US2312121A - Tube bending jig - Google Patents

Description

Feb. 23, 1943. A. L. PARKER ET AL TUBE BENDING JIG 4 Sheets-Sheet 1 Filed March 31, 1941 Feb. 23, 1943. A; L. PARKER ET AL TUBE BENDING JIG Filed March 31, 1941 4 Sheets-Sheet 2 Q um m WO TH Feb. 23, 1943. A. 'L. PARKER ET AL TUBE BENDING JIG 4 Sheets-Sheet 4 Filed March 51, 1941 Feb 23,

' umrso STATES PATENT OFFICE 2,812,121 I mnmnnvcnc I Arthur L. Parker and Henry E. Hull, Cleveland, Ohio; saidlluli alsignor to said Parker Application March :1, 1941, Serial Nasser The invention relates generally to the art of tube bending and primarily seeks to provide a simple and inexpensivelyconstructed bending .1 8

which will enable exact and accurate duplication or bent tubes regardless of the number of bends or the degree of each bend. or the relative relationship of the planes of the different bends to be made in said tubes.

It is the custom at the present time, in filling tion to provide a Jig structure including novel tube holding and bending eq ipments, and novel means, all adjustable, for locating the position of each bend, limiting the angular degree of each bend, and for setting the plane oi each bend relative to the planes of the preceding bends.

of two channel beams I disposed in parallel spaced relation and. secured, as at I, at one end to a cross bracket 1 and at the other end to a crossbracket I.

The cross bracket 1 includes an upward extension '8 supporting a boss I! in the bore of which a mandrel anchor rod II is adjustably secured as at II. A mandrel rod i3 is removably secured, as at it, to the anchor rod and carries a mandrel ii at its free end, said mandrel including a form tip it which is always placed at the bend point so as to bear within the tube while it is being bent, thereby to prevent flatt'ening of the tube during the bending thereof.

.At the other end, of the frame, and above the bracket 8, a cross bracket "is secured, as at ll, to the beams I. The cross bracket I1 is equipped with a transverse mounting slot is in which a with the above and other objects in view which will more iully appear, the nature of the inven- Figure 4 is a vertical cross section taken on the linel-lonFigureL I Figure 5 is an enlarged fragmentary vertical cross section taken on the line 5-'-I on Figure 2. Figure 6 is a vertical cross section taken on the line '6 on Figure 1. Figure '1 is a fragmentary vertical longitudinal section taken on the line 1-1 on Figure 1.

Figure 8 is a fragmentary vertical longitudinal section taken on the line H on Figure 1.

.Figure 9 is a fragmentaryvertical longitudinal section taken on the line l--l on Figure 1.

Figure 10 is a fragmentary longitudinal section illustrating a modified form of tube end stop.

Figure 11 is a fragmentary side elevation illustrating a modified form of clamp handle.

In the tube bending jig structure herein disclosed asanexample of embodiment of the inon said pin. The block 22 is grooved 'atits periphery, as at 23, and includes a tangential extension 24 which is similarly grooved. It is to be understood that the radius blocks 21 are selective, that is, blocks of different sizes are provided and the one to be used is selected according to the radius of the bend or bends desired and the diameter of the tubes to be bent. For this purpose also the mounting pin 2| is adiustably mounted in the cross slot is so that the selected radius block can be made to properly line up with the tube and mandrel. A link 25 is pivoted, as

at 2G to the block 22, and as at 21 to a clamp lever II, said lever having a grooved clamping portion 20 which is opposed to the grooved tangential extension 24 of the selected radius block in the the drawings.

A mounting ear ill projects from each end of the cross bracket l1, and each of these cars is equipped with taps II to receive pivot screws 32,

one of which pivotally mounts a vise lever 33 vise slide block 38 having a tube face receiving groove of distinct size in each of the four faces thereof as indicated, in Figures 1 and '6 of the 'vention, there'is included a base frame composed drawings. The block ll hastong'ue and groove connection, as at 40, with the vise block 35 so as to prevent inadvertent displacement thereof.

A stop bail 4| is provided toward the end of the machine at which the bracket 1 is included, and it will be observed by reference to Figure 4 of the drawings that the main body portion of this bail is generally circular in form and extends approximately 240 about the axis of the mandrel rod i3. The ball includes side arms 42 which are adjustably secured, as at 43, to the side beams 5. A stop pin 44 is mounted on the main body portion of the bail and extends radially inward therefrom in the manner illustrated in Figure 4.

Other similar bails 45 and 4B are disposed in spaced relation along the side beams. These balls are shaped and mounted in exactly the same way as is the ball 4 I, but they differ from the bail 4i in that the external surfaces thereof are equipped with stop adjustment facilitating scales 41, and instead of a fixed stop pin such as the pin 44 carried by the bail .4l, each of the balls 45 and 46 carries an adjustable stop 48 equipped with a yieldable spring stop element 49 in the manner best illustrated in Figures 1, 2 and of the drawings.

A shaft 50 is rotatably mounted at its ends, as at M, in the brackets 'I and 8, said shaft extending centrally between the beams 5 in the manner illustrated in Figures 1 to 4 of the drawings. A handle 52 is fixed upon the end of the shaft which projects through the cross bracket 8, and this handle is engageable with stop pins 53 mounted, as at 54, at opposite sides of the bracket 8 in the manner.best illustrated in Figures 1 and 3 so as to definitely determine rotative movements ofthe shaft II, in opposite directions, exactly 180 about the center thereof.

A bend positioning or gaging stop II is adjustably clamped, as at 50, to .the shaft ill in association with each of the balls 4|, 4! and 4|, and a bend angle limiting stop 51 is similarly secured, as at 5!, to the shaft 50 in association with each of the said balls and in longitudinally spaced relation to the stop I! in the manner, clearly illustrated in Fiugre 2. It will also be observed by reference to Figures 2 and 4 that the three stops 5! project diametrically-oppositely from the three stops I1. In other words, when the lever 52 engages one of the vshaft position 10 which may engage the end of the tube in the manner illustrated in Figures 2 and 8.

In Figure 10 of the drawings, there is illustrated an alternative tube end stop member which takes the form of an end abutment sleeve 1i mounted in the end of a clamp sleeve of the general form illustrated in Figure 8.

Another form of tube end stop may be provided, and this equipment is best illustrated in Figures 3 and 9 of the drawings. A bearing 12 is provided in the crossbracket I1 and rotatably supports a rod 13 having limiting collars l4 thereon, one of which is equipped with a spring detent- I! receivable in recesses 16 formed in the bearing hub, said detent and recess equipment serving to yieldably hold the rod in different positions of adjustment about the rod axis. An end stop member 11 is adjustably clamped to the rod and may be disposed as illustrated in Figure 3 of the drawings in position for engaging and determining the position of the end of the tube being initially mounted in the bending equipment.

In Figure 11 there is illustrated a slightly modiiled form of clamp lever 28 in which said lever includes an offset portion I8, the purpose of which determining stops I the three stops II will be projected upwardly, and when the handle is in engagement with the other position determining pin 53 the direction of projection of the stops" will be reversed and the stops 51 will be directed upwardly in the manner illustrated in Figure 2. Each stop 55 and the associated, adjacent stop 51 comprises a stop set.

A tube clamp 50 is provided and is slidably mounted, as at N, on the beams I. See Figures 1, 2 and 4. This support includes a sleeve hub I in which a gage sleeve 82 is rotatably mounted.

The. gage sleeve has an enlarged portion which extends beyond the hub portion ii and carries a pair of stop arms I projecting diametricallyoppositely from the sleeve and longitudinally oifset in the manner best illustrated in Figure 1.

A split clamp sleeve 44 is keyed, as at I, in the bore of the sleeve $2 and is flared, as at ,to engage a complementary receiving flare in the sleeve 62 in the manner best illustrated in Figure 8. The opposite end of the clamp sleeve 04 is externally threaded, as at 81, to receive a hand wheel 88, and it will be obvious that as the hand wheel is rotated on said threaded end extension claims.

only three bails 4|, 4! and 40, and associated stop will later become apparent.

In the foregoing description, there is described apparatus embodying means, all adjustable, for

locatingthe position of each bend, for determin-' ing the direction of the bend, for limiting the angular degree of each bend, and for setting the plane of each bend relative to the planes of the preceding bends. It is to be understood that the present disclosure is but an example of embodiment of the invention and that the details of construction and arrangement of the parts can be varied to suit different demands of use within the scope of the invention as defined in the appended It' will be readily understood that while equipment sets II, 51 are illustrated herein, these individual sets of equipments may be multiplied according to the number, the directionand the position of the bends to be made in a particular order of tubes. It will be understood also that the slide block 3! and the radius block 22 will be selectedgand positioned at one side or the other I of the pparatus according to the direction of bend and the size of the tube.

The tube may be properly located for positioning the first bend by several methods. It is e!- pccted that the great majority of tubes to be bent ,will be previously cut to the exact length and will also be relatively short, that is, perhaps-not more than'iive or six feet long. For such tubes it"will be possible to utilize the positioning stop I. engageable with the clamped end of thetube in the manner illustrated in Figures 2 and 8 of the drawings. AsiopsuchasisillustratcdinFigure 10 alsocouldbeusedinsuch cases.

As previously described the clamping sleeve I4 is held against rotation by means of the key I, and during clamping adjustments following the formation of one or more bends in the tube, the sleeve '42 maybe held against any rotational tendencies by being grasped in the hand of the with the sleeve the stop 55 is engaged withithe support 59 to which the tube is now clamped in proper position for forming the first bend so as to be engageable by that support for determining alike initial position of every subsequent tube prior to commencement of bending operations thereon. Following this inltialadjustment of parts, the balls 4|, 45 and 46, and the bail stop 48, are suitably positioned according to the number of bends to be made and the direction and positions thereof. The stop sets 55 and 51 are successively and alternately engageable by th support 59 in the manher and for the purposes hereinbefore stated and these stops are suitably positioned to control the formation of the desired tube bends. By thus adjusting the stops they can remain in said positions throughout the bending of all of the tubes of the order, and it becomes necessary only to shift the support 59 into successive'engagement with the stops and to utilize the shaft rocking handle 52, andto engage the stop arms 83 with the bail stop equipments in order to definitely gage all subsequent bending operations.

It should be understood that when the support 59 has been initially positioned against the first mentioned. stop 55, the bail 4| is adjusted along the beams 5 so as to place the stop pin 44 thereof for engagement by one or the other of the gage arms 63. The clamped tube 89 is first rotated to bring one or the other of said arms 63 into contact with the pin 44 in the manner illustrated in Figure 4. This registers the angular position of the selected arm 83 as zero degree with respect to the plane of the first bend, and the particular arm 43 thus registered may then be used in connection with the setting of the bending plane for succeeding bends.

In the bending of the tube, the handle 33 is moved from the dot and dash line position illustrated in Figure 1 to the full line position so as to hold the slide vise block 39 against the tube is which is engaged in the peripheral groove of the radius block 22 and clamped against said block by the clamp lever 28. It will be obvious that by swinging the lever 28 to the position illustrated in Figure 1, the tube will be bent about the turning radius block 22 in the manner illustrated in Figure l, and during this bending-operation the slide vise block 39 slides along on thesupporting shelf ll so that no abrasive contact with the tube occurs, and the mandrel tip l8 positioned at the bending point assures against flattening out of the tube. During the bending ofthe tube the support 59 which is clamped to the tube will slide After the completion of the-first bend in the tube, the tube is unclamped by movement of the lever 28, and the sliding block 39 may be disengaged by moving the lever 33 to the dot-and dash line position illustrated in Figure l. The

the handle 52 to thereby effectively position the stop 55 and to displace the stop 51 or turn the same downwardly. The support 59 is then slid along the beams 5 until its movement is stopped by the bend gage stop 58 associated with the ball 48. It is to be imderstood that in this newly shifted position of the parts the bail .4! is so placed that the stop 48, 49 thereon will be engageable by the particular gage arm 83 which has been selected as eifective during the first bend control operation, assuming, of course, that the second bend now to be made is to be made in any plane from zero to 180 from the plane of the first made bend. The clamped tube is then rotated until the selected gage arm 83 engages the properly positioned stop 48 which will determine the plane of the bend now -to .be made with respect to the plane of the previously made bend. With the parts now properly positioned for making this second bend, the shaft 50 is again rotated 180 by movement of the handle 52 to thereby displace the previously effective stop 55 and effectively position the stop 51 as indicated in Figure 2, the bending devices are positioned and actuated in the manner previously described and the bending operation is performed, and proper attainment of the intended degree of bend will be definitely determined by engagement of the support 59 with the properly positioned stop 51.

It is to be understood that should it have been intended to make a second bend from any plane from 180 to 360 from the plane of the will be permitted by the yieldable nature of the I stop portion 49.

It is to be understood that succeeding bends in the tube can be properly determined by the ball 46 and its associated stop equipments and any additional bail and complementary stop set equipments which might be included in the ap- Daratus.

.70 shaft 50 will be rotated 180 by movement of In some cases it may be desirable to make a bend of approximately to in one direction, and then a second bend close by and in the same plane but in the opposite direction. In order to avoid interference between the handle 28 and the first made bend; it may be desirable to provide this handle with an oifset as indicated at 18 in Figure 11. i

It is tails of structure and arrarmement of parts may be variously changed and modified without departing from the spirit and scope of my in- I vention.

I claim:

1. In a tube bending jig, a frame, tube bending means mounted on the frame, tube clamping means slidable along the frame for presenting a tube to said bending means and movcourse to be understood that the del ing means mounted ing' means-mounted on the-frame, tube clamp-*- lng'means slidable along the frameffor presentinga tube to said bendin'g'means'andmovable with;- the tube-as it is being-ibent, means-for accurately determining the'initial' positioninggof the tube in the clamping mean'sptwo stops successively engageable by the clamping means the first engaged stop serving to determino the position of the'bend'and the second engaged" stop serving to determine the" degree of bend; is

-. a: m. a tube bending 'jig, a' frame, tube new ing means-mounted on the frame operable .for

' bending .tubes to the right or to the left: aside movable support on whichthe-stops are-lonsitu'dinallyadjustably mounted-{and means :for moving said-movablesupport tit-alternately podtion'" the stops for engagement by Y clamping 3.'In atube bendins'jim -rframe, tube bendon the frame-operable for bending tubes to the-right or to the left as desired, tube clamping means slidable along the "frame for presenting a tube to said bending 'means'and movable with the tube as itis being bent, and-a plurality of sets ofstops disposed in longitudinally spaced relation along the frame for engagement by said clamping means each the first engaged onelof which serves to determine the position of a bend and the second ena set- "comprising two successively engageable stops mind one of which serves 'todetermlnethe de- 'gree'ofa'bend. a a In a tube bending jig; aframe, tube bending means mounted on the frame operable. for

bending tubes to the right of to the left as desired; tube clamping means slidable along the frame for presenting" a tube to said bending means and mo'vablewith the tube as it is being I 'bent','"a"plurality ofsets'of stops --disposed in.

-'longitudinally spaced relation along the frame i-for 'engagement" by said clamping means each 7 set' 'comp'rising two successively engageable stops 7 the" first engaged one of which serves to deter minethe position of a bend the second ensaged one of which serves to determine the de"- "gree ofa bend, "a shaft disposed longitudinally of the frame and carrying all said'stop sets, and

means forimovingthe shaft; about its axis to 1 selectively presentthe stops of said-sets for en- --ga'gement by saidclampingmeans;

5. In a tube bending jig, a frame, tube'bend- Y ing means mounted 'on'th mane" operable for 'gree of a bend, a gage arm equipmentas'sociated v with the tube clamping means and nnw'able long'itudinally ;tlierewi'th' 'a'nd*rntaftionaliywith the clamped tubafim'eans-associatedwithonesetof as :61- biscing the'benaw se-form d under 7 en to liof said one set" bfstop" sgauu means" assof- 'nga'geable b'yjsaid arm equipciatdwith at least dine subseduently' 'enmble "set of stops and somatic time gage equipment through movement of "the" clamped tube about its 'for'deterinining the emnant or the plane 'oib'en w befforiiied under 'eontroi mm e uyeameasw set or stops to the plane of the band, formed 'cbntrol of insane or sired, tube clamping means slidable along 'the frame for presenting a tube to said bending means and movable with the tubeas it is being I bent, a plurality of sets of stops disposed in ion"- gitudinally spaced relation along the frame for engagement by said clamping, means each set comprising two successively engageable stopsithe first-engaged one of which serves .to determine. the position of a bend and thesecond engaged.

one of which serves to determine the degree of a'bend, a-gage arm equipment associated, with the tube clamping means and movable longitudinally therewith and rotationally with the clamped tube, a ball at least partially encircling the tube in cooperative relationwith oneset of stopsand carrying a stop member engageable by said gage arm equipment for placing the bend to be formed under control of said one set of stops, and a ball at least partially encircling the tube incooperative relation'with at least one subsequently engageable set of stops and carry ing a stop member engageable by said gage arm through-movement of the clamped tube about its axis for determining the relation of the plane of bond to be formed under control of said subsequently engageable set of stops to the plane of the bend formed under control of said one set of stops, a rock shaft common to and supporting all of the stop sets and movable aboutn its, axis for'selectively presenting the stops of said sets.

for engagement by said clamping means, said bails being mounted'for selective adjustment along the frame, the stops .of said stop sets being mounted for individual adjustment along said shaft, and the stop carried by said second men'- tioned bail being mounted for adjustment about said bail. 1 v

'I. In a tube bending'jig, a frame, tube bending means mounted onthe frame operable for bending tubes to the right or to the left as desired, tube clamping means slidable along the frame for presenting a tube to said bending means and movable with the tube as it is being bent. a plurality of sets of stops disposed in'lon-' gitudinally spaced relation along the frame for engagement by said clamping means each set comprising two successivelyengageable stops the first engaged one of which serves to determine the position of a'bend and the second engaged one of which serves to determine the degree of a bend, a 8 88] arm' equipment associated with the tube cl mping means and movable longitudinally therewith; and rotationally with the clamped tube, [bail .at least partially encircling the tube in cooperative relation with one set' of stops and carrying a stop member engageable by said gage arm equipment for placing the to be formed under control of said one set of stops, and a ball at least partially encircling the in cooperative relation with at least one subsequently eiislge bie set of stops and carry;- ing a stop member engageable by aid gage arm.

'I-t'hrough-movement of the clamped tube about its was for determining the relation; of the plane 'of'bend to be formed under control of. said subseduently ensalu le set of stop to the plane of the bend formed under. control of said one of stops, a rock'snaft common, to and supporting all of the stop sets and movable about its axis for presenting tha'stops of said sets for-engagement by said clampins means, :said bails being mounted for selective adjustment means slidable along the frame for presenting a tube to. saidbending'means, means for accurately determining the initial positioning of the tube inthe clamping means, and means on the frame and nzageable by said clampingmeans for determining the position in the length of the tube at which a bend .is to be made, said-clamping means comprising a standard slidably supported on, the frame and having a sleeve. hub through which the tube extends, a sage sleeve rotatably mounted in said hub, a clamp sleeve surrounding theastube. within the gage-sleeveand having a flareopposed to a flare in said gage sleeve and 3*;jhi68d8d end portion, and a hand wheel threaded on said threaded end portion and abutting said gage sleeve for moving the clamp sleevelongitudinallyin. said gage sleeve and clamping it around thetube;

. 3.9.113'8 tube bending jig, a frame tube'bending means mounted on the frame, tube clamping means ,.slidable along-the frame for presenting a tubato said bending .means, means for accurately determining the initial positioning of the tube -in:.thec1amping means, means on the frame and ,engageable' .by said. clamping means for determining the-position in the-length of the tube at which a bendis to be made, said clamping means comprising a standard slidably supported on the frame and having a;sleeve hub through which .theztube extends, a-gage sleeverotatably mounted in said hub, .a clamp sleevesurrounding the tube within the gage sleeve and having a flare opposed to. a flare in said .gage: sleeve and a threaded end .portion, anda hand .wheel threaded on said threaded .end portion and -=.abutting said gage le v f r movin .the.clampsleeve,longitudinall ing means mounted on the frame, tube clampin said gage sleeve and clamping it around the tube,1j'said"i initial; position determining means comprising;a1,stop'.-.iingerjcarried by the handjustable as to position across the width of the frame, a'radius block rotatable on and removable from the mounting pin and having a circular peripherally grooved bending surface and a grooved tangentially extended clamping surface, and a tube clamping and block turning lever pivotally attached to said block.

11. In a tube bending jig, a frame, tube bending means mounted on the frame, tube clamping means slidable along the frame for presenting a tube to said bending means, means for accurately determining the initial positioning of the tube in the clamping means means on the frame and engageable by said clamping means for determining the position in the length of the tubeat which a .bend is to be made, said tube bending means including a mounting pin adjusttable as to position across the width of the frame, a radius block rotatable on and removable from the mounting pin and having a circular peripherally grooved bending surface and a grooved tangentially extended clamping surface, a tube clamping and block turning lever pivotally attached to said block, and a slide vise block supporting means mountable in opposition to the radius block at one or the other side of the machine accordingly as said mounting pin is mounted at one side or the other of the machine.

. 12. In a tube bending jig, a frame, tube bend- Iing means mounted on the frame, tube clamping .engageable by saidclamping means for determining the position in the length of the tube at .which a bend is to be made, said tube bending .means including a mountingpin adjustable as .to position across the width of the frame, a radius block rotatable on and removable from the niounting pin and having a circular peripherally grooved bending surface and a grooved tangentially extended clamping surface, a tube clamping and block turning lever pivotally attached to said block, and a slide vise block' supporting means mountable in opposition to the radius block at one or the other side of the machine accordingly as said mounting pin is mounted at one side or the other of the machine and including a slide viseblock, a supporting block and parallel -links supporting said supporting block one of which is extended in the form of an operating handle.

13. In a tube bending jig,. a frame, tube bending means slidable alongthe frame for presenting a tube to said bending means, means for accurately determining. the initial positioning of the tube in the clamping means, means on the frame and engageable -by said clamping means for determining the position in the length of the tube at which a bend is to be made, said tube a inc u in a mounting pin adjustable as to position across the width of the frame, a radius block rotatable on and removable from the mounting pin and having a circular peripherally grooved bending surface and a grooved tangentially extended clamping surface, and a tube clamping and block turning lever pivotally attached to said block, said lever including an offset portion effective to avoid interference between successively made tube bends made in the same plane but in opposite directions.

14. In a tube bending jig, a longitudinal frame, tube bending means mounted adjacent one end of 'the frame and including a radius block about which the tube is bent, tube clamping means, stop means for accurately determining the initial positioning -of the tube in'the clamping means, means for mounting said clamping on said frame for'sliding movement therealong toward the radius block and with the clamped tube for presenting the clamped tube to said radius block, and means on the frame and engageable by said clamping means as it is slid along the frame for definitely placing the tube relative to the radius block and determining the position in the length of the tube at which a bend isto be made.

15, In a tube bending jig, a longitudinal frame, tube bending means mounted on said irame and including a radius block about which the tube is bent, clamp means for gripping the v tube and holding the same while itis being bent,

means for mounting said clamping means on the framefor sliding movement therealong toward the radius block and with the clamped tube as an incident to the bending operation, and means i for determining the initial position of the tube relative to the radius block and including s rotatably mounted shaft disposed longitudinally of the frame adjacent the bending'means, and a stop member carried by the shaft and swingsble into and out of position for intercepting the end of a tube extending through'the clamping means and beside the radius block for definitely placing said tube relative to the radius block.

16. A tube bending iig structure as deilnedin claim 5 in which said clamping means eomprises a standard slidably supported on the frame and having a sleeve hub through which the tube extends, a gage sleeve rotatably mounted in said hub. a clamp sleeve surrounding the tube within the gage'sleeve and having a iiare opposed toa flare in said gage sleeve and a threaded "end portion, and a hand wheel threaded on said threaded end portion and abutting said gage sleeve for moving the clamp sleeve longitudinally in said gage sleeve and clamping it around the tube. and said gage sleeve having a portion extending from said hub and'upon which said gage arm equipment is mounted.

17. A tube bending Jig as defined in claim 3 in which there is included a gage arm equip- I ment associated with the tube clamping means and movable longitudinally therewith and rotationally with the clamped tube, a ball at least partially encircling the tube in cooperative relation with'one set of stops and carrying a stop member engageable by said gage arm equipmentfor placing the bend to be formed under control of said one set of stops. and a-bail at least partially encircling the tube in cooperative relation with at least one subsequently enga eable set of stops'and carrying a stop member engageable by said gage arm throughmovement of the" clamped tube about its axis for determining the control of said subsequently engageable set oi stops to the plane of the bend formed under control of saidone set of steps, a rock shalt common to and supporting all of the stop sets and movable about its axis for selectively presenting the steps of said sets for engagement by said clamping means, said bails being mounted for selective adjustment along the frame, the stops of said stop sets being mounted for individual adjustment along said shaft, and the stop carried by said second mentioned bail being mounted for adjustment about said ball.

18. A tube bending jig asdeflned in claim} in which there is included'a gage armequip ment associated with the tube clamping means engageable by said gage arm through movement of the clamped tube about its axis for determining the relation of the plane of bend to be formed under control of said subsequently engageable set of stops to the plane of the bend formed under control of said one set of stops.

7 a rock shaft common to and supporting allof relation of theplane. of bend to be formed under, 4

the stop sets and movable about'its axis for se' lectively presenting the stops of .said sets for engagement by said clamping means, said bails being mounted for selective adjustment along the frame, the stops'of said step sets being mounted for individual adjustment alongesaid shaft, and the stop carriedby said secondmentioned bail being mounted for adjustment about said bail, said gage sleeve having a portion extending from said hub, and said ga e arm equi ment comprising two selectively e sageable arms projecting radially in longitudinally oilsetrelation from said extended sleeve'portion at diametrically opposite sides thereof.

ARTHUR L. PARKER,

m s:. nuns.

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