US3448602A - Hand held tube bender - Google Patents

Description

Jun 10, 1969 J. HSTANLEY ETAL 3 48,602

HAND HELD TUBE BENDER Filed Oct. 24, 1965 INVENTORS JOHN H. STANLEY 8 DUANE R. GROSSETT am,m;m

ATTORNEY$ United States Patent US. Cl. 72-217 2 Claims ABSTRACT OF THE DISCLOSURE There is disclosed a hand tool for bending tubes including a radius block having an in-part circular periphery and a chordal face portion, the periphery having a groove therein shaped to receive and closely engage and fit against one side portion of a tube-to-be-bent, a handle rigidly secured to and projecting from the radius block, a link on which the radius block is supported and a second handle rigidly secured to and projecting from the link and swingable with the link 180 about the radius block periphery to and from positions at opposite sides of the periphery and paralleling the chordal face, a securing member attached to the chordal face and engageable over a tube-to-be-bent to hold it in the radius block groove during a bending operation, and a freely rotatable roller carried on the link with its periphery spaced away from the periphery of the radius block a distance greater than the outside diameter of said tube and having a groove therein shaped to engage and fit snugly against a substantial portion of the tube during bending thereof incidental to a swinging of the link about the center of the radius block.

The invention relates generally to tube bending and seeks to provide a novel form of tube bender which is very simple in construction and subject to relatively inexpensive manufacture, light in weight so that it can be hand held and manipulated, and yet is very efficient in the accomplishment of its intended purpose.

Hand held and operated tube benders have been known heretofore, and have included radius blocks or dies grooved to receive a tube to be bent and opposed by devices for engaging the tube and bending it against the die grooving, but such known benders have not been entirely satisfactory because of being cumbersome and difficult to handle, or complicated provisions for placement of the tube between the radius block and cooperating bending devices have been necessary, some requiring longitudinal threading of the tube between said block and devices, or even removal of parts, in conditioning the bender for the bending of a tube. Some of the best known benders of this type have employed elongated shoes opposing the radius block and which must be presented against the tube in sliding contact during bending, but in such benders the shoes must be swingably mounted during placement and removal of the tube, usually must be carried on pivoted links with provision of stop means fixing the relation of the shoes to the radius blocks, and always are subject to the objection of having the shoes in friction drag contact against the tube during the bending operation. It is a purpose of the present invention to provide a novel tube bender wherein all of said objectionable features are avoided.

3,448,602 Patented June 10, 1969 "ice In its more detailed nature the invention resides in the provision of hand tube bender including a radius block having a grooved in-part circular periphery and a chordal face portion, a handle rigidly secured to and projecting from the block, a link supporting the block and swingable about the center of its in-part circular periphery, a second handle secured to and projecting from the link, a securing member attached to the chordal face and engageable over a tube to hold it in the radius block groove during a bending operation, and a freely rotatable roller carried on the link with its periphery spaced away from the radius block a distance greater than the outside diameter of the tube and having a peripheral groove therein shaped to engage and fit snugly against a substantial portion of the tube during a bending thereof incidental to a swinging of the link about said center.

Another object of the invention is to provide a hand tube bender of the character stated wherein the tube securing member is in the form of a hook flatwise opposed to and swingably attached to the chordal face of the radius block.

Yet another object of the invention is to provide a hand tube bender of the character stated wherein the groove in the radius block is proportioned to receive a full half cross section of the tube and includes two opposed parallel wall portions deepening the groove and extending tangentially outward away from the half circular sectioned tube contacting portion of the groove and effective to overcome any tendency on the part of the tube to flatten during bending.

A further object of the invention is to provide a hand tube bender of the character stated wherein the link is fixed on a pin extending freely through a receiving bore in the radius block, the block being recessed to provide an annular surface surrounding the pin and having thereon a link swing degree indicating scale, and there being included an indicator secured on and movable with the pin in cooperative relation to the scale.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawing.

In the drawing:

FIGURE 1 is a plan view illustrating the invention, a tube being shown secured on the radius block and the parts in the position of the completion, or partial completion of a bending of the tube.

FIGURE 2 is a side elevation illustrating the bender in the position illustrated in FIGURE 1.

FIGURE 3 is a plan view illustrating the bender with the tube clamp or securing hook swung away to release a bent tube, the follower or bending roller carrying link being shown as swung to the tube releasing or initial tube receiving position.

FIGURE 4 is an enlarged detail vertical cross section taken on the line 44 on FIGURE 3.

In the example of embodiment of the invention herein disclosed, there is included a radius block or bend defining die 5 having a peripheral portion 6 extending over slightly more than and a flattened or chordal portion 7. The radius block includes a centrally raised portion 8 which is recessed at 9 to provide a raised annular indicator area 10 having indicia thereon as indicated at 11, preferably a scale sector of equidistantly spaced markings extending from through 180, as clearly illustrated in FIGURE 1. The radius block also includes a raised socket portion 12 in which a handle 13 is secured in any approved manner, as at 14, to project radially in the manner clearly illustrated in FIGURE 1.

The radius block is centrally bored at 15 to freely rotatably receive a pivot pin 16 projecting from a link member 17 wherein it is rigidly secured at one end as at 18. At its other end, the link member 17 is provided with a socket 19 in which a handle 20 is secured in any approved manner to project in the manner illustrated in FIGURE 2 for cooperation with the previously mentioned handle 13.

At the end from which the handle 20 projects the link member 17 also has fixed therein, at 21, a pin 22 on which is mounted a freely rotatable follower or bending roller 23. The roller 23 may be releasably held in place on its mounting pin in any approved manner, as by employment of a commonly used snap ring 24. The roller 23 is peripherally grooved at 25 for engagement with a tube being bent.

The groove in the follower or bending roller is placed to cooperatively oppose the tube receiving groove 26 formed in the peripheral portion of the radius block 5, and it will be observed by reference to FIGURE 4 of the drawing that the radius block groove 26 is complementary with the groove 25 in the roller 23, but is deeper. In other words, it will be apparent by reference to FIGURE 4 that the groove 26 in the radius block peripheral portion has a curved section for receiving one-half of the section of a tube-to-be-bent, and in addition, has two flat parallel portions 27 extending tangentially outward away from the half circular sectioned portion of the groove. The Opposing flattened extensions 27 in the radius block groove are effective to overcome any tendency on the part of a tube T being bent to flatten during bending.

A clamp hook or tube securing clip 28 is pivotally secured at 29 to the chordal face 7 of the radius block and is swingable to an out-of-the-way position or as illustrated in FIGURE 3, or to its effective, tube securing or clamping position illustrated in FIGURES 1 and 2.

An indicator finger or pointer 30 is secured at 31 on the upper end of the pin 16 in position for cooperating with the indicator scale 11 for visually indicating the degree to which a tube has been bent, as will be clearly apparent by reference to FIGURE 1.

If desired, the peripheral portion of the radius block may be rabbetted at 32 at its upper edge portion to provide an inwardly stepped, upstanding shoulder 33 which will lie directly over the center of a tube-to-be-bent, or secured in the radius block groove and being bent, thus to act as a visual indicator of the position of the tube center.

In the use of the bender, the handle 20 is held in the hand of an operator and the cooperating handle 13 is swung from the FIGURE 1, FIGURE 2 position to the tube receiving position illustrated in FIGURE 3. It will be observed that the tube follower or bending roller 23 is fixedly placed on its mounting pin 22 so that the periphery of the roller 23 will always be spaced from the periphery of the radius block a distance greater than the outside diameter of the tube-to-be-bent, thus making it possible to introduce the tube between the peripheral surface 6 of the radius block and the opposing roller 23 sidewise, and without the necessity of any endwise threading action, thus greatly facilitating the placement of the tube in the radius block groove, as indicated in FIGURES 1 and 2, and the manipulation of the clamp hook or securing clip 28 into position for holding the tube in place during the bending action.

With the parts placed as above described, the indicator finger or pointer 30 will be at the zero mark on the indicator scale 11 as indicated in FIGURE 3. By now swinging the handle 20 about the radius block from the position illustrated in FIGURE 3 in a clockwise direction, the roller 23 will engage the tube and force the same to be bent into conformity with the peripheral groove in the radius block in the manner clearly illustrated in FIGURE 1. In said illustration a bending of the tube about is shown, and the pointer or indicator finger 30 will indicate the accomplishment of the intended bend.

The spacing of the roller 23 in the manner described provides increased leverage and minimizes frictional contact during the bending operation, as compared to operations in which sliding shoes have been employed, and thus the bending operation is greatly facilitated. Also, the formation of the radius block grooving with its outwardly extending and opposed flattened surfaces 27 serves to overcome the tendency of tubes to flatten during bending operation.

In FIGURE 3 a tube which has been bent is shown as being released from the radius block, the particular spacing of the follower or bending roller 23 greatly facilitating this removal, without endwise threading action, as previously described.

While example part structures and arrangements have been illustrated and described in detail herein, it is to be understood that changes in part structure and arrangement may be resorted to without departing from the spirit and scope of the invention as defined in the appended claims.

We claim:

1. In a hand tool for bending tubes, the combination of a radius block having an in-part circular periphery and a chordal face portion, said periphery having a groove therein shaped to receive and closely engage and fit against one side portion of a tube-to-be-bent, a handle rigidly secured to and projecting from the radius block, a link on which the radius block is supported and which is swingable about the center of said in-part circular periphery, a second handle rigidly secured to and projecting from said link in radial relation to the center of said in-part circular periphery of the radius block, said second handle and link being swingable about said radius block periphery to and from positions at opposite sides of said periphery and paralleling said chordal face, a securing member attached to said chordal face and engageable over a tube-to-be-bent to hold it in the radius block groove during a bending operation, and a freely rotatable roller carried on the link with its periphery spaced away from the periphery of the radius block a distance greater than the outside diameter of said tube and having a peripheral groove therein shaped to engage and fit snugly against a substantial portion of said tube during a bending of the tube incidental to a swinging of the link about said center, said link being fixed on a pin extending freely through a receiving bore in the radius block, said block defining a recess and an annular surface surrounding said pin and said recess and having thereon a degree-of-bend indicating scale disposed at least partially about the periphery of said recess, and an indicator secured on and angularly movable with said pin within said recess and in cooperative relation to said scale.

2. A hand tool as defined in claim 1 wherein the groove in the periphery of the radius block is proportioned to receive a full 'half cross section of a tube-to-be-bent and includes two opposed parallel wall portions deepening the groove and extending tangentially outward away from the half-circular sectioned tube contacting portion of the groove and effective to overcome any tendency on the part of a tube being bent to flatten during bending, one face of the radius block being rabbetted at its peripheral edge to provide an arcuate upstanding peripheral shoulder disposed to directly overlie the center of a tube when bent about the block in its peripheral groove and serve as an accurate sighting line indicating the center line of said bent tube.

References Cited UNITED STATES PATENTS Spencer 72 217 Whitecotton 72 217 Haddock 72-217 Dick 72 217 Shiley 72 217 Bizak 72156 Gryniewicz 72459 X Huet 72-156 X Franck 72387 7/1965 Small et al. 72319 X 3/1966 Hamlin 72--156 FOREIGN PATENTS 2/1949 Canada. 12/ 1953 Italy.

5/ 1952 Germany.

' US. Cl. X.R.

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