US2908216A - Tensioner for automatic wire-tying machine - Google Patents

Description

Oct. 13, 1959 s, usE ETAL 2,908,216

TENSIONER FOR AUTOMATIC WIRE-TYING MACHINE Filed May 28, 1957 5 Sheets-Sheet 1- Wm M m T A 3. fi: L w W Oct. 13, 1959 s, BRQUSE ETAL 2,908,216

TENSIONER FOR AUTOMATIC WIRE-TYING MACHINE Filed May 28, 1957 SHIRLEY 8. Mouseand PAUL m mwcsrr,

Attorney.

5 Sheets-Sheet 2 Oct. 13, 1959 s. B..BROUSE ETAL 2,908,216

TENSIONER FOR AUTOMATIC WIRE-TYING MACHINE Filed May 28, 1957 5 Sheets-Sheet 3 Attorney.

o 1959' s. B. BROUSE ET AL 2,908,216

TENSIONER FOR AUTOMATIC WIRE-TYING MACHINE Filed May 28, 1957 I 5 Sheets-Sheet 5 5% Ana Adda-u A fro/nay.

United States Patent Ofiice TENSIONER roR AUTOMATIC MACHINE Application May 28, 1957, Serial No.662,245

Claims. (Cl. 100-26) WIRE-TYlNG The present invention relates generally to automatic machines for applying a wire tie to a bundle, tightening it therearound and securing the'lapped ends of the wire by a twist or knot. An example of .such a. machine is shown in Vining et al. Patent No.'2,416,859. More particularly, this invention relates to an improved tensioner for automatic wire-tying machines. In the operation of this type of wire-tying machine'the supply wire, from which a tie is to be made, is fed around a guide track in the form of a loop with the ends of the tie overlapped in the slot of a knotter pinion. Then, when a tie is to be applied to a bundle, the bundle is placed within the track, the wire is retracted to draw the tie tight around the bundle and is then tensioned to the desired final value. The'overlapped ends of the tie' are then twisted together by the knotter pinion and the tie is cut free from the supply wire and ejected from the pinion. v

The improvements claimed herein relate to the means for finallytensioning the tie wire after it has been initially drawn taut around the bundle and before the knot has been formed. The novel features of .the'tensi oner of H our invention, as herein described and claimed may be employed in any known automatic tying machine of the same general type as the Vining et al. machine. vDetails of parts other than the tensioner and associated elements are not included herein.

It is, accordingly, an object of our in vention to provide 1 i a tie wire tensioner adapted to be installed in an automatic tying machine for gripping a tie wire after it has been initially drawn taut about a bundle and then exerting a predetermined fina1.tension on the tie wire just prior to knotting.

It 'is a further object of the invention to provide a tensioner as described above having a novel jaw arrangement wherein the tie wire is securely gripped for tensionting, without damage to the wire; between a fixed jaw and a positively actuated movable jaw.

.It is another object of the invention to provide a tensioner for use in automatic tying machines which is provided with control means whereby it may be readily adjusted to vary the tensions of ties applied around a bundle as desired.

These and other objects will become more apparent after referring to the following specification and attached drawings,inwhich: I V Figure l'is an elevation of a tying machine, partly broken away, having the invention incorporated therein, showing the general arrangement of the principal operative units of the machine and their relation to the tensioner of the invention;

Figure 4 is a longitudinal sectional View taken along the plane of line IVIV of Figure 2;

Figure 5 is a cross-sectional view taken along the plane of line VV of Figure 4;

Figure 6 is a view similar to Figure 5 taken along the plane of line VIVI of Figure 4;

Figure 7 is a view similar to Figure 4 on a reduced scale with parts omitted showing the tensioner in operative position just prior to the tensioning operation;

Figure 8 is a cross-sectional view taken along the plane of line VIII-VIII of Figure 2;

Figure 9 is a sectional view taken along the plane of line IX-IX of Figure'S; and

Figure 10 is a diagrammatic illustration of an electrical control circuit for the tensioner.

Referring now in detail to the drawings and more particularly to Figures 1' and la for the present, the invention is shown incorporated in an automatic tying machine 2 having a table 4 with which a feed-in conveyor. 6 and a carry-away conveyor 8 cooperate. A guide track, indicated generally at 10, includes an elevated portion in the form of an arch or gate which bridges the common center line of the conveyors and a bottom portion parallel with table 4. The track receives and holds tie wire W in the form of a loop. ,Bundles B moving along the conveyors are stopped one or more times while under the arch for the application of a tie T, the formation of a knot or twist on the bottom side of the bundle as it rests on the table 4, and the cutting of the completed tie from a supply coil of wire. Other elements of the guide track 10 as well as'other principal elements of the tying machine are mounted on a vertically disposed plate 12 which is secured to the main frame of the machine normal to the table 4. These elements include a sheave-and-pinch roll feeding mechanism 14 for feeding into the track the tie wire W from the supply coil (not shown); a pocket or escapement 16 to receive temporarily the surplus length of wire when the tie is pulled back and tightened around the bundle; a lefthand guide tube 18; a right-hand guide tube 20; a tiltable gripper 23; a knotter and shear 24; and a right-hand guide 26. The knotter' includes the usual slottedtwister pinion. The wire W is pushed, into the machine from left to right during feeding and is retracted from right to left during the tensioning stage of the tying cycle, by

the pinch-roll mechanism 14. I

The parts of the tying machine thus far described are not partof the present invention and are not claimed herein but have been included to insure a clear understanding of the invention.

The tensioner of the invention, indicated. generally by reference numeral 28, includes a block 29'which is disposed for movement parallel with the table 4 and the bottom of track 10 in a slot 30 formed in the top edge of the plate 12, as best shown in Figure 4. A U-shaped yoke 32 is fastened to the rear face'of plate 12 with its legs disposed one adjacent each end of slot 30. The yoke 32 projects above plate 12 and supports a horizontal rod 34. The block 29 is slidably supported on rod 34, alongitudinal hole 36 being provided through the body of the block forthis purpose. Sleeve bearings 36' for rod 34 may be provided adjacent each end of the hole 36.

An entrance guide member 38 having a longitudinal passage 40 therethrough is secured to the top portion of Figure la is a plan view of the tying machine of block 29 by means of set screws. The guide 38 is made up of a grooved main body 38' and a grooved cover body 38" removably secured together by means of cap screws 42. Guide 38 extends toward the left-hand guide. tube 18 and is telescoped over the exit end of the latter for conducting wire W from the guide tube to the tensioner. A

bushing 44 may be fitted in the inner end of guide 3'8 for accurately guiding the entering wire end on initial threadtube 48 projects from the shoulder .52 formed by recess .46 and is-slidably telescoped at its outer end in the guide tube 20 to conduct the wire W from the tensioner into the guide tube .20. Asbest seen in Figure 4, the telescoping arrangement of the entrance guide -38 and tube 48 with the guide tubes 18' and 20 insures that the wire is confined at all times asthe tensioner reciprocates the slot 30 as will become apparent hereinafter.

Ahorizontal recess 54 extendsthrough the body of the block 29 parallel with the plane of table 4 for slidably accommodating a bar 56. A roller 58 is rotatably mounted adjacent one end of bar 56. The periphery of roller 58 extends beyond the top and bottom of the bar for a purpose which will become apparent.

A vertical guideway 60 intersects, at substantially-right angles, the recess 54 for slidably accommodating a movable jaw 62. A fixed jaw 64 having a wirc-receiving groove 66 in the gripping surface thereof is rigidly disposed in block 29 in the upper end of guideway 60. A projection 68 is formed on the upper surface of jaw 62 dimensioned to fit into the wire-receiving groove'66'to 4 bore and its other end bearing against the head of cylinder 92. Spring 1% constantly urges the cylinder'away from block 94. The rod 98 is retained in position by means of a pin 102 which is inserted through a transverse opening in the end of the rod. Pin 102 fits in a slot 103 in the block, as best shownin Figures 2 and 3. The pin '102 also prevents rotation of cylinder 92.

A. spring loaded micro-switch :104iismounted on block 94 and is adapted to be closed on rearward movement of cylinder 92 against the tension ofspring 100 by anarm 106 which projects from the head of the cylinder. Switch 104 is connected with and actuates 'knotter 24 after the tie wire has been drawn taut around the bundle.

The operation of the tensioner 28 will now. be described. As shown in Figures 2, 3,4, 8 and 9, the tensioner is shown in normal retracted and inactive position. The tensioner remains in this position until the stage of the tying cycle is reached wherein it is necessary to tensionthe tie wire W to draw it taut around the bundle. When this stage of the tying cycle isreached the leading end of wire W is clamped by the tiltable gripper 23. At this point the gripper 23 is pulled and tilted by the, end of the retracting wirelW'. lnitilting, the gripper actuates a switch 130' (shown diagrammatically in Figure 10) to actuate cylinprovide a tongue and groove arrangement for gripping V the wire W. The wire-contacting surfaces of the groove 66are smooth while the wire-contacting surface of projection 68' is provided with smooth corrugations having rounded edges so that'the wire is not damaged while being tightly gripped. The groove 66 permits positive confinement of the wire while it is passing thru the tensioner when it is inactive and also serves to insure positive gripping of the wire when the tensioner is in operation.

The movable jaw 62 'is provided with a tapered slot 70 in itsbody portion for receiving thev roller 58'. Bearing of the roller 58 on the upper bearing surface of slot 70 as it enters the slot causes themovable jaw to move upwardly when the bar '56 is moved toward the left to the position shown in Figure 7. When the roller 58 is retracted from slot 70 the movable jaw is positively caused to move away from the fixed jaw by bearing of roller 58 on the bottom bearing surface of slot 70. 7 When the bar is in retracted position, as shownin Figure 4, the movable jaw is maintained in lowered position away from the fixed jaw by roller 58.

' A cover plate 72, which is removably affixed to thev 7 front face of the block 29 by means of cap screws 74, confines the bar 56 and movable jaw 62' within the tensioner. Wear strips 75 and 76 may be disposed on the bottom of recess 54 on opposite sides of guideway 60 for theundersurface of bar '56. 2

. A longitudinal-1y elongated slot 78 is formed through the rear face of the block 29 which communicates with the recess 54. Slot 78 functions as a guideway for one leg the cylinder.

80 of a slidable bracket 82. Another leg 84 of bracket 82 i fits'into a cut-out portion 86 of the rear face of the block 29 adjacent its forward end, as best shown in Figure 9; Both legs 80 and 84 are rigidly connected with bar 56,

The bracket 82 is connected with a fluid pressure motor which is in the formof a double-acting fluid-pressure cylinder 92 having a piston rod 90 projecting slidably therefrom. A third leg 88of'the brack'et 82 looselysup ports the projecting end of the piston rod 90. The head of cylinder 92 is supported in a block 94 which is mounted on the rear face of plate 12. Cylinder 92 by means'of piston rod 90 and bracket 82 serves to advance and retract bar 56in recess 54.

Block 94 has a counterbored openingv 96 therethrough der92. and cause the projection of piston rod 90. Projection of the piston'rod causes the bar 56 to advance in recess 54.n1oving roller 58 into the slot 70. As the roller progresses into slot 70 it causes the movable jaw 62 to move upwardly to clamp the wire Win the slot-'66 of fixed jaw 64 by projection 68. During this initial movement of bar 56 the block 29 is prevented from moving by a springloaded ball detent 108 which cooperates'with a V-notch '1 10in the bottom of the block. Afterthe wire has been clamped the resistance of the spring-loaded ball is 'overcome by the wedging of projection 68 in the slot 66 which causesthe block 29 to move to the left in slot 30,. as viewed in Figures 2, 3 and 4, on continued projection of .pistonrod 90. Since the wire W is now securely clamped movement of the entire tensioner pulls the wire against the resistance of gripper 23 to draw the tie taut around the bundle B. v

A horizontally disposed roller 112 is journaled in a bracket bearing i114 aflixed to the front face of plate 12 and engages a slot 1116 on the underside of the block 29 to maintain the block in proper 'vertical alignment so that it moves parallel with the path ofwire W.

The. amount of'tension applied to wire W which in turnldetermines the degree of tension of the tie around the bundle B is controlled byregulating theflow of pressure fluid to the cylinder 92. This is done 'by means of an. adjustablepressure reducing valve 1&18 (shown dia-i grammaticallyin Figure 10) in the'fluid supply line to Thus, thepressure in the cylinder 92 may be varied for anygauge wlre. used for tying and for any desired tie tension around the bundle.

When the desired pressure within the cylinder 92 has been attained and it is equaled by the tension of the wire W, continued flowoffluid into the cylinder causes it to move rearwardly against the pressure .of spring 100. When the cylinder depresses the spring 1100 thearm 106 closesswitch'104 to actuate the knottingmechanism 24 to form the knot in the tie. After the knot has been formed, the knotter actuates other means, which will be more fully explained hereinafter in the description of the control circuitshown in Figure 10, to de-energize cylinder 92 and cause retraction of piston rod 90. 7 Upon retraction, piston rod 90, through bracket82, retracts bar 56 to move roller 58 substantially out of the slot causing for receivin'g a ;rod9;8 which is attached to and projects from the head of cylinder 92. A helical spring 100 is'circumferentially mounted on rod 98 with one end bearing against the shoulder in opening 96 tformed by the counter;

the movable jaw 62 to move downwardly away from fixed jaw 64. and release the wireW. As thebracket 82 continu'es to retract bar '56 the leg '80jof the bracket 82 bears against the rear end of slot 78 and moves the block 29gback to its retracted and inactive position and the spring-loaded ball 108 is again engaged by notch 1110. The tensioner isthen ready for the nexttensioning eyele.

I A control circuit for the tensioner-of the invention is illustrated diagrammatically in- Figure 10 and functions as follows. The pressure fluid for cylinder 92 is delivered from a reservoir 120 by a pump 122 under the control of a solenoid operated valve I124. Valve 124 isoperated automatically in one direction or another from a neutral position by solenoids 126 and 128, Thus, valve124 controls projection or retraction of-piston' 'rod90.; The adjustable pressure-reducing valve {118 in the supply line to the cylinder 92 controls the amount bf'press ure in the cylinder as described above. v

- During that part of the tying cycle of machine 2 wherein the leading end of the wire W is gripped in gripper 23 and the wire is being retracted to strip it from guide track 110 and draw it loosely around the package, a switch 130 is actuated by the tiltable gripper 23 to close a contact 2132. This completes a circuit to and energizes solenoid coil 128 to move the spool of valve 124 to the left to allow pressure fluid to flow into the cylinder 92. This causes piston rod 90 to be projected and the wire W to be tensioned and drawn t-aut around bundle B. After the wire W has been tensioned to the desired degree cylinder 92 moves rearwardly depressing spring 100 and tripping switch .104 causing it to close completing a circuit to a coil 134 which in turn initiates action by the knotter 24. After the knot has been formed in the tie, the knotter causes switch 130 to be again actuated to open contact '132 and close contact 1136. Opening of contact 132 causes de-energizing of solenoid coil 128 and closing of contact 136 causes energizing of coil 126. Energization of coil 126 causes the spool of valve 124 to move to the right to reverse the flow of pressure fluid to'the cylinder 92 causing the piston rod 90 to retract. Relieving pressure in cylinder '92 causes the tensioner to move back to its normal retracted and inactive position as shown in Figures 2, 3, 4, 8 and 9 and the switch 104 to reopen.

While one embodiment of our invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

We claim:

1. In a wire-tying machine including a table adapted to support an article to be tied, a tensioner for tightening a tie wire drawn about the article, said tensioner comprising a block slidable parallel to said table, a wire gripper mounted on said block including a movable jaw, said block having a fixed jaw with which the movable jaw coacts, a fluid-pressure motor for reciprocating said block, said motor being free for axial movement in one direction, yieldable means constantly urging the motor axially in the other direction, and means whereby said fluid-pressure motor causes movement of said movable jaw on the block toward the fixed jaw before it actuates the block.

2. Apparatus as defined by claim 1 including switch means actuated by bodily movement of the motor.

3. In a wire-tying machine including a table adapted to support an article to be tied, a tensioner for tightening a tie wire drawn about the article, said tensioner comprising a block slidable parallel to said table, a wire gripper mounted on said block including a movable jaw,

said block having a fixed jaw with which the movable jaw coacts, means for reciprocating said block, said block having a recess therein parallel to its line of travel and a guideway transverse to and intersecting said recess, said movable jaw being slidable in said guideway, a slide bar movable in said recess, and means actuated by movement of the slide bar in the block whereby said block-reciprocating means causesmovement of said movable jaw on the block toward the fixed jaw to set said gripper before it actuates the block in one direction and causes movement of said movable jaw on the block away from the fixed jaw to release said gripper before it actuates the block in the opposite direction, said slide-bar-actuated ,6 means including a cam surface onsaid movable jaw and a roller on said slide bar engaging said camsurfacea:

4. In a wire-tying machine including a table adapted to support an article to be tied, a tensioner for tightening a tie wire drawn about the-article, said tensioner comprising a block slidable parallel .to said table, a'wire gripper mounted on'said 'blockihcluding. a movable jaw, said block having'a fixed jaw' with which the movable jaw coacts, tubular wire-guiding passages on opposite sides of said jaws, tubular wire-guiding members, on the block extending in opposite directionsfrom said .jaws and in telescoping relation withsaid. passages, means for .reciprocating said block, and. means whereby saidxblockreciprocating means causes movement of said movable jaw on the block toward the fixed jaw before it actuates the block.

5. In a wire-tying machine including a table adapted to support an article to be tied, a tensioner for tightening a tie wire drawn about the article, said tensioner comprising a block slidable parallel to said table, a wire gripper mounted on said block including a movable jaw, said bloc-k having a fixed jaw with which the movable jaw coacts, a fluid-motor for reciprocating said block, a frame plate normal to said table, means secured to said frame plate mounting said motor, a guide rod carried on said frame plate parallel thereto, said block having a bore through which said rod extends, said block being slidable on said rod, and means whereby said motor causes movement of said movable jaw on the block toward the fixed jaw before it actuates the block.

6. In a wire-tying machine including a table adapted to support an article to be tied, a tensioner for tightening a tie wire drawn about the article, said tensioner comprising a block slidable parallel to said table, a wire gripper mounted on said block including a movable jaw, said block having a fixed jaw with which the movable jaw coacts, a fluid motor for reciprocating said block, a. frame plate normal to said table, means secured to said frame plate mounting said motor, said motor being free for axial movement in one direction, yieldable means constantly urging the motor axially in the other direction said block having a longitudinal slot inthe bottom thereof, a vertical guide roller on said frame plate fitting in said slot for guiding said block during reciprocation thereof, and means whereby said motor causes movement of said movable jaw on the block toward the fixed jaw before it actuates the block.

7. In a wire-tying machine including a table adapted to support an article to be tied, a tensioner for tightening a tie wire drawn about the article, said tensioner comprising a block slidable parallel to said table, a wire gripper mounted on said block including a movable jaw, said block having a fixed jaw with which the movable jaw coacts, a fluid-motor for reciprocating said block, a frame plate normal to said table, means secured to said frame plate mounting said motor, said motor being free for axial movement in one direction, yieldable means constantly urging the motor axially in the other direction means whereby said motor causes movement of said movable jaw on the block toward the fixed jaw before it actuates the block, and a detent resiliently projecting from said frame plate and engaging said block for yieldably restraining reciprocal movement of said block in one direction while said motor causes movement of said movable jaw on the block toward the fixed jaw before it actuates said block.

8. In wire-tying machine including a table adapted to support an article to be tied, a tensioner for tightening a tie wire drawn about the article, said tensioner comprising a block slidable parallel to said table, a wire gripper mounted on said block including a movable jaw, said block having a fixed jaw with which the movable jaw coacts, the opposed surfaces of said fixed and movable jaws being of tongue and groove conformation, means for 'to supportaan article to ,saidmotor and-said movable jaw, respectively,

reciprocating said 21510014,; and means; whereby said blocki 9. In l a :rwire-tving gmachine including a. table. adapted .beltied, altensioner for tightening a tie .wire drawnrabout the; artic1e,i saidrtensioner comprisinga block :sli'dable par allel tosaid tab1e,- said block having' aguideway thereini nor-maltousaid' table, a wire grippercarried by: said block: includinga movable jaw slidable in said guideway; said .blockhaving a fixed jaw with which the movable'jaw.coacts,a:.fiuid:pressure motor for reciprocatingsaid lblock, and-cooperating wedging-rneans on whereby 8 7 said r'notor'cause's movement of saidm'ovable jaw onythe block toward the fixed jaw. before itysactuates the block; 10;.'."App1aratus as defined by e1aim.9; characterized, by. saidblock having a recess .therein parallel to its lineof; travel and intersecting .said guideway,v and a :slide ban movable; inzsa'id recess, said motorbeing connected with said sliderbar, one of said wedging-meansbeing' a! roller carried by. said-slide bar.

I i i References Cited in the file of this patent i [UNITED STATESPATENTS 2,416,859- 1 vim-11g et a1. Mar. 4,1947- 2,624,270

- Sykes Jan. 6, 1 953"

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