US3908425A

US3908425A - Rod bending apparatus and method

Info

Publication number: US3908425A
Application number: US430631A
Authority: US
Inventors: Donald G Ware
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-01-04
Filing date: 1974-01-04
Publication date: 1975-09-30
Anticipated expiration: 1992-09-30

Abstract

A portable, handheld apparatus having the capability to bend structural members or rods having one end fixed. A movable force exerting means in the form of a spaced pair of force exerting rollers is carried on a frame. A stationary, but rotatable roller is mounted on the frame opposite the force exerting means. The apparatus is positioned relative to a fixed rod to be bent so that the rod is between the force exerting rollers and the stationary roller. The apparatus also includes power means for moving the force exerting rollers toward the stationary roller and against the rod to cause it to bend. As the bending of the rod occurs, in addition to the movement of the force exerting rollers towards the stationary roller, the apparatus can tilt relative to the rod and adjust its position longitudinally of the rod, to thereby maintain contact between the force exerting rollers and the rod during bending. Rotation of the rollers accommodates this movement of the apparatus relative to the rod. The tilting of the apparatus effects a change in the direction of the force exerted on the rod by the force exerting means as the bending is taking place, which change in direction maintains at least a major component of that force acting normal to the rod axis. In the illustrated apparatus, the force exerting rollers and the stationary roller define an open space between them for direct transverse insertion and removal of the rod. Analogous bending methods are provided.

Description

United States Patent [191 Ware 1 Sept. 30, 1975 1 ROD BENDING APPARATUS AND METHOD Donald G. Ware, 1 1262 Sierra, Fontana, Calif. 92335 [221 Filed: Jan. 4, 1974 [2]] Appl. No.: 430,631

[76] lnventor:

Primary Exunziner-Milton S. Mehr Allurncy, Agent, or Firm-Robert M. Ashen [57] ABSTRACT A portable, handheld apparatus having the capability to bend structural members or rods having one end fixed. A movable force exerting means in the form of a spaced pair of force exerting rollers is carried on a frame. A stationary, but rotatable roller is mounted on the frame opposite the force exerting means. The apparatus is positioned relative to a fixed rod to be bent so that the rod is between the force exerting rollers and the stationary roller. The apparatus also includes power means for moving the force exerting rollers toward the stationary roller and against the rod to cause it to bend. As the bending of the rod occurs, in addition to the movement of the force exerting rollers towards the stationary roller, the apparatus can tilt relative to the rod and adjust its position longitudinally of the rod, to thereby maintain contact between the force exerting rollers and the rod during bending. Rotation of the rollers accommodates this movement of the apparatus relative to the rod. The tilting of the apparatus effects a change in the direction of the force exerted on the rod by the force exerting means as the bending is taking place, which change in direction maintains at least a major component of that force acting normal to the rod axis. In the illustrated apparatus, the force exerting rollers and the stationary roller define an open space between them for direct transverse insertion and removal of the rod. Analogous bending methods are provided.

7 Claims, 3 Drawing Figures Sept. 30,1975 Sheet 1 of 2 U.S. Patent US. Patent Sept. 30,1975 Sheet 2 of2 3,908,425

RED BENDING APPARATUS AND METHOD BACKGROUND OF THE INVENTION l. Field of the Invention The invention relates to apparatus and methods for bending rods and other elongated structural members, particularly ones having one end fixed.

2. Description of thePrior Art In virtually all construction projects, structuralmembers comprising metal bars or rods having other than rectilinear form are utilized. Such structural members are often pre-bent into the desired shape and then transported to the construction site. The transportation and handling is difficult and costly.

Some prior art devices have arisen for bending and forming structural members on site. Such devices have, however, exhibited certain deficiencies. For example, many such devices are bulky, unwieldy, and/or stationary, so that the members to be formed must be transported from various points of the construction site at which they are stored to the bending apparatus and then transported to the points of the site at which they are to be used. Another drawback of existingdevices is that, generally speaking, they require that both ends of the member to be formed be free. Thus,-such devices have lacked the capability of forming a structural member after it has been fixed in place. This constitutes a substantial deficiency since it is often difficult to determine exactly what angle, height or position of bend will be appropriate for a particular member until it has been put in place. Generally, under the prior art capabilities, shaping and forming of structural members in place have been effected by a relatively unsophisticated apparatus and methods such as simple hammering of a fixed bar until the desired angle is achieved. Such procedures are inherently unsatisfactory because of the disproportionate amount of time and effort required,

and the imprecision of bend, as well as the danger to workers and to the integrity of the structural member;

Therefore, there has been a recognized but unfulfilled need for a portable apparatus for bending and forming structural members such as rods, bars, and pipes, especially when such members have one end fixed.

bending structural members including solid or hollow metal bars or rods, particularly those have one end fixed. Rod bending apparatus includes a portable frame means upon which is mounted movable force exerting roller means for exerting bending force upon a structural rod or bar member; a stationary roller means for reacting against the rod during exertion of force thereupon is also mounted upon the frame means, spaced from and opposite the force-exerting roller means. Power means are operable to move the force-exerting roller means against the rod. In operation, as bending of a rod fixed at one end proceeds, the apparatus adjusts its position to accommodiat'e the changing shape of the rod. In the illustrated embodiment,'tl1e frame means tilts and the rollermeans rotate so as to maintain the roller means in contact with the rod and the bending force applied to the rod. Thus, the direction of thrust of the bending force changes in a manner maintaining a large proportion of the force exerted normal to the rod axis; this facilitates fu'rtherbending The'apparatus further includes handle means by'which the frame means can be positioned relative to the rod and Apparatus and methods are provided for forming and supported while the bending occurs. The force-exerting means may be hydraulically powered in a preferred embodiment.

In the drawings: I

FIG. 1 is a sideelevation of rod bending apparatus in accordance with the invention, aligned with a rodtto be bent;

FIG.'2 comprisesa top plan view of the apparatus and rod of FIG. 1; and

FIG. 3 comprises-a side view of the rod bending apparatus and the rod of FIG. -1, the rod being bent in accordance with the invention.

As shown in FIGS. 1 and 2, rod bending apparatus 10 includes a frame means 12. The illustrated frame means 12 is a generally rectangular fiat metal plate. It is preferably made of strong and rigid, but relatively lightweight, material such as aluminum. The plate 12 is shown disposed in a generally vertical plane, and the other portions of the apparatus, to be described, are conveniently mounted on one vertical face 13 of the plate. Theapparatus is illustrated in this orientation for bending a vertical rod 52 that is fixed at its lower end 54. The apparatus is usable in any other desired orientation. A.hydraulic cylinder'14 is secured to the rearward portion of the face 13. The cylinder 14 which is generally cylindrical has its axis extending generally horizontal and from end to end of the plate 12. The cyl-. inder 14 has extension portions 17 at its front and rear ends. Each extension portion 17 is received in a mounting bracket 16 that is solidlyfixed to the face 13 of the frame plate 12 as by means of screws 15.

Cylinder l4 defines aninterior volume or chamber 18 which receives piston means20. Piston means 20 includes a head portion 22 whose periphery, slides within chamber 18 and. further includes a plunger portion 26. The plunger portion 26 comprises an. elongated section connected to the head portion 24 and extend: ing substantially perpendicular thereto in alignment with the cylinder axis. The forward end of the plunger portion 26 extends through an opening 27 in the forward end of the cylinder 14 and in the forward extension portion 17. i

A pair of apertures 28 defined by cylinder 14 communicate with opposite ends of chamber 18. A hose 30 is connected to each aperture 28. At their outer ends, hoses 30 couple to a control box or means 36, which is in turn coupled by hose means 34 to a pump unit 32. Pump unit 32, shown schematically, pumps hydraulic fluid through

hoses

30 and 34 to the hydraulic cylinder 14. The control means 36 is affixed to the top of frame plate 12 and includes a pair of control buttons 38 for controlling the action of piston means 20.

At the forward end of plunger portion 26, a yoke 42 of force-exerting means 40 is attached. (As used herein, forward or advanced is defined as toward a rod to be bent or as to the right as depicted in the drawings','conversely rearward" or retracted is defined as away from a rod to be bent or as to the left" in the drawings.) Attachment of the yoke 42 to plunger portion 26 may be by conventional means, such as a welded connection, or the plunger portion and yoke may be integral. The yoke 42 has a generally U-shaped configuration with the open end facing forward. The yoke 42 isdisposed parallel to and spaced from the plate face 13. At the forward end of each of the arms of the yoke 42 is mounted a contact means in the form of a roller 44. Each roller 44 serves to transmit force from piston means 20 to a rod to be bent as described below. Each of the rollers 44 is rotatably mounted upon a transversely extending pin 46 affixed in the bifurcated end of the associated yoke arm.

In specific embodiments of the invention, the yoke may be of different shape than the U configuration described herein, and the number and positions and motion of the rollers may vary. These features should be such as to permit the force exerting means to adapting to the changing shape of a rod being bent.

Forward of, and spaced from yoke means 42 is disposed reaction means in the form of a stationary roller 48 rotatably mounted by means of a thrust bearing 50 on a transverse shaft 51 affixed to face 13 of the frame plate 12. Roller 48 is stationary" in the sense that it is not movable translationally with respect to the frame plate 12. A spacer 53 is provided to position the roller 48 outwardly from face 13 and maintain it approximately the same distance from face 13 as the rollers 44. Thus, as shown in FIG. 2, the

rollers

44 and 48 lie in a common reference plane spaced from face 13. As will be described, the rod is disposed and the bending action also occurs in this reference plane.

FIG. 1 shows a generally upright structural rod 52 having its lower end 54 embedded and thereby fixed in a body of concrete 55. It is desired to bend the upper portion of the rod 52 about 90 into a generally horizontal position, the bending to take place generally about the point along the rod indicated as X. The apparatus may be handheld as by means of a handle 56 mounted on the top of the frame plate 12, and positioned about the rod 52 as shown in FIGS. 1 and 2. In this connection, the

rollers

44 and 48 define a vertical space between them, which is open and unobstructed from the side (FIG. 2). Preferably, as shown in the drawings, the space between

rollers

44 and 48 is larger than the dimension of the rod 52 so that the rod can be easily positioned from the side into that space. Alternatively, the spacing could be reduced so that the rod has to be inserted longitudinally between the rollers 44 and roller 48. As depicted in FIG. 2,

rollers

44, 48 may have a concave curvature so that as the movable rollers 44 advance, rod 52 is nestable within the side-to-side curvature of the

rollers

44, 48 to retain the rod in contact and prevent it from moving sideways out from between the rollers.

The specific arrangement of these elements to produce a bend at a desired portion of a rod may vary with specific embodiments. In the depicted embodimet, force exerting means 40 is aligned so that contact means 44 are substantially centered along the rod to either side of the desired point X for initiation of bending.

Forward thrust for the yoke 42 is provided by passage of hydraulic fluid through the rearward hose 30, into the chamber 18 behind the piston head portion 22, producing hydraulic pressure forwardly against portion 22. The fluid simultaneously flows out of the chamber 18 in front of the head portion through front hose 30. Passage of hydraulic fluid in such a manner is controlled by control unit 36, by the depression of the appropriate one of buttons 38.

In operation, upon forward motion of the yoke 42, rod 52 is first engaged by rollers 44 and is then thrust into contact with roller 48. The rod then begins to bend around the stationary roller 48. As the yoke 42 advances and rod 52 bends,

rollers

44 and 48 rotate and permit motion of the apparatus along the surface of the bending rod. The contact rollers 44 roll longitudinally along the rod surface toward the free upper end of the rod, and the reaction roller 48 rolls longitudinally along the rod surface in the opposite direction. The rear of the frame plate 12 also tilts upwardly. Thus, in addition to providing forward movement of the yoke 42, the apparatus permits the tilting of the frame plate 12, and the rotation of the

rollers

44, 48 to accommodate movement of the apparatus longitudinally of and/or angularly with respect to the bending rod 52. Thus, the apparatus adapts its position and/or orientation to the changing shape of the rod. The direction of the thrust of the force exerting means and of the force transmitted to the rod is thereby changed as the rod is bent. In this connection, as the frame plate 12 tilts and the rod is bent, a major component of the force is exerted in a direction normal to the rod axis.

In a final position, as depicted in FIG. 3, rod 52 is bent to a right angle. Of course, other angles of bend may be effected in accordance with the invention. The depicted angle of tilt of frame means 12 is approximately 45. It will be appreciated that particular angles of tilt depend upon the specific dimensions of the

rollers

44, 48, as well as the distances between the centers thereof and the dimensions of the bar 52.

Positive retraction of force exerting means 40 from the advanced, forward position depicted in FIG. 3, is effected by passage of hydraulic fluid through the forward hose 30 into the chamber 18 in front of head portion 22 and exit of fluid through rear hose 30 from the chamber 18 behind head portion 22. This causes the piston means 20 to move rearwardly. This passage of fluid is controlled by control means 36 through depression of the appropriate one of buttons 38. The apparatus 10 then may be readily separated from the bent rod.

Alternatively, a return spring (not shown) of sufficient strength might be utilized for some applications in combination with a single action cylinder, although the illustrated double-action cylinder is preferred.

Bending of rods with both ends free may also be effected by apparatus in accordance with the invention.

It should be noted that apparatus 10 may be conveniently handheld by handle 56 during operation. Pump unit 32 and hose means 34 are configured so that the pump unit may rest upon the ground during operation of apparatus 10. The pump unit may be wheel mounted for movement from place to place.

By way of example, in one particular working model, the frame plate is fabricated of aluminum for light weight and has a total length of about 2 feet. The total weight of the model does not exceed about 22 pounds. Thus, an apparatus in accordance with the invention may be conveniently handheld during operation and may be transported conveniently to sites where its use is required. In this model, the hydraulic cylinder develops a thrust of about 9 tons and effectively bends a No. 7 ASTM Standard Reinforcing Bar having a nominal diameter of 0.875 inch. The initial space between the force-exerting and stationary rollers is about one inch, the force-exerting rollers advance about 3 inches, the rollers are all about 1 /2 inch thick, the front to rear length of the yoke is about 3% inches, the distance between centers of the force-exerting rollers is about 5 inches, the radius of each force-exerting roller is about k inch and the radius of stationary roller is about 1% inches.

The roller means are illustrated as solid, metal rollers. Such rollers have been found to be strong and durable while being relatively economical to produce, and troublefree in operation. Other forms of roller means to provide desired rotational movement may be utilized, as for example, ball bearings or members mounted for limited pivotal movement. Such roller means thus provide low-friction, rolling movement to accommodate the motion of the apparatus relative to the rod incident to the bending of the rod.

In a modified form, the frame plate might be pivotally mounted on a self-standing support structure rather than being handheld. Such structure could be relatively lightweight and provided with wheels for movement from place to place.

Thus, apparatus in accordance with the invention provides the capability of precise and efficient on-site bending of structural members, particularly those in place. The easy portability of the apparatus in accordance with the invention lends itself to ready and convenient use.

The description above does not define the invention, which is defined by the appended claims.

I claim:

1. Apparatus for bending elongated members comprising:

a. a rigid, portable frame having means that define a mounting side surface;

b. a hydraulic cylinder means mounted on said side surface and with its axis generally parallel to said side surface;

0. force exerting roller means coupled to the cylinder means for reciprocating movement in the direction of said axis, said force exerting means being movable between a rearward position and a forward position upon energization of said hydrailic cylinder means;

d. reaction roller means mounted on said side surface and spaced forwardly from the force exerting means when the latter is in its rearward position a sufficient distance to permit an intermediate portion of an elongated structural member to be disposed in the space therebetween;

e. a separate hydraulic fluid pumping unit connected by flexible hose means to and in fluid communication with said cylinder means supported by structure other than said frame; and

f. handle means on said frame for supporting said frame, cylinder means, force exerting roller means and reaction roller means for permitting movement thereof relative to the portion of the axis of an elongated member prior to bending thereof, as said elongated member is bent by force exerted thereon by said cylinder means and roller means;

g. said handle means and the member being bent providing the entire support for said frame, cylinder means, force exerting roller means and reaction roller means during bending of said member.

2. The apparatus of claim 1 wherein said reaction roller means and said force exerting means defining an unobstructed entrance to the space therebetween from opposite said side surface.

3. The apparatus of claim 2 wherein said reaction roller means and said force exerting means are spaced outwardly from said side surface.

4. The apparatus of claim 3 wherein said roller means comprise rollers having concave roller surfaces for centering and maintaining the structural member in place between the rollers in a reference bending plane that extends generally normal to the axes of the rollers and spaced from said side surface.

5. The apparatus of claim 1 wherein said force exerting means comprises a spaced apart pair of contact rollers.

6. The apparatus of claim 1 wherein said hydraulic cylinder means comprises a double-action cylinder for powered retraction as well as force exertion.

7. The apparatus of claim 1 wherein said frame comprises a plate of light-weight metal.

* l l l

Claims

1. Apparatus for bending elongated members comprising: a. a rigid, portable frame having means that define a mounting side surface; b. a hydraulic cylinder means mounted on said side surface and with its axis generally parallel to said side surface; c. force exerting roller means coupled to the cylinder means for reciprocating movement in the direction of said axis, said force exerting means being movable between a rearward position and a forward position upon energization of said hydrailic cylinder means; d. reaction roller means mounted on said side surface and spaced forwardly from the force exerting means when the latter is in its rearward position a sufficient distance to permit an intermediate portion of an elongated structural member to be disposed in the space therebetween; e. a separate hydraulic fluid pumping unit connected by flexible hose means to and in fluid communication with said cylinder means supported by structure other than said frame; and f. handle means on said frame for supporting said frame, cylinder means, force exerting roller means and reaction roller means for permitting movement thereof relative to the portion of the axis of an elongated member prior to bending thereof, as said elongated member is bent by force exerted thereon by said cylinder means and roller means; g. said handle means and the member being bent providing the entire support for said frame, cylinder means, force exerting roller means and reaction roller means during bending of said member.