US2937485A

US2937485A - Packaging machine for flat articles

Info

Publication number: US2937485A
Application number: US384228A
Authority: US
Inventors: Howard M Wall
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-10-05
Filing date: 1953-10-05
Publication date: 1960-05-24
Anticipated expiration: 1977-05-24

Description

May 24,1960 H. M. WALL PACKAGING MACHINE FOR FLAT ARTICLES 10 Sheets-Sheet 1 Filed Oct. 5, 1955 Z/ENTUF L A n D R A w o H WWW/M May 24, 1960 H. M. WALL PACKAGING MACHINE FOR FLAT ARTICLES 10 Sheets-Sheet 2 Filed Oct. 5, 1953 nvZ/sw TU}? HOWARD n -WAL L WW A T'TU/FNE May 24, 1960 H. M. WALL PACKAGING MACHINE FOR FLAT ARTICLES 10 Sheets-Sheet 3 Filed Oct. 5, 1953 MW flTTUl-T-"NEVE a i; x T 7 o x o w an O Q N o J flu 6 m o. N

May 24, 1960 H. M. WALL PACKAGING MACHINE FOR FLAT ARTICLES 10 Sheets-Sheet 4 Filed Oct. 5, 1953 NVME/VTUF HOWARD m. WALL. M/

H. M. WALL PACKAGING MACHINE FOR FLAT ARTICLES 10 Sheets-Sheet 5 //\/L/E/\ 7"UR= HOWARD M. WALL 2? flwz. 0 TrmFFwav j May 24, 1960 Filed Oct. 5, 1953 May 24, 1960 H. M. WALL 2,937,485

PACKAGING MACHINE FOR FLAT ARTICLES Filed Oct. 5, 1953 10 Sheets-Sheet 6 V I l I A 21- Z5 {7 174 17 a i Q 9 HOWARD M.wAL\

WM/M ,4 7' TUE/V5 W5 May 24, 1960 H. M. WALL PACKAGING MACHINE FOR FLAT ARTICLES 10 Sheets-Sheet 7 Filed Oct. 5, 1953 mu/z/v TUE- HOWARD M. WALL TTUFNEWE IMIM LLLL IIIIl /I/I I y 4, 19 0 H. M. WALL 2,937,485

PACKAGING MACHINE FOR FLAT ARTICLES Filed Oct. 5, 1953 10 Sheets-Sheet 8 III-III HI-JI May 24, 1960 H. M. WALL PACKAGING MACHINE FOR FLAT ARTICLES 10 Sheets-Sheet 9 Filed Oct. 5, 1953 May 24, 1960 H. M. WALL 2,937,485

PACKAGING MACHINE FOR FLAT ARTICLES Filed Oct. 5, 1953 1o Sheets-Sheet 1o //\/1/& N TU HOWARD M- WALL United states Patent PACKAGING MACHINE non FLAT ARTICLES Howard M. Well, Terminal Sales Bldg, Portland, Oreg.

Filed on. s, 1953, S81. No. 384,228

25 Claims. (31. 53-187) This invention relates to a machine for packaging flat articles such as doors, plywood, fiberboard, mattresses, and the like, for shipment.

In the case of panels of the types mentioned, there are frequently one or more finished surfaces, sometimes of an expensive wood, which are easily marred in handling. The corners, ends and edges are particularly susceptible to denting and splintering if left unprotected. Also, in addition to the consideration of protection, in the case 'of relatively thin and flexible panels it is advantageous to bind together a number of them so that they may be handled as a more rigid and self-sustaining unit.

Objects of the invention are, therefore, to provide an improved wrapper and packaging procedure for articles of the types mentioned, to provide apparatus for performing the packaging operation, and to provide automatic control equipment for operating the apparatus with a minimum of manual effort.

A more particular object is to provide a machine for aligning panels in a stack, inserting said stack in a paper bag, and then folding and sealing the bag.

Another object is to provide end and side aligner mechanism for evening up a stack of panels.

Another object is to provide improved means for folding the end flaps of a wrapper against an article therein.

The illustrated embodiment of a machine of the invention is arranged to support doors or stacks of panels in horizontal position, moving the articles in two different directions between stations where the individual steps of the operation are performed. When panels are to be wrapped in groups they are first laid on a table equipped with pneumatically operated aligning devices to even up the stack. An open ended paper tube is clamped in horizontal position at one end of the stack. Then the stack is pushed longitudinally into the tube and the assembly is moved a short distance farther in a longitudinal direction to clear the bag holding device. Finally, the assembly is moved in a transverse direction between folding and sealing devices which close the ends of the tube. Certain functions are regulated by manual controls while others are initiated in step by step sequence by automatic controls in an electric system involving electric motors, pneumatic cylinders, solenoid valves and electric switches and relays.

Additional objects and advantages will become 'apparent, and the invention will be better understood, with reference to the accompanying drawings illustrating a preferred embodiment. Various changes may be made in the construction and arrangement of parts and certain features may be used without others without departing from the spirit of the invention as defined by the appended claims.

In the drawings:

Figure 1 is a general perspective view of a machine embodying the principles of the invention;

. Figure 2 is a perspective view of a door or the like which is to be enclosed in a protective wrapper;

Figure 3 is a perspective view of an empty tubular wrapper or bag in flat condition; Figure 4 is a perspective view showing the door of Figure 2 partially inserted in the wrapper of Figure 3;

Figure 5 is a perspective view showing the completed package;

Figure 6 is a fragmentary perspective view of a portion of the right end of the machine of Figure 1, with parts broken away to show features of the operating and control mechanism; t

Figure 7 is a fragmentary perspective view showing the bag holding means;

Figure 8 is a plan view of the parts shown in Figure 7;

Figure 9 is a sectional view taken on the line 9-9 of Figure 8; r

Figure 10 is a sectional view taken on the line 10-10 of Figure 1;

Figure 11 is a sectional of Figure 10;

Figure 12 is a perspective view of a block for removably mounting the pusher element;

view taken on the line 11-1J1 Figure 13 is a perspective view of the pusher element;

Figure 14 is a cross sectional view showing the pusher element and block assembled on the pusher chain;

Figure 15 is a sectional view showing the side aligner in raised, operative position;

Figure 16 is a view similar to Figure 15 showing the side aligner in lowered, inoperative position;

Figure 17 is a view taken on the line 17-17 ofFigme 15; v

Figure 18 is a fragmentary plan view of one of the end folder assemblies; 7

Figure 19 is a sectional view taken 19 of Figure 18;

Figure 20 is a view taken on the line 20-20 of Figure 18;

Figure 21 is a sectional view taken on theline 21-21 of Figure 18;

Figure 22 is a fragmentary top plan view of end com pression mechanism extending in continuation of th parts shown in Figure 18;

Figure 23 is a view taken'on the line 23-23 of Figure 22;

Figure 24 is a wiring diagram for the pusher motor;

Figure 25 is a diagrammatic illustration gripper controls;

Figure 26 is a schematic diagram of the electric and pneumatic control system for the longitudinal belt conveyor motor and the lift for the off-bearing or lateral conveyor; and

Figure 27 is a diagrammatic illustration of the controls for the end folders.

Referring first to Figure 1, the machine comprises a plurality of components for performing certain opera-' tions on the panels and on the'bags to accomplish theequipped with devices for first properly aligning wpo sitioning the articles. A bag 12 is laid flat on a conveyor table 13 with its end held open in alignment with the article 10. A pusher on the loading table 11 pushes the article 10 into the bag 12 which is then released from its holding device and carried a short distance to the left on a longitudinal conveyor system in the table 13, both ends of the bag being open at this time. An ofibearing or lateral conveyor then rises beneath the encased article and moves it between end folding and sealing devices 15 which close the ends of the bagto complete the package. This conveyor continues the move I Patented May 24, 1960 on the line 19- of the bag ment to carry the packaged article, designated by the numeral 16, to a suitable conveyance to remove the articles for storage or shipment.

The nature of the packaging operation performed by the machine is illustrated in Figures 2 to 5. The bag 12 which is to form a wrapper for the door a is shown in Figure 3 in flat, collapsed condition. This wrapper or so-called bag comprises a tubular envelope of heavy paper or other suitable material having fiat side folds 18 and open ends 20 and 21. The machine holds the end 21 spread open and anchors it against movement while the door 10a is pushed lengthwise into the tube, as shown in Figure 4. As the door is pushed into the tube, the corners on the leading end of the door expand the tube straightening out the side folds 18 and forming square corners 19 in the tube to fit the door. In the completed package shown in Figure 5, the door is completely encased and the end portions of the bag have been folded over and sealed by the action of the folding and sealing devices 15, as will be described in detail as the description proceeds.

Loading table Referring again to Figure 1, when an article 10 such as a door or a stack of panels is placed on the supporting' surface 25 of loading table 11, it is crowded laterally against a series of guide rollers 26 by a pair of side aligning plates 27 connected to piston rods 28 in horiaontal cylinders 29, as shown in Figures to 17. Plates 27 are extended and retracted by a manual valve lever 30 at the operators station, to align the article with its first path of movement from table 11 to table 13. The article 10 is shown in Figures 15 and 16 to comprise a stack of relatively thin panels which are to be packaged as a unit.

The necessary endwise movement is effected by a pusher element 31 which is connected to the upper horizontal reach of an endless pusher chain 32 travelling just beneath the top surface of the table in a longitudinal guide track 33. The chain 32 is trained over a series of sprocket wheels, as shown at 34, 35 and 36 in Figures 6 and 9, and is driven in opposite directions by a reversible electric motor 61, appearing in Figure 1, having a reduction gear drive beneath the sprocket 36. Sprocket wheel 35 drives a cam shaft 40 by means of chain 41 and sprocket wheel 42 keyed to the cam shaft.

Cam discs

43, 44, 45 and 46 are thereby driven in coordination with the movements of pusher 31 to actuate the gang of

switches

47, 48, 49 and 50 in timed relation for controlling certain functions of the machine.

The pusher 31 is equipped, with a forwardly projecting lip 37 onits top edge, as shown in Figure 13, designed to ride over the uppermost panel of a stack to insure that all the panels will be engaged and pushed by the vertical end face 38 of the pusher. The rear end of pusher 31 is slotted at 39 to fit the pusher block 52 in Figure 12 having grooves 53 in its upper portion. The aperture 54 and slot 55 are adapted to receive pins in upstanding lugs 56 to connect the block 52 with the chain 32, as best shown in Figure 9. Slot 55 permits relative movement of lugs 56 so that the block and pusher can travel around the sprocket wheel 35, as shown in Figure 6. The upper wall of the slot 39 may be provided with a shallow depression 57 to receive the rounded nose of a spring pressed latch pin 58 for removably securing the pusher 31 on the block 52, as shown in Figure 14. It is desirable to have a number of diiferent pusher elements 31 available for use on stacks of different thicknesses, and the means just described facilitates quick interchangeability of the pusher elements.

- The details of the mechanism for operating the side aligner plates 27 are shown in Figures 15 to 17. The cylinder 29 has one end pivotally connected at 170 to the frame of table 11 beneath the. top work supporting surface.25.. This. surface. is slotted: at.171 to accommodate 175. When the piston rod is retracted the plate 27 tilts up to vertical position above the table top as it moves against a pile of panels to be evened up.

In Figure 1 the numeral 51 designates an end aligner which is movable to theright for use in aligning a stack of panels against the pushing element 31 as a stop when the pushing element is resting in the position shown in Figure 1. The actuating mechanism for end aligner 51 is similar to that just described for the side aligners 27, except that the cylinder and guide track are disposed longitudinally of the loading table 11 closely adjacent the pusher chain 32. V

To clear the table for loading, the side aligners 27 and end aligner 51 are retracted beneath the table top, as illustrated in Figure 16, and the pusher 31 is similarly retracted to its broken line position shown in Figure 6 whereby there is no obstruction on the top of the table except the guide rollers 26 which serve as abutments for one side edge of the panels. Before operating the end aligner 51, which may be accomplished either by the valve 30 or by a separate valve 60, the pusher 31 is moved to its Figure 1 position to serve as an abutment for the ends of the panels. Further details of this feature of the construction will be explained in connection with the control system and operation.

Thus, the panels may be manually placed on the loading table 11 without particular care, the laterally movable side aligners 27 aligning the panels at one side against the guide rollers 26 and the longitudinally movable end aligner 51 aligning the panels lengthwise against the stationary pushing element 31 before the latter is put into motion in its feed stroke.

Panel inserting mechanism A bag 12 to receive the panel or stack of panels indicated at 10 in Figure 1 is laid in fiat, collapsed condition on a series of belts 65 which are normally stationary and form the supporting surface of conveyor table 13. One of the open ends of the bag is pulled over a pair of spaced sheet metal shoes 66 between which the panels are pushed into the bag. The shoes 66 are mounted on and project from one end of the loading table 11 toward the con veyor table 13, further details of this feature being shown in Figures 7, 8 and 9. Stops 67 determine the proper position for the end of the bag. A plurality of bag grippers 69 are actuated by vertical cylinders 70 to clamp the bag against the shoes 66. A plurality of roller guards 71 mounted on a transverse shaft 72 extending across the width of table 11 hold the leading end of the stack of panels down, in case they do not lie flat, and guide the panels in between the shoes 66. A switch 75 is engaged by the bottom of the stack as it passes over the bottom shoe 66 and into the bag.

As the pusher 31 pushes the panel or stack of panels 10 into the collapsed bag, the leading end of the panel or stack encounters resistance in expanding the bag to straighten out side folds 18 and form square corners 19 as shown in Figure 4. This resistance plus the sliding friction of the panels against the inside surface of the bag creates considerable tension in the bag and requires the end 21 to be heldsecurely by the grippers 69.

When the pusher 31 approaches the limit of its movement to the left in Figures 1 and 9 it projects beyond the sprocket wheel 36 and enters between the shoes 66 to push the panels a short distance inside the open end of the bag. Thus, it will be seen that the end of pusher 31 projects a short distance to the left of bag stops 67 to provide proper positioning of the stack of panels within the bag.

It will be observed in Figure 1 that there are three sets of belts 65 arranged in end to end relation across the top of conveyor table 13. The pulleys for these belts are mounted on six shafts 78 having sprocket wheels driven by a chain 79 from an electric motor 80, as shown in Figure 11. The drive chain 79 is disposed to provide clearance for vertical gaps 82 between the respective sets of belts 65 for vertical movement of a pair of lateral or off-bearing conveyor chains 85 appearing in Figure 10. The lateral chains 85 are equipped with upstanding lugs 86 and are trained around driving sprockets 87. The upper reaches of chains 85 continue to the left over sprockets 88 on a shaft 89 and thence around idler sprockets, not shown.

Sprocket wheels 87 are mounted on a shaft at one end of a lift frame 90 which is pivotally mounted at its other end on the shaft 89. The frame 90, together with sprocket wheels 87 and chains 85, may be raised and lowered by a piston rod 91 in a vertical cylinder 92. When the frame 90 is lowered, the encased panels may ride in a longitudinal direction on the belts 65, and then after the longitudinal motion is arrested the frame 90 is raised to lift the panels off the belts 65 for lateral movement by lugs 86 on chains 85. Smooth slide surfaces 93 may be provided alongside the guide tracks for chains 85 to prevent damage to the wrappers by the chains, the runners projecting slightly above the level of the chains 85 to support the panels thereon for sliding movement.

Driving sprockets 87 are driven by a chain 94 from metor 95 mounted on the underside of lift frame 90 or in some other convenient location. Lift frame 90 comprises essentially a pair of parallel truss members which are disposed in the aforementioned gaps 82 between the three sets of belts 65.

When the encased panels reach the proper position on belts 65 for transfer to the lateral chains 85, the leading end of the package engages switch 98 shown in Figure 1. It will be explained briefly that belts 65 are started after the panels are inserted in a bag on the shoes 66 and the pusher 31 has been withdrawn. The function of switch 98 is to stop the belts and raise the lift frame 90 to change the direction of movement of the package. The control system will be described in detail hereinafter.

As the panel moves laterally on chains 85, it passes between the end folding and sealing devices, generally indicated at 15 in Figure 1. When a pressure sensitive adhesive is employed, the mere folding of the open ends of the bag completes the sealing of the wrapper. However, the present machine includes a glue spreader for use on bags having no adhesive previously applied thereto.

Bag folding and sealing mechanism Figure 18 illustrates the construction and arrangement of the folding and sealing devices 15 for one end of the package, it being understood that the other devices 15 are of a similar construction and perform the same function on the other end of the package. A roller 100 is mounted on an arm 101 of a swinging lever having a second arm 102 extending angularly from a pivotal support 103. Arm 102 is connected with a piston rod 104 in a cylinder 105 having a pivotal connection with the frame of the machine at 106.

Fluid pressure pipes

107 and 108 connect the opposite ends of cylinder 105 with the corresponding cylinder of the other folding and sealing device on the opposite side of the machine and with the four-way solenoid valve 110. Preferably, each arm 101 is equipped with a spring extended slip joint (not shown) causing the roller 100 to bear against the end of the package with a resilient, yieldable pressure.

The valve 110 is of conventional construction, having a pressure connection at 111 and a spool-type balanced valve member 112 to connect the fluid pressure supply with one or the other of the

pipes

107, 108, leading to opposite ends of the cylinders. V The

pipe

107 or 108;- which is not connected with pressure, communicates with.

one of the

exhaust ports

113, 114. The valve member 112 is actuated in one direction by a solenoid 115, and when the solenoid is deenergized it is returned by spring 116 to the normal position shown. Solenoid is connected with a pair of

switches

120 and 121 which are engaged by the bottom side of the package which is. being advanced by the conveyor chains 85.

The roller 100 operates to fold in the side. edge flap 123 on the leading edge of the door shown in Figure 5, while the lever 101 remains in its normal rest position shown in Figure 18. The stationary curved former plate 125 then folds up the bottom flap 126 and subsequently the similar former plate 128 folds down the top flap 129 after it has passed over the glue spreader wheel 127.

While the

flaps

126 and 129 are thus being folded -pro-.

gressively toward the trailing edge of the panel, the piston rod 104 is retracted to swing the roller 100 outwardly away from the envelope as the trailing edge of the package approaches the roller. Then, when the trailing edge reaches the approximate position of the leading edge in- Figure 18, the piston rod is again extended causing roll er 100 to swing rapidly in a forward direction relative to the direction of movement, at a greater speed than the package is travelling, to engage. and fold forwardly the trailing edge flap 130. As the trailing edge of the panel passes through the former plates '1'25 and 128, the remaining portions of flaps 126 and. 129 are folded over the short flap 130. Wheels press all the flaps flat against the ends of the panels, the glue on the inside of top flap 129 holding all four of the flaps securely closed.

The bottom former plate 125 is elongated in the direction of travel and has a flat horizontal portion underlying the package at the end of the plate which is first engaged by the package. The outer portion of this plate then bends upwardly, as shown in Figure 19, and finally assumes a vertical position at its other end 141 which The upper former plate 128 is flat and horizontal to overlie the top of the package at the end 145 which first engages the package. The outer portion of this plate then bends down and assumes a vertical position at its other end 146 to press the downturned top flap 129 flat against the end of the panel on top of flap 126.

The upper former plate 1'28 is mounted on a pair of vertical rods 150 secured in adjusted position by set screws 151- in bracket supports 152. The bracket supports 152 are mounted on vertical posts 153.

.The trailing ends of both

former plates

125 and 128 ,are pressed laterally against the end of the package by' resilient pressure units 131 in Figure 18. The details of construction of one of these units is shown in Figure 21. The former plate 128, for example, is mounted on a horizontal rod 128a having a collar 128b. Rod 12811 is mounted for sliding movement in a horizontal tubular guide 132. Compression spring 133 is interposed between the collar 1281; and the end of guide 132 to urge the trailing end 146 of the former plate firmly against the package to seal the top flap against the underlying flaps. In some cases it is desirable to provide an additional short pressure shoe extending from roller 100 almost to the vertical portion 141 of the bottom former plate to hold flaps 123 and 130 in folded position.

As shown in Figure 18, the wheels or rollers 135 are mounted in guide housings 136 containing compression springs 137 to urge the rollers against the end of the package and continue the pressure on the overlapped flaps tains a uniform pressure over the entire length of the flaps, and the package may be allowed to rest momentarily in engagement with this pressure plate to insure adhesion of the flaps. This portion of the machine may be referred to as a glue setting stage when wet adhesives are used.

During the end folding, gluing and glue setting stages illustrated in Figures 18 and 22, the ends of the package are preferably supported on a bottom roller track 141 starting at a point adjacent the horizontal leading end portion 145 of the bottom former plate 125 as shown in Figure 19. An upper roller track 142 is pressed down against the top of the package to hold the panels fiat and compress them tightly together at theends of the package while the flaps are being folded and glued. This roller track is mounted on overhanging bracket supports 143, as shown in Figures 18 and 22, the details of construction being further shown in Figure 20.- The bracket supports 143 are adjustably mounted on rigid upstanding posts 144 for disposition above and extending across the former plates and also pressure plate 138. Each of these bracket supports includes a vertical rod 145 connected with the guide track 142. The guide track 142 is urged downwardly by a compression spring 147 to the lower limit of its travel as determined by a stop collar 146 on the upper end of rod 145. The lower and upper guide tracks 141 and 142 thereby comprise a resilient clamp acting on end portions of the package until the adhesive on the flap of the wrapper has set sufficiently to hold the panels substantially in their flattened condition within the package. Additional roller tracks 142 may also be mounted over the chains 85 if desired.

In order to handle panels of different length, width and thickness, various adjustments are provided in the machine which will not require detailed description for persons skilled in the art. Thus, for panels of different width, the guide rollers 26 may be shifted laterally in slots 26a in Figure 8. For panels of different thickness, or stacks of panels of different thickness, different pusher elements 31 may be provided having appropriate thickness in a vertical direction to engage all the panels in the stack, and, at the same time, clearing the shoes 66 to pass therebetween. The vertical spacing of shoes 66 may be varied, and the width of the shoes in a direction transversely of the line of thrust of pusher 31 may be made variable, or different sets of shoes may be provided for panels of different width.

If the variation in length of the panels exceeds the length of stroke of end aligner 51, provision may be made for adjusting the end aligner unit bodily along the guide track 33, or, alternatively, the pusher 31 may be returned to a different rest position in Figure l by the provision of an additional cam controlled limit switch for this purpose, in Figure 6, the function of which will be better understood with reference to the pusher control system to be presently described in connection with Figure 24.

A change in the length of panels would also require suitable adjustment of the switch 98 in Figure l to center the panels relative to lugs 86 on chains 85, and lateral adjustment of the end sealing devices relative to the chains 85. Thus, the equipment is readily adaptable to handle panels of all different sizes ordinarily encountered in production.

Control system and Operation Referring first to Figure 24, the pusher motor 61 is energized from a three-wire power supply 200 under the control of forward and reverse relays 201 and 2262;, respectively. The switch positions are illustrated for the position of pusher 31 illustrated in Figure 1, after the

aligners

27 and 51 have been retracted. Forward relay 201 is energized through push button starter switch 203 to make a circuit through

wires

204, 205, 206, normally closed switches 175, normally closed'emergency push buttonstop switch 2.07 and wire 208. :One of the switches 8 is associated with one of the side aligners 27 and the other is associated with end aligner 51 to prevent starting the pusher motor when the panels 10 are restrained by the aligners. The switches 175 are closed in the Figure 16 (retracted) position of the aligners and open in the Figure 15 (operating) position of the aligners.

Cam switch 47 has a switch arm 210 connected with Wire 206 and normally held in engagement with contact 211 when the pusher 31 is in its retracted or rest position as shown in Figure l. The energization of relay 201 by push button switch 203 raises the relay armature to start motor 61 in the forward direction to advance pusher 31. As soon as the motor starts, switch 50 closes. Armature bar 212, thus raised, engages

contacts

213 and 214 completing a holding circuit for the relay solenoid through wires 204, relay coil 201, armature bar 212, wire 215, switch 50, switch arm 210, wire 206,

closed switches

175 and 207 and wire 208. The forward movement of pusher 31 may be arrested at any time, in case of emergency, by pressing push button switch 207 to open this holding circuit. Push button start and stop

switches

203 and 207 are located at the operators station adjacent valve levers 30 and 60 in Figure 1.

In each normal cycle of operation the cam 43 effects the movement of switch arm 210 out of engagement with contact 211 and into engagement with another contact 216 when pusher 31 reaches the end of its forward stroke shown in Figure 9. This breaks the holding circuit for forward relay 201, deenergizing pusher motor 61, and makes a new circuit to energize reverse relay solenoid coil 202 through wires 204, coil 202, wire 217, switch arm 218 of cam operated switch 43, contact 219, wire 220, switch arm 210, wire 206, switches 175, push button switch 207 and wire 208. Energization of reverse relay solenoid coil 202 lifts the relay armature to reenergize pusher motor 61 for reverse rotation to withdraw the pusher 31 from its Figure 9 position where it projects into the mouth of the bag 12. At the same time, a holding circuit for relay coil 202 is established through wire 204, coil 202, wire 217, switch arm. 218, wire 220, contact 221, relay bar 222, contact 223, wire 206, switches 175, push button switch 207, and wire 208. This holding circuit maintains the energization of reverse relay coil 202 after the cam 43 releases the switch arm 210 from engagement with contact 216 as the pusher starts to back away from its Figure 9 position.

The holding circuit just described is broken by switch arm 218 under the actuation of cam 44 when the pusher 31 has returned to its retracted position illustrated in Figure 6, deenergizing reverse relay 202 and motor 61. The pusher may also be stopped at any point in its return movement by the opening of emergency stop switch 207.

After the desired number of panels 10 have been placed on the table 11, start switch 203 is closed momentarily, thereby energizing forward relay 201 to start the motor 61. As soon as the motor starts forward, cam switch 43 is re-closed. The closing of forward relay 201 establishes its own holding circuit through relay bar 212, wire 215 and switches 47 and 50 (contact 211) as previously described.

When pusher 31 reaches its Figure 1 rest position, cam 46 opens switch 50 to interrupt the holding circuit just described and stop the motor. All the switches are thereby returned to the positions shown in Figure 24 in preparation for the next pushing stroke.

As previously mentioned, the guide rollers 26 and pusher 31 serve as fixed ahutments for straightening up the stack of panels 10 by the action of side and end

aligners

27 and 51. In order to hold pusher 31 stationary under the thrust exerted by end aligner 51 the motor 61 is preferably equipped with a conventional magnetic brake which is applied automatically whenever the motor is deenergized. While the aligners are operating, the switches 175 remain open to prevent operation of the 9, pusher motor but when both aligners have been retracted beneath the table top the switches 175 are reclosed, as shown for convenience in tracing the circuits in Figare 24.

Referring now to Figures 8, 9 and 25, the switch 75 controls the operation of the plurality of bag grippers 69 to prevent the panels from pushing the bag off the holding shoes 66 while the panels are being inserted. The physical position of switch 75 is adjusted so that it will be engaged and closed by the panels during their movement into the bag. The coil 230 of solenoid valve 231 is thereby energized to connect fluid pressure supply line 232 with pipe 233 connecting with the closed ends of cylinders 70. The grippers 69 are thereupon thrust outwardly to clamp the upper and lower sides of the bag against the shoes 66 to hold the bag stationary against the sliding friction of the panels entering therewithin. When the panels leave contact with switch 75 it returns to open position, deenergizing solenoid coil 230 and allowing spring 234 to return the valve to its off position illustrated. Springs 235 in cylinders 78 then retract their respective pistons, exhausting the air in the cylinders through pipe 233 and port 236. There is sufficient delay in the movements of the parts and the release of the air to allow pusher 31 to reach the end of its forward stroke, as shown in Figure 9, before the grippers release the bag.

The control system for belt conveyor motor 80 and lateral conveyor lift cylinder 92 is shown in Figure 26. When the pusher 31 reposes in its rest positions shown in Figures 1 and 6, the switch arm 240 of cam switch 49 remains out of engagement with contact 241, as shown, but when the pusher arrives at its Figure 9 position, the cam 45 closes the

switch elements

240, 241, to energize relay coil 242 through

wires

243, 244 and 245, causing the relay armature to lift and energize the motor 80. Relay 242 is sufiiciently slow acting to allow the pusher to reach the limit of its movement before motor 80 starts to turn. Upon opening of the

switch elements

240, 241, when the pusher backs up from its limit position shown in Figure 9, a holding circuit for relay coil 242 is maintained through wires 245, contact 246, armature bar 247, contact 248, wire 249, contact 250 of switch 98, switch arm 251, and wire 243. This circuit is maintained until the belts 65 driven by motor 80 carry the encased panels into engagement with the switch 98 in Figure 1 to break the relay circuit at contact 250 and deenergize motor 80.

When the panels thus engage switch 98, switch arm 251 is moved out of engagement with contact 250 and into engagement with a second contact 252, in series with switch 254. Switch 254 is arranged as shown in Figure 10 to be engaged and closed by a lug 86 on one of the chains 85 at a time when none of the lugs are passing immediately beneath the package. The closing of switch 254 then energizes relay coil 253 lifting relay contact bar 255 into engagement with

contacts

256 and 257. The solenoid winding 259 of valve 260 is thereby energized through

wires

261 and 262 to move the valve into a position admitting fluid pressure from supply pipe 265 into pipe 266 connecting with the bottom of conveyor lift cylinder 92.

The motor 95 in Figure 10, driving the lateral or offbearing conveyor chains 85, is started by a switch (not shown) and left running all the time that the machine is in operation. The admission of fluid pressure to the lower end of cylinder 92 raises frame 90 to lift the wrapper encased panels off the belts 65 and bear the package away to the left as viewed in Figure 10. Switch 254 prevents this lift movement from occurring at a time when any of the lugs 86 are immediately beneath the package where they might tear the wrapper and mar the panels.

,When the package leaves contact with switch 98 in the course of its lateral movemen produced by lugs 86 on the chains 85, switch arm 251 leaves engagement with contact 252, deenergizing relay coil 253. This relay has a delayed opening characteristic as exemplified schematically by the dash pot 270, whereby the contact bar 255 i does not leave engagement with

contacts

256 and 257 until the package has had suflicient time to travel past the sprocket 88. After such a predetermined time interval, the armature bar 255 drops, deenergizing valve solenoid coil 259 and allowing spring 271 to connect the pipe 266' with outlet port 272. The weight of frame then depresses the piston rod 91, exhausting the air from cylinder 92 through outlet port 272. Frame 90 drops to its original position with lugs 86 and skids 93 beneath the level of belts 65 and the chains 85 continue to run.

The action of the end folding and sealing devices 15 involving the shifting of rollers was previously described in connection with Figure 18. The control system for effecting the movements of these rollers at the proper times is illustrated in Figure 27. Switch is normally closed and is arranged to be opened by engagement with the package while switch,121 is normally open and is arranged to be closed by engagement with the package. The physical position of these switches in relation to the rollers 100 is shown in Figure 18. It will be apparent that when the package starts to pass between the rollers 100 at opposite ends of the package, the two switches will be engaged in succession without effecting energization of solenoid coil 115. When switch 120 is first engaged by the package this switch will be opened and the subsequentengagement and closing of switch 121 by the package will then have no effect on the energizing circuit. However, when the package leaves engagement with switch 120, this switch will return to closed position, energizing solenoid coil 115 to operate the valve 110 to admit fluid pressure from supply pipe 111 into pipe 108 to retract the piston-rods 104 in rapid movement. Rollers 100 are thereby swung outwardly away from the package as its trailing edge approaches.

Then, as the package continues to move by the action of lugs 86 on chains 85, the switch 121 is also disengaged, effecting the opening of the circuit to solenoid winding 115. Spring 116 then returns the valve member 112 to the position shown in Figure 27, admitting pressure to pipe 107 and swinging the rollers 108 back to the position shown. In this movement the rollers swing rapidly forward to fold forward the trailing edge flaps as previously described, in which position the rollers are ready to engage the leading edge flap 123 on the next package, as shown in Figure 18.

In Figure 22 an independent chain belt conveyor 96 having no lugs and driven by a motor 97 is utilized to allow the sealed packages to rest for a short interval in contact with pressure plates 138 to set the glue on the end flaps. This conveyor, normally at rest, may be started and stopped at intervals, as desired, by manual switch 98 or other suitable means. This conveyor is merely representative of a suitable support for the packages during their rest interval and may take other forms such as skids or a table surface onto which the packages are pushed one after another by the conveyor 85. Conveyor 96 must run faster than chains 85 in order to pull each package away from the pushing lugs 86 before the latter turn down around the end sprockets (not shown) for chains 85.

When a wet adhesive is used the pressure plates 138 preferably include electric heating elements (not shown) to dry the glue quickly. Greater pressure may be applied to the glued joint, if desired, by connecting the heated plates 138 with suitable fluid pressure devices similar to

bag clamp devices

69, 70, in Figure 7, and such devices may also be arranged to retract the plates 138 when the packages are to be moved. This may conveniently be accomplished by controlling the pressure devices by solenoid valves actuated by switch 98 or other suitable means. The structure in Figure 22 is designated as a whole by the numeral 17 in Figure 1. When using a pressure sensitive adhesive the conveyor 96, pressure plates 138 and

roller tracks

141 and 142 might be omitted in Figure 22.

As soon as the frame 90 has returned to its lower position, another bag may be placed on the belts 65 in en gagement with the shoes 66 and another panel or panels may be placed on the loading table 11 in preparation for the next cycle of operation.

It will be apparent to persons skilled in the art that the starting switch 203 in Figure 24 may be closed, if desired, in response to the lowering of frame 90 or by operation of the end folding and sealing devices 15 to start the next cycle automatically. These and other variations of the system and mechanical arrangement within the scope of the appended claims are contemplated in the application of the broader principles of the invention to the packaging requirements of dilferent types of articles and materials.

Figures 1 and 18 show successive steps in the same views for convenience of illustration. It is to be understood that an empty bag 12 would not be placed on the belts 65 until after the ofi bearing chains 85 had dropped beneath the belts 65 in Figure 1 and that one package 16 would not follow immediately after another on the chains 85 as shown in Figure 18. The different operations shown in these views do not necessarily occur simultaneously.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. -In a machine for packaging fiat rectangular panels and the like, a table on which a plurality of said panels may be stacked, abutment means on one side of said table projecting above the table to engage one side of said stack, a side aligner retractible beneath said table and movable to an operative position above said table to engage the opposite side of said stack and crowd said stack against said abutment means, a pusher operable in longitudinal movement above said table to engage one end of said stack and push said stack longitudinally across the table, and an end aligner movable to an operative position above the table in engagement with the opposite end of said stack and having longitudinal sliding movement to crowd said stack against said pusher, said pusher and aligners being retractible beneath said table while the table is being loaded, said pusher forming a stationary abutment above said table while said end aligner is being operated, and all of said aligners being retractible beneath said table while said pusher is being operated.

2. In a machine for packaging fiat rectangular panels and the like, a table on which a plurality of said panels may be stacked, a pusher engageable with one end of a stack of said panels for moving said stack longitudinally across the table, said pusher being connected with an endless chain for travel above and beneath said table, and an end aligner engageable with the opposite end of said stack, means operable in one direction to move said end aligner toward said pusher for crowding said panels against said pusher while said pusher is held stationary, said means being operable in the opposite direction to retract said end aligner beneath said table when said pusher is operated.

3. In a stacking table on which a plurality of rectangular panels and the like may be stacked, a motor driven pusher engageable' with one end of a stack of said panels for moving said panels across the table, said pusher being connected with an endless chain for travel above and beneath said table, an end aligner engageable with the opposite end of said stack, means operable in one direction for moving said end aligner toward said pusher to crowd said panels against said pusher when the pusher is held stationary, said means being operable in the opposite direction to retract said end aligner beneath said table, and means responsive to the retraction of said aligner to prevent operation of said pusher until said aligner is retracted.

'4. In a machine for packaging fla't rectangular panels and the like, means for supporting a stack of said panels in horizontal position, an endless chain extending longitudinally of said stack therebeneath, a pusher element on said chain to engage the panels at one end of said stack, aligning means to engage the panels at the opposite end of said stack, means operable in one direction to move said aligning means toward said pusher element and crowd said panels against said pusher element, said means being operable in the opposite direction for retracting said aligning means below the level of the bottom of said stack, gripping means for holding one end of a partially collapsed tubular wrapper in open horizontal position at said other end of said stack, and means for operating said chain to push said stack endwise into said wrapper, said pusher having return movement beneath said stack supporting means.

5. In a machine for packaging flat rectangular panels and the like, means for supporting a stack of said panels in horizontal position, abutment means at one side of said stack, fluid pressure operated means acting against the panels at the opposite side of said stack to crowd said panels against said abutment means, an endless chain passing beneath said stack, means for retracting said crowding means beneath said supporting means, a pushing element on said chain to engage one end of said stack, fluid pressure operated aligning means to engage the panels at the opposite end of said stack and crowd said panels against said pushing element, said aligning means being retractible beneath the level of the bottom of said stack, spaced shoes having fluid pressure operated clamp means for holding one end of a partially collapsed tubular wrapper in open horizontal position at said other end of said stack, and means for driving said chain for pushing said stack endwise into said wrapper, said pushing element having return movement beneath said stack supporting means.

6. In a packaging machine, releasable gripping means for holding one end of a partially collapsed elongated tubular wrapper in open horizontal position, means for pushing an article into one end of said wrapper, means for moving said wrapper and article together in an endwise direction to a predetermined position on a support to clear said holding means, a transverse conveyor disposed beneath said wrapper encased article in said predetermined position, means for elevating said conveyor above said support to engage and lift said wrapper encased article and move the same in a transverse direction above said support, and folding and sealing means engaging the ends of said wrapper during said transverse movement.

7. In a packaging machine, releasable gripping means for holding one end of a partially collapsed elongated tubular wrapper in open horizontal position, means for pushing an article into said one end of said wrapper to form a package, said pushing means tensioning said wrapper from said gripping and holding means by sliding friction of the pushed article against the inside of the wrapper, said gripping and holding means constituting the sole restraint against movement of said wrapper with said pushing means, means actuated by retraction of said pushing means to move said package in a longitudinal direction to a predetermined position, means for moving said package in a transverse direction, means actuated by said package upon arrival at said predetermined position to operate said transverse moving means to move said package in said transverse direction, and folding and sealing means engaging the end of said wrapper during said transverse movement.

8. In a packaging machine, a normally stationary longitudinal conveyor for supporting an elongated tubular wrapper in partially collapsed horizontal position, releasable gripping means for holding one end of said wrapper open to receive an article to be packaged, means for pushing said article into one end of said-wrapper, means responsive to completion of the movement of said pushing means to release said holding means, means actuated by retraction of said pushing means to start said conveyor, a transverse conveyor disposed beneath said longitudinal conveyor, means for raising said transverse conveyor into engagement with said package, means actuated by said package upon arrival at a predetermined position on said longitudinal conveyor to stop said longitudinal conveyor and raise said transverse conveyor for moving the package in said transverse direction, and folding and sealing means engaging the ends of said Wrapper during said transverse movement.

9 In a machine for packaging flat rectangular panels and the like, a normally stationary longitudinal conveyor for supporting a tubular wrapper in partially collapsed horizontal position, gripper means for holding one end of said wrapper open, means for pushing a panel endwise into said wrapper, means responsive to completion of the movement of said pushing means to release said gripper means and start said conveyor, a transverse conveyor disposed beneath said longitudinal conveyor, means for raising said transverse conveyor to lift said wrapper encased panel off said longitudinal conveyor, and means actuated by said wrapper encased panel upon arrival at a predetermined position on said longitudinal conveyor to stop said longitudinal conveyor and raise said transverse conveyor for moving the wrapper encased panel in said transverse direction.

10. In a machine for packaging flat rectangular panels and the like, a normally stationary longitudinal conveyor for supporting a tubular wrapper in partially collapsed horizontal position, pneumatic gripper means for holding one end of said wrapper open, a solenoid valve controlling said gripper means, means for pushing a panel endwise into said wrapper, switch means responsive to completion of the movement of said pushing means ,to actuate said solenoid valve to release said gripper means, switch means responsive to retraction of said pushing means to start said conveyor, a transverse conveyor disposed beneath said longitudinal conveyor, means for raising said transverse conveyor into engagement with said wrapper encased panel, switch means actuated by said wrapper encased panel upon arrival at a predetermined position on said longitudinal conveyor to stop said longitudinal conveyor and raise said transverse conveyor for moving the wrapper encased panel in said transverse direction, air pressure operated folding and sealing means arranged to engage the ends of said wrapper during said transverse movement, a solenoid valve controlling said folding and sealing means, and'switch means engaged by said wrapper encased panel during said transverse movement to actuate said valve for operating said folding and sealing means.

11. In a packaging machine, a normally stationary longitudinal conveyor for supporting an elongated tubular wrapper in horizontal partially collapsed position, a pair of shoes extending into one end of said wrapper for holding said end of the wrapper open to receive an article to be packaged, releasable grippers engaging said one end of said wrapper on said shoes, and means for pushing said article into said open end of said wrapper, said pushing means tensioning said wrapper from said gripping and holding means by sliding friction of the pushed article against the inside of the 14 gaged by said panel as it enters said wrapper for first actuating and then releasing said grippers.

13. *In a machine for packaging flat rectangular panels and the like, a horizontal bag support, a pair of upper and lower horizontal guide shoes extending into one end of said bag to hold the bag open for receiving said panels, and a plurality of fluid pressure operated grippers cooperatingwith said shoes to clamp portions of the mouth of the bag against the outer surfaces of said shoes whereby an object may be guided into the gripped bag between the inner surfaces of said shoes.

14. Ina packagingmachine, a plurality of conveyor elements spaced apart in end-to-end relation leaving gaps between said elements for supporting a tubular wrapper in horizontal position, releasable means for holding one end of said wrapper open to receive an article to be packaged, means for pushing said article into said open end of said wrapper, a transverse ofi-bearing'conveyor normally disposed below the level of said conveyor elements, and means for raising said elf-bearing conveyor through said gaps above the level of said conveyor elements to lift a packaged article off said conveyor elements and move it transversely of' said elements.

15. In a machine for packaging flat panels and the like, a plurality of belt conveyor elements for supporting a package, said elements being spaced apart in end-to-end relation leaving gaps therebetween, a transverse off-bearing conveyor having conveyor elements disposed for vertical movement in said gaps, said oif-bearing conveyor having a normal rest position below the level of said conveyor belts whereby said conveyor belts are operative to move said package into a position above said oif-bearing conveyor, and means for raising said ofi-bearing conveyor through said gaps to a position above the level of said conveyor belts to lift said package off said conveyor belts and 'move it transversely away therefromJ 16. In a machine for packaging elongated rectangular fiat panels and the like, means for inserting a panel endwise in a partially collapsed tubular wrapper withboth ends of the wrapper projecting beyond the ends of the panel, means for moving said wrapper encased panel in a transverse direction, rollers engaging vertical side portions of the projecting ends of the wrapper at opposite ends of the panel to fold back short edge flaps from the leading edge of the panel at both ends thereof, means for retracting said rollers and then moving them forward along the ends of the panel in the direction of its travel to fold forward similar short edge flaps from the trailing edge-of the panel at both ends thereof, and stationary former plates engaging both ends of the moving panel for folding top and bottom flaps over said edge flaps.

17. In a machine for packaging elongated rectangular flat panels and the like in tubular wrappers having a length greater than the length of the panels, means for moving panels encased in open ended wrappers ofsaid type inatransverse direction, a roller mounted on a swinging lever adjacent one end of the moving panel and arranged in one position of the lever to engage said end of the panel and fold back a flap of said wrapper from the leading edge of the panel, and means to swing said lever in one direction to move said roller out of engagement with the panel and then back to move said roller forward into engagement with the end of the panel to fold forward a flap of said wrapper from the trailing edge of the panel. 1

18. In a machine for packaging elongated rectangular flat panels and the like in tubular wrappers havinga length greater than the length of the panels, means for 7 swinging arm adjacent one end of the moving panel and having a'first position to engage said end of the'panel and fold back a fiap ofsaid wrapper from the leading edge of the panel as the leading edge of the panel passes the roller, said arm being movable to a second position to retract said roller away from engagement with said panel, a pair of switches mounted adjacent the path of travel of said panel and adapted to be engaged thereby in succession by the movement of the panel, and means connected with said switches for swinging said arm between said two positions, said arm. reposing in said first position as the leading edge of the panel engages said switches in succession, said arm moving to said retracted position as the trailing edge of the panel disengages the first switch and said arm being caused to swing back rapidly to said first position in response to disengagement of the trailing edge of the panel from said second switch, said return movement swinging said roller forward rapidly in the direction of travel of the panel to engage and fold forward a flap of said wrapper from the trailing edge of the panel.

19. In a machine for packaging elongated rectangular flat panels and the like in tubular wrappers having a length greater than the length of the panels, means for moving panels encased in open ended wrappers of said type in a transverse direction, a roller mounted on a swinging arm adjacent one end of the moving panel and having a normal rest position arranged to engage said end of the panel and fold back a flap of said wrapper from the leading edge of the panel as the panel advances past the roller, fluid pressure operated means for swinging said arm between said rest position and a retracted position and return, a solenoid valve controlling said fluid pressure means, and a pair of switches connected in a circuit to control the operation of said valve, one of said switches being located in advance of said roller and the other switch being positioned opposite said roller, said switches controlling said valve and said fluid pressure means to retract said roller and then return said roller to said normal rest position as the trailing edge of the panel approaches said rest position of the roller wherein said return stroke causes said roller to fold forward a short edge flap on the trailing edge of the panel.

20. In a machine for packaging elongated rectangular flat panels and the like in tubular wrappers having a length greater than the length of the panels, means for moving panels in open ended wrappers of said type in a transverse direction, a movable folding element having a first position adjacent one end of the moving panel to engage and fold back a short edge flap from the leading edge of the panel as the panel passes the folding element and a second position retracted out of engagement with the panel, and means actuated by the trailing edge of the panel to move said folding element from said first position to said retracted position and then back to said first position in a return stroke which engages said folding element with a short edge flap on the trailing edge of the panel to fold said flap forward.

21. In a packaging machine, spaced means for gripping and holding upper and lower sides of one end of a partially collapsed and flattened tubular wrapper open in horizontal position, means for pushing an article to be packaged between said holding means into said one end of said tube expanding said tube to the thickness of the article, said pushing means tensioning said tube from said gripping and holding means by sliding friction of the pushed article against the inside of the tube and by the resistance encountered by the article in expanding the flattened tube, said gripping and holding means constituting the sole restraint against movement of said tube with said pushing means, means for folding and sealing the ends of said tube, and means for moving the package comprising said article and tube into cooperative engagement with said folding and sealing means.

22. In a packaging machine, means for gripping and holding upper and lower sides of one end of a partially collapsed and flattened tubular wrapper in open position, means for pushing an article to be packaged endwise into said one end of said tube expanding said tube to the thickness of the article and leaving both ends of the tube extending beyond the ends of said article, said pushing means tensioning said tube from said gripping and holding means by sliding friction of the pushed article against the inside of the tube and by the resistance encountered by the article in expanding the flattened tube, said gripping and holding means constituting the sole restraint against movement of said tube with said pushing means, means for folding and sealing the ends of said tube flatly against the ends of said article, and means for moving said tube containing said article transversely between a pair of said folding and sealing means.

23. A machine for packaging elongated, rigid articles comprising means for supporting a flattened tubular wrapper and article at rest in aligned horizontal position, means for gripping one end of the wrapper at opposite sides and holding said end open to receive one end of the article, and a pusher arranged to engage the other end of the article and push the article into the wrapper expanding the wrapper to the thickness of the article and tensioning the wrapper from said gripping means, and means for folding and sealing said end of the wrapper.

24. A machine for packaging flat rectangular panels comprising means for supporting at rest in aligned horizontal position a panel and a flattened tubular wrapper longer than the panel and having flattened side folds, means for gripping upper and lower sides of one end of the wrapper and holding said end open to receive one end of the panel, and a pusher arranged to engage the other end of the panel and push the panel into the wrapper straightening out said side folds and forming square corners on opposite sides thereof to accommodate the thickness of the panel, said gripping means restraining the wrapper against movement with said pusher, and means for folding and sealing the ends of the wrapper.

25. In a packaging machine, a bag supporting surface, a pair of upper and lower horizontal guide shoes arranged to extend into the mouth end of a bag disposed at full length on said supporting surface to hold said mouth end open for receiving an article to be packaged, a plurality of movable grippers cooperating with said shoes to clamp portions of the month end of a bag against the outer surfaces of said shoes whereby an article to be packaged will be guided between the inner surface of said shoes into the bag, means for pushing said article between said shoes and into a bag clamped on said shoes, a switch adjacent one of said shoes arranged for engagement by an article passing between said shoes, and a control system for said grippers arranged to actuate said grippers when said switch is engaged by the leading end of an article entering between said shoes and to release said grippers when said switch is disengaged by the trailing end of the article passing between said shoes.

References Cited in the tile of this patent UNITED STATES PATENTS 519,203 Putnam May 1, 1894 803,357 Pile Oct. 31, 1905 1,188,193 Molins June 20, 1916 1,749,415 Colby et al. Mar. 4, 1930 2,128,316 Paul Aug. 30, 1938 2,215,545 Demler Sept. 24, 1940 2,291,645 Nordquist Aug. 4, 1942 2,555,584 Fairbank June 5, 1951 5,775 Tamarin Ian. 20, 1953 2,641,974 Sperling et al June 16, 1953 ,651,896 Woodruff Sept. 15, 1953 2,685,996 Shofiner Aug. 10, 1954