US2242539A - Press operating mechanism - Google Patents

Description

y 20; 1941. E. N. NECKEL 2,242,539

PRE-SS OPERATING MECHANISM Filed May 9, 1938 2 Sheets-Sheet 1 FIG. "I

lNVEN"l'OR BYEDMUND N. NECKEL ATTORN EYS May 20, 1941; E. N. NECKEL PRESS OPERATING MECHANISM Filed May 9, 1938 2 Sheets-Sheet 2 mvsmbk v BYEDMUND N. NECKEL Patented May 20, 1941 uNiTs STTES PRESS OPERATING MECHANISM Application May 9, 1938, Serial No. 206,713

8 Claims. (Cl. 3825) This invention relates to improvements in press operating mechanism and particularly to that type of press in which coacting head and bed pressing members move each toward the other.

An object of the present invention is to provide novel operating mechanism for that type of pressing machine in which a pressing head is first moved to a pressing position adjacent a bed, after which the bed is moved into powerful pressure engagement with the head. In such a machine I provide a strut forming member adapted to hold the head in pressing position and operating mechanism for moving the bed into pressure engagement with the head so dependent on the strut forming member that it is effective to move the bed into pressure engagement only after the head has reached a safe closed pressing position.

Among the objects of the present invention are the provision of a small number of simple parts effectively arranged to sequentially move a pressing head into position adjacent a bed and for thereafter moving the bed into final heavy pressure engagement against the head. The parts are so arranged that one actuating mechanism is operable to produce these results sequentially and without depending upon complicated control apparatus. My invention also providesnove'l connections between a single power means and head and bed operating mechanisms so that one stroke of the power means actuates both mechanisms sequentially toclose the press. The invention also includes the novel parts and their arrangement as disclosed in the accompanying specification and drawings and the essential features thereof will be set forth in the claims.

In the drawings, Fig. l is an end elevation of a pressing machine embodying my invention with certain of the parts broken away or shown in section so that the operation will be more clearly understood, the control mechanism of this machine being shown diagrammatically, the position of the parts with the press open being shown in full lines and certain of the parts being shown in safe closed position in dot-dash lines; Fig. 2 is a view of a portion of the mechanism of Fig. 1 showing in full lines the safe closed position corresponding to the dot-dash position of Fig. 1 and in dot-dash lines in Fig. 2 the fully closed position of the parts; Fig. 3 is a view similar to Fig. 1 showing the press in fully closed position; Fig. 4 is a rear elevation of the press in the open position of Fig. 1 with certain of the parts in section; while Fig. 5 is a detail sectional View taken on the line 5-5 of Fig. 4.

In the machine illustrated, a frame l0 supports a pressing bed I l for limited vertical movement in the frame. In the form here shown the bed is mounted on a bracket or pedestal l2 and is guided in its vertical movement by pins I3 which pass through suitable bores in the bracket and are spring pressed downwardly so that the bed normally lies in its lowermost position. Extending downwardly below the bed is a pressure pin M by which the raising and lowering of the bed is controlled. Pivotally mounted in the frame for the latter purpose is: a bellcrank l5 having a short arm l5a operatively engaging the pressure pin I4. and having a longer arm 15b which is connected with the operating mechanism later described. It will be noted that [the multiplication of this lever is of the order of five or six to one and when coupled with the rest of the operating mechanism supplies a very powerful pressure when the press is closed.

Pivotally mounted in the frame at l6 inter mediate its ends is a head lever H which carries at its forward end a pressing head 18 adapted to coact with the bed II in a pressing operation. Either or both of the pressing members may be heated in any suitable manner as desired. Between the point [9 on the rear end of the head lever and the point 20 on the frame is connected a toggle 2| which breaks forwardly as shown in full lines in Fig. 1 when the press is open but is movable rearwardly to' and slightly beyond a straightened position as shown in dot-dash lines so as to form a strut between the rear end of the head lever and the frame It. When moved to this position the head I8 is in safe closed position just above the bed as shown in dot-dash lines in Fig. l. The toggle 2| holds the head in this position against retrograde movement during a pressing operation.

Stop means is provided on the frame to hold the toggle 2| in its strut forming position. This is best seen in Figs. 1 and 5 as comprising a generally U-shaped stop member 22 having a central portion adapted to embrace the toggle 2| and laterally extending wings 22a which are con nected to the rear uprights or vertical channels llia of the frame by means of pins 23. These pins are threaded into the frame and locked in position by suitable lock nuts. As best seen in Fig. 5, these pins have shoulders thereon and the wings 22a are bored out to lit the smaller diameter of the pins. The larger diameter of the pins form shoulders against which the wings engage when the toggle reaches its predetermined over center position. Coil compression springs 24 are interposed between the wings 22a and the heads of pins 23, These springs are loaded when the toggle moves to limiting position against the stop means. Noise or shock absorbing pads 25 may be provided as shown in Fig. 5. Springs 26 connected between the rear end of the head lever and the lower rear portion of the frame normally bias the head toward open position and bias the toggle 2| toward broken position.

The means provided for actuating the bellcrank lever in a manner to raisethe bed is dependent upon the movement of toggle 2| to strut forming position before the bed raising mechanism is effective. In the embodiment shown, a second toggle 21 has one end connected to the lower link of toggle 2| at 28 and the other end connected to the longer arm |5b of the bellcrank lever at 29. Any suitable means may be provided for moving the toggle 21 in straightening direction, the result of which will be to first straighten the toggle 2| and move the head to a safe closed pressing position until the toggle 2| engages the stop means 22. When this occurs the toggle 21 has a fixed abutment at its left end and further straightening of the toggle will rotate the bellcrank lever |5 in a counterclockwise direction raising the bed into pressure engagement with the head.

In the press shown, power means is provided for straightening toggle 21, the mechanism com-- prising a cylinder and piston motor 30 whose piston rod 30a is connected to the knuckle of toggle 21 at 3|. The cylinder of motor 30 is pivotally mounted in the frame at 32. It will be noted that the motor has a power stroke substantially in linewith the link 21a. of tog le 21 as it moves from the full line position to the dotdash line position of Fig. 1. During this movement the link 21a acts as a. compression member while the link 2'") is a tension member and serves to control the movement of point 3| in an arcuate path about point 29. Stop means 33 on the frame suitably cushioned at 33a the movement of bellcrank lever l5 in a clockwise direction. The members 21a and 21b act in this manner until they reach the full line position of Fig. 2 or the dot-dash line position of Fig. 1, at which point the wing portions 22a. of the stop means have closed the gap and engaged against the larger diameters of pins 23 so that toggle 2| is in its limited position over center. Thus the critical position where centers 28, 3| and 32 are in a straight line has been passed through, this being permitted by reason of the fact that when they reached such critical position the toggle 2| had not quite reached its limiting position against the stop means 22. To further insure passage through this critical position a spring 34 is provided connected between the adjacent links of toggles 2| and 21. As toggle 2| mo-ves toward straightened position this spring 34 is elongated reaching its maximum elongation as the centers 28, 3| and 32 pass through dead center. Upon reaching the full line position of Fig. 2, the function of links 21a and 21b becomes that of a to gle acting against the stationary pivotal point 28 so that continued movement of piston rod 30a acts to straighten toggle 21 and moves the bellcrank lever I5 is a counterclockwise direction forcing the buck upwardly into a. powerful pressure engagement with the head. This position of the parts is shown in full lines in Fig. 3.

When the press is closed, springs 24 are loaded for movement in press opening direction. Springs 26 are also loaded but their tendency is to hold toggle 2| in its over center position. The springs 24 are so calculated that when the: toggle 2| is over center to the rear the springs 26'- and motor 30 preponderate over springs 24 so' that the press remains closed, but when the:

motor 30 is deenergized then the springs 24 will overcome the springs 26 sufliciently to move toggle 2| back over center in toggle breaking direction.

The control of motive fluid for motor 30 is by way of conduits 35 and 36, valve casing 31, conduit 38, valve casing 39 and conduit 40. Since the valves in casings 31 and 39 are alike, one only will be described. In valve casing 31 a normally closed inlet valve 31:; and a normally open outlet valve 312) are mounted on a. common stem 310 for actuation by the branch 31d of a manual 3': which is pivotally mounted on a suitable bracket of the frame. The manuals are so located at the front of the machine as to require a hand of the operator on each of manuals 31c and 39e to supply motive fluid to motor 30 until the pressing head reaches safe closed position. Until this position is reached if either manual is released the valves return to their normal position thus exhausting motor 30. Means is provided for holding the motor energized after the head reaches safe closed position. In the embodiment shown a valve casing 4| having a normally closed inlet valve and a normally open outlet valve lies in a position to have its valves actuated to fluid supply position as the toggle 2| passes over center toward the rear. Motive fluid is then supplied through conduits 35, 42, 43, 44 and 45 to servo motors 46 and 41 which are adapted respectively to engage suitable branches of manuals 31c and 39e so as to hold these manuals in their operated positions indicated in dotdash lines in Fig. l and in full lines in Fig. 3..

The press will thus remain closed as long as desired. To open the press either or both of the manuals is moved to the dot-dash position of Fig. 3 so'as to evacuate motor 30. whereupon springs 24 and 26 will open the press.

A snubber for the head lever is shown at 48.

The operation of the press is as follows: VTith the parts in the full line position of Fig. 1, the operator arranges the work on the pressing bed II and then depresses the manuals 31c and 39a thus supplying fluid through conduits 35 and 36, valve 31a, conduit 38, valve 39a and conduit 40 to themotor 30. The piston rod 30a moves outwardly straightening the toggle 21 which at the same time through the connection 28 straightens the toggle 2|. So long as the head, the head lever and the toggle 2| are free to move, the bed II and its connected parts do not move as they are heavy enough to remain in place during this period of press operation. However when the lower link of toggle 2| engages the stop 22 on the frame, the left end of toggle 21 is held substantially fixed and further operation of motor 30 straightens the toggle 21. This causes movement of hell crank lever |5 in a counterclockwise direction raising the bed into pressure engagement with the head l8 which at this time is held in the dot-dash position of Fig. 1 or the full line position of Fig. 3 by the toggle 2| which is now over center toward the rear of the press. When the parts reach this position valve 4| is opened by engagement with the toggle 2| to supply fiuid to the servo motors 46 and 41 through conduits 42, 43,44 and 45. This holds the man-,

uals We and 39e in depressed or actuated position so that the press remains closed. To open the press either of the manuals is moved upwardly against the action of its holding servo motor which exhausts the motor 30 and permits springs 24 to kick toggle 2| over center forwardly, after which springs 26 complete the opening movement of the head.

What I claim is:

1. In a pressing machine, a frame, coacting head and bed pressing members, each movable toward the other for a pressing operation, two toggles each having an end operatively connected respectively one with each of said members to move the same in press-closing direction as said toggles are straightened, the other end of each toggle having a connection with the frame, one of said toggles having an operative connection with the other toggle so as to straighten the latter by movement of said one toggle toward straightened position, and one power means having operative connections with each of said togg'les and arranged to straighten said toggles sequentially for a press-closing operation.

2. In a pressing machine, a frame, coacting head and bed pressing members, each movable toward the other for a pressing operation, a toggle operatively having one of its ends connected with said bed member to move the latter in pressclosing direction as said toggle is straightened, the other end of said toggle being carried by the frame, one power means, means operatively connected with said power means for moving said head member to pressing position adjacent said bed and for holding it there, and an operative connection between said power means and said toggle effective to move said toggle toward straightened position only when said head has been moved to pressing position.

3. In a pressing machine, a frame, coacting head and bed pressing members carried by said frame, each movable toward the other for a pressing operation, a stop on said frame, means operatively connected with said head and movable into strut-forming position against said stop when said head is in pressing position adjacent said bed whereby said means holds said head in pressing position, power means having an opera- ,tive connection with said bed for moving the latter in press-closing direction, and said last named operative connection utilizing said first named means as an abutment in such a manner as to exert a pressing force when said first named means reaches position against said stop.

4. In a pressing machine, a frame, a bed mounted for limited vertical movement in said frame, a bell-crank lever having a short arm operatively connected with said bed for raising it and having a long arm extending downwardly in said frame, a head lever pivotally mounted intermediate its ends in said frame, a head mounted on the forward end of said lever and movable by lever oscillation into and out of pressing position over said bed, a stop on said frame, a memher connected to the rear end of said lever and movable against said stop and between; said frame and head lever in position to form a strut adapted to hold said head in pressing position, a toggle connected with said strut-forming member and said long arm of said bell-crank lever in a manner to move said bed upwardly as said toggle is straightened, said toggle being arranged to move the strut to head-holding position by movement of said toggle toward straightened position, and means for moving said member to strut-forming position and for moving said toggle toward straightened position.

5. In a pressing machine, coacting head and bed pressing members, each movable toward the other for a pressing operation, two toggles each having an end operatively connected respectively one with each of said members to move the same in press-closing direction as said toggles are straightened, the other end of said head-moving toggle being connected with the frame, said bed moving toggle having its other end connected to said head moving toggle so as to straighten the latter by movement of said bed moving toggle toward straightened position, means for stopping said head moving toggle when said head reaches pressing position over said bed, and means for moving said bed moving toggle in toggle-straightening direction.

6. In a pressing machine, a frame, a bed mounted for limited vertical movement in said frame, a bell-crank lever having a short arm operatively connected with said bed for raising it and having a long arm extending downwardly in said frame, a head lever pivotally mounted intermediate its ends in said frame, a head mounted on the forward end of said lever and movable by lever oscillation into and out of pressing position over said bed, a toggle connected between the rear end of said lever and said frame and breaking forwardly, said toggle being arranged when straightened slightly over center to hold said head in pressing position over said bed, stop means on said frame for holding said toggle in said over center position, a second toggle connected with said first named toggle and said long arm of said bell-crank lever in a manner to move said bed upwardly as said toggle is straightened, said second toggle being arranged to straighten said first toggle by movement of said second toggle toward straightened position, and means for moving said second toggle toward straightened position.

7. A pressing machine as in claim 6 in which said stop means is spring pressed in toggle-breaking direction when :the press is closed.

8. A pressing machine as in claim 6 in which said last named means is a cylinder and piston motor having a power stroke generally in line with that link of said second toggle which is connected with said first named toggle in the position that link occupies when the press is open.

EDMUND N. NECKEL.

Images