US 3604192 A
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Description (OCR text may contain errors)
United States Patent  Inventor Oscar G. Garner Riverside, Conn.  Appl. No. 846.074 122] Filed July 30, 1969  Patented Sept. 14, 1971  Assignee General Cable Corporation New York. N.Y. Continuation-impart of application Ser. No. 524,243, Feb. 1, 1966.
 TELEPHONE CABLE ASSEMBLY SYSTEM 7 Claims, 12 Drawing Figs.
 U.S. Cl 57/3, 57/13, 57/59, 57/66  Int. Cl H011) 13/02, H01b 13/08  Field of Search 57/3,6, 13, 14, 59, 66, 66.5
 References Cited UNITED STATES PATENTS 1,911,925 5/1933 Reed 57/66.5X
2,815,638 12/1957 Curtiss et a1. 57/3 X 2,933,880 4/1960 Pliaro 57/66.5 3,024,588 3/1962 Reichelt et al.. 57/66.5 3,030,762 4/1962 Pizzi 57/66.5 3,091,074 5/1963 Demmel 57/66.5 X 3,251,179 5/1966 Reichelt 57/66.5
Primary Examiner-John Petrakes Attorney-Sandoe, Hopgood & Calimafde ABSTRACT: This specification discloses apparatus for winding strand units into a single cable, taping the cable and winding it on a revolving takeup cabler. The strand units pass directly from a spacer or lay plate to a twist compensator which winds the cables to a desired lay and which has wheels gripping the assembled strand units from opposite sides with sufficient force to twist them together but with the wheels on PATENTEI] SEP] 4191:
SHEET 1 UF 3 INVI'INTOR. OSCAR G.GARNER SQS: Eb 8.3
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I sum 2 OF 3 OSCAR G.GARNER 266 246 BY M mun... want ATTORNEYS.
PATENTED SEP] 4 l97| SHEET 3 0F 3 FIG. 9.
POWER LINE 1/306 INVENTOR ATTORNEYS.
TELEPHONE CABLE ASSEMBLY SYSTEM This application is a continuation-in-part of application Ser. No. 524,243, filed Feb. I, 1966, now abandoned.
' BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to the manufacture of telephone cables.
It is an object of the invention to provide improved apparatus for bringing together strand units, commonly known as telephone cable units, each of which is preferably made up of 25, 50 or 100 wire pairs, depending upon the size of the wire, and for twisting the strand units into a cable, taping the cabled strand units, and winding the cable on a reel. Some features of the invention can be used with apparatus where the strand units are single conductors or wire pairs.
Another object is to provide apparatus of the character indicated with constant tension payoffs for the strand units. A
constant tension payoff is advantageous when used in a system;
that has a capstan, but is a necessity and has outstanding advantages in' retaining constant tension in all of the telephone cable strand units irrespective of load, acceleration and deceleration of the machine, and other variable factors, and facilitates the assembly of strand units, cabling the units together and wrapping the assembly with tapes without requiring the use of a capstan in the system.
Another object of the invention is to facilitate the taping of the cable and to maintain uniformity of the tape lay by providing a twist compensator ahead of the taping station. This compensator prevents any twisting or tension from developing between the compensator and the takeup cabler on which the taped cable is wound on a reel. This makes possible a constant lay application of a paper tape by an essentially conventional taping head using a pad of the necessary size.
Still another object is to combine the revolving takeup cabler with a twist compensator having synchronous operation with the revolving takeup cabler, or overfeed at a slightly higher speed of from one-half percent to 1 percent. This slight excess of speed may be considered synchronous operation. The twist compensator holds the cable against further twisting as the result of the revolving movement ofthe takeup cabler.
Still another object of this invention employing the revolving cable takeup, the motor operated compensating taping head for the application of the belting tapes over the core, and the motor operated compensating payoff for the telephone cable units, is the ability of reversing the machine operation, facilitating the untwisting of the assembled cable and unwinding the tapes and cable units on both the respective taping head and payoffs. The machine can be reversed to perform in both directions if this proves necessary or advantageous for correction.
Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.
BRIEF DESCRIPTION OF'THE DRAWING In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views:
FIG. 1 is a diagrammatic assembly view of a telephone cable assembly system made in accordance with this invention;
FIG. 2 is an enlarged diagrammatic view of a portion of the system shown in FIG. 1 but with certain structure shown in greater detail;
FIG. 3 is an end view, on a greatly enlarged scale, of one of the constant tension payoffs shown in FIG. 1;
FIG. 4 is a top view of the apparatus shown in FIG. 3 with part of the apparatus shown in section on the line 44 of FIG.
FIG. 5 is a side elevation of the apparatus shown in FIGS. 3 and 4, the view being taken from the right of FIGS. 3 and 4 and being partly broken away along the section line 55 of FIG. 3 to show the supports for the reel;
.substantially FIG. 6 is a sectional view, on a greatly enlarged scale, taken on the lines 66 of FIG. 1, and is a sectional view on the same scale on the line 6-6 of FIG. 7;
FIG. 7 is a greatly enlarged sectional view of the rollers and supporting frame of the twist compensator shown in FIGS. 1 and 2; 1
FIG. 8 is a top plan view of the twist compensator structure shown in FIG. 7; H
FIG. 9 is an enlarged, diagrammatic, side elevation of tension control apparatus for the taping head shown in FIGS. 1 and 2; I
FIG. 10 is a diagrammatic plan view of the course of the tape in the apparatus shown in FIG. 9;
FIG. 11 is an enlarged, fragmentary, sectional view on the line 1 l ll of FIG. 9; and
FIG. 12 is a wiring diagram for the control circuit of the tape reel motors of FIGS. 9 and 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The telephone cable assembly system shown in FIG. 1 includes a payoff section 10 having a plurality of individual payoffs 12 from which strand units of insulated paired wires 14 are supplied through a lay plate or separator plate 16 to a twist compensator 18. The strand units 14 are twisted into a cable by the twist compensator l8 and the cable, indicated by the reference character 14a, travels from the twist compensator through a taping head 22 which applies a spiral wrap of tape 24 to the cable 14a. The wrapped cable, designated by the reference character 14b, then passes into a revolving takeup cabler 28 which rotates in the same direction as the twist compensator 18 and at substantially the same speed.
The revolving takeup cabler 28 includes a frame 30 rotatably supported at one end by idler rollers 32; and this frame 30 has its other end supported by a fixed bearing 34. The frame 30 is driven by power means including an electric motor 36 which transmits motion to the frame 30 through an endless belt or chain 38.
A reel 39 is carried by the frame 30 on stud axles 40 which can be projected into the hub of the reel 39, or withdrawn from the hub, by motors 42 operating motion-transmitting connections 44. Thus successive reels 39 can be inserted into the frame 30, and while in the frame 30, each reel 39 is rotated about the axis of the axles 40, by a motor which drives one of the axles 40, to pull the cable 14b through the system. The reel 39, also rotated about the axis of rotation, designated by the reference character 46, of the frame 30.
There are guide rollers 52 on axles supported by the frame 30 near the end of the frame through which the cable 14b enters and these guide rollers 52 define a roll pass substantially concentric with the axis 46 and from which the cable 14b moves angularly as it wraps in successive convolutions axially along the reel 39.
The taping head 22 may be of substantially conventional construction. It includes two reels of paper, or other tape, and these reels are carried by axles 72 on a frame 64 which rotates about the axis 46 of the system. It will be understood that the frame 64 is supported by bearings at fixed locations and such taping heads are well understood. In the system illustrated, there is a measuring device 66 located between the taping head 22 and the revolving takeup cabler 28 for measuring the length of cable supplied to the revolving takeup cabler.
The twist compensator 18 includes a plurality of upper rollers 70 rotatable as idlers on axles 72 carried by a common frame 74. The twist compensator also has lower rollers 76 on axles 78 carried 'by a frame 80 and these rollers 76 preferably rotate as idlers.
The frames 74 and 80 are urged together, by mechanical means, which will be described in connection with oneof the other FIGS., to grip the strand units 14 which are pulled into the twist compensator from the separator 16. The frames 74 and 80 are carried in a revolving frame 84 supported by suitable bearings for rotation about the axis 46.
This frame 84 is driven, by the motor 36, through motiontransmitting means including a shaft 88, a transmission 90 and a belt or chain 92.
The same shaft 88 preferably drives the taping head 22 through a transmission 94 and a belt or chain connection 96.
In the payoff section 10, each of the payoffs 12 supports a reel 98 from which a strand unit 14 is supplied to the system.
Each strand unit may consist of 25, 50 or 100 wire pairs, in accordance with conventional telephone cable practice.
Power is supplied to each of the reels in the payoff section but this power is for the purpose of overcoming the friction, weight, and moment of inertia of the payoffs and it is not sufficient to feed the strand units 14 from the payoffs. A predetermined and controlled pull or tension on the payoffs is required; and in the system illustrated this tension is supplied by the wrapping of the cable 14b on the reel 39. By having means at each payoff 12 controlling the power supplied to each payoff in such a manner as to maintain each strand unit 14 under constant tension, it is practical to operate the system without the usual capstan for pulling the cable without deformation normally caused by the capstan and with the utmost uniformity of tension in the cable. The elimination of the capstan is one of the new results obtained by this invention, but features of the invention can be used in systems which employ a capstan.
All of the power driving means can be reversed so that cable unwinds from the takeup cabler 28, and passes backward through the taping head 22 which unwraps the tape and rewinds the paper tapes on the reels 60. Conventional torque motors can be used to maintain the tension on the tapes unwound from the reels 60, these motors turn the wheels in a direction to rewind the tape when the power driving mechanism is reversed to unwind the cable as will c more fully explained in describing FIGS. 912. The twist compensator, when its rotation is reversed, untwists the cable or strand units so that they pass back through the lay plate or separator 16 and rewind on the spools of the payoffs. When reversing the motors that turn the spools of the payoffs, the power to these motors is increased somewhat to provide the necessary pull for rewinding, but the tension control still operates.
FIGS. 3, 4'and 5 show one of'the payoffs 12. Each payoffincludes a fixed frame 102 which rests on a floor or other support. The frame 102 has an arm 104 connected to each side by a pivot bearing 106; and at the other ends of the arms 104 there are bearings 108 and 109 for supporting the reel 98 on which the strand units are wrapped.
At one end of the reel 98, there are fingers 110 which project onto openings in one end of the reel 98 for causing the reel to rotate as a unit with a flange 112 which is an integral part of an axle 114 extending through the bearing 109. i
A sprocket 116 is secured to the outer end of the axle 114 and this sprocket 116 is driven from a smaller sprocket 118 by an endless chain 120. The sprocket 118 is keyed to ajackshaft 122 to which there is fastened another sprocket 124 driven by a chain 126 from a sprocket 128 on an armature shaft 130 of an electric motor 132 secured to the fixed frame 102 of the payoff.
The jackshaft 122 has its axis coincident with the axis of the pivot bearing 106 about which the arms 104 move. This makes it possible to swing the arms 104 without changing the length of the driving chains I and 126. The arms 104 can be raised and lowered when successive reels 98 are to be removed from the payoff and replaced.
This raising and lowering of the arms is accomplished by means of cylinder and piston motors 136, best shown in FIGS. 3 and 5, connected to the frame 102 by a pivot 138, and connected with the arms 104 by another pivot 140.
The strand unit 14 unwraps from the reel 98 and passes around a caster pulley 144. This caster pulley 144 is supported by a horn 146 and bracket 148 which swing about a vertical pivot 150 supported from a fixed bracket 152 extending from the main frame 102 of the payoff. Thus the caster pulley 144 can swing into line with the strand unit regardless of the particularportion of the reel 98 that the strand unit may be coming from at any particular time. There is guard 154 extending around a substantial angular portion of the lower part of the pulley 144.
After passing around the caster pulley 144, the strand unit 14 travels upward to a guide pulley 158. This guide pulley rotates about an axle supported by a bearing 162 on a part of the fixed main frame 102. Beyond the guide pulley 158, the strand unit passes around a tension control pulley rotatably supported by an axle 172 at the upper end of an arm 174 which is attached to the main frame 102 by a fulcrum bearing 176.
The arm 174 extends for some distance below the fulcrum bearing 176 and is connected with a tension spring 178 (FIG. 5 connected at one end to an anchor 180 on the arm 174 and at the other end to a yoke 182 at the end of a bolt 184 extending through a fixed bracket 186 rigidly attached to the fixed frame 102 of the payoff. A nut 190 can be screwed one way or the other along the bolt 184 to regulate the tension of the spring 178.
The payoff is oriented so that the pull on the strand unit 14, as the strand unit is drawn into the system, tends to rock the arm 174 counterclockwise about its fulcrum bearing 176, as the arm is viewed in FIG. 5. Thus the pull on the strand unit 14, as indicated by the arrow 192, is counter to the force of the spring 178 and the position which the arm 174 will occupy at any particular time depends upon the balancing of the pulling force 192 and the tension of the spring 178.
It will be evident that the amount of tension required to pull the insulated cable strand unit 14 away from the payoff depends upon the extent to which the torque of the motor 132 overcomes the friction and any other resisting factors which oppose the unwinding of the strand unit 14 fromthe reel 98 and the friction which opposes the rotation of the pulleys 144, 158 and 170, and the advancing of the strand unit from these pulleys.
The tension is regulated, therefore, by changing the torque of the motor 132. This is done by providing a gear 200, best shown in FIGS. 4 and 5, which moves angularly as a unit with the a arm 174, and which meshes with a pinion gear 202 on an axle 204 of a rheostat 206 which regulates the torque of the motor 172. The rheostat 206 is connected with the motor 132 in such a way as to reduce the torque of the motor when the arm 174 swings clockwise in FIG. 5 and to increase the torque of the motor 132 when the arm 174 swings counterclockwise. By adjusting the tension of the spring 178, the amount of tension on the strand unit to move the arm 174 into any particular angular position, can be regulated. Thus while the tension is uniform for any particular adjustment, it can be regulated by changing the adjustment of the spring 178.
The lay plate or separator plate 16 to which the strand units travel from the different payoffs 12, is preferably a plate having a separate opening for the strand unit from each of the reels 98. This separator 16 thus keeps the strand units at a uniform spacing from one another until they pass beyond the plate 16 and thus insures that all of the strand units are brought together in the twisting operation within the same length of run so as to obtain uniform results.
FIG. 2 shows the strand units 14 coming into the twist compensator 18. This FIG. shows a fixed frame 212 for supporting the twist compensator from the floor or other underlying support and shows a bracket 214 by which the separator 16 is supported from the frame 212. There is a fixed cage 220 over the revolving frame 84 of the twist compensator, and the revolving frame turns in bearings 224 which are supported by the fixed frame 212. There are sleeves 226 at both ends of the revolving frame 84 and these sleeves are welded to, and form a part of, the revolving frame 84.
The sleeve 226 at the downstream end of the revolving frame 84 is secured to a gear 230 concentric with the sleeve 226 and with the axis 46. The gear 230 is driven by another gear 232 on a jackshaft 234 which is, in turn, driven from the shaft 88 by the belt or chain 92 passing around a pulley or sprocket 236 on the jackshaft 234.
Further details of the twist compensator are shown in FIGS. 6, 7 and 8. The upper frame 74 has four openings 246 through which parallel rods 248 pass. These rods 248 have, athreaded portion 251 with a right-hand thread and a threaded portion 252 with a left-hand thread. The lower threaded portion 252, of each of the rods 248, screws through an opening 254 in the lower frame 80. The upper threaded portion 251 of each the rods 248 threads through a thrust element 256 which is attached to the upper frame 74 by screws 258.
Each of the parallel rods 248 has a thrust bearing 262 at its lower end for preventing downward movement of the rod, 248 with respect to the frame 84; and each of the rods 248 has an upper thrust bearing 264 for preventing upward movement of the rod with respect to the frame 84. There is a sprocket 266 secured to the upper end of each of the rods 248. A chain 268 passes around all of the sprockets 266, as shown in FIG. 8, so that all of the sprockets 266 turn in unison. Another sprocket 270 engages the outside of one run of the chain 268 at a location between two of the sprockets 266 and this single sprocket 270 maintains the chain 268 under tension and can be rotated by av screw driver inserted into a slot 272 for the purpose of moving the chain 268 one way or the other to turn the sprockets 266 and avoided asconnected rods 248.
Referring again to FIG. 7, rotation of the rods 248 in one direction causes the threads 251 and 252 to draw the frames 74 and 80 closer together. In the preferred operation of the twist compensator, the frames 74 and 80 are brought toward one another until the circumferential faces of the rollers 70 and 76 grip the assembled strand units between them with sufficient force to twist the strand units into a cable as the strand units advance through the twist compensator.
In the illustrated construction, the upper rollers 70, which contact with one side of the strand unit assembly whilethe lower rollers 76 contact with theother side of the assembly, are staggered so as to permit relative movement of the strand units with respect to one another as they are twisted into a cable.
The twist compensator frame 84. is preferably rotated at substantially the same speed as the revolving takeup cabler to which the cable passes and by which he cable is pulled through the twist compensator. There is some advantage in having'the twist compensator rotated slightly faster than the revolving takeup cabler; for example: one-half percent to 1 percent faster, so as to insure that thecable will be held against relative movement of the strand units, as the result of the revolving takeup cabler pull beyond the twist compensator and after the application of the tape to the cable. This excess of speed or overfeed is obtained by means of the transmission 90, already illustrated in FIGS. 1 and 2, which has the gear ratio selected to obtain a slight gain in speed.
FIGS. 9 and 10 show control means for maintaining the tension of the tapes 24 as they come from the reels 60. Each tape passes around a guide roll 280 and then reverses its direction around a dancer roll 282 which rotates on an axle 284 extending downward from a carriage 286 that slides along a track consisting of rods 288 which extend generally parallel to the direction of movement of the cable through the apparatus.
From the dancer roll, the tape 24 extends successively around other guide rolls 290, 291, 292 and 293 to the cable around which the tape winds, or unwinds, depending upon the direction of operation of the apparatus. A spring 296 urges the carriage 286 and the dance roll 282 in a direction to increase the loop of tape that extends from the roll 280 around the dancer roll 282 to the roll 290.
If the tension in the tape 24 increases, the carriage 286 moves to the right in FIG. 9 along the rods 288. Conversely, any decrease in the tension of the tape permits the loop of tape to increase, and the spring 296 moves the carriage 286 toward the left in FIG. 9. The tension controller for the lower tape in FIG. 9 includes a torque motor 298 which urges rotation of the tape reel in a direction to supply tape, or which turns the reel in a direction to wind tape back from the cable when the apparatus is reversed.
Motion of the carriage.286,in;response to change in the tension of the tape, is-transmittedto thetensi change, the, power supplied to the torque mot change the direction in whichthe motor 298. tend to turn.
, respectively These collector rings 32 1, 322, and 323 arecarried by the taping head 22 and areconcentric with the axis of rotation of the taping head. I
A brush 325 of the powerstat operates over a sector 326 having taps at its opposite ends connected with conductors 328 and 330 of the controller circuit/The brush 325' at its center of rotation is connected with one end of a coil 332; and a center tap 333- of the sector 326 is connected with the other end of the coil 332 and with another coil 334.
When the tension in the tape rises and the dancer roll loop decreases in length, the, brush 325. moves toward one end of the sector 326 to increase the. power of the motor 298 to rotate the motor 298 in a direction to turn the tape reel to unwrap. As the tape tension decreases, the, dancer roll moves the brush 325 toward the center tap 333 and progressively decreases the. torque of the motor 298. When the motor torque is less than the. friction of the reel and tape, the pull of the cable in wrapping the tape supplies tension.
Ifthe apparatus stops or is reversed, there is no longer any pull on the tape by the cable. In fact, the tape unwinds from the cable when the apparatus is reversed. This increases the length of the, tape in the dancer roll loop and the resulting movement of the dancer roll causes the powerstat brush 325 to move toward the other end of its sector 326 beyond the center tap 333 to reverse the torque of the motor 298 to rewind the tape on the reel. Further decrease in the tension causes an increase in the power of the torque motor to rewind the tape faster and thereby increase the tension in the tape.
The second tape reel on the taping head is driven by a torque motor 298' which iscontrolled by a tension controller similar to that of the motor 298 and corresponding parts. are
indicated by the same reference characters with a prime appended. Each torque motor 298 and 298' has its own dancer roll and powerstat, but power for both of the motors and its tape tension control is supplied through the same brushes 311,
312 and 313 and the same slip rings 321, 322 and 323 (FIG. 9-).
The preferred embodiment of the invention has been illustrated and described, and the invention is defined in the appended claims.
I. A telephone cable assembly system having successive operating stations including in combination a payoff comprising a plurality of spool holders for supporting spools each of which has a strand unit wound thereon, means for maintaining the strand units under substantially uniform tension as they come from the spool holders, a separator plate station with separated guides through which different strand units pass, said guides holding the strand units spaced from one another as they advance toward the nest station, a rotating twist compensator at the next station beyond the separator plate and constituting the next structure with which the strand units contact after passing through the separator plate, said twist compensator including a plurality of successive wheels having rolling contact with the strand units to eliminate longitudinal friction while bringing the strands together and gripping the strand units with force for twisting said units, a revolving takeup cabler, and a taping head between the compensator and the takeup cabler, means for rotating the compensator at substantially the same speed as the takeup cabler, said compensator and takeup cabler constituting means for twisting the strand units. together into a cable. I
2. The telephone cable assembly system described in claim 1 characterized by power means for driving the takeup cabler and the twist compensator simultaneously and at substantially the same angular speed of rotation, the power means including a common motorrand, motion-transmitting connections throughewhich the motor rotates lthe twist compensator at a slightly higher speed than that ofthe takeup cabler.
3. The telephonecable assemblysystem described in claim 1 characterized by the payoff havingtpower means for supplying at least part ofthe; power reqniredv to operate the payoff, and all of the additionalIpower required for advancing the cable from the payoff ;to the takeup cabler being supplied by thepull of the takeup cabler on the cable. 4. The telephone cable assembly described in claim 1 characterized by including in combination a revolving takeup cabler on which the cabler winds, twisting means through which strand units pass and that twist the strand units together into a cable, means for driving the twisting means at substanstaggered in the direction of the length of thestrandunits whereby the strand units have relative movement with respect to one another as they are twisted into a cable, a payoff having a plurality of separate units each of which comprises a frame having means for rotatably supporting a reel on which strand units consisting of wire pairs are wound, a grooved castor wheel on the frame to which the strand units run and over which said strand units pass as they unwind from the reel, guide wheels over .which the strand units pass beyond the castor wheel including a final guide wheel across which strand units from the payoff pass on their way to the twisting means, an arm on each payoff unit angularly movable about an axis and with respect to said frame and by which the final guide wheel is carried, a spring urging the arm to swing one way about said axis, by increase in the pull on the strand unit away from the payoff unit, and a motor that supplies power to rotate the reel supported by the frame, means in the electric circuit 'of the motor including a device operably connected with the arm and movable: with the arm in a direction to decrease the power supply of the motor when the arm'is moved in one direction by; the spring and to increase the power supply of the motor when the arm is' moved inth opposite direction by an increase in the pull onthe strandunit.
5, A telephone cable assembly system Including Pal/Offs for a plurality ofindividual cableunits, a lay plate, a twist compensator beyond the layplate for winding the cable units into a cable, a taping headincluding a tape supply reel from which a tape wraps ,onlthe cable, a takeup cabler beyond the taping head, means for rotating the twist compensator and takeup cabler at substantially the same .angular speed, and reversable driving means for said payoffs, winding apparatus and taping head operable to unwind the tape from the cable back onto the tape supply reel, and to disassemble the cable units from the cable and to return them to the payoffs.
6. The telephone cable assembly system described in claim 5 characterized by the taping head having a motor means for driving the tape supply reel, and control means responsive to the tension of the tape between the reel and the cable for operating the motor means in a direction to rewind the tape on the reel when the tension in the tape is relaxed by reversal of the assembly.
7. The telephone cable assemblysystem described in claim 6 characterized by the motor means having a torque electric motor, and the control means including guide means around which the tape passes as it travels from the reel to the cable to form a loop of tape, a dancer roller in contact with the tape of said loop and that .is movable in response to chan es of the tape m said loop, and an electric circuit with a rush that moves with thevdancer roller into positions to operate the motor in a direction to assist the unwinding of the tape when the tension is above a predetermined value and to reverse the motor and increase the reverse force of the motor progressive ly as the tension of the tape in the loop drops below said predetermined value. t
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 604 192 Dated eptember 14 l 971 Oscar G. Garner Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 3, line 34, "e" should read be Column 4, line 41, "a arm" should read arm Column 5, line 23, "avoided as" should read their Column 6, line 65, "nest" should read next Signed and sealed this 1st day of August 1972.
EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM PC4050 (10-59) USCOMM DC 60376 pee U 5 GOVERNMENT PRINTING OFFICE I969 O36G-J3l,