US3152539A

US3152539A - Strapping apparatus

Info

Publication number: US3152539A
Application number: US289635A
Authority: US
Inventors: Kresten T Sorensen
Original assignee: FMC Corp
Current assignee: CYKLOP STRAPPING Corp A CORP OF
Priority date: 1963-06-21
Filing date: 1963-06-21
Publication date: 1964-10-13
Anticipated expiration: 1981-10-13

Description

Oct. 13, 1964 K. T. SORENSEN STRAPPINGAPPARATUS 5 Sheets-Sheet 1 Filed June 21, 1963 Oct. 13, 1964 K. 1'. SORENSEN STRAPPING APPARATUS 5 Sheets-Sheet 2 Filed June 21, 1963 Oct. 13, 1964 K. 'r. SORENSEN 3,152,539

STRAPPING APPARATUS Filed June 21, 1963 5 Sheets-Sheet 3 Fig? 6 CHAIN. CARRIAGE PRESS START UP DOWN RETRACT UP ,I /O D /ao //l ,54

STOP EXTEND DOWN Q //4 Q Q /08 //z /:4

Oct. 13, 1964 K. T. SORENSEN STRAPPING APPARATUS 5 Sheets-Sheet 4 Filed June 21, 1963 K. T. SORENSEN 3,152,539

STRAPPING APPARATUS Oct. 13, 1964 5 Sheets-Sheet 5 Filed June 21 1963 United States Patent "ice 3,152,539 STRAPPING APPARATUS Kresten T. Sorensen, Media, Pa., assignor, by mesne assignments, to FMC Corporation, San Jose, Caiif a corporation of Delaware Filed June 21, 1963, Ser. No. 289,635 16 Claims. (Cl. 100-8) This invention relates to apparatus for facilitating the strapping of bundles or articles and especially to apparatus for drawing a strap about a relatively large bundle to thus position the strap for convenient manual securement about the bundle. In its more particular aspects, the invention relates to apparatus for facilitating, especially in a press, the strapping of a load onto a pallet.

Corrugated paper box blanks and other light-weight but bulky articles are generally packaged by stacking a relatively large number of them together and securing bands about the stack to provide a load which can conveniently be handled by fork-lift trucks. Sometimes the load is secured to a pallet to facilitate the use of the forklift truck and sometimes a pallet is not employed, the entire load then consisting of the stacked articles with the bands thereabout. So -called double-faced pallets oifer many advantages and are frequently used for this purpose even though there are problems involved in threading the hand through the pallet between the face thereof. Particularly in the case of paper box blanks, it is desirable to do the banding or strapping while the load is under compression in a press. The press force is generally light, usually just enough to squeeze the air from between the individual articles. Since the individual articles are light in weight, a great number of them may be packaged together and the total height of the stack frequently runs six feet or more and this has made for further difficulty in positioning the band thereabout.

While various types of banding material such as wire, rope, and strap have been used for securing large loads of the kind referred to, the present invention is particularly advantageous for use with strap. In general, the invention provides an improved means for pulling an end of strapping material from a supply and drawing it about three sides of the load so that an operator may then grasp the strap and draw it about the fourth side and secure the end by suitable means to a portion of the strap which extends to the supply.

It is an object of the present invention to provide an improved apparatus for pulling a strap at least part way about a load in order to facilitate the securement thereof about the load.

A further object of the invention is to provide an apparatus for pulling a strap about three sides of a large load which apparatus has improved means for connecting the strap thereto and wherein said improved means is automatically brought to rest at points of desired attachment of the strap thereto and detachment therefrom.

Another object of the invention is to provide an apparatus for pulling a strap at least part way about a load which is resting on a double-faced pallet, the apparatus being so arranged as to pull the strap between the faces of the pallet.

Still a further object of the invention is to provide a strap feeding apparatus for positioning a strap around three sides of a large load whether or not the load includes a double-faced pallet.

3,152,539 Patented Oct. 13, 1964 Yet a further object of the invention is to provide a strap feeding apparatus associated with a press which will pull a strap end to a certain predetermined position along the pressure platen irrespective of the lowered or elevated position of the platen.

Other and further objects, features and advantages of the invention will become apparent as the description of certain preferred embodiments thereof proceeds.

Referring now to the drawings:

FIG. 1 is a side elevational view showing a preferred embodiment of the invention;

FIG. 2 is an end elevational view;

FIG. 3 is an enlarged end elevational view of the low er portion of the apparatus;

FIG. 4 is an enlarged detail in side elevation showing the means for attaching a strap to the apparatus;

FIG. 5 is an enlarged detail in end elevation of the mechanism shown in FIG. 4; a

FIG. 6 is a schematic electrical diagram;

FIG. 7 is a view of the control panel for the apparatus;

FIG. 8 is a side elevational view of the lower portion of the apparatus showing the manner of using the same with a load supported on a double-faced pallet; and

FIG. 9 is a side elevational view of the upper portion of the apparatus as modified to provide a press.

The framework of the apparatus comprises a pair of vertically extending channel members 16 and 11 spaced apart as shown in FIG. 2 and suitably supported by a base generally indicated at 12. Near the top of the members 10 and 11, a cross brace 13 is provided and extending cantilever style with respect to said members are a pair of parallel arms 14 and 15 welded or otherwise secured to cross brace 13. A roller conveyor 16 is provided alongside upright members It and 11 near the bottom thereof so that a load 17 may conveniently be moved into strapping position beneath arms 14 and 15.

Extending between the lower portions of members 19 and 11 and secured thereto are a pair of

members

18 and 19 between which are secured a pair of vertically extending

guide rods

20 and 21. Slidable on

rods

20 and 21 respectively are

sleeves

22 and 23. A channel 24 is secured to sleeves 22 and 23 and to one end of channel 24 and to the sleeves 22 is secured a heavy plate 25. A heavy plate 26 is secured to the opposite end of channel 24 and to the sleeve 23 and a second channel 27 is secured between

plates

25 and 26.

Plates

25 and 26 together with

channels

24 and 27 and the

sleeves

22 and 23 thus constitute a unit generally designated 28 which is slidable up and down on

guide rods

29 and 21.

Secured to the underside of member 18 is an air cylinder 29 having a piston rod 39 which is fixed to a bracket 31 extending from channel member 24 of the unit 28. Air under pressure may be admitted to cylinder 29 be neath the piston thereof through a line 32 so as to raise unit 28 from the position shown in FIGS. 1, 2 and 3 wherein sleeves 22 and 23 rest on the member 19 to the position shown in FIG. 8 with the upper ends of said sleeves abutting member 18. Line 32 is provided with a valve 33 which may be manually operated but more conveniently is a solenoid valve operated by a remote selector switch. Valve 33 is three-way and in one position admits air from line 32 to cylinder 29 and in another closes line 32 and vents the cylinder to the atmosphere. With cylinder 29 vented, the unit 28 moves to the down position under the force of gravity. The purpose in rais- '3 a) ing and lowering unit 28 will be subsequently explained.

Rotatably mounted on pins fixed in plate are two pairs of double-flanged rollers, one pair being indicated at 34 and 35 and the other pair at 36 and 37. A lance or elongated carriage 38 is guidably supported by the doubleflanged rollers for movement between an extended position shown in full lines in FIG. 1 and a retracted position shown in FIG. 8. The retracted position of carriage 38 is indicated in FIG. 1 by dashed lines. A roller chain 39, see FIG. 8, is fixed at one end to a pin 40 secured to carriage 38 near the rearward end thereof and at the other end said chain is fixed to a pin 41 secured to a forward portion of said carriage. Intermediate the ends, chain 39 is trained about a pair of freely rotatable sprockets 42 and 43 carried by plate 25 and a sprocket 44 secured to a cross shaft 45 which shaft is rotatably mounted in

plates

25 and 26. By rotating sprocket 44 in one direction or the other, as will presently be explained, chain 32 moves carriage 38 between retracted and extended positions.

As indicated in FIG. 3, a lance or carriage 46 is movably mounted on plate 26 of unit 28. Carriage 46 is mounted and operated similarly to carriage 38 and the construction is therefore not shown in side elevation. However, in FIG. 3, a pair of the double-flanged supporting rollers corresponding to rollers 34 and 35 are indicated at 47 and 48 and a driving chain 49 corresponding to chain 39 is shown trained about a sprocket 50 secured to cross shaft 45. Thus, rotation of shaft 45 causes the carriages 38 and 46 to move in unison.

Shaft 45 has secured thereto near the center a sprocket 51 connected by a roller chain 52 to a sprocket 53 on the drive shaft of a reversible air motor 54 mounted on the upper flange of channel member 27 of the unit 28. An air line 55 is connected to motor 54 through a four-way solenoid operated valve 56. As will presently be more particularly alluded to, two solenoids control valve 56 so that when one of the solenoids is energized air is admitted to motor 54 to drive it in a direction to move carriages 38 and 46 to the retracted position shown in FIG. 8 and when the other is energized air is admitted to the motor to drive the motor in the direction to move said carriages to the extended position shown in full lines in FIG. 1. A block 57 secured to carriage 38 engages the forward edge of plate 25 to limit the retracted movement of the carriage and a block 58 secured to said carriage contacts the rear edge of said plate to limit the projected position of the carriage. When the carriage reaches either extreme of movement, motor 54 stalls.

The reason for having two carriages 38 and 46 as well as the two upright frame members 10 and 11 and two horizontal arms 14 and 15 is so that two straps may be drawn around the load 17 simultaneously but since in essence the invention is the same whether one or more straps are employed, only the mechanism for handling one strap will be hereinafter referred to.

When carriage 38 is in the extended position and unit 28 is in its lower position as shown in FIG. 1, said carriage extends between a pair of the rollers forming roller conveyor 16 and said carriage is below the surface of the rollers so that load 17 may be pushed into position without contacting said carriage. Carriage 38, upright 10 and horizontal arm 14 form over-all a generally C- shaped configuration for supporting an endless conveyor in the form of a roller chain 68 as will now be explained. At the right-hand end beyond the confines of roller conveyor 16, a freely rotatable sprocket 61 is mounted on carriage 38. Chain is trained about this sprocket and extends horizontally along the carriage to a sprocket 62, see enlarged FIG. 8, which is rotatably mounted upon the same shaft that carries the double-flanged roller 3'5. From sprocket 62, the chain passes upward more or less along upright 10 to a sprocket 53 rotatably mounted on the supported end of upper horizontal arm 14. The chain passes along arm 14 to a sprocket 64 adjacent the free end of said arm and thence back along the arm to a sprocket 65 from which said chain passes downward and around a sprocket 66 secured to a shaft 67 which is rotatably mounted in a pair of brackets 68 and 69 extending upwardly from member 18, see also FIG. 3. From sprocket 66, the chain passes upward and about a floating sprocket 70. Sprocket 79 is rotatably supported by a bail 71 which is connected through a spring 72 to a cable 73 which extends upwardly about a pulley 74 to an anchorage 75 on arm 14. From sprocket 7t roller chain 60 proceeds downward and about a sprocket 76 rota tably supported on plate 25. From sprocket 76, the chain passes to a sprocket 77 carried by carriage 38 from whence the chain extends along said carriage and over an inter mediate sprocket 78 and finally back to sprocket 61 at the outer end of said carriage. The floating sprocket 70 and its resilient support 72 serve to keep the chain taut for both previously referred to raised and lowered positions of unit 28.

All of the above referred to sprockets are freely rotatable except sprocket 66 which latter serves to drive the chain. Shaft 67, to which sprocket 66 is connected, is provided with a sprocket 79 which is driven through a roller chain 8% from a sprocket 81 secured to the drive shaft of an air motor 82 mounted upon the member 18, see FiG. 8. Motor 82 is supplied with compressed air through a line 83, the admission of air to the motor being controlled by a solenoid-operated valve 84.

Chain 68 is provided with a strap holding means generally indicated at 85 which has a rest position adjacent the extended end of carriage 38 beyond the roller conveyor 16. As best shown in FIGS. 4 and 5, a plurality of adjacent pins 86 of roller chain 60 protrude outwardly from the side of said chain to form the strap holding means 85 and at the beginning of a strapping operation, the end portion of a strap 87 is pulled from a supply 88 and snubbed about the extended pins 86 as shown in FIG. 4 to thereby engage the strap with endless chain 60. After the strap is engaged with the strap holding means 85, motor 82 is set in operation as will presently be explained to drive chain 69 in a manner to cause the strap holding means to draw the strap beneath load 17, up along one side of the load and over the top along arm 14 with the strap holding means 85 coming to rest in the dotted line position shown in FIG. 1 adjacent the outer end of arm 14. The strap is now around three sides of the load and the operator disconnects the end from the strap holding means 85 and pulls upon the free end of the strap and upon a portion extending from beneath the load to the strap supply 88 and joins the two portions of the strap together in any suitable manner to thereby complete the encirclement of the load.

In order to stop the strap holding means at the desired position near the outer end of arm 14, a limit switch 151 is provided and this switch is incorporated in a circuit, as will presently be explained, for controlling solenoid valve 84 of air motor 82. When the long pins 86 of the strap holding means strike the limit switch, motor 82 is stopped and after a short coasting movement the strap holding means comes to rest in the dotted-line position shown in FIG. 1. A limit switch LS2 is provided on carriage 38 adjacent sprocket 61, and when the strap holding means 85 engages this limit switch, motor 82 is stopped and the chain coasts about sprocket 61 with the strap holding means coming to rest in the full line position of FIG. 1. Chain 60 is driven in only one direction and in order to avoid the delay involved in bringing strap holding means 85 all the way around from the outer end of arm 14 to the forward end of carriage 38, a second strap holding means, generally designated at 92, is provided at a location half way around the length of the chain from strap holding means 85. Strap holding means 92 is identical in construction with strap holding means 85, and it is equally effective for operating the two limit switches LS1 and LS2.

The machine is operated from a control panel shown in FIG. 7 which may be located in any convenient position. After the operator has engaged strap end 87 with strap holding device 85 when said device is in the full line position at the lower right of FIG. 1, he presses the chain START button 100 to close a circuit between power lines L1 and L2 through

lines

101 and 102 to the coil of a relay CR-1, as indicated in the wiring diagram of FIG. 6. Energizing the relay causes a blade 103 thereof to close a circuit through

lines

104 and 102 to thus hold the relay coil energized after push button 100 is released. Upon energization of the relay a blade 105 thereof closes a circuit through

lines

106 and 107 to energize a solenoid 5-1 of the solenoid opera-ted valve 84 to thus start air motor 82 as aforesaid, to drive chain 60 and strap holding means 85 around the package to the dotted-line posiion at the upper right in FIG. 1. As the strap holding means 85 approaches the dotted-line position, it engages and opens the limit switch LS1, which as indicated in the wiring diagram is in the line 104 of the holding circuit of relay CR-l. Thus, operation of switch LS1 de-energizes the relay and opens the circuit to solenoid S1, whereupon valve 84 is closed to thereby stop motor 82 and permit the strap holding means to coast to rest in the dotted-line position. There is a STOP push button 188 in line 102 whereby relay CR1 may be de energiZed at any time but ordinarily this is used only in emergencies or when making repairs. After disconnecting the strap from the holding device, the operator again presses START button 100 to start lair motor 82. When the other strap holding device 92 reaches limit switch LS2, the circuit through

lines

102 and 104 to relay CR1 is again broken to de-energize solenoid 8-1 of solenoid valve 84 whereupon strap holding device 92 coasts to a stop after passing around sprocket 61. It might be noted that limit switches LS1 and LS2 re-close after being engaged by either of the

strap holding devices

85 or 92.

With carriage 38 in the extended and lowered position shown in full lines in FIG. 1, the apparatus is conditioned for strapping unpalletized loads which may be shoved into and out of position along roller conveyor 16. Since carriage 38 is below the surafce of roller conveyor 16, said carriage may be left in the extended position so long as unpalletized loads are being strapped.

As previously indicated, the apparatus is also intended for use with loads which are supported on double faced pallets, in which case it is necessary for the carriage 38 to extend through the pallet between the upper and lower faces thereof since it is generally desirable to have the strap secure the load to the pallet by passing between the faces of the pallet. When loads carried by double faced pallets are used, carriage 38 is moved to the retracted position shown in FIG. 8, and unit 28 is raised to the position shown in FIG. 8 before the load is moved into strapping position.

As previously mentioned, movement of carriage 38 back and forth between the extended full line position of FIG. 1 and a retracted position shown in FIG. 8 is controlled by reversible air motor 54 which in turn is controlled by the two-solenoid actuated four-way valve 56. In the wiring diagram of FIG. 6, the solenoid which operates valve 56 to admit air to drive motor 54 in the direction to move carriage 38 to the retracted position is indicated at S3 and the solenoid which admits air to drive the motor in the opposite direction at S4. Solenoids S-3 and 8-4 are in

parallel circuits

109 and 110 respectively controlled by mechanically interlocked push buttons 111 and 112 located on the control panel as indicated in FIG. 7. Op eration of push button 111 closes the circuit to solenoid S3 and opens the circuit to solenoid 8-4 to thus cause motor 54 to drive carriage 38 to the retracted position shown in FIG. 8. When it is subsequently desired to extend carriage 38, push button 112 is operated to close the circuit to solenoid S-4 and open the circuit to solenoid S-3. Motor 54 stalls when either stop block 57 or 58 engages the plate 25, so that it is not necessaryto regulate valve 56 after carriage 38 reaches either of its extremes of movement.

In FIG. 8, a load 114 is shown supported on a double faced pallet 115 in position to be strapped, and it is apparent that before carriage 38 can become positioned between the upper and lower faces of the pallet, it is necessary not only to retract said carriage but to raise the unit 28 carrying the carriage from the position shown in FIG. 1 to the position shown in FIG. 8. As previously mentioned, unit 28 is raised by admitting air through valve 33 to the lower end of cylinder 29. Preferably, valve 33 is solenoid operated and in the wiring diagram of FIG. 6 the solenoid is indicated at S-2 in .a circuit 113 which is opened and closed by a selector switch 114 located on the control panel. With solenoid S2 energized, air is admitted to the lower end of cylinder 29 to raise unit 28 to the FIG. 8 position with carriage 38 aligned with the opening through the pallet 115 and when the solenoid is deenergized the cylinder is vented to the atmosphere so that unit 28 moves down under the force of gravity to the FIG. 1 position.

After elevating carriage 38 and extending it thnough the pallet, the operator connects the end 87 of the strap to whichever of the strap holding devices, or 92, is in the strap connecting position and depresses START button 108 to cause chain 60 to draw the strap through the pallet and up and about the load. During the upward movement of the carriage, the resultant slack is taken out of chain 60 by the floating sprocket 70 and this may pull the

strap holding device

85 or 92 clockwise about sprocket 61 to an inaccessible position, so that for the first strapping operation after carriage 38 is raised, it may be necessary to operate START button to bring the strap holding device back to the full line position of FIG. 1 before connecting the strap thereto.

It has been previously mentioned that one of the objects of this invention is to provide a strap feeding apparatus in association with a press and such an embodiment will now be explained in connection with FIG. 9. In FIG. 9, only the upper portion of the apparatus is shown since this is the only portion which is different from the apparatus thus far described. The press includes an upright frame member 10 corresponding to previously described frame member 10. An arm 14' extends horizontally from near the upper end of upright 10 and said arm carries a cylinder of a press ram 151 to which is secured a platen, genenally designated 152. Press ram 151 may be operated in any desired conventional manner, hydraulically, pneumatically, or electrically. The movement of said ram may be controlled by a pair of push buttons, 153 and 154, provided in the control panel as shown in FIG. 7.

i A roller chain 60 is trained about a freely rotatable sprocket 63' and extends along platen 152 to a sprocket 64 and back to a sprocket 65. A limit switch'LSl is mounted on platen 152 for operation by a pair of strap holding devices simliar to those referred to in the previously described embodiment, one of said strap holding devices being indicated generally in FIG. 9 at 85. A cable 73 corresponding to cable 73 is connected through a spring 72' at its lower end to a floating sprocket 70' engaged with a loop in chain 60' to keep said chain taut while permitting up and down movement of a carriage carrying unit similar to unit 28. Cable 73' extends about a pulley 74' and is connected at 75 to platen 152 Whereby cable 73 serves to keep chain 60 taut not only during up and down movements of unit 28, but also during up and down movements of platen 152. The upper portion of the load to be strapped is shown at 17' and said load is supported on a roller conveyor in the previously eX-' plained manner, either on a double faced pallet I01 directly on the roller conveyor. The only distinction between this embodiment of the invention and that previously described is that the FIG. 9 embodiment incorporates the invention intoa press.

Having thus described the invention, what is claimed is:

l. Strap feeding apparatus comprising an endless conveyor, an element supporting a portion of said conveyor for horizontal movement, a framework supporting a portion of said conveyor for vertical movement adjacent one end of said element, a longitudinally reciprocatable carriage mounted on said framework, means directing a portion of said conveyor longitudinally along said carriage, means for moving said carriage back and forth between a retracted position and an extended position of substantially vertical alignment with said element, said carriage being at a lower elevation than said element, said element, said framework and said carriage forming in side elevation a substantially C-shaped configuration when said carriage is in the extended position whereby said conveyor will encompass three sides of a load placed within the C-shaped configuration, strap holding means on said conveyor for permitting attachment of an end portion of a strap to said conveyor, said strap holding means having a rest position adjacent the outer end of said carriage when said carriage is in the extended position, drive means for driving said conveyor so as to move said strap holding means along said carriage, said framework and said element whereby a strap attached to said strap holding means is drawn around three sides of a load positioned within the aforesaid C-shaped configuration, said strap holding means having a second rest position along said element in substantially vertical alignment with said first-mentioned rest position, and means for stopping said drive means to arrest said strap holding 6 means in the second rest position.

2. The apparatus set forth in claim 1 comprising means for relatively moving said element and said carriage toward and away from each other, and slack take-up means for said conveyor for preventing the conveyor from becoming loose as said element and said carriage move closer together.

3. The apparatus set forth in claim 1 comprising support means for supporting a load within the C-shaped configuration formed by said element, said framework and said carriage, means for moving said element toward said support to compress the load, and slack take-up means for said conveyor for preventing the conveyor from becoming loose when said element is moved toward said support.

4. The apparatus set forth in claim 1 wherein said conveyor is a roller chain and wherein a plurality of pins of the chain protrude outward from the side of the chain to form said strap holding means.

5. The apparatus set forth in claim 4 wherein a plurality of strap holding means are carried by said chain.

6. The apparatus set forth in claim 1 comprising support means for supporting a load within the C-shaped configuration formed by said element, said framework and said carriage, said carriage in the extended position being below the load supporting surface of said load supporting means.

7. The apparatus set forth in claim 1 comprising support means for supporting a load carrying pallet within the C-shaped configuration formed by said element, said framework and said carriage, and means for moving said carriage between upper and lower elevations, said carriage when in the lower elevation moving beneath the surface of said support means when moved from the retracted position to the extended position, said carriage when in the upper elevation being adapted to pass through a pallet resting on said support means when said carriage is moved from retracted position to extended position.

8. In an apparatus for facilitating the palletizing of large loads, a stationary framework comprising a vertical arm, a substantially horizontal arm extending cantilever style from the upper end of said vertical arm, a longitudinally movable carriage mounted on said framework adjacent the lower end of said vertical arm, means for moving said carriage back and forth between a retracted position and an extended position of substantially vertical alignment with said horizontal arm, said horizontal arm, said vertical arm and said carriage forming a substantially C-shape/i configuration when said carriage is in the extended position, an endless conveyor, means supporting said conveyor for movement along said horizontal arm, said vertical arm and said carriage, strap holding means on said conveyor for permitting attachment of an end portion of a strap to the conveyor, said strap holding means having a rest position adjacent the outer end of said carriage, drive means for driving said conveyor so as to move said strap holding means along said carriage, said Vertical arm and said horizontal arm, and means for stopping said drive means to arrest said conveyor when said strap holding means reaches the outer end of said horizontal arm.

9. The apparatus set forth in claim 8 wherein the means for stopping said drive means is actuated by said strap holding means.

10. The apparatus set forth in claim 8 wherein said conveyor is a roller chain and wherein a plurality of pins of the chain protrude outward from the side of the chain to form said strap holding means.

11. The apparatus set forth in claim 8 comprising means for raising and lowering said carriage, and means for maintaining constant the length of travel of said conveyor in both the raised and lowered positions of said carriage.

12. In a press, load supporting means having a load supporting surface, a vertical standard alongside said load supporting means, a pressure applying element located above said load supporting means, an endless chain, means on said pressure applying element and said vertical standard for directing the chain therealong, chain carrying means directing said chain beneath the load supporting surface of said load supporting means and beyond said load supporting means to a point out of vertical alignment therewith, strap holding means on said chain for permitting attachment of an end portion of a strap to the chain, said strap holding means having a rest position along said chain carrying means out of vertical alignment with said load supporting means, drive means for driving said chain so as to move said strap holding means from said rest position to a second rest position along said pressure applying element whereby a strap attached to said strap holding means may be pulled around three sides of a load supported on said load supporting means, said second rest position being substantially in vertical alignment with said first-mentioned rest position, means for raising and lowering said pressure applying element, said element comprising a load engaging platen adapted to compress a load against said load-supporting means when said element is lowered, and slack take-up means for said chain for preventing said chain from becoming slack when said pressure applying element is lowered.

13. The apparatus set forth in claim 12 comprising manually operable means for starting said drive means when said strap holding means is in the first-mentioned rest position, and automatically operating means for stopping said drive means when said strap holding means reaches the said second rest position.

14. The apparatus set forth in claim 12 comprising manually operable means for starting said drive means when said strap holding means is in said second rest position, and automatically operating means for strapping said drive means when said strap holding means reaches the first-mentioned rest position.

15. The apparatus set forth in claim 12 wherein said chain is a roller chain and wherein a plurality of pins of the chain protrude outward from the chain to form said strap holding means.

16. Strap feeding apparatus comprising an endless chain, means supporting said chain in a generally C-shaped configuration having substantially horizontal upper and lower arms, support means for supporting a load within the C-shaped configuration of the chain, drive means for said chain, first and second strap holding means on said chain for permitting attachment of an end portion of a strap to the chain, said first and second strap holding means having a strap connecting position adjacent the outer end of the lower arm of the C-shaped configuration of the chain, said first and second strap holding means having a strap disconnecting position adjacent the outer end of the lower arm of the C-shaped configuration of the chain, manually operable means for starting said drive, and automatically operable means for stop- 10 ping said drive means when either of said strap holding means arrives at either the strap connecting position or the strap disconnecting position.

References Cited in the file of this patent UNITED STATES PATENTS 1,325,916 Smirle Dec. 23, 1919 2,420,498 Pojman May 13, 1947 2,632,381 Buckland Mar. 24, 1953 2,985,098 Winkler May 23, 1961 3,052,178 Hall Sept. 4, 1962