and more particularly to a press which utilizes fluid pressure as a means for furnishing the major portion of the pressing force.

A main object of the invention is to provide a novel and improved press which is relatively simple in construction, which provides ample pressing force, and which may be accurately controlled by the exertion of relatively light pulling force on its actuating lever.

A further object of the invention is to provide an improved press which is relatively inexpensive to fabricate, which is durable in construction, which is compact in size, and which is safe to operate.

A still further object of the invention is to provide an improved air-operated press using a simple lever principle which furnishes pressures at the press ram head which have not heretofore been available in air-operated presses, and which accomplishes this with synchronized valve operation, either by lever or by foot pedal means.

A still further object of the invention is to provide an improved air-operated press which by simple lever action converts power delivered by an air cylinder at a long stroke into high pressures at its press arm at a short stroke, without requiring the use of heavy and large-bore cylinders and excessively high hydraulic pressures.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE 1 is a top plan view of an improved handoperated press constructed in accordance with the present invention.

FIGURE 2 is a vertical cross sectional view taken subtantially on the line 2-2 of FIGURE 1.

FIGURE 3 is an enlarged fragmentary elevational view, partly in vertical cross section, of the upper portion of the press of FIGURES 1 and 2, showing the operating handle in a position at the end of its actuating stroke, with the piston of the fluid pressure cylinder substantially in its fully extended position, and with the ram member of the press in its bottom position.

Referring to the drawings, 11 generally designates a hand-operated press constructed in accordance with the present invention. The press 11 comprises a frame 12 consisting of a base portion 13 adapted to be mounted on a suitable support, such as a table or other horizontal supporting member. Formed integrally with the base 13 is a vertical post portion 14, and integrally formed with the top of the vertical post portion 14 is a horizontal hollow top arm 15 which is formed with the generally rectangular top opening 16. The forward end portion of the top arm 15 is formed with the vertically spaced apertured guide lugs 17 and 18 in which is slidably engaged the vertical ram member 19, whereby the ram member is guided vertically, namely, for lengthwise move ment.

As shown in FIGURE 2, the ram member 19 is located immediately above a table surface 20 provided on the top wall of the base 13, said table surface being adapted to receive a work piece to be acted upon by the ram member 19.

As shown in FIGURE 2, the top arm 15 is open between the guide lugs 17 and 18, and extending through the opening, shown at 21, is a lever arm 22 which is pivotally connected at its forward end to the intermediate portion of the ram member v19, as by a transversely atenr extending pivot pin 23. The lever arm 22 comprises a pair of parallel, vertically disposed bar members 24, 24 whose forward end portions engage respective flattened areas 25 on the opposite sides of the vertical ram member 19 and which are pivotally connected thereto by the transversely extending pivot pin 23. The rear end portions of the bar members 24, 24 similarly extend adjacent flattened opposite side surfaces 26 of the top portion of a piston rod 27 which extends slidably and sealingly through the top end wall 28 of a substantially vertical cylinder 29 pivotally connected at 30 to the frame 12 at the side thereof opposite the table surface 20, the cylinder 29 being partially received inside the frame, as shown in FIGURE 2, but being free to pivot in the rear end portion of the frame. The rear portions of the vertical bar members 24, 24 are pivotally connected to the top portion of the piston rod 26 by a transverse connecting pin 31.

The piston rod 27 is rigidly connected to a piston 32 which is slidably and sealingly mounted inside the cylinder 29 and which is normally in a lowered position in the cylinder. A conduit connection 33 is provided at the lower portion of the cylinder and a similar conduit connection 34 is provided at the top portion thereof, said conduit connections providing communication respectively with the bottom and top portions of the cylinders for flexible conduits 35 and 36 connected to said conduit connection members 33 and 34.

Mounted in the vertical post portion 14 of frame 12 is a valve chamber 37 which is provided at the intermediate portion of its main vertical wall 38 with a fluid inlet port 39 to which is connected the fluid supply line 40 which extends from the outlet of a suitable fluid pressure supply source, such as a compressor, or the like.

Designated at 41 and 42 are respective upper and lower piston elements which are slidably and sealingly engaged inside the bore 43 of the chamber 37 and which are connected together by a vertical piston rod 44. As shown in FIGURE 2, the spacing between the piston members 41 and 42 is such as to allow a substantial clearance space 45 in the top portion of the bore 43 when the piston members are in their lowered positions, shown in FIG- URE 2. A similar clearance space is provided in the bottom of the chamber when the pistons 41 and 42 are elevated to their dotted view positions, shown in FIGURE 2. Restricted equalization openings 46 are formed in the piston members 41 and 42 to allow pressures to equalize on opposite sides of the piston members. However, the openings 46 are relatively constricted in size, so that equalization of pressures on opposite sides of the piston elements requires a definite period of time, and impose suflicient restriction to flow of fluid therethrough to allow substantial unbalancing of pressures to occur on the opposite sides of the piston members before pressure equalization can be achieved.

The main wall 38 of the chamber 37 is formed opposite the fluid pressure supply port 39 with the respective vertically spaced ports 47, 48 and 49. Conduit 35 is connected to the ports 47 and conduit 36 is connected to the port 49. A vent conduit 50, leading to a fluid pressure reservoir, substantially at atmospheric pressure, is connected to the intermediate port 48. Designated at 52 is a slide element which is connected to the intermediate portion of the piston rod 44 and which is of sufficient size to at times overlap either the lowermost or the uppermost two of the three ports 47, 48 and 49. Thus, in the lowered position of the piston rod 44, shown in FIG- URE 2, the slide element 52 overlaps the lower ports 47 and 48, and the cavity 5 3 of the slide element 5-2 places the ports 47 and 48 in communication with each other, namely, allows the bottom of the cylinder 29 to exhaust to atmosphere. At this time, the upper port.49 is ex- 3 posed to the interior of casing 37 in communication with the fluid pressure supply port 3-9, whereby fluid under pressure is admitted into the top portion of the cylinder 29, urging the piston 32 downwardly and consequently retracting the piston rod 27, whereby the lever member 22 is in the position thereof illustrated in FIGURE 2. The clearance space 45 is under the same pressure as the portion of the bore 43 between the pistons 41 and 42, namely, the pressure of the fluid supplied at the port 39.

Designated at 5-4 is an operating lever which is pivoted to the frame 12, being secured on a transversely extending shaft 55 which is journaled in the top portion of the upper arm 15 of the frame adjacent to the ram member 19. The top wall ofthe frame is formed with a rectangular notch 57, and secured on the shaft 5 5 is a cam member 58 which is movable through the notch 57 responsive to the rotation of the operating shaft 54. As is shown in FIGURES 1 and 2, the cam member 58 is located immediately above the forward portion of the lever mem ber 22 and is engageable with a bearing roller 59 mounted between the forward portions of the vertical plate members 24, 24, the roller 59 projecting above the top edges of the vertical bar members 24, 24 and being engageable by the cam member 58. Thus, when the operating lever 54 is rotated in a clockwise direction, as viewed in FIG- URE 2, the cam member 58 engages the roller 59'and e erts a downward force on the forward end portion of the lever member 22 which is transmitted to thevertical ram member 19.

The forward portion of the lever member 22 is biased upwardly by a coiled spring 60 which surrounds a glide pin member 61 pivoted at 62 between the vertical bar members 24, 24 and extending slidably and pivotally through an opening 63 provided in the bottom wall of top arm 15. The spring 60 bears between a recess 64 provided in the bottom wall of arm 15 and the bottom surface of the transversely extending bearing block 66 disposed between the vertical bar members 24, 24 and secured to the transversely extending pivot shaft 62 of the guide pin 61.

Designated at 67 is an upwardly projecting abutment pin member which is secured in the bottom wall of arm 15 subjacent the roller 59" and which is engageable by said roller when the lever 22 is rotated in a clockwise direction from the position thereof shown in FIGURE 2, whereby to limit the downward movement of the ram member 19. Elevation of the ram member 19* is limited by the engagement of the roller 59 with the bottom edge of cam member 58.

Secured between the vertical bar members 24 in a position to be engaged by a triggering arm 70 secured to the cam member 58 is a plunger valve 71 which is connected by a flexible conduit 72 to the top end of the chamber 38, namely, to the clearance space 45 normally existing in the top end of bore 43. Valve 71 is ofa conventional nature and is provided with an exposed stem 77 which is engageable by external means to depress its plunger and open the valve.

The cam 58 is formed with the depending arm 80 which is provided at its end with a groove 81 in which the triggering arm 70 is pivoted, the arm 70 being formed so that its rotation is limited to one direction, namely, to a counterclockwise direction with respect to the arm 80*, as viewed in FIGURE 3, whereby the triggering arm 70 is constrained to rotate in a clockwise direction with cam 58. Thus, the triggering arm 70 is engageable with the exposed actuating portion 77 of the plunger of valve 71, so that the valve 71 is opened responsive to rotation of the cam 58 through a predetermined angle, namely, through an angle sufficient to depress the ram member 19 by a preset amount, as will be presently explained. An automatic release valve 90, identical in construction to the valve 71, is secured between the vertical bar members 24, 24 at the rear portion of the lever 22, subjacent an adjustable, vertical triggering, screw 91 mountedv in the rear portion of the top wall of arm 15. As shown in FIGURE 3, the actuating element 77' of the valve 96 is engageable by the bottom end of the release screw 91 when the piston rod 27 is in its fully extended position. Both valves 71 and include a valve plunger 75 which is biased upwardly toward closing position by a coiied spring 76'. i

A vertical guide rod 94 is secured in a depending position to the top wall of the arm 15 and extends between the vertical bar members 24, 24 adjacent the pivotal connection 31 of said bar members to the piston rod. As shown in FIGURE 2, the guide. rod 94 is rigidly secured in a position wherein the vertical bar members 24, 24 slidably engage the opposite sides of the rod member 94, whereby the guide rod 94 guides the rear end portions of the lever bar elements 24, 24 for vertical movement and similarly guides the piston rod 27 for movement relative to the cylinder 29.

In operation, when the lever 54 is rotated in a clockwise direction, as viewed in FIGURE 2, the cam element 58 first engages the roller 59 and moves the ram member 19 down through a preset preliminary distance by rotating the lever member 22 in a clockwise direction around the pivotal connection 31 thereof to the piston rod 27'. This preliminary movement of the lever member 22 is sufiicient to bring the roller 59 substantially into abutment with the upstanding support post member 67, and also, the rotation of the cam member is suflicient to bring the triggering arm 70 into operating engagement with the exposed portion 77 of the control plunger of the release valve 71. The valve 71 opens, thus venting the space 45 of the chamber 38 to atmosphere. This causes a substantial unbalance in pressures on the piston members 41, 42, since the lower portion of bore 43 is under the pressure of the working fluid at port 39. The piston members 41, 42 are therefore moved upwardly, elevating the slide member 52 to a position wherein the port 47 is exposed to the fluid pressure port 39 and the ports 48 and 49 are placed in communication with each other by the slide member 52. Fluid under pressure is thus admitted to the bottom of the cylinder 29, and the upper portion of the cylinder is exhausted through conduit 36, port 49, the cavity 53, the port 48 and the vent conduit 50. Piston rod 27 is thus extended upwardly from the position of FIGURE 2, raising the left end of the lever member 22, as viewed in FIGURE 2, causing said lever member to pivot clockwise around the axis of the roller 59, as a fulcrum. This forces the ram member 19 further downwardly, whereby substantial pressing force is available therefrom on a work piece positioned on the table surface 20.

At the end of the upward stroke of the piston rod 27 the release screw 91 engages the exposed operating portion 77' of the plunger valve 90, venting the bottom of the chamber. 38 through a flexible conduit 97 connecting the bottom of chamber 38 to the venting valve 90. With valve 90 open, the space below the lowermost piston 42 is vented and since the space immediately above the piston 42 is at the working fluid pressure, being in communication with the port 39, a substantial unbalance of pressure develops which forces the pistons 41 and 42 downwardly to the position thereof shown in FIGURE 2. This vents the lower portion of cylinder 29, since the ports 47 and 48 are placed in communication by the slide element 52, and at the same time admits fluid under pressure to the top portion of the cylinder 29, since the port 49 then becomes exposedto the fluid supply port 39,. The piston 32 of cylinder 29 therefore moves downwardly, lowering the rear end portion of the lever member 22. This allows the spring 60 to elevate the forward end portionof the lever member 22 to the position thereof shown in FIGURE 2, when the control lever 54 is returned to its starting position, namely, to the position thereof shown inFIGURE 2. Thus, the-ram member 19.

is completely elevated and assumes its starting position, shown in FIGURE 2.

As previously mentioned, the triggering arm 70 is free to rotate in a counterclockwise direction with respect to the arm 80, as viewed in FIGURE 3, so that the lever 54 may be returned from the position shown in FIGURE 3 to the position shown in FIGURE 2 without opening the valve 71.

The distance between the center of the connecting pin 31 and the axis of roller 59 is considerably greater than the distance between said roller axis and the ram pivot 23, providing a substantial mechanical advantage, whereby the force provided by the air cylinder 28, at a long stroke of piston 32, is converted into a much higher force with a shorter stroke at the ram 19.

The operating lever 54, which is manually operated, is for the purpose of pre-setting the depth of downward movement of ram 19 before it becomes air-operated, and for energizing the power stroke through the actuation of the pilot valve 71. It can also be used as a power arm for strictly manual operation of the press.

The press may be operated also by means of a foot pedal, leaving the operator's hands free, by installing a pilot valve similar to valve 71, operated by the foot pedal, and connected to space 45.

While a specific embodiment of an improved handoperated press has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In a press, a frame, a ram member, means on the frame slidably supporting said ram member for lengthwise movement, a cylinder pivotally mounted on said frame, a piston in said cylinder, a piston rod secured to said piston and projecting slidably and sealingly through an end of said cylinder, a lever arm connecting said piston rod to said ram member, an operating lever pivoted to said frame above said lever arm and adjacent the ram member, a cam on the operating lever engageable with the lever arm and being formed to move the ram member in its lengthwise direction responsive to rotation of said operating lever, a fluid pressure supply line, a control valve, rigidly mounted on the frame, conduit means connecting the end of the cylinder opposite said piston rod to said supply line through said control valve, and means opening said control valve responsive to the continued rotation of said.operating lever subsequent to the engagement of the cam with said lever arm to allow fluid under pressure to enter the cylinder below said piston, whereby the piston rod is extended and rotates the lever arm around the cam as a fulcrum, moving the ram member forward in its lengthwise direction, the distance between the cam and the ram member being relatively small as compared to the distance between the cam and said piston rod along the length of said lever arm.

2. In a press, a frame, a vertical ram member, means on the frame slidably supporting said ram member for lengthwise movement, a cylinder pivotally mounted on said frame, a piston in said cylinder, a piston rod secured to said piston and projecting slidably and sealingly through an end of said cylinder, a lever arm connecting said piston rod to said ram member, an operating lever pivoted to said frame above said lever arm and adjacent the ram member, a cam on the operating lever engageable with the lever arm and being formed to move the ram member downwardly responsive to rotation of said operating lever toward said ram member, a fluid pressure supply line, a control valve rigidly mounted on the frame, conduit means connecting the end of said cylinder opposite said piston rod to said supply line through said control valve, means opening said control valve responsive to the continued rotation of said operating lever toward said ram member subsequent to the engagement of the cam with said lever arm to allow fluid under pressure to enter the cylinder below said piston, whereby the piston rod is extended and rotates the lever arm around the cam as a fulcrum, moving the ram member downwardly, spring means biasing the ram member upwardly, means returning the control valve to closed position responsive to a predetermined amount of extension of said piston rod, and means venting said opposite end of the cylinder responsive to the return of the control valve to closed position, whereby said spring means is free to elevate the ram member, the distance between the cam and the ram member being relatively small as compared to the distance between the cam and said piston rod along the length of said lever arm.

3. In a press, a frame, a vertical ram member, means on the frame slidably supporting said ram member for lengthwise movement, a cylinder pivotally mounted on said frame, a piston in said cylinder, a piston rod secured to said piston and projecting slidably and sealingly through an end of said cylinder, a lever arm connecting said piston rod to said ram member, an operating lever pivoted to said frame above said lever arm and adjacent the ram member, a cam on the operating lever enagageable with the lever arm and being formed to move the ram member downwardly responsive to rotation of said operating lever toward said ram member, a fluid pressure supply line, a control valve rigidly mounted on the frame, conduit means connecting the end of said cylinder opposite said piston rod to said supply line through said control valve, means opening said control valve responsive to the continued rotation of said operating lever toward said ram member subsequent to the engagement of the cam with said lever arm to allow fluid under pressure to enter the cylinder below said piston, whereby the piston rod is extended and rotates the lever arm around the cam as a fulcrum, moving the ram member downwardly, spring means biasing the ram member upwardly, cooperating means on the frame and the lever arm constructed and arranged to return the control valve to closed position responsive to a predetermined amount of extension of said piston rod, and means to vent the said opposite end of the cylinder when the control valve is in closed position, the distance between the cam and the ram member being relatively small as compared to the distance between the cam and said piston rod along the length of said lever arm. I

4. In a press, a frame, a vertical ram member, means on the frame slidably supporting said ram member for. lengthwise movement, a cylinder pivotally mounted on said frame, a piston in said cylinder, a piston rod secured to said piston and projecting slidably and sealingly through an end of said cylinder, a lever arm connecting said piston rod to said ram member, an operating lever pivoted to said frame above said lever arm and adjacent the ram member, a cam on the operating lever engageable with the lever arm and being formed to move the ram member downwardly responsive to rotation of said operating lever toward said ram member, a fluid pressure supply line, a control valve comprising a chamber, a piston rod in said chamber, spaced upper and lower piston elements slidably and sealingly mounted in said chamber, a slide element connected to said last-named piston rod, said chamber being provided with a pair of vertically spaced ports spaced to be covered by said slide element, said slide element having a cavity of sufflcicnt length to communicatively connect said ports, the upper port being vented to atmosphere, conduit means connecting the lower port to the cylinder below the first-named piston, said fluid supply line being connected to the chamber between said spaced piston elements, said chamber having a clearance space above the upper piston element, and means venting said clearance space responsive to the continued rotation of said operating lever toward said ram member subsequent to the engagement of the cam with said lever arm, whereby the slide element is forced upwardly to expose the lower port to the chamber and to allow fluid under pressure to enter the cylinder below the first-named piston, and whereby the first-named piston rod is extended and rotates the lever arm around the cam as a fulcrum, moving the ram member downwardly, the distance between the cam and the ram member being relatively small as compared to the distance between the cam and said first-named piston rod along the length of said lever member.

5. In a press, a frame, a vertical ram member, means on the frame slidably supporting said ram member for lengthwise movement, a cylinder pivotally mounted on said frame, a piston in said cylinder, a piston rod secured to said piston and projecting slidably and sealingly through an end of said cylinder, a lever arm connecting said piston rod to said ram member, an operating lever pivoted to said frame above said lever arm and adjacent the ram member, a cam on the operating lever engageable with the lever arm and being formed to move the ram member downwardly responsive to rotation of said operating lever toward said ram member, a fluid pressure supply line, a control valve comprising a chamber, a piston rod in said chamber, spaced upper and lower piston elements slidably and sealingly mounted in said chamber, a slide element connected to said last-named piston rod, said chamber being provided with a pair of vertically spaced ports spaced to he covered by said slide element, said slide element having a cavity of sufficient length to communicatively connect said ports, the upper port being vented to atmosphere, conduit means connecting the lower port to the cylinder below the first-named piston, said fluid supply line being connected to the chamber between said spaced piston elements, said chamber having a clearance space above the upper piston element, and means venting said clearance space responsive to the continued rotation of said operating lever toward said ram member subsequent to the engagement of the cam with said lever arm, whereby the slide element is forced upwardly to expose the lower port to the chamber and to allow fluid under pressure to enter the cylinder below the first-named piston, and whereby the first-named piston rod is extended and rotates the lever arm around the cam as a fulcrum, moving the ram member downwardly, spring means biasing the ram member upwardly, and means venting the lower portion of the chamber responsive to a predetermined amount of extension of said first-named piston rod, to cause the slide element to descend to a position communicatively connecting said ports, venting the cylinder and allowing the spring means to elevate the ram member, the distance between the cam and the ram member being relatively small as compared to the distance between the cam and said first-named piston rod along the length of said lever member.

6. In a press, a frame, a vertical ram member, means on the frame slidably supporting said ram member for lengthwise movement, a cylinder pivotally mounted on said frame, a piston in said cylinder, a piston rod secured to said piston and projecting slidably and sealingly through an end of said cylinder, a lever arm connecting said piston rod to said ram member, an operating lever pivoted to said frame above said lever arm and adjacent the ram member, a cam on the operating lever engageable with the lever arm and being formed to move the ram member downwardly responsive to rotation of said lever toward said ram member, a fluid pressure supply line, a control valve comprising a chamber, a piston rod in said chamber, spaced upper and lower piston elements slidably and sealingly mounted in said chamber, a slide element connected to said last-named piston rod, said chamber being provided with a pair of vertically spaced ports spaced to be covered by said slide element, said slide element having a cavity facing said ports and of sufficient length to communicatively connect said ports, the upper port being vented to atmosphere, conduit means connecting the lower port to the cylinder below the firstnamed piston, said fluid supply line being connected to the chamber between said spaced piston elements, said chamber having a clearance space above the upper piston element, and means venting said clearance space responsive to the continued rotation of said operating lever toward said ram member subsequent to the engagement of the cam with said lever arm, whereby the slide element is forced upwardly to expose the lower port to the chamber and to allow fluid under pressure to enter the cylinder below the first-named piston, and whereby the first-named piston rod is extended and rotates the lever arm around the cam as a fulcrum, moving the ram member downwardly, spring means biasing the ram member upwardly, a vent valve on the lever arm, conduit means connecting the vent valve to the lower portion of the chamber, and means on the frame above the vent valve engageable therewith to open same responsive to a. predetermined amount of extension of said first-named piston rod, to cause the slide element to descend to a position communicatively connecting said ports, venting the cylinder and allowing the spring means to elevate the ram member, the distance between the cam and the ram member being relatively small as compared to the distance between the cam and said first-named piston rod along the length of said lever member.

References Cited in the file of this patent UNITED STATES PATENTS France Sept. 8, 1930

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