US3339481A

US3339481A - Free floating ram members for punch presses and the like

Info

Publication number: US3339481A
Authority: US
Inventors: Richard E Lang
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-02-15
Filing date: 1966-02-15
Publication date: 1967-09-05
Anticipated expiration: 1984-09-05

Description

Sept. 5, 1967 v R. E. LANG 3,339,481

I FREE FLOATING RAM MEMBERS FOR PUNCH PRESSES AND THE LIKE Filed Feb. 15, 1966 2 Sheets-Sheet IN VENTOR. RICHARD E. LANG Buff/(aw ATTORNEY R. E. LANG Sept. 5, 1967 FREE FLOATING RAM MEMBERS FOR PUNCH PRESSES AND THE LIKE 2 Sheets-Sheet 2 Filed Feb. 15, 1966 N: o= Mg INVENTOR. RICHARD E. LANG fi/M M ATTORNEY United States Patent 3,339,481 FREE FLOATING RAM MEMBERS FOR PUNCH PRESSES AND THE LIKE Richard E. Lang, 100 Greenbriar Drive, Carnegie, Pa. 15106 Filed Feb. 15, 1966, Ser. No. 527,586 6 Claims. (Cl. 100-214) This invention relates to apparatus of the type having a ram member adapted to perform work-operations, such as, piercing, stapling and the like, and more particularly to improvements in the drive and in the support for said rams.

Although not limited thereto, the present invention is particularly adapted for use in punch presses. As is known, punch presses are employed to pierce openings in, for example, structural members such as H-beams, I-beams and the like. The punch press includes a punch bit carried by a ram member, and a die block having a die opening positioned to receive the punch bit. The ram member is powered to move the punch bit toward and into the die opening during the power or piercing stroke, and is retracted in the opposite direction during the return stroke.

In prior art punch presses, the ram member is powered both toward the die block and away from the die block. The ram member is powered toward the die block in order to pierce the workpiece. The ram member must also be powered away from the die block in order to extricate the punch bit from the workpiece. Consequently, in one cycle of operation, the ram member undergoes one reciprocation, that is, it is moved sequentially toward and then away from the die block.

As is known, the punch bit must be lowered and centered over the exact point on the workpiece at which an opening is to be pierced. The ram member and the punch bit may be lowered manually. However, since the ram member is always connected to its drive means, great difficulty is encountered in lowering the ram member and the punch bit manually. The punch bit may also be lowered by quickly energizing and deenergizing the drive means. One disadvantage of employing the drive means for lowering the punch bit, is that the punch bit may be lowered'too far causing the bit to be embedded in the workpiece, usually at the wrong location. In this instance, the punch bit may be elevated manually, with great difficulty, or it maybe elevated by reversing the drive means if a reversing mechanism is provided. I

- Punch presses wherein the ram member is always connected to the drive means, have a further disadvantage. It should be evident that when the punch bit is in a lowered positiomless than the full impact capacity of the drive means is available for piercing the workpiece.

Accordingly, as an overall object, the present invention seeks to provide an improved drive and support arrangement for ram members.

Another object of the invention is to provide an improved support means for a ram member wherein the ram member is freely movable in its direction of reciprocation whereby the position of a ram member relative to the workpiece may be readily and easily adjusted.

A further object of the invention is to provide an improved ram drive which imparts its full impact capacity to the ram regardless of the position of the ram relative to the drive.

Still another object of the invention is to provide improved means for retracting the ram, which means is operable only during the return stroke of the drive means and, hence does not interfere with the positioning of the ram relative to the workpiece prior to a power stroke.

The present invention is described and illustrated herein in conjunction with a punch press which pierces open- Patented Sept. 5, 1967 ings in workpieces. It should be noted, however, that the principles of the present invention may be adapted to other apparatus wherein work-operations, such as, cutting, stapling, shaping, and the like are performed.

As described and illustrated herein, apparatus, such as, a punch press, is provided having a ram member, one end of which is adapted to perform a work-operation on a workpiece disposed adjacent thereto. The ram member is supported by a frame and is movable reciprocally such that during one cycle of operation of the apparatus, the rammember is moved in one direction during a power stroke and in the opposite direction during a return stroke.

In accordance with the present invention, the ram member is provided with a generally rectangular opening whose periphery is defined by opposed side faces and upper and lower end faces. A pitman member resides within the opening and has a generally rectangular configuration corresponding to the configuration of the opening. Eccentric rotary means is slideably engaged with the pitman member and serves to move the same in a circular path whereby the pitman member is moved sequentially toward one of the side faces and then into engagement with the lower end face of the ram during the power stroke, and then toward the other of the side faces during the return stroke. The pitman member is smaller than the opening whereby its sides are spaced from the corresponding side faces of the opening when the pitman member is in a centered position relative to the opposed side faces. Consequently, the ram member is freely movable in its direction of reciprocation whereby the position of a ram member relative to the workpiece may be adjusted prior to the power stroke. Cooperating catch means are provided for moving the ram member in the opposite direction, that is, retracting the ram member away from the workpiece. The cooperating catch means are operable only during the return stroke and hence does not interfere with the positioning of the ram member relative to the workpiece. Drive means is provided including actuating means for rotating the eccentric rotary means through a single revolution and hence, for moving the ram member through a single reciprocation. The overall arrangement is such that the ram member may be lowered and thereby centered over a point on a workpiece at which an opening is to be pierced. Thereafter, the actuating means is depressed so that the drive means rotates the eccentric rotary means through a single revolution during which the pitman member strikes the ram member to pierce the workpiece and thereafter the cooperating catch means are engaged to retract the ram member and thereby extricate the punch bit from the workpiece.

The above and other objects and advantages of the present invention will become apparent from the following detailed description by reference to the accompanying drawings, in which:

FIGURE 1 is a schematic side view of a punch press provided with the apparatus of the present invention;

FIG. 2 is a front elevation view illustrating the sup port and drive arrangement for a ram member having a punch bit secured at one end thereof;

FIGS. 3A3H are schematic front views, similar to FIG. 2, illustrating one cycle of operation of the apparatus of the invention;

FIG. 4 is a schematic front view, similar toFIG. 2, illustrating an alternative arrangement of the cooperating catch means of the invention;

FIGS. 5 and 6 are fragmentary front elevation views, similar to FIG. 2, illustrating a further alternative arrangement of the cooperating catch means of the invention; and

FIG. 7 is a fragmentary elevation view, partially in cross section, illustrating the cooperation catch meansv of FIG. 6, on an enlarged scale.

Reference is now directed to FIG. 1, wherein there is illustrated a punch press generally indicated by the numeral 10. The punch press includes a C-shaped main frame 12 having an upper arm 14 and a lower arm 16 and a power section schematically illustrated at 18. The power section 18 normally is carried at the rear of the main frame 12. At the forward end of the upper arm 14 there is provided a housing 20 which supports a ram member (not visible) to which is attached a punch holder 22 carrying a punch bit 24. A shaft 26, driven by the power section 18, extends forwardly along the upper arm 14 and is connected to the ram member as will be described. At the forward end of the lower arm 16 there is provided a die block 28 which preferably comprises the reversible die block described and claimed in my US. Patent No. 3,222,973, issued Dec. 14, 1965, and entitled, Reversible Die Block. As described in the aforesaid US. Patent No. 3,222,973, the die block 28 may be positioned as shown in FIG. 1, to support a structural member, such as the I-beam 29 so as to pierce openings in the flange of the I-beam 29. The die block 28 may be repositioned such that the flanges of the I-beam may also be pierced.

The power section 18 is connected to the shaft 26 and serves to reciprocate the punch holder 22 in a vertical direction. Thus, during a power stroke, the punch holder 22 and, hence, the punch bit 24 are forced downwardly toward the I-beam 29 so as to pierce an opening therein. During the return stroke, the punch holder 22 is retracted so as to extricate the punch bit 24 from the opening pierced in the I-beam 29. The power section 18 consists of a flywheel 30 which is connected to a driven pulley 32, for example, by means of belts or chains 34. The driven pulley 32 is connected to and driven by a motor schematically illustrated at 36. Interposed between the flywheel 30 and the shaft 26 is a clutch 38 of the type which causes the shaft 26 to rotate through a single revolution. Associated with the clutch 38 is clutch control apparatus schematically illustrated at 40 and an actuating mechanism such as a foot pedal 42. The construction of the clutch 38 and the clutch control apparatus 40 are well known in the art and, therefore, a complete description thereof is not believed to be necessary.

The overall arrangement is such that when the foot pedal 42 is depressed, the clutch control 40 causes the clutch 38 to be engaged whereupon the shaft 26 rotates through a single revolution, that is, 360, whereupon the clutch 38 is disengaged. During the single revolution of the shaft 26, the punch holder 22 undergoes one reciprocation, that is, the holder 22 is moved toward the die 28 and then retracted away from the die 28 into its normally elevated position.

Referring now to FIG. 2, the housing or frame 20 comprises spaced, substantially parallel side pieces 44 and a crosspiece 46 connected in corresponding ends of the side pieces 44. A ram member 48 is disposed between and slideably engaged with the side pieces 44, the arrangement being such that the ram member 48 is slideable in a vertical direction. The ram member 48 has a generally rectangular opening 50 whose periphery is defined by opposed side faces 52, 54 and lower and upper end faces 56, 58.

Residing within the generally rectangular opening 50 is a pitman member 60 having a generally rectangular configuration corresponding to the configuration of the opening 50. Accordingly, the pitman member 60 has

opposite sides

62, 64 and lower and upper ends 66, 68 corresponding, respectively, to the opposed side faces 52, 54 and the lower and upper end faces 56, 58 of the ram member 48. The pitman member 60, however, is smaller than the opening 50 and, hence, the position of the ram member 48 is adjustable in a vertical direction through a distance indicated by the dimension line 70 connecting the lower face of the full-line and dotted-line illustrations of the punch bit 24. A handle 72 is secured to the ram member 48 and extends through a vertical slot 74 provided in one of the side pieces 44. The handle 72 is employed to raise and lower the ram member to position the punch bit 24 relative to the workpiece being pierced. At the top of the frame 20 there is provided a counterbalance mechanism which comprises a shaft 76 extending through the crosspiece 46 and secured to the ram member 48. The shaft 76 is surrounded by a coil spring 78 which is interposed between the upper surface of the frame 20 and an enlarged plate 80 threaded onto the upper end of the shaft 76. Rotation of the plate 80 in the appropriate direction will cause the coil spring 78 to be compressed or to be relaxed so as to counterbalance the weight of the ram member 48.

Eccentric rotary means 82 is slideably engaged with the pitman member 60 and serves to move the pitman member 60 in a circular path. The eccentric rotary means 82 comprises an eccentric cam member 84 slideably engaged in a circular opening 86 provided in the pitman member 60. The eccentric cam member 84 is keyed or otherwise secured to the shaft 26 and has a geometric center at 88 which is spaced from the rotational axis 90 of the shaft 26. The overall arrangement is such that as the shaft 26 is rotated through 360, the pitman member 60 will be displaced laterally and vertically through a distance equal to twice the radial distance between the geometric center 88 of the cam member 84 and the rotational axis 90 of the shaft 26. While the pitman member 60 is moved along its circular path of travel, the ram member 48 is caused to reciprocate vertically in a manner which will be described in conjunction with FIGS. 3A-3H, inclusive.

During the power stroke, the ram member 48 is moved downwardly through a distance approximately equal to the distance indicated by the dimension line 70. During the return stroke, cooperating catch means 92, carried by the pitman member 60 and the ram member 48, are engaged to retract the ram member 48 through a distance approximately equal to the distance indicated by the dimension line 70. The ram member 48 is returned to the position illustrated in FIG. 2.

In the preferred embodiment, the cooperating catch means 92 comprise a pin 94 projecting from the side face 54 of the ram member 48 and a notch 96 cut in the side 64 of the pitman member 60. The pin 94 is preferably narrower than the notch 96 and has a bottom face 98 spaced above the lower end face 56 by a distance indicated at 100. The notch 96 has a lower shoulder 102 which is spaced above the lower end 66 of the pitman member 60 by a distance indicated at 104. The distance 100 is greater than the distance 104. As will be described, this differential spacing permits the lower shoulder 102 to move laterally beneath and engage the bottom face 98 during the return stroke so that the pitman member 60 is connected to and raises the ram member 48 to substantially the position shown in FIG. 2.

The pitman member 60 is provided with an arcuate corner 106 which is disposed on the same side of the ram member 48 as the notch 96. If, for some unforeseen reason, the pin 94 does not engage the notch 96, the absence of material at the arcuate corner 106, permits the pitman member 60 to engage the side face 54 and rotate about the cam member 84 whereby the pin 94 is by-passed. It should be evident that if the pitman member 60 could not rotate about the cam member 84, the pitman member 60 would jam causing considerable damage to the press 10.

Reference is now directed to FIGS. 3A-3H, inclusive, for a description of one cycle of operation. FIGS. 3A-3H are schematic front views illustrating certain positions of the ram member 48, the pitman member 60 and the eccentric rotary means 82.

In FIG. 3A, the eccentric rotary means 82 is shown in its initial top dead center and the ram member 48 is shown in an elevated position. The punch bit 24 is shown spaced above a workpiece 108 which rests on a die block 110 having a die opening 112.

As shown in FIG. 3B, the ram member 48 is lowered, by means of the handle 72, such that the punch bit 24 is directly above that point on the workpiece 108 at which an opening is to be pierced. At this time, the foot pedal 42 (FIG. 1) is depressed to cause the eccentric rotary means 82 to be rotated through a single revolution.

In FIG. 3C, the eccentric rotary means 82 has rotated through 90 in a clockwise direction. Accordingly, the pitman member 60 is moved laterally into engagement with the sidetface 52 of the ram member 48 and downwardly into engagement with the lower end face 56.

As can be seen in FIG. 3D, the eccentric rotary means 82 has moved through an additional 90 in a clockwise direction. The pitman member 60, already engaged with the lower end face 56. of the ram member 48, is moved downwardly causing the ram member 48 to move therewith. The punch bit 24, therefore, is forced through the workpiece 108 causing an opening to be pierced therein. At this point in the operation, the pitman member 60 is centered in the generally rectangular opening 50, that is, equidistantly spaced from the side faces 52, 54 of the ram member 48. Also, the pin 94 is disposed adjacent the notch 96 preparatory to entering the same.

In FIG. 3E, the eccentric rotary means 82 has rotated through an additional 45 in a clockwise direction. During this rotation, the pitman member 60 is moved laterally to the left of FIG. 3B and upwardly. As can be seen, the lower shoulder 102 of the notch 96 has moved beneath and upwardly into engagement with the bottom face 98 of the pin member 94. At this time, the pitman member 60 is connected to the ram member 48 and the ram member 48 commences to move upwardly away from the workpiece 108.

In FIG. 3F, the eccentric rotary means 82 has rotated through an additional 45 in a clockwise direction. During this amount of rotation, the pitman member 60 has moved to the left of FIG. 3F into engagement with the side face 54 of the ram member 48. Simultaneous with the lateral movement of the pitman member 60, the ram member 48 is moved upwardly by virtue of the connection between the pin member 94 and the notch 96. The punch bit 24 has been extricated from the opening previously punched in the workpiece 108.

In FIG. 3G, the eccentric rotary means 82 is rotated through an additional 45 in a clockwise direction. The ram member 48 and hence the punch bit 24 are further elevated away from the workpiece 108. The pitman member 60 also is moved laterally to the right of FIG. 3G so that the pin member 94 is being moved out of engagement with the notch 96.

Finally, in FIG. 3H,- the eccentric rotary means 82 is moved through an additonal 45 in a clockwise direction to bring it to its initial top dead center position. At this time, the ram member 48 and the punch bit 24 are in their maximum elevated positions. Furthermore, the pitman member is again centered with respect to the generally rectangular opening 50 so that the pin 94 is disengaged from the notch 96. At this time, the workpiece 108 may be repositioned for the piercing of another opening. Inasmuch as the pin 94 is disengaged from the notch 96, the ram member 48 is freely movable in a vertical direction so that the punch bit 24 may be lowered adjacent to a new point on the workpiece 108 preparatory to punching another opening therein.

Alternative arrangements Reference is now directed to FIG. 4 and to FIGS. 5-7, inclusive, wherein alternative arrangements of the cooperating catch means are illustrated.

As can be seen in FIG. 4, cooperating catch means 114 is shown comprising a pin member 116 projecting from the side 64 of the pitman member 60 and a groove 118 formed in the side piece 44 of the ram member 48. The

6 pin member 116 is preferably disposed slightly above the groove 118 as in the preferred arrangement of the cooperating catch means 92 of FIG. 2.

Reference is now directed to FIGS. 5-7, inclusive, wherein there is illustrated a cooperating catch means 120 of an alternative configuration. As best shown in FIG. 7, the cooper-ating catch means 120 comprises an L-shaped finger 122 depending from the lower end 66 of the pitman member 60 and an L-shaped recess 124 formed in a lower portion 126 of the ram member 48. The L-shaped finger 122 has a laterally extending terminal portion 128 positioned to be received in a lateral recess portion 130 of the L-shaped recess 124.

As shown in FIG. 5, the eccentric rotary means 82 is disposed in its top dead center position. The L-shaped finger 122 is positioned with respect to the pitman member 60 such that the ram member 48 is movable vertically to position the punch bit (not shown) relative to a workpiece. The throat or entrance 132 of the L-shaped recess 124 has a width sufficient to permit lateral movement of the pitman member 60 during the first half of a cycle of operation, that is, during which the eccentric rotary means 82 is rotated through In FIG. 6, the eccentric rotary means 82 has been rotated through 225 angular degrees and is disposed in a position corresponding to the position of the eccentric rotary means 82 in FIG. 3E. At this time, the laterally extending terminal portion 128 of the L-shaped finger 122 has moved into the lateral recess portion 130 of the L- shaped recess 124 to connect the pitman member 60 to the ram member 48. Continued rotation of the eccentric rotary means 82 to its top dead center will cause the pitman member 60 to raise the ram member 48 to its initial elevated position. Thereafter, the laterally extending terminal portion 128 will be disengaged from the lateral recess portion 130 and the ram member 48 will, again, be free for vertical movement.

Although the present invention has been shown in connection with certain specific embodiments, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without department from the spirit and scope of the invention.

I claim as my invention:

1. In apparatus having a ram member including one end adapted to perform a work-operation on a workpiece disposed adjacent thereto, and a frame supporting said ram member for reciprocal movement wherein during one cycle of operation, said ram member is movable in one direction during a power stroke and in the opposite direction during a return stroke, the improvement comprising: said ram member having a generally rectangular opening whose periphery is defined by opposed side faces and upper and lower end faces; a pitman member residing within said opening and having a generally rectangular configuration corresponding to the configuration of said opening; eccentric rotary means slidably engaged with said pitman member for moving the same in a circular path and, hence, sequentially toward one of said side faces and then into engagement with said lower end face during said power stroke, and then toward the other of said side faces during said return stroke; said pitman member being smaller than said opening and having sides which are spaced from the corresponding side faces of said opening when said pitman member is in a centered position relative to said opposed side faces, said ra-m member being freely movable in its direction of reciprocation whereby the position of said ram member relative to said workpiece may be adjusted prior to said power stroke; cooperating catch means operable only during the said return stroke for moving said ram member in said opposite direction; and drive means including actuating means for rotating said eccentric rotary means through a single revolution and, hence, for moving said ram member through a single reciprocation.

2. The improvement as defined in claim 1 wherein said cooperating catch means comprises a projection on one said member and a catch on the other said member, said catch being positioned for engagement by said projection during movement of said pitman member in said opposite direction.

3. The improvement as defined in claim 1 wherein said cooperating catch means comprises a pin projecting from one said member toward the other said member, the other said member having a notch positioned to receive said pin during movement of said pitman member in said opposite direction.

4. The improvement is defined in claim 1 wherein said pitman member has an arcuate corner adjacent said c0- operating catch means, said arcuate corner engaging said other of said side faces and permitting said pitman member to rotate about the axis of said eccentric rotary means in the event said cooperating catch means does not connect said pitman member to said ram member.

5. The improvement as defined in claim 1 including adjustable spring means acting on said ram member and said frame for counterbalancing the weight of said ram member whereby said ram member remains in its adjusted position.

6. The improvement as defined in claim 1 wherein said cooperating catch means comprises an L-shaped finger depending from said pitman member and an L- shaped recess formed in a bottom portion of said ram member and positioned for engagement by said L-finger during movement of said pitman member in said opposite direction.

References Cited UNITED STATES PATENTS 732,101 6/1903 Morris 83-554 1,076,163 10/1913 Shirley 100292 1,597,138 8/1926 Zimmer 83-554 3,273,491 9/1966 Calvert 100-53 FOREIGN PATENTS 140,630 4/ 1920 Great Britain.

BILLY I. WILHITE, Primary Examiner.

Claims

1. IN APPARATUS HAVING A RAM MEMBER INCLUDING ONE END ADAPTED TO PERFORM A WORK-OPERATION ON A WORKPIECE DISPOSED ADJACENT THERETO, AND A FRAME SUPPORTING SAID RAM MEMBER FOR RECIPROCAL MOVEMENT WHEREIN DURING ONE CYCLE OF OPERATION, SAID RAM MEMBER IS MOVABLE IN ONE DIRECTION DURING A POWER STROKE AND IN THE OPPOSITE DIRECTION DURING A RETURN STROKE, THE IMPROVEMENT COMPRISING: SAID RAM MEMBER HAVING A GENERALLY RECTANGULAR OPENING WHOSE PERIPHERY IS DEFINED BY OPPOSED SIDE FACES AND UPPER AND LOWER END FACES; A PITMAN MEMBER RESIDING WITHIN SAID OPENING AND HAVING A GENERALLY RECTANGULAR CONFIGURATION CORRESPONDING TO THE CONFIGURATION OF SAID OPENING; ECCENTRIC ROTARY MEANS SLIDABLY ENGAGED WITH SAID PITMAN MEMBER FOR MOVING THE SAME IN A CIRCULAR PATH AND, HENCE, SEQUENTIALLY TOWARD ONE OF SAID SIDE FACES AND THEN INTO ENGAGEMENT WITH SAID LOWER END FACE DURING SAID POWER STROKE, AND THEN TOWARD THE OTHER OF SAID SIDE FACES DURING SAID RETURN STROKE; SAID PITMAN MEMBER BEING SMALLER THAN SAID OPENING AND HAVING SIDES WHICH ARE SPACED FROM THE CORRESPONDING SIDE FACES OF SAID OPENING WHEN SAID PITMAN MEMBER IS IN A CENTERED POSITION RELATIVE TO SAID OPPOSED SIDE FACES, SAID RAM MEMBER BEING FREELY MOVABLE IN ITS DIRECTION OF RECIPROCATION WHEREBY THE POSITION OF SAID RAM MEMBER RELATIVE TO SAID WORKPIECE MAY BE ADJUSTED PRIOR TO SAID POWER STROKE; COOPERATING CATCH MEANS OPERABLE ONLY DURING THE SAID RETURN STROKE FOR MOVING SAID RAM MEMBER IN SAID OPPOSITE DIRECTION; AND DRIVE MEANS INCLUDING ACTUATING MEANS FOR ROTATING SAID ECCENTRIC ROTARY MEANS THROUGH A SINGLE REVOLUTION AND, HENCE, FOR MOVING SAID RAM MEMBER THROUGH A SINGLE RECIPROCATION.