US2267467A

US2267467A - Pressing machine

Info

Publication number: US2267467A
Application number: US234081A
Authority: US
Inventors: George W Johnson
Original assignee: American Laundry Machinery Co
Current assignee: American Laundry Machinery Co
Priority date: 1938-10-10
Filing date: 1938-10-10
Publication date: 1941-12-23
Anticipated expiration: 1958-12-23

Description

Y Dec. 23, 1941. G. w. JOHNSON v 2,267,467

PRESSING MACHINE vFiled oct. 1o, 1958 5 sheets-Sheet 1 INVENTOR GBFGE W. JOHNSON NEYS' Dec. 23, 1941. G. w. JOHNSON PRESSING MACHINE 3 Sheets-Sheet 2 Filed Oct. l0, 1958 www R S Jv E 0N N T H O No WJ T A mW. Amm E G Dec. 23, 1941. G. w. JOHNSON PRESSING MACHINE 3 Sheets-Sheet 5 Filed Oct. lO, 1958 lNvENToR GEORGE W. JOHNSON ATTORNEY? Patented Dec. 23, 194,1y

PBESSING MACHINE George W. Johnson, Cincinnati, Ohio, assignor to The American Laundry Machinery Company, .1 Norwood, Ohio, a corporation of Ohio Application october 1o, 193s, serial No. 234ml (c1. .is-41) 9 Claims.

-inis invention relates to improvements in pressing machines, and particularly to operating and control mechanism therefor.

This is concerned with a type of press in which a movable pressing member, as for instance a pressing head, is mounted in a frame and controlled by a lever and in which an energy storing unit is so connected between the head control lever and the frame that it exerts little or no eiect upon the head controlling lever when the press is open, but upon closing of the press the energy storing unit is placed in such a position that it is rotatable about a point so that it exerts its stored energy on the head controlling lever in a manner to produce heavy pressure between the pressing members. Very emcient action in such a pressing machine is obtained if upon closing of the pressing head to a self-closed position the energy storing unit is moved to such a point that the energy stored therein automatically moves the unit to pressure applying position. However in such a machine where the energy storing unit is suiiiciently strong to exert a very heavy pressure between the pressing members, `the operator is likely to crush her hand if the hand should be lying between the pressing members when the force of, the energy storing unit is applied in pressing direction. An object of the present invention is to provide a safety two hand control to keep both hands of the operator occupied until the pressing head is safe closed and the energy storing unit is moved tothe critical position where it automatically completes its own movement to pressure applying position.

Another object of the present invention is to utilize the energy storing unit to open the press and to supply power means for moving the energy storing unit to that point where it is effective to cause press opening.

The invention also consists of various structural features and arrangements necessary to carry out the above deiined objects and the same will be more fully described in the specification and illustrated in the drawings.

In the drawings, Fig. 1 is an end elevation of a pressing machine embodying one form of my invention and showing in full lines the head open position of the parts and in dot-dash lines showing an intermediate safe closed position of the head and the parts of the energy storing unit; Fig. 2 is a diagrammatic view of the energy storing unit, with the parts in the full line position of Fig. 1; Fig. 3 is an end elevation of the same machine showing all parts in the pressure applied position; Fig. 4 is a diagrammatic view of the energy storing unit, with the parts in the intermediate safe closed position shown by the dash-dot lines in Fig. 1: Fig. 5 is a diagrammatic view( of the energy storing unit showing the parts in the pressure applied position of Fig. 3; Fig. 6 is a sectional view taken on the line 6 6 of Fig. l but showing the parts in the intermediate position represented by the dash-dot lines of Fig. 1; Fig. I is a sectional view taken on the line 1--1 of Fig. 1: Fig. 8 is an end elevation of another modiiication embodying my invention; Fig. 9 is a diagrammatic view of the parts of the energy storing unit of Fig. 8 when the head is in open position; `while Fig. 10 is a diagrammatic view of the same parts showingA in full lines the pressure applied position of Fig. 8 and in dotdash lines the intermediate position of the parts corresponding to a safe closed condition Vof the press. n

For purposes of simplification I have hereinafter used the word spring in connection with the description of the energy storing unit in the speciiication and claims intending to indicate by that term not only a spring such as that disclosed in the drawings but anyv other resilient device performing substantially the same function, such as for instance a fluid iilled bellows or a cylinder and piston device.

My invention is concerned with a pressing machine wherein one of the pressing members, such as the pressing head illustrated, is controlled by a lever pivoted in the frame. The energy storing unit comprises a spring part and a link part, one end of the spring part being connected with one end of the link part to form a reaction point4 there, the other end of the link part having a pivot connection with either the head controlling lever or the frame and the other end of the spring part having an anchorage on either the frame or the head controlling lever providing always that it is the other one of these members which does not carry the link part pivot. The parts are so arranged that the spring is always held stressed and is never allowed to expend but a small fraction of its energy. When the head controlling lever is in open position the above mentioned reaction point is substantially alined with the pivot point of the head controlling lever. As the head is closed the link part pivot and the other end of the spring are brought substan- 4tially into alinement and the parts are moved to such a position that the spring exerts a turning moment about the link part pivot so as to automatically swing the energy storing unit to a position at an angle to the head controlling lever where the force of the spring is exerted on this lever to hold the press closed under heavy pressure. The arrangement of the parts is such that this automatic swinging of the energy storing unit to pressure applying position occurs :lust after the head reaches safe closed position where an operators hand cannot be caught between the pressing members. My invention is applicable to this type of pressing machine where the energy storing unit is placed in the lower portion of the frame as shown in Figs. 1 to 7, in which case it acts on a secondary head controlling lever, or where as in Figs. 8 to 10 the energy storing unit is in the upper portion of the frame and act directly upon the head carrying lever itself. My invention operates in substantially the same way whether a compression spring is used in the energy storing unit as in Figs. 1 to 7 or whether a tension spring is used as shown in Figs. 8 to 10.

My invention is here shown in connection with a type of pressing machine generally used in laundry and garment ironing and pressing operations. In the modiiication of Figs. 1 to 7 a frame II supports a pressing bed I2 which if desired may be made adjustable relative to the frame. In the form shown a pedestal I3 in the frame has a threaded connection at Ila with the pressure pin Il engaging the bed. The lower end of pin I 4 has keyed to it a notched wheel I5. Rotatably mounted on the pin I4 is an arm I6 which is manipulated by the handle IGa and carries a pin I1 normally biased out of engagement the handle I6a relative movement of the threaded parts at I 4a is produced so as to adjust the bed up or down. The bed carries guiding pins 20 which move in suitable bores in pedestal I3 and springs 2l bias the bed downwardly. The pressing frame also carries a head lever 22 pivotally mounted in the frame at 23 and carrying at its forward end the pressing head 24 which by head lever oscillation moves into and out of engagement with the pressing bed I2. A rod 25 is pivotally connected with the head lever at 26 and extends downwardly into the frame where its clevis end 25a is pivotally connected to the head controlling lever 21 at the point 28. This lever comprises two lever bars 21a pivotally mounted in the frame on the axis F.

The energy storing unit comprises the spring part 29 and the link part 30. The spring 29 in vthis form is a very heavy compression spring which is mounted between yoke 3| and the collar 32a of rod 32 and held in place by the nut 32h. The yoke 3| is pivotally connected to the lever bars 21a on the axis R. The rod 32 is pivotally connected between the arms of bifurcated end of link 30 on the axis R. The link 30 comprises angularly related parts which at their other end provide two pivotal connections with the frame, one on each side alined on the axis Ff. carries a branch 39a having a resilient cushion 30h which engages a. portion of the frame to limit the movement of the link in a counterclockwise direction as shown in the various views. It will be understood that the parts of this energy storing unit are originally assembled under very heavy compression so that the spring exerts a force of the order of several thousand pounds. Indeed. this spring may be so arranged that the The link pressure exerted between the pressing members is 5,000 pounds or more.

In the open position of the head as shown in Fig. 2 and in full lines in Fig. 1, the axes R and F substantially coincide. If desired these axes could be absolutely alined and the pressing head could be opened by a counterweight or -another spring as is customary. However in the form of the device here shown a small portion of the energy of spring 29 is utilized to open the pressing head and to hold it in open position. To this end the axis R is positioned to one side of the axis F as best seen in Fig. 2 so that the spring exerts a tendency to cause relative approach between the axes R and R' with a lever arm approximately equal to RF. Thus a turning moment is exerted on lever 2l to move it in a clockwise direction and this is counteracted by the weight o1' the head, tending to move it in the opposite direction. When these two forces balance the head is in a stable open position'. As the head is moved toward closed position the parts move from the position of Fig. 2 to the position of Fig. 4 or the dot-dash position of Fig. 1. This causes relative approach between the axes F and R. Because the distances between the axes F and R and between the points R and R are substantially equal little change in the condition of the spring 29 occurs at this time. However because of the relationship o1 the parts and because the lever 21 is pivoted at the point F a slight compression of spring 29 occurs as the head is closed. A critical position is reached when the axis R', when moving in a counterclockwise direction, reaches and then passes the line FR. as best illustrated in Fig. 4. Prior to this time the tendency of the spring 29 is to cause the head to open if the same is released. When the parts reach the critical position, however, the head has engaged the bed so that lever 2'I can move substantially no farther in a counterclockwise direction. The spring 29 now exerts a turning moment on link 30 tending to rotate the link in a clockwise direction about its pivot F with a lever arm equal to the perpendicular distance from R' to the line RF'. This causes the link 30 to swing to the position shown in Figs. 3 and 5 where the force of the spring is applied at the point R and at such an angle to lever 21 that it exerts a very strong force tending to turn this lever in a counterclockwise direction but actually accomplishing very little movement of the arm except insofar as the pressing head compresses the padding, if any, on the pressing bed. Thus the spring exerts a very heavy pressure to hold the press closed and to produce a pressing or ironing action with very little elongation of spring 29. In fact such elongation may be of substantially the same order as the additional compression added to the spring above described during the closing of the head. It will be obvious that the adjusting means of the bed may be utilized to insure that the parts passing through the critical position of Fig. 4 to place R' just below the line FR as the pressing head reaches safe closed position which preferably will be in actual contact with the bed so as to expend very little of the spring energy.

Since the force of spring 29 is so great and since because of human fallibility and wear o1' machine parts the movement of the energy storing unit to the position of Figs. 3 and 5 is likely to occur when the operator has a hand on the pressing bed, I have provided a safety control so as to keep both hands of the operator occupied during thepress closing operation Incidentally this same control makes the operation of the press much easier. To this end I have provided a servo motor 33 suitably mounted on the press frame as by the pivotal connection of cylinder 33a at the point 34 and having a piston rod 33h pivotally connected at 35 with the clevis 25a. A power stroke oi' this motor downwardly from the position of Fig. 1 to that of Fig. 3 closes the head to safe closed position and at the same time swings the lever 21 to the position of Fig. 4 which is just past the intermediate or critical position, after which the energy storing unit swings itself to pressure applying position'.l Fluid for motor 33 is supplied through conduit 38, valve casing 31, conduit 38. valve casing 39 and conduit `49. The parts in the two valve casings are just alike and one only will be described, the other being given similar reference characetrs. In valve casing 31 a normally open exhaust valve 31a and a normally closed inlet valve 31h are mounted on a common stem 3'lc for manipulation by manual 31d. A spring normally maintains the valves in their normal positions. It will be understood that manuals 31d and 39d are so spaced apart on the press frame as to require a hand of the operator on each of them to hold them in their actuated position. If either of them is released before the head reaches safe closed position, motor Preferably I also provide power means for- `swinging the link 38 from the position of Figs. 3

and to the position of Fig. 2 so as to cause press opening. This means comprises the servo motor 4I suitably mounted in the frame at 42 and having its piston rod 4Ib pivotally connected at 43 with an arm c which is rigid with the link 30. Fluid is supplied to cylinder 4 la through conduit 44 and valve casing 45. This casing has parts similar to those in 31 and 39 which valve parts are manipulated by manual 45d. Obviously a depression of manual 45d will supply motive iluid to'motor u when it is in the position of Fig. 3 so as to cause counterclockwise movement of link 3|) carrying the axis R to a position past the axis F as shown in Fig. 2 where the force of spring 29 is available to cause opening of the press head.

In the modication of Figs. 8 to 10, the press frame 46 has pivotally mounted thereon at 4l a head lever 48 which carries the head 49 into and out of engagement with the bed 58 which is mounted on the frame 48 and may be provided with an adjustment shown in Figs. 1 and '7, if desired. 'I'he axis 41 corresponds to the axis F of the first described modification. Here the energy storing unit is mounted directlyvon the rear end of the head lever 48. The energy storing unit comprises the spring 5| and the link 52 which are pivoted together on the axis R. The other end oi link 52 is pivotally mounted at R on the rear end of lever 48. The lower end of spring 5| is mounted at F', on the bracket 46a of frame 48. The position of the parts with the head open is shown in Fig. 9 and here again the point R is to one side of the point F so that the effect of spring 5I is to cause opening of the press head and is eective to hold the press open. The movement ci' link 52 in a clockwise direction about its pivot R is here limited by the 'stop member 48a on the head lever. As the head is moved to closed position link 52 moves with the lever 48 until the dotdash position of Fig. 10 is reached because up until this time the eiect of spring 5I is to hold link 52 against the stop 48a. Because of the relationship between the parts there is a slight elongation of spring 5| during this movement. The point R' gradually approaches F' and the critical point is reached when R' passes F' or slightly thereafter when the pull of the spring is at an angle to the line RR' such that spring 5| tends to rotate the link 52 in a counterclockwise direction from the dot-dash position of Fig. l0 to the full, line position of Figs. 8 and 10. The parts come to rest when the points R, R' and F' are in the same straight line.

" As in the former modification, a motor 33 is provided to move the head to safe closed position while at the same time moving the energy storing unit to the critical position described in connection with Fig. 10, that is to the point where the spring 5I will automatically cause rotation of link 52 tothe pressure applying position. This motor has its piston rod 33h pivotally connected with bell crank 53 which is pivotally mounted in the frame at 54. 'I'he other arm of the bell crank is pivotally connected at 55 with a link 56 which in turn is pivotally connected to the head lever at 51. The supply of iiuid to motor 33 is the same as that already described in connection with the first modification and requires depression of manuals 31d and 38d coincidentally until the head has reached safe closed position and the parts of the energy storing unit have passed the critical position where the link and spring rotate automatically to the full pressure position. Release is by means of motor 4I acting through lever 58 and link 59. The supply for this motor is through valve casing 45 upon depression of manual 45d in a manner analogous to that already described for the release oi' the first described press.

Referring to Fig. 1, which illustrates the press open, the operator depresses the two manuals to open valves 3l, 39 and permit the flow of pressure to servo motor 33, the piston of which advances and moves the pressing head toward closed position, the parts of the energy storing unit at the same time moving toward the position shown in dot-dash lines in Fig. 1 and in full lines Fig. 4. Up to the time the head reaches safe closed position, the tendency of the spring of the energy storing unit is to return the head to open position, but the power of the servo motor 33 preponderates. But if the operator removes her hands from one or both of the manuals of the

valves

31, 39, before the press reaches safe closed position, the servo motor 33 will evacuate its pressure and the energy storing unit will return the head to open position. If the hands are not removed, the head finally reaches safe closed position and the parts of the energy storing unit move beyond the critical position, finally turning to the position shown in Fig. 3, applying full pressure between the head and bed. I'he hands can now be removed from the control valves 31. 39 and the press will remain closed. To open the press valve 45 is opened and pressure permitted to flow to the servo motor 4I, which returns the parts of the energy storing unit past the critical position referred to until the tendency thereof is exerted on the original side of the critical position, thereby opening the press.

What I claim is:

l. A pressing machine comprising a frame member, a work supporting bed, a lever member pivoted inthe frame member, a pressing head operated thereby and movable toward and from engagement with the bed, an\energy storing unit comprising a heavily stressed spring part adapted to exert a heavy pressure and a link part, one end of said spring part being connected at a reaction point with one end of said link part, the other end of said link part being pivoted to one of said members, the other end of said spring part having an anchorage on the other of said members, the distance between said pivots being approximately equal to the distance between said anchorage and said reaction point, said reaction point being substantially alined with said lever member pivot when said head is in open position, one of said parts being movable with said lever member as said head closes to cause relative approach of said anchorage and said link part pivot approximately to alinement, safety two-hand controlled means operatively connected with said head and with said lever member and requiring coincidental use of both hands of an operator for causing movement of said head from open position to a safe closed position close to said bed and for coincidentally moving said lever member to place said anchorage to one side of said link part pivot where said spring part is effective to cause rotation of said energy storing unit about said link part pivot to a position to cause said spring part to apply pressure where one of said parts is connected with said lever member, and said energy storing unit being rotatable reversely to permit the press to open.

2.. A pressing machiney comprising a frame member, a work supporting bed, a lever member pivoted in the frame member, a pressing head operated thereby and movable toward and from engagement with the bed, an energy storing unit comprising a heavily stressed spring part adapted to exert a heavy pressure and a link part, one end of said spring part being connected at a reaction point with one end of said link part, theother end of said link part being pivoted to one of said members, the other end of said spring part having an anchorage on the other of said members, the distance between said pivots being approximately equal to the distance between said anchorage and said reaction point, said reaction point being substantially alined with said lever member pivot when said head is in open position, one of said parts being movable with said lever member as said head closes to cause 'relative approach of said anchorage and said link part pivot approximately to alinement, power means operatively connected with said head and with said lever member for causing movement of said head from open position to a safe closed position close to said bed and for coincidentally moving said lever member to place said anchorage to one side of said link part pivot where said spring part is effective to cause rotation of said energy storing unit about said link part pivot to a position to cause said spring part to apply pressure where one of said parts is connected with said lever member, safety two-hand control means for said power means requiring coincidental use of both hands of the operator to keep said power means energized until said head storing unit being rotatable reversely to permit the press to open.

3. A pressing machine comprising a frame member, a work supporting bed, a lever member pivoted in the frame member, a pressing head operated thereby and movable toward and from engagement with the bed, an energy storing unit comprising a heavily stressed spring part adapted to exert a heavy pressure and a link part, one end of said spring part being connected at a reaction point with one end of said link part, the

other end of said link part being pivoted to one oi said members, the other end of said spring part having an anchorage on the other of said members, the distance between said pivots being approximately equal to the distance between said anchorage and said reaction point, said reaction point being approximately alined with said lever member pivot and slightly to one side thereof when said head is in open position so that said spring part is effective to swing said lever member about its pivot to hold said head open, one of said parts being movable with said lever member as said head closes to cause relative approach of said anchorage and said link part pivot approximately to alinement, power means operatively connected with said head and with said lever member for causing movement of said head from open position to a safe closed position close to said bed and for coincidentally moving said lever member to place said anchorage to one side of ,said link part pivot where said spring part is effective to cause rotation of said energy storing unit about said link part pivot to a position to cause said spring part to apply pressure where one of said parts is connected with said lever member, safety two-hand control means for said power means requiring both hands of the operator to keep said power means energized until said head reaches said safe-closed position, and power means for causing rotation of said energy storing unit about said link part pivot to cause relative movement between said reaction point and said lever member pivot to place the former slightly to one side of the latter where the spring part is effective to swing said lever member about its pivot and to return said head to open position.

4. A pressing machine comprising. a frame, a work supporting bed, a lever pivoted in the frame, a pressing head operated thereby 'and movable toward and from engagement with the bed, an energy storing unit comprising a heavily stressed spring part adapted to exert a heavy pressure and a link part, one end of s'aid spring part being connected at a reaction point with one end of said link part, the other end of said link part being pivoted to said frame, the other end of said spring part having an anchorage ron said lever, the distance between said pivots being approximately equal to the distance between reaches said safe-closed position, and said energy said anchorage and said reaction point, said reaction point being substantially alined with said lever pivot when said head is in open position, said spring part being movable with said lever as said head closes to cause relative approach of said anchorage and said link part pivot approximately to alinement, power means operatively connected with said head and with said lever member for causing movement of said head from open position to a safe closed position close to said bed and for coincidentally moving said lever to place said anchorage to one side of said link part pivot where said spring part is effective to means energized until said headreaches said safe-closed position, and said energy storing unit being rotatable reversely to permit the press to open.

5. A pressing machine comprising a frame, a work supporting bed, a lever pivoted in the frame, a pressing head operated thereby and movable toward and from engagement with the bed, an energy storing unit comprising a heavily stressed spring part adapted to exert a heavy pressure and a link part, one end of said spring part being connected at a reaction point with one end of said link part, the other end of said llink part being pivoted to said lever, the other end of said spring part having an anchorage on said frame, `the distance between said pivots being approximately equal to the distance between said anchorage and said reaction point, said reaction point being substantially alned with said lever pivot when said head is in open position, said link part being movable with said lever as said head closes to cause relative approach of said anchorage and said link part pivot approximately to alinement, power means operatively connected with said head and with said lever member for causing movement of saidl head from open position to a safe closed position close to said bed and for coincidentally moving said lever to place said anchorage to one side of said link` part pivot where said spring part is effective to cause rotation of said energy storing unit about said link part pivot to a position to cause said spring part to apply pressure where said link part is connected with said lever, safety twohand control means for said power means requiring both hands of the operator to keep said power means energized until said head reaches said safe-closed position, and said energy storing unit being rotatable reversely to permit the press to open.

6. A pressing machine comprising relatively movable pressing elements, an energy storing unit having two positions, in one of which positions said unit tends to cause relative separation of said elements and in the other of which positions said unit tends to cause relative approach of said elements, said unit having link and spring parts respectively connected to the two pressing elements, and servomotor means operatively connected both to at least one` of said elements and to one of said parts of said unit and arranged when operated to close said elements and to move said unit to said other position.

7. A pressing machine comprising relatively movable pressing elements, an energy storing unit having two positions, in one of which positions said unit tends to cause relative separation of said elements and in the other of which positions said unit tends to cause relative approach of said elements, said unit having link and spring parts respectively connected to the two pressing elements, servomotor means operatively connected both to at least one of said elements and to one of said parts of said unit and arrangedI when operated to close said elements and to move said unit to said other position, and separate servomotor means operatively connected 'tothe other of said parts of said unit for returning the latter to its one position whereby to open the press.

8. A pressing machine, comprising a fixed pressing element, a coacting pressing element movable relative thereto from an open position through a safe-closed position to a fully closed position in which ironing pressure is exerted upon an article between said elements, a stressed spring having one end operatively connected with said ilxed element and having its other end op, eratively connected with said movable element, said spring being provided with a mounting which enables it to be moved relative to said movable element to opposite sides' of a critical position wherein said movable element is in safe closed position and where said spring exerts no force tending to move said movable element in either direction, said spring when on the rst side of said critical position tending to move said movable element toward open position and when on the second side thereof tending to move it toward fully closed position, power means operatively connected with said movable element for moving it in the press closing direction to a position slightly beyond safe closed position, and control means for said power means requiring coincidental -use of two hands of an operator, whereby upon release, of the control means beforev the safe closed psition of the movable pressing member is reached, said spring opens the press.

9. A pressing machine of the character described in claim 8, including power means for moving said spring from the second to the rst side of its critical position and adapted for operation, when the press is fully closed, to release the press.

GEORGE W. JOHNSON.