US2414926A - Tube bending machine with pivoted sweep arm - Google Patents

Description

Jan. 28, 1947. R. FQBU-RKE I v TUBE BENDING- MACHINE WITH PIVOTED SWEEP ARM Filed June 28, 1943 2 Sheets-Sheet 1 MN 9w QN mu Jan. 28, 1947. BURKE 2,414,926

TUBE BENDING- MACHINE WITH PIVOTED SWEEP ARM Patented Jan. 28, 1947 TUBE BENDING MACHINE WITH PIVOTED SWEEP ARM Robert F. Burke, Phoenixville, Pa assignor to Boiler Engineering & Supply 00., Phoenixville,

Pa., a partnership com and Robert F. Burke posed of Russell E. Keen Application June 28, 1943, Serial No. 492,631

Claims.

My invention relates to a new and useful tube bending machine and has for one of its objects to provide an exceedingly simple and effective apparatus that may be operated manually with considerable speed by relatively cheap labor thus greatly reducing the cost of bending tubes such as are used in steam power or other boilers.

Another object of the invention is to so dispose the elements of th apparatus relative to one another that either one, two or three bends may be made in a tube when the latter is once clamped in the machine thus positively insuring that all bends will be in pro-per alignment. While the most common number of bends in boiler tubes is two there are some instances where three are required and a few cases where one bend is sufficient. In any case, after clamping a tube at one point, in proper location, the necessary bends can be made without moving or relocating the tube.

Another object of this invention is to provide a construction that allows the positions of the bending dies to be preselected for predetermining the points at which a number of similar tubes will be bent.

A further object of this invention is to provide a unique means, which is adjustable, for initially positioning the tubes in the machine.

With the above and other objects in view this invention consists of the details of construction and combination of elements hereinafter set forth and then designated by the claims.

In order that those skilled in the art to which this invention appertains may understand how to make and use the same I will describe its construction in detail referring by numerals to the accompanying drawings forming a part hereof, in which:

Fig. 1 is a plan view of the tube bending machine or apparatus.

Fig. 2 is a front elevation thereof.

Fig. 3 is an enlarged fragmentary plan view of the machine in the region of one of the bending dies.

Fig. 4 is a cross sectional view of Fig. 3.

Fig. 5 is a section on the line 55 of Fig. 3, showing the clamp in an open position.

Fig. 6 is an edge View of tube bending lever and component parts.

Fig. '7 is a view similar to Fig. 5 showing the clamp in a closed position.

Fig. 8 is a section on the line 88 of Fig. '7 showing the relative position of the jaw in dotted lines.

Fig. 9 is a section on the line 9-9 of Fig. '7.

Figs. 10, 11 and 12 are isometric views of several stop pins.

Fig. 13 is an end view of the means for locating the tube bends.

In carrying out my invention as herein embodied 15 represents a suitable supporting frame, the top cross bars of which constitute a bench l6. for temporarily holding tubes that have been bent. On said supporting frame I5, preferably as a part thereof, is an inverted channel l1 and to provide for bending tubes at three points, one end of said channel projects at an angle to the main body thereof, as indicated at l8. Of course, it will be apparent that where only two bends are required these may be made within the length of the'straight body portion of the channel I'l. Said channel has longitudinal slots 19 for adjustably'mounting the bending dies and holding component parts of said dies in proper position as described below.

A separate bending die 20 is provided for each bend to be made in a tube so there may be one or more of said bending dies and those at opposite ends of the channel will operate in opposite directions although the construction of all of them is similar. In view of their similarity the description of one will apply to all of them.

Each bending die includes a plate 21 resting on top of the channel I! and on the underside of the plate are lugs or keys 22 which project into the channel slot l9 to hold said plate against turning or misalignment while permitting it to slide along the channel within the limits of a slot. The plate 2| also carries a fastening'device 23 to temporarily clamp the bending die in any adjusted position and said fastening device is, preferably, a stud fixed in the underside of the plate and projecting through the channel slot with a nut and washer to enga e the underneath face of the channel. In lieu of the stud and nut, a bolt can be used which is projected through the slot and screwed into the plate.

A die segment 24 is carried by the plate 2|, being mounted in place, in spaced relation to and above said. plate, by a bolt 25 and a lug 26 projecting from the top face of said plate. This die segment has a tail 2! which is straight and lies parallel with the adjacent edge of the plate 2| and in the rim of said segment and its tail is a semi-circular groove 28 to receive a portion of the tube being bent.

A bending lever 29 has a long arm 30 projecting into the space between the die segment 24 and the plate 2| and fulcrumed at its extreme inner end on the bolt 25 which is in the axis of the curved rim portion of the die segment. In addition to the long arm 36, there is a short arm 3| which overlies the outer portion of the long arm in spaced relation thereto. The inner end of'the short arm 3! terminates short of the rim of the die segment 24 leaving a space for the insertion of a tube. Both arms 30 and 3| have L-shaped slots 32 directly in line with each other. body portions of these slots are longitudinal of the arms and the foot portions of said slots extend transversely and in a direction opposite to the path of movement of the bending lever during a bending operations. An axle 33 is mounted on the bending lever 29 and projects through both arms 30 and 3|, being slidably mounted in the L-shaped slots 32 in said arms. The axle 33 is held in place by a head 34 and a cotter key 35 with washers between them and the respective arms and the upper end of the axle extends a sufficient distance above the short arm to be readily grasped by an operator for use as a handle. On the axle between the long and short arms is mounted a grooved wheel 36 to engage and run upon a tube being bent as will be later more fully described.

The amount of bend placed in a tube is determined by a stop button 31 selectively placed in any one of the series of holes 38 in the plate 2!. The holes 38 are disposed in the arc of a circle adjacent the rim of the die segment 24. There are more of these stop buttons having different sized heads. The various sizes of heads makes it possible to regulate the movement of the bending lever to very small fractions of an inch although the holes 38 are evenly spaced apart.

A clam on one 01' both of the die structures mounted on the straight portion of the channel I! includes a base 39 extending from the forward edge of a plate 2|. This base may be an integral part of the plate or it may be fixed to the plate in any suitable manner. Said base has its central portion'cut out and grooves 46 formed in the inside edges to receive the laterally projecting ears 4|, Fig. 9, of the clamp jaw 42 which has an arcuate groove in its inner face.

The clamp jaw is pushed forward by the eccentric cam 43 having a handle 44 and mounted on an axle 45 supported by the threaded bearing rods 46 mounted in the upstanding foot 4'! projecting from the outer end of the base 36. The bearing rods are held in their adjustments by nuts on said rods engaging opposite faces of the foot 41.

In order to properly position a tube for bending, a'tube stop'is provided which includes a pair of brackets 48 secured to the front edge of the channel ll. Extending across the space between said brackets and secured thereto is a rod 49 and on the latter is slidably mounted a mast 56, held in any adjusted position by a set screw The mast carries an apertured boss in which a short reach rod 52 is slidably mounted and secured in any desired adjustment by a set screw 53. That portion of the mast above the reach rod functions as a handle. On the outer end of the reach rod 52 is fixed a stop plate 54 to be engaged by the end of a tube 55 prior to being clamped for bending.

In operation, assuming that the clamp jaws 42 are retracted as in Fig. 5, the bending levers 29 drawn back and the wheels 36 on said bending levers in their outermost positions, then the tube 55 is inserted in the machine by passing it vertically between the inner ends of the short arms 3| of the bending levers 29 and the rims of the die segments 24 which-are located on the The straight portion of the channel ll. Thus the tube is simultaneously placed in two dies and the clamps. The handles 44 of the cams 4-3 now are drawn up which will swing said cams over to move the clamp jaws 42 inward and clamp the tube 55 against the tail 21 of the die segment, as in Fig. 7. Of course it is to be understood, that when the tube is first inserted in the machine vertically, it is then moved longitudinally until an end strikes against the tube stop plate 54 for locating the bending points. Next, the upper extending ends of the axles 33 are moved inward along the body or shank portions of the L-shaped slots 32 to the foot portions thereof so that parts of the tube are in the grooves of said wheels 36 and the grooves of the die segments 24 located on the straight portion of th channel IT. The bending levers are then swung in the proper directions towards the adjacent ends of the tube, one clockwise and the other counterclockwise, until their movements are arrested by their respective stop buttons 31 which have been previously positioned according to the amount of bend to be made in the tube. Upon the initial bending movement of the bending levers the axles 33 will be forced into the feet of the L-shaped slots 32 so as to retain the wheels 36 in proper relation to the die segment. Since the wheels 36 run over the tube and the latter is embraced between said wheels and the die segment, the tube will be bent without deforming the cross sectional contour thereof.

The above operations complete the making of two bends in the tube but where another or other bends are to be made also, the bending lever of the die on the oblique portion of the channel H is thrown over to an extreme position as shown in Fig. 1. In this case, the making of the intermediate bend will force the end of the tube into the groove of the tail of die at the left hand side of Fig. 1. By swinging the bending lever of said left hand die inward, the arms 36 and 3i thereof will be passed over the end of the tube and the grooved wheel 36 may then be moved inward and the bending lever swung outward to make a subsequent bend.

Upon completion of the bending operations, the bending levers are returned to their inoperative positions and the cam handles 44 are thrown back to relieve the clamping pressure from the tube. Thereafter the tube is pulled back laterally which will slide the clamp jaws outward permitting the tube to be lifted upward out of the clamps and between the inner ends of the short arms of all bending levers and their respective die segments. After removal, the tube may be transported to any desired location or temporarily laid upon the bench I6.

This method of bending tubes on an apparatus of the character described accomplishes the work at an exceedingly high rate of speed and since it only requires the manual labor of an unskilled operator the cost is very low.

Of course I do not wish to be limited to the exact details of construction herein shown and described as these may be varied within the scope of the claims without departing from the spirit of my invention.

Having described my invention what Iclaim as new and useful is:

l. A tube bending machine including an inverted channel having one oblique end, said channel having a number of longitudinal slots therein, die mechanisms mounted on said channeL means carriedby said mechanisms and registering with the slots to hold said mechanism in any preselected adjustments within the limits of the respective slots, means carried by said mechanisms and also registering with said slots to prevent turning of said mechanisms, each of said mechanisms including a die segment having an arcuate groove in the rim thereof, a bending lever pivoted axially of the rim of said segment, a grooved wheel axially adjustable on the lever, means to clamp a tube to be bent, brackets on the channel and projecting forwardly, a rod secured in said brackets, a mast slidably mounted on said rod, a reach rod slidably mounted on the mast, a stop plate carried by the outer end of the reach rod, and means to temporarily hold said first mentioned rod and the reach rod in any preselected adjustment.

2. A tube bending machine including a support member having one oblique end, said support member having a number of longitudinal slots in endwise spaced relation, die mechanisms mounted on said support member, means carried by said mechanisms and registering with the slots to hold said mechanisms in any preselected adjustments within the limits of the respective slots, means carried by said mechanisms and also registering with said slots to prevent turning of said mechanisms, each of said mechanisms including a die segment having an arcuate groove in the rim thereof, abending lever pivoted axially of the rim of said, segment, a grooved wheel mounted on said bending lever and axially adjustable lengthwise and laterally thereof, and means to clamp a'tube to be bent.

3. In a tube bending machine, a support memher having a straight portion and one oblique end, die mechanisms slidably mounted on both the straight portion and the oblique end of said support member for adjustment to and from one another to position, them at preselected locations where a pipe is to be bent, each of said mechanisms including a die segment and a bending lever and a grooved wheel, and means to clamp a tube in a stationary position while being bent.

4. In a tube bending machine, a support member having longitudinal slots therein, a plurality of die plates mounted on top of said support member, means on said die plates and projecting through the slots to hold said die plates in any adjusted position, die segments having grooves in the rims secured to said die plates, bending levers each including a long arm pivoted beneath a segment and a short arm spaced above the outer portion of said long arm and terminating short of the segment rim to permit passage of a tube between the inner end of the short arm and the segment, said arms having L-shaped slots in vertical alignment, with the feet of said slots in the region of the inner end of the short arm, an axle in said slots, a grooved wheel on each axle, each of said die plates having a series of holes disposed about the rim of the segment, and a button stop selectively placed in one of said holes.

5. In a tube bending machine, a support member having longitudinal slots therein, a plurality of die plates mounted on top of said support member, means on said plates and projecting through the slots to hold said plates in any adjusted position, die segments having grooves in the rims secured to said die plates, bending levers each including a long arm pivoted beneath a segment and a short arm spaced above the outer portion of said long arm and terminating short of the segment rim to permit passage of a tube between the inner end of the short arm and the segment, said arms having L-shaped slots in vertical alignment, with the feet of saidslots in the region of the inner end of the short arm, an axle in said slots, and a grooved wheel on each axle, in combination with clamping means, each including a base with track grooves in the sides thereof, a foot at the outer end of the base, a clamping jaw having an arcuate groove for cooperation with a portion of the die segment and 'slidably mounted in the track grooves of the base, a pair of threaded bearing rods adjustably mounted on the foot, a cam pivoted between the bearing rods, and a handle on the cam to operate' the latter.

ROBERT F. BURKE.

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