US2939228A - Rotary pressing machine and control - Google Patents

Description

June 7, 1960 o. H. LANGEN 2,939,228

ROTARY PRESSING MACHINE AND CONTROL Filed March 16, 1956 3 Sheets-Sheet l I H 2 INVENTOR.

OLE H- LRN GEN June 7, 1960 O. H. LANGEN ROTARY PRESSING MACHINE AND CONTROL Filed March 16, 1956 [ll/l I11] 3 Sheets-Sheet 2 lll/ Ill/J INVENTOR. OLE H- LRN$EN June 7, 1960 o. H. LANGEN ROTARY PRESSING MACHINE AND CONTROL Filed March 16, 1956 3 Sheets-Sheet 3 INVENTOR. OLE H- LHNGEN Paw 4&

ERGTARY PRESSENG MACHTNE AND CONTROL Gie H. Langen, Minneapolis, P/HIIIL, assignor to The Unipress Company, Incorporated, Minneapolis, Martin, a corporation of Minnesota Filed Mar. 16, 1956, Ser. No. 572,019

15 Claims. (Cl. 38-5) This invention relates to rotary pressing machines of the type having a plurality of individual presses mounted on a platform of low elevation which is arranged to rotate on a vertical axis. Such rotary pressing machines are exemplified in Patent No. 2,669,044 and various other patents of the prior art.

All modern pressing machines of this type, as exemplified by the aforesaid patent and other patents of the prior art utilize individual presses having a cooperative stationary buck and movable presser head, the latter being normally biased to open position and connected to the motor so as to be moved toward and against the buck for cooperating pressing action when the motor is energized. The motors of such presses are usually of the fluid operated type, or more specifically, air-cylinders operated by compressed air. In rotary presses the valving or the air to the individual presses is usually accomplished by a master valve on each press which, in one position introduces air to the motors of the press to close it, and in another position, exhausts the air from the motors and permits the press to open. In such rotary pressing machine the operation of the master valve is accomplished either directly or indirectly by cams as the rotary turntable revolves, the objective being to close each of the presses at a certain point along the rotary path alo'ng which the presses are carried and then, at another point to open each press. The several available modes of accomplishing these objectives have not always been satisfactory especially in respect to cost of manufacture and operation of the devices.

it is an object of the present invention to provide an improved rotary pressing machine having an improved mode of press control.

It is another object of the present invention to provide an improved form or" control wherein added factors of safety are provided.

it is another object of the invention to provide a photo electric control for a rotary press.

it is an additional object of the invention to provide a combined photo electric and timer controls in a rotary pressing machine.

Other and further objects of the invention are those inherent in the invention herein illustrated, described and claimed.

The invention is illustrated in the drawings in which:

Figure l is a plan view of a rotary press which is illustrative of the invention;

Figure 2 is a vertical sectional view partly schematic of the pressing machine of Figure 1, this view being taken along the line and in the direction of arrows 22 of Figure 1;

Figure 3 is schematically a view, illustrating the presses and their associated controls;

Figures 4 and 5 are fragmentary views illustrating forms of the invention involving modifications of certain elements.

Throughout the drawings the same numerals refer to the corresponding parts.

nited States Patent 0 ice In eneral it may be stated that rotary pressing machines of the type of which the present invention is an improvement consist of a rotary turntable of low elevation that is adapted to be placed on the floor and uponwhich there are mounted a plurality of individual pressing machines. The individual presses may be of the laundry or garment pressing type and may have the same or diiferent types of bucks and heads for pressing the same or different portions of garments or laundry items. While rotary pressing machines of this type may be built as a unitary structure, for ease of manufacture and reduction in cost, it has been found that ordinary individual air driven, steam heated, pressing machines of a design that are normally mounted directly on a floor, may be used to advantage, such individual pressing machine being mounted in regularly spaced relationship around the periphery of the rotary turntable of low elevation. In such mechanical organization the presses are thus rotated one at a time in front of an operator station. At or slightly ahead of the operator station, each press is automatically controlled by its rotary movement so as to actuate the press to open-press position and the operator may, Without moving from her position, remove the pressed garment and lay an unpressed garment on the buck. Usually the rotation of the pressing machine rotary platform is continuous (but it may be operator-controlled), the removal of the pressed garment and replacement of the unpressed garments on the bucks of the several presses being edected while each press moved at its regular pace in succession through the operator station. Then as each press of the pressing machine progresses in succession along its rotary path of motion it reaches a position adjacent to but slightly beyond the operator station where provision is made for automatically actuating controls of each press to cause the presser head to move against the buck into pressing relationship therewith.

It is in this class of pressing machines that the invention hereinafter described constitutes improvements. For purposes of illustration, but not by way of limitation there is herein illustrated a rotary pressing machine resembling that shown in the Patent 2,669,044.

Referring to the drawings, particularly Figures 1 and 2, the pressing machine includes a central floor plate 10 which is adapted to be placed or bolted upon the floor 11 on which the pressing machine is installed. Upon the plate 10 which serves as a central stationary pivot there are mounted a suitable bearing 18 which is mounted in the center hub 16 of the circular rotary frame plate 17. The bearing 18 serves as a thrust bearing and pivot hearing so as to receive the weight load at the center of the rotary frame plate 17 and provide a center of rotation.

The plate 17 is preferably of circular shape and near its periphery it is reinforced by ring channels 20 and 21 which are positioned so that their flanges are oppositely directed and are of such a diameter as to leave a space between the webs of the flanges. Within this space are mounted a plurality of wheels 22. Greatest rigidity is provided *by placing two or more of the wheels 22 under each of the presses that are mounted upon the rotary frame plate '17 so as to steady the plate 17 against vibration due to the opening and closing of the presses. Plate 17 may, if desired, have radial stiifening webs not illustrated in order to increase its rigidity. The wheels 22 may have rubber tires, if desired, and the wheels 22 may run directly upon the floor 11 where the floor has sufficient evenness. Where the installation is made on a rough or uneven floor '11, it is preferable to place a circular sheet metal track 24 on the floor along the path where the wheels 22 track. The axis of each of the wheels 22 is radial in respect to the central pivot axis.

For rotating the circular frame plate 17 and all elements canied thereon, there is provided a belt 25 which may be a chain belt, as shown in Figure l, which passes over a pulley 26 that is mounted on radial arm 27, the arm being pivoted at 28 to the floor. An adjustment screwi30 mounted in the stationary "bracket 31, is positioned so as to bear against the arm 27' so as to move it'arcuat'c'ly and thus permit tightening or loosening of the belt25; [The belt125 also runs over the driven pun ley 3 2. The pulley 32 rotates at slow speed and is preferably driven by an electric motor 34 through a gear box. It is'p'referable to use a motor 34 which is capable of speed variations, such as a wound-rotor repulsion in- 1 duction motor, a shunt type direct current motor orthe like. It is perfectly feasible to utilize an air driven motor 34 forconstant or variable speed application where such is desired. .The On-Oil and-speed controls for motor 34'a're appropriately selected 'for controlling speed and ope'rationof the motor} 34andmay' be mounted on a panel 46 which forms a vertical fence at the left of operator station 37, V

Heating of the presses is accomplished via steam line 4?,lc'ondensate water' being returned via line 50. Air under pre'ssure is delivered to the presses via line 48. Each of these lines is concentric'with the of rotation ofthe turntable 17 and is provided with a rotary gland .as'a- t 48A, 49A and 50A, as is well known.

' U on the rotary base 17 there are mounted a plurality of pressing machines generally designated A, B, C and D in Figures 1 and 2. Any suitable number of pressing machines greater than one may be utilized, depending upon thesize and capacity of the unit and the type of work'desired to be done by means'of the installation. Four pressing machines are shown in the illustrated embodiment of the invention and are spaced evenly around the-rotary frame plate 17. The rotation of the frame plate '17 is in the direction of the arrow 35 and rotation of the drive pulley 32 is shown by the arrow 36. An operator station indicated by the hoofpad 37 extends through approximately one-quarter ofthe circular path of motion of the floor plate 17 and presses A-D mounted thereon. Adjacent the terminating edge 38 of the operator station, there is provided a protective guard- 40 which likewise extends through approximately onequarter'of the path of rotation of the floor plate 17 and the presses mounted thereon. The guard -40 roughly defines the position of a press fat'the'closing station, it

, being understood that the guard extends somewhat ahead there is a portion of the path of motion during which the pressing part of the cycle takes place. During this portion of the cycle the pressing head is closed down upon the buck and is held down (closed) so long as line air pressure is maintained on the air motor of the press.

The opening station is between the position in which press B is shown inFigure 1, which isstill closed, and the leading edge 41 of the operator station. At the opening' station each press is opened by discontinuing the applieation of line air-pressure and exhausting the airmotor of the press, whereupon the press will then be opened by its springs (not illustrated), as is well known.

Adjacent the leading edge of the guard 40 there is a control panel generallydesignated 46, which serves as a fence, and on which the On-Off controls of motor 34 and speed controls therefor, and Emergency controls are located convenient to the operator.

The presses A-D (or 'anynumber which are mounted upon the'rotary floor plate 17), may be of any desired "individually power driven presses. Present day' presses are usually air driven andin theembodimen-t of the vention herein illustrated, the presses A-D are of the type shown in Patent Re. 22,041, although it is to beunderstood that any suitable one or two cylinder air press, or other power driven press may be utilized. Thus, for example, the presses A-D can be single cylinder air driven presses of which the type shown in Patent 2,265,- 449 is exemplary, or they can be multiple air cylinder presses. Y

In the exemplified showing of the invention illustrated in Figure 2, each of the pressing machines includes a frame 52 which is suitably attached to the circular revolving frame plate 17; In the presses shown, each has a press frame and uponftheframe 52 is mounted a stationary buck 54 and a presser arm 55 which is pivoted at 56. The presser arm carries a presser head 57 which is movable from an open position (as shown for press A at the left in Figure 2), to the closed position (as shown for press D atthe right Figure 2). The movement of the press from open to closed position and from closed to open position is accomplished by means of air or other fluidmotors suitably controlled. as herein described.

Thecornpressed air, steam, and condensatereturn lines are illustrated respectively at 48, 49 and 50 and terdividual press,'located near the .front of the pressing machine, on the work tablebeneath the buck. vThese twohandcontrols, through the. provision of a pneumatic linkage, operat'ea two position master. valve, which in one position admits air under'pressure to the air-motor, to close the press and'in another position shuts oft the supply of compressed air and exhaust the air-motor, with the result that the press opens. Hence by operating such master valve control of the press is achieved.

j Referring to Figure 3, 17 illustrates the turntable and it revolves in the direction of arrow 35 around centerline C-L. Each press faces outwardly on the turntable as illustrated. The portions of the apparatus below and outside the turntable 17 are stationary. I

The stationary equipment serves allpresses. 'Each press includes a frame 52 of which only portions are illustrated. Buck 54 is mounted on the frame above shield 74. A presser arm 55, pivoted at 56 on frame.

52 is movable from the Open position shown for press 0, to a Closed position shown for press C. The press is normally biased to the Open position by springs (not shown). For moving the presser arm 55 and head'57 against the bucks 54, there is provided an air-motor, here illustrated as having two cylinder-piston arrangements 53 and 61, both pivoted to frame 52. Cylinder 58 is the closing cylinder and acts directly upon presser arm 55 whereas cylinder 61 is the squeezing cylinder and acts through linkage 64, 65, 66, 68 to apply great force to the presser arm for generating great ironing pressure.

' Both cylinders 58 and 61 operate .to close the press when air' underpressureis introduced into line which is connected to both cylinders. When air in line 80 is exhausted, the press moves to Open position (shown in Figure 3). .In commercial presses," time or position control valves and mechanisms-a quick exhaust valve and other refinements may'be incorporated in the press controls for'1ine80. But for clarity, these are omitted here. 'For'energizin'g (introducing air into) and de-energizing (exhausting the air from) the press air motor 58-61, to thus close and open thepr'ess, each such press is equipped with a two position, rotary (oscillatable) valve 100. This valve has one port 101 connected toline 80; an exhaust port 102, usually connected to a muffier; and a compressed air supply line port 103. The valve has a casing104 and a rotor inside carrying channel 105, an operating shaft 115 and lever 116. These are all shown schematically. When the lever 116 (and hence rotor channel 105) are in the full line position shown for press 0 in Figure 3, channel 105 connects port 101 (and line 80) to exhaust 102 and hence the press moves to open position. When the valve 100 is moved to the position shown for press C in Figure 3, channel 105 connects air supply line 103 to port 101 and line 80, and the press moves to closed position. Valve 100 stays in either position in which it is placed.

For achieving such two position movement of valve 100 the following is provided: To opposite ends of lever 116 there are pivotally suspended pendant rods 118 and 119, the lower ends of these being loosely guided by holes in turntable 17 (or frame 52). These rods are of a length such that when either is raised as by movement of the valve 100 to one or the other of its operating positions, the lower end of the rod so elevated will be about flush with the underside of turntable 17 or at least high enough so as to be clear. Since both rods are attached to the lever 116, movement of one rod upward will push the other downward. Now, at that part of the circular path of travel of the turntable whereat the press closes, namely the closing station as shown for press 0, behind guard fence 40-46 (see Figure 1) there is situated a small solenoid-operated actuator generally designated 130. This is composed of a small stationary pivot mounting 131 on which a lever 132 is pivoted, and it is weighted or spring biased so as normally to permit the broad bladed end 133 to descend. A solenoid core 134 is pivotally attached at 136 to the opposite end of lever 132 and when coil 135 is energized the lever 132 and paddle end 133 are swung up to the dotted position. The actuator assembly 130 is positioned so that paddle end 133 is beneath the end of rod 118 at the time coil 135 is energized and hence rod 113 is pushed upward, consequently to rotate valve 100 to its position shown in dotted lines (for press 0) with consequent actuation of the press to closed position. This also brings the lower end of rod 119 down to its dotted position and such end will be ready to be engaged later on for opening the press.

At the opening station, a similar actuator 140, which is, in all respects identical to unit 130, is so located that paddle 143 will strike the lower end of rod 119 when the latter arrives in place above actuator 143 and the solenoid coil 145 is energized.

The timing of energization of the coil 145 at the opening station is primarily by virtue of a cam located on each press (or on the turntable 17, wherever convenient), in cooperation with a normally open electric switch operated thereby. At the opening station switch 156 has one terminal connected to line L1 and its other terminal connected by line 152 to one terminal of coil 145, the other terminal of the coil being connected to line L2. When cam 150 of the still closed press runs onto the actuator of switch 156 at the opening station, switch 156, which is normally open, closes to complete the circuit from line L1, closed switch 156, coil 145 to line L2, and coil 145 is energized. The cam and switch locations (or the position of unit 140 in respect to the rod 119) are adjusted so that such energization will occur as the turntable 17 brings the closed press C to the opening station and hence its rod 119 will be fairly over paddle 143 of unit 140. Hence as energization of coil 145 occurs, paddle 143 rises, pushes rod 119 up to rotate valve 100, and the press 0 ens. As the turntable carries the press along, switch 156 opens and paddle 143 descends, ready for the next operation.

Now, the press closure operation at the closing station represented by press 0 is similar, at least, to the following extent. Here also power at line L1 connects at junction 153 to manual switch 154, which when closed puts line L1 potential on junction 155 which is connected to one terminal of manually operated switch 170, and then on to one terminal of switch 151 which closes due to action of cam 150 at the closing station. It may be noted that switch 170 is connected to shunt switch 151, and is for a special mode of operation to be described. Switches 154 and 170 may be interlocked mechanically so that when one opens, the other closes, but I prefer that they should be independent. In one mode of operation switch 170 is left open. The circuit continues via line 157, through coil 135, to line L2. Unit is aligned so as to be beneath rod 118 when cam closes switch 151. Hence, with switch 154 closed, each press through its cam 150 closes switch 151 to actuate unit 130 to actuate rod 118 and hence valve 100 to close the press as the press is brought to the closing station. Such electro-action for closing and opening the presses in succession is a feature of this invention.

Another feature which adds to the over-all safety of the system may be achieved through the instrumentalities now to be described, which becomes effective when switches 154 and 170 are opened. Upon, preferably, the control panel 46, there is mounted a lamp 160, served by lines L1 and L2, and from which a focused light beam is projected generally radially inwardly in respect to the turntable 17, see Figure 1. Along the trailing edge (in respect to turntable rotation) and toward the rearward part of the panel 74 of each press, there is mounted a light handling element such as a reflecting prism or a mirror (or mirrors) 161 which serve to redirect the light beam along a selected path which returns to photocell 162 when the press and hence the element or elements 161 are carried to a particular safe position behind protective barrier 4046. The reflection of the light beam and its return to photocell 162 of course is not possible until the elements 161 are brought into a certain position which, in itself insures that the press is also brought to a guarded position. This is a feature of the invention. In addition, by judicious selection of the light path, the possibility that even when properly aligned, such light path may be broken by the operator inserting a body part into the beam, adds an additional factor of safety. Here, the closure will occur due to light beam falling on the photocell provided the light beam is not interrupted as would occur if one attempted to reach in behind barrier 46 to the buck 54. The light beam, in effect, forms a fence which is capable of being interrupted should one attempt to reach toward the buck. Photocell 162 feeds input terminals 163 of amplifier 164 which is powered by lines L1 and L2. The output at terminals 165 feeds coil 166 which, when energized, lifts relay contact 167 to close contacts 168, the latter being in parallel with switch 154 across junctions 153 and 155.

Coil 166 is energized only when the photoelectric cell 162 is illuminated, and light reflectors 161 are so arranged as to redirect the light beam to cell 162 at the time cam 150 closes switch 151 (or the turntable has moved the press to a guarded position). Consequent upon these simultaneous occurrences, coil 135 will be energized through a circuit from line L1, through contacts 167-168, switch 151, line 157, coil 135 to line L2, provided the light beam is not interrupted. If it is, coil 166 will not be energized and contacts 167-168 will open (or stay open). This is a safety feature.

For another mode of operation there is provided switch 170, which is connected to shunt switch 151. When switch 170 is closed, switch 154 must then be left open (so as not continuously to energize coil 135). But assuming switch 170 to be closed (and 154 open), it is as though no cam operated switch 151 were provided, and the energization of coil 135 is then dependent solely upon photoelectric actuation. Hence as each press reaches the safe position so that its light redirecting surface 161 moves into proper position, as shown in Figure l, the photoelectric cell 162 will be illuminated, coil 166 energized, relay contacts 167--168 closed and coil 135 energized. But this will occur only if the light .7 V beam is not interrupted by improper insertion of body parts toward the press. ture of the invention. i y, a M

It will be understood that the locations shown for the light manipulating instrumentalities 161 and the particular light path, are merelysuggestive of'many locations of one ,or several light guarding paths which may be used around the entrance to the buck-head area.

Referring to Figure 4, there is illustrated a modified form of press opening control; 7 in Figure 3'the press opens at 'a prescribed location (of switch 151 and unit 140)." In Figure 14, the pressing cycle is terminated on a time basis, which may be varied. This is accomplished as follows: To line'80of each press there is connected branch 172 which leads to a pneumatic timer valve 173 having an adjustment 180; The timer valve may be of the nature more 'fully described in the U.S. Patent 2,292,380 to Kerstenand therefore will not be described in detail. Timer 'valvej173 isnormally closed so as normally to close flow from itsinlet port 181 to its controlled outlet port182." The timing cycle always resets to zero and begins when line 172 applies'pressure to inlet 181; Then, ,at a prescribed time interval later, as

This operational-mode is a fea- 1 determined by the setting of 'adjustment dial 180, the

valve of 173 opens to'permit flow to outlet 182 and hence via line 174through T 176 to a small pilot cylinder 178, the piston of which is connected to lever 116 in place of rod 119., Piston 179, when actuated, throws lever 116 and valve 100 to'the'press opening position. To permit recovery of line 174 and cylinder 178 to atmosphericcondition line 174 is provided with a small (preferably adjustable) orifice'177 which is so small as to ,be of no consequence to the operation of cylinder 179 during its short period of operation, but large enough to bleed off pressure from line 174 while the press passe from the opening to the closing station,

Figure 5 illustrates a mechanical cam 19% which, is located'in' the path'of travel of the lower end of rod 119,and so shaped as to' make the rod ride'up thereby to move master valve 100 to the press opening position atthe opening station. Cam 190 may be used in lieu of the electromechanical elements 151-156 and 140.

The forms of-the invention shown and described must be considered only as illustrative. Many variations within the scope of the invention illustrated, described and claimed will be apparent to those skilled in the art, and the invention is therefore not to be limited except as stated in the appended claims. 7

What' I claim is: a 1; A rotary'pressing machine comprising a rotary turntable having thereon a plurality of presses, each of which has a buck and a presser head, the latter being mounted on the press for movement toward and from a press open position in which the presser head is away from the'buck and a press close position in which the presser head is against the buck, each press including motor means connected to the presser'head for moving it and a control means for said motor means, said rotary turntable having a normal cycle of rotation wherein the presser head is moved from a press open position to a press close position and thence back to a press open position, control actuator means'for contacting and moving said control means to a close position at one location around turntable" and for contacting and moving said control means to a press open position at another location around saidturntable, said control actuator means actuator means including a moveable mechanical device against which aportion of the control means is engaged at said press open position for moving said control means 'toa press open position; a

1 2. A rotary pressing machine comprising a rotary turn table havingthereon a plurality of presses each of which has a buck and apresser head, the latter being mounted means to a press close position at one location around theturntable and for contacting and moving said control means to a press open position at another'location around said turntable, saidcontrol actuator means stationarily mounted relative to the movement of the turntable and normally out of contact with said control means during the normal cycle of rotation, means responsive to the movement of each press to the prescribed location for actuating the control actuator means, said means being connected to said control actuator means.

1 3. A rotary pressing machine comprising a rotary turntable'having thereon a plurality of presses, each of which has a buck and a presser head, the latter being mounted on the press for movement toward and from a press open position in which the presser head is away from the buck and a press close position in which the presser head is against the buck, each press including motor meansconnected to the presser head for moving it and a control means for said motor means, said rotary turntable having a normal cycle of rotation wherein a presser head is moved from a press open position'to a press closed position and thence back to a press open position, control actuator means for engaging and moving said control means to a press close position at one location around the turntable and for engaging and moving said control means to pressopen position at another location around said turntable, said control actuator means stationarily mounted relative to the movement of the rotary turntable and normally out of contact with saidrcontrol means during a normal cycle. of rotation, said control actuator means including a moveable member and a magnetic actuator for actuating said moveable member to contact the control means, and electric circuitry connected to said magnetic actuator to operate said magnetic actuator.

4. A rotary pressing machine comprising a rotary turntable having thereon a plurality of presses, each of which has a buck and a presser head, the latter being mounted on the press for movement toward and from the press open position in which'the presser head is away from the buck and a press close position in which the presser head is against the buck, each press including motor means connected to the presser head for moving it and a control means for said motor means, said rotary turntable having a normal cycle of rotation wherein a presser head is moved from a pressopen position to a press close position and thence back to a press open position, electrical control actuator means for engaging and moving said control means to press close position at one location around the turntable and for engaging and moving said control means to a press open position at another location around the turntable, said control actuator means stationarily mounted relative to the movement of the rotary turntable and normally out of contact with said control means during-a normal cycle of rotation, circuit closure means responsive to the movement of each press to a prescribed position for operating said control actuator means, and electric circuitry connecting said closure means to said control actuator means.

5. A rotary pressing machine comprising a rotary turntable having thereon a plurality of presses, each of which has a buck and a presser head, the latter being mounted on the press for movement toward and from a press open position, in which the presser head is away from the buck and a press close position in which the presser head is against the buck, each press including motor means connected to the presser head for moving it and a control means for said motor means, said control means having a vertical member extending beneath the turntable, said rotary turntable having a normal cycle of rotation wherein the presser head is moved from a press open position to a press close position and thence back to a press open position, control actuator means for contacting and moving said control means to a press open position at another location around said turntable, said control actuator means stationarily mounted relative to the movement of the turntable and normally out of contact with said control means during a normal cycle of rotation, said control actuator means including circumferentially spaced portions for contacting said vertical member to operate the control means.

6. The apparatus of claim 4 further characterized in that said circuit closure means is a mechanically operated switch.

7. The apparatus of claim 4 further characterized in that said circuit closure means includes photo-controlled relay means.

8. The apparatus of claim 4 further characterized in that the circuit closure means includes a serially connected mechanically operated switch and photo controlled relay means, both normally open.

9. The apparatus of claim 7 further characterized in that said photo controlled relay means includes a light source for providing a light beam and a photocell re sponsive thereto for closing a relay means when the light is illuminated.

10. The apparatus of claim 9 further characterized in that said light source and photocell are mounted stationary in respect to the turntable and presses.

11. The apparatus of claim 9 further characterized in that said light source is arranged to project a beam along a light path near the buck and presser head area of the press while at said closing station.

12. The apparatus of claim 9 further characterized in that said light source is arranged to project a beam along the buck and presser head area and means is provided on each press for returning said light beam to the photocell.

13. A rotary pressing machine comprising a rotary turntable having thereon a plurality of presses, each of which has a buck and a presser head, the latter being mounted on the press for movement toward and from a press open position in which the presser head is away from the buck and a press closed position in which the presser head is against the buck, each press including motor means connected to the presser head for moving it and a control means for said motor means, control means actuator for moving said control means to press closed position when the press is at the closing station, said control actuator means normally being out of contact with the said control means, a timer on each press and actuator means connected thereto and to said control means for moving said control means to press open position at a prescribed time interval after the press has been closed.

14. The apparatus of claim 13 further characterized in that said timer is an air operated timer.

15. The apparatus of claim 13 further characterized in that said timer includes means for adjustably varying the length of the time interval.

References Cited in the file of this patent UNITED STATES PATENTS

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