US3452571A

US3452571A - Tube bending dies

Info

Publication number: US3452571A
Application number: US618374A
Authority: US
Inventors: Frank Sassak
Original assignee: BEND RITE Inc
Current assignee: MCINERNEY SPRING AND WIRE Co
Priority date: 1967-02-24
Filing date: 1967-02-24
Publication date: 1969-07-01
Anticipated expiration: 1986-07-01

Description

F. SASSAK TUBE BENDING DIES 7 Jul 1, 1969 Sheet Filed Feb. 24, 1967 (2 llllllllllllllln LL INVENTOR FRANK SASSAK BY %,flmw {i ATTORNEYS I o) I I United States Patent US. Cl. 72-219 3 Claims ABSTRACT OF THE DISCLOSURE The present invention is directed to a tube bending apparatus which considerably reduces the number and amount of equipment necessary for a large range of bending operations. The present invention therefore is specifically directed to a single tube carrier consisting of a series of segments which are flexibly interconnected and which have in their top surface a channel defining groove adapted to receive a tube of a predetermined corresponding radius and wherein the proposed tube receiver is capable of use for the particular tube to be bent for a very large number of bending radii throughout a large range, depending upon the particular preselected curva ture of bending device upon which the carrier is applied. The present invention contemplates also a mounting base or bending base having a curvature or bending surface of a predetermined radii, which for that radii will accommodate any one of a large range of carriers adapted to receive tubes in a large range of diameters. It is contemplated that there may be a plurality of bending bases, each having predetermined radius of curvature, any one of which is adapted to receive any one of the aforesaid tube receivers. This therefore provides for a large range of tube diameters for bending and for a large range of bending radii, and accordingly an extremely large number of possible combinations with a minimum amount of equipment.

The present invention relates to a certain new and useful improvement in tube bending apparatus of which the following is a specification.

Heretofore in the tube bending art it was necessary to have on hand considerable amount of expensive tube bending machinery in order to accommodate a large range of tube diameters to be bent, and tube bending dies of various sizes in order to accommodate a large range of bending radii.

This application relates to a tube bending apparatus of extremely simple yet most satisfactory form. An embodiment of such apparatus is shown in the appended drawings in which:

FIG. 1 is an elevational view of the apparatus prior to the bending of the tube.

FIG. 2 is a similar view but showing the position of the parts when the tube is bent.

FIG. 3 is a view from the left side of FIG. 2.

FIG. 4 is a view from the right side of FIG. 2.

FIG. 5 is an end view of a segment.

FIG. 6 is a side view thereof.

It will be understood that the above drawings illustrate merely a preferred embodiment of the invention, and that other embodiments are contemplated within the scope of the claims hereafter set forth.

FIG. 1 of the drawings shows the apparatus as comprising a base 10 having a curved outer surface 11 of a predetermined pre-selected radius, against which bears a tube receiver indicated as a whole at 12 mounted on such base, and secured by fasteners 13. A tube 14, to be bent, is nested upon said receiver as in FIGS. 1 and 4.

Means are provided to bend the receiver 12 and assembled tube so that its inner surface 15 conforms to the curvature 11 of the base 10 so as to bend the tube 14 on the receiver 12, corresponding to the curvature of the outer surface 16 of the receiver.

Means in the form of flexible connectors 20 are provided for clamping one end 21 of the receiver to block 22 secured on base 10, on which the receiver is to be bent.

Means are provided to clamp the tube 14 to the receiver 12 when the tube 14 is laid against the outer surface 16 of the receiver.

The receiver The receiver itself comprises a series of thin perforated segments 17, FIGS. 5 and 6, having inner seats 24, outer grooves 25, and openings 26, these being shown as notches. These segments are interposed between

blocks

22 and 23 and flexibly connected thereto.

The segments are placed together in alignment for the following purpose. The openings 26 align to form passageways for receiving the flexible connector assemblies 20, which pass through such passageways to connect the segments 17 into a unitary flexible tube receiver and likewise to serve as the means for clamping the receiver segments flexibly between

blocks

22 and 23. Said blocks have lateral slots 18 corresponding to and in registry with openings 26.

The grooves 25 are aligned, FIG. 3, to define an outer trough into which the tube 14 is laid for and during bending.

The seats 24 align to form a bearing surface for the receiver as a whole on the outer surface 11 of the base. The outer lower side surfaces of segments 17 are tapered inwardly at an included angle of approximately 7", FIG. 5, in order to take the form shown in FIG. 2.

In the embodiment shown the flexible connectors comprise two exposed parallel lengths of sprocket chain 19 seated in aligned

notches

26, 26 with the parallel lengths being connected at their ends to tension rods 21. These nest in notches 18 of

blocks

22 and 23, extend through washers 27 with their threaded ends 28 adjustably receiving nuts 29. Howeevr, the flexible connector 20 can be a flexible cable passed through a bore formed by perforations 30.

The clamping effect provided by the flexible connector, whether it be a two-part cable of chain links seated in the notches 26 of the segments, or a one-piece cable run through the bore formed by perforations 30, is provided with screw threaded shanks 28 and threaded nuts 29.

Operation When the apparatus is assembled with a selected base 10 having a preselected radius or curvature 11 and a selected receiver 12 with a preselected radius of groove 25, and a tube 14 is laid in the trough formed by notches 25, and the tube is properly clamped by means not shown to the receiver, but means which are conventional and well known to those skilled in the art, the bending force is applied to the tube and receiver as a unit, by means not shown, but well known to those skilled in the art, and in a manner also known to those skilled in the art, whereupon the receiver and tube as a unit bend around the base surface 11 with the parts moving from the position of FIG. 1 to that of FIG. 2 to complete the bending operation.

The receivers 12 are preassembled and stored according to the radius of the tube receiving groove 25, FIG. 6. There may be any number in the range of A inch to 10" for example, corresponding to the radius of groove 25.

The bases 10 are stored by the user in a large range or curvatures 11 between one inch and 10 inches for illustration. Any receiver can be used with any base. If one had 30 of each for example, namely: 30 receivers and 30 bases there would be provision for 900 different com- 3 binations of tube radius and tube bends. Thus a small amount of tooling is needed in comparison for a very large number of bending operations. This could save many thousands of dollars.

A conventional form of rotative tube bending device is shown in FIG. 2 which includes a rotative lever adapted to rotate about the axis of the aperture in the base which includes a grooved roller operatively engageable with the tube 14.

An illustration of said device 35 includes lever segment 36 mounting a hub 37 journaled within the aperture in base and connected by interiorally threaded sleeve 39 to the lever segment 38. The latter journals at 40 a suitable grooved roller 40 adapted to operatively engage tube 14. Rotation of the lever segment 38 as indicated by arrows with respect to base 10 retains tube 14 within the segment grooves and simultaneously bends the receiver from the position shown in FIG. 1 to the position shown in FIG. 2 with the corresponding bending of the tube 14.

Now having described the apparatus herein disclosed reference should be had to the claims which follow. I claim:

1. Apparatus comprising a base having a curved outer surface; an elongated segmented tube receiver mounted on said base and on which a tube to be bent is laid; means journaled on the base retainingly engaging the tube with the receiver to bend the tube and receiver so that the inner surface of the receiver snugly engages and conforms to the curvature of the base so as to bend a tube on the receiver to the curvature of the outer surface of the receiver; means to clamp one end of the receiver to the base on which the receiver is to be bent;

said receiver comprising a series of thin segments having openings, inner seats, and outer grooves; the openings being aligned to define a longitudinal passageway in the receiver; the grooves being aligned to define an outer trough into which the tube is nested; the seats being aligned to form a bearing surface for 4 the receiver on the outer curved surface of the base; and a flexible connector extending through the passageway to maintain the segments in face to face connected relation to form a unitary flexible tube receiver; said receiver adapted to be replaced by other receivers respectively, whose segment grooves are in a wide range of radii for the bending of tubes of a corresponding range of radii to a curvature corresponding to the base curvature; said base being replaceable by other bases respectively whose outer surface curvatures are in a wide range of radii for the bending of tubes into a corresponding range of radii corresponding to the curvature of the base outer surface selected.

2. In the tube bending apparatus of claim 1, said receiver including blocks at its opposite ends enclosing said segments, similarly grooved to receive said tube and with openings in registry with said segment openings to receive said connector; said connector at its ends adjustably secured to said blocks respectively; and means fastening one block to said base.

3. In the tube bending apparatus according to claim 2, wherein the segment and block openings are notches in the edges of the segments and blocks, and the connector in the passageway formed by said notches is exposed at the side of the receiver.

References Cited UNITED STATES PATENTS 1,741,840 12/1929 Harmon et a1. 72-465 1,773,430 8/1930 McDonnell 72157 1,837,060 12/1931 Offutt 72-157 1,847,200 3/1932 Vollmerhaus 72--465 RONALD D. GREFE, Primary Examiner.

US. Cl. X.R. 72157, 465