GB2088760A

GB2088760A - Tube and section bending

Info

Publication number: GB2088760A
Application number: GB8135029A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-11-21
Filing date: 1981-11-20
Publication date: 1982-06-16
Also published as: AU7766781A; ZA818129B

Abstract

A machine for bending tube or light walled extrusions comprises a support frame, a pair of slide arms 4, 5 mounted thereto about an upright pivot axis whereby to be moveable between a position in which said arms lie alongside each other to a position in which they extend oppositely from the axis, a shaft member 10 which extends upwardly to mount a former 9 thereon, one slide member including a slide block 11a moveable thereon to control the position of a guide 15 in relation to said former; the other slide arm including a slide block 19 movable thereon to control the position of clamp means 19a in relation to a workpiece 16. The clamp means 19a are adapted to clamp a free end 16a of the workpiece. Means 6 to move one of the slide arms about its pivot axis to perform the bending action on said workpiece are provided. <IMAGE>

Description

SPECIFICATION Improved tube bending machine This invention relates to a tube bending apparatus. Existing tube bending devices which give good results are complex, expensive and difficult to service. The present invention provides a simpler type apparatus which is not unduly difficult to service and the manufacture of which is simple and economical. The operation thereof is also a routine task readily learned by unskilled labour.

According to the invention there is provided a machine for bending tube or like elongate members comprising a support frame, a pair of slide arms mounted thereto about an upright pivot axis whereby to be moveable between a position in which said arms lie alongside each other to a position in which they extend oppositely from their respective pivot axis of one of said slide arms being embodied in the shaft member which extends upwardly to mount a former thereon, said one slide member including a slide block moveable thereon to control the position of a former guide in relation to said former; the other slide arm including a slide block moveable thereon to control the position of clamp means in relation to a workpiece held in said form, said clamp means being adapted to clamp a free end of said workpiece, and means to move said one slide arm about its pivot axis to perform the bending action on said workpiece.

Further objects and advantages of the invention will become apparent from a consideration of the following description and accompanying drawings in which:~ Figure 1 shows a perspective view of the machine of the invention; and Figure 2 shows a perspective view of the Fig. 1 machine in operation on a workpiece.

In the drawings a tube bender machine indicated generally as 1 comprises various equipment mounted on a frame having a main structural top member 3 supported by a plurality of legs 2. Two slide arms indicated generally by 4 and 5 pivot about vertical pin or shaft members 4a and 10 respectively from positions parallel to 3 (Fig. 1) to positions orthogonal thereto (Fig. 2). A double acting hydraulic cylinder 6 (or alternatively it may be operated e.g. by compressed air) is mounted to the frame at one end and the ram is connected to arm 5 to move it about pivot shaft 10. Line connectors 7, 8 attach to a supply of controlled pressurized fluid for operating the rams of cylinder 6. In this respect the power source is not shown, but it could be motor, reservoir or manual supplied e.g. an electric motor driving and fluid pump via an accumulator system.A former 9 is mounted on pivot shaft 10. Notched bar 11 can be adjusted longitudinally of slide arm 5 to move slide block 1 la. This is done by means of a ratchet arrangement operated by lever 13, and locking in position is done by a cam arrangement operated by lever 12. Consequently, former guide 15, which is held in block 11 a by means of guide bar or holder 14, connected to 15 by crosspiece 14a (Fig.

2) can be moved parallel to slide arm 5 to 'load' workpiece 16 in former 9. Note that guide holder 14 is slideable longitudinally of its length in block 11 a, whereby to correctly position former guide 15. Slide arm 4 includes clamp lever arrangement 17 for holding end 16a of workpiece 16. Lever 18 controls a clamp device for setting slide block 19 (which comprises lever arrangement 17 and faces 19a) in position on slide 19b. Tie bar 20 connects between the upper portion of pivot shaft 10 and the distal end of slide arm 5 to which it is affixed by bolt means 20a to a block mounted on pivot 20b, thus retaining former 9 on shaft 10.Tie bar 20 can thus pivot in a vertical plane about the horizontal pivot 20b, thus releasing the upper end of shaft 10, and enabling former 9 to be removed and replaced by a former of different curvature form and have a different crosssection groove for other than round workpieces.

The lower end 1 Oa of pivot shaft 10 may be held in socket 21 on linkage arrangement 22 operated by foot pedal 23, the whole being supported on base 24. Operation of pedal 23 raises shaft 10 and former 9 hence enabling bends to be made in different planes. Note that the pivoting action of slide arm 5 under action of the ram of cylinder 6 performs the actual bending of workpiece 16; however, the amount of bending is increased by reason of the pivoting action of slide arm 4, which clamps end 16a of workpiece 16.

When clamped in the position shown in Fig.

2, it enables a further basic 90 bending over end above that possible when it is in its Fig. 1 position i.e. in operation from Fig. 1, slide arm 5 moves out to a position or through to member 3, thus making a basic initial 90 bend in workpiece 16. Slide arm 4 is then unclamped and the ram of cylinder 6 retracted-arm 4 is then orthogonal to member 3 while arm 5 lies alongside said member.

Further operation of the ram of cylinder 6 then causes a further basic 90 bend in the workpiece 16 and the apparatus is then in the fully operated position shown in Fig. 2. The term "basic" is used as the final amount of bending may depend on the elasticity of the workpiece.

By means of this invention any metal extrusions including stainless steel, mild steel, aluminium, copper et al can be bent. A desirable minimum wall thickness is 1.2mm or 18 gauge. A preferred maximum wall thickness is 3.0mm or 0.125 inch. The tube capacity may be 1 5-75mm i.e. 3-3 inches. The weight of a representative machine is approximately 163kg i.e. 360it. The unit described could be powered e.g. by a 240 volt single phase electric motor/hydraulic power pack developing a pressure of about 2000psi.

Member 5 may be replaced by a sliding member which telescopes and moves in a reciprocal manner for a sufficient distance from the throat of the machine to close and open whereby the tube being worked may be bent and removed respectively. This embodied ment is an improvement on that particularly shown and it allows the bending operation to take place in one movement i.e. the machine is serni-automated.

it should be noted that the present invention is not restricted to the particular construction exemplified, but is to be given a wider connotation than the specific denotation: for example the ram could be powered by a manually operated hydraulic pump or could be substituted by a manual hydraulic pick or screwjack. Similarly, while the machine is shown supported on legs, it could in practice be bolted to a bench. Again, the pipe bender described in Australian Patent No. 508,040 could be affixed to the frame of the present apparatus, whereby a composite machine is formed.

Claims

1. A machine for bending tube or like elongate members comprising a support frame, a pair of slide anns mounted thereto about upright pivot axis whereby to be movea ble between a position in which said arms lie alongside each other to a position in which they extend oppositely from their respective pivot axis, the pivot axis of one of said slide arms being embodied in the shaft member which extends upwardly to mount a former thereon, said one slide member including a slide block moveable thereon to control the position of a former guide in relation to said former; the other slide arm including a slide block moveable thereon to control the position of clamp means in relation to a workpiece held in said form, said clamp means being adapted to clamp a free end of said workpiece, and means to move said one slide arm about its pivot axis to perform the bending action on said workpiece.

2. A machine as defined in claim 1, wherein said means to move said one slide arm comprises fluid pressure operated cylinder and ram means.

3. A machine as defined in claim 1 wherein the slide block on said one slide arm is positioned by means of a notched bar aligned with the slide arm, the position of said bar being controlled by a lever operated ratchet mechanism, and said bar being locked in position by a lever operated cam mecha nism.

4. A machine as defined in any preceding claim wherein said support frame is mounted on a plurality of legs.

5. A machine as defined in any preceding claim wherein said pivot shaft of said one slide arm extends below said support frame to be connected to a pedal operated linkage whereby said pivot shaft and the former mounted thereon can be moved to different vertical positions for bending in more than one place.

6. A machine for bending tube or like elongate members substantially as hereinbefore described with respect to the accompanying drawings.