Tube bending apparatus
A portable bending apparatus includes a frame, a major gear, a forming member, a workpiece guide and a gear mechanism. The major gear is mounted rotatably to the frame about a bending axis. The forming member is carried on a front side face of the major gear, the forming member having an arcuate forming surface and a restraint. The workpiece guide is mounted to the frame. The gear mechanism has an input connected to a geartrain connected to an output gear, the geartrain providing a speed reduction between the input and the output gear. The input is configured to receive rotary input from a handheld motorized driver, such as a portable drill. The output gear is enmesh with gear teeth of the major gear. When a workpiece to be bent is placed on the tube guide and within the restraint and against the forming surface, and the input receives rotary motion from the handheld motorized driver, the restraint and the forming surface are driven to orbit about the bending axis and the forming surface bends the workpiece braced between the restraint and the workpiece guide.
The present invention relates to tube bending apparatus. Particularly, the present invention is directed to an improved portable tube bending apparatus.
BACKGROUND OF THE INVENTIONKnown tube bending apparatus typically comprise a mandrel and forming member components supported for relative angular displacement about a bending axis. The mandrel has a bending groove extending about the bending axis. A tube positioned between the mandrel and forming member is adapted to be bent during selected relative angular displacement of the mandrel and forming member about the bending axis. Relative angular displacement between the mandrel and forming member can be achieved in a number of different ways.
In some motor driven benders, the mandrel is mounted on a support and the forming member is mounted on the support for angular displacement relative to the mandrel and is so displaced by a motorized drive arrangement.
U.S. Pat. Nos. 5,022,249; 4,986,104; and 5,301,530 describe portable tube bending apparatus.
The present inventors have recognized that a need exists to improve the aforementioned tube benders and to provide a tube bender that is lightweight and easily portable, that is of a simplified construction, and that can bend tubes to variable bend radii.
SUMMARY OF THE INVENTIONThe invention provides an improved portable bending apparatus for bending tubes or other elongated workpieces.
According to the preferred embodiment, the portable bending apparatus includes a frame, a major gear, a forming member, a tube guide and a gear mechanism. The major gear is mounted rotatably to the frame about a bending axis. The major gear has gear teeth on an outer perimeter thereof. The forming member is fixed to a front side face of the major gear, the forming member having at least one arcuate forming surface and a restraint. The tube guide is mounted to the frame. The gear mechanism has an input connected to a geartrain connected to an output gear. The geartrain provides a speed reduction between the input and the output gear.
The input is configured to receive rotary input from a handheld motorized driver, such as a portable drill. Alternately, a dedicated, permanently attached electric motor can be mounted to the frame.
The output gear is enmesh with the gear teeth of the major gear. When a workpiece to be bent is placed on the tube guide, or in some cases simply held by the operator, and within the restraint and against the forming surface, and the input receives rotary motion from the handheld motorized driver, the restraint and the forming surface are driven to orbit about the bending axis and the forming surface bends the workpiece braced between the restraint and the tube guide, or braced between the restraint and the operators hand.
Preferably, the frame comprises a base bar, a vertical column, and an angular brace. The vertical column is fixed at a base end to the base bar and at an elevated end to a gear mechanism support plate. The angular brace is fixed at a base end to the base bar and at an elevated end to the vertical column. The tube guide is mounted to the base bar.
A strut can be attached to the frame and extends to a position to engage a body of the motorized driver. The strut is sufficiently rigid to resist reaction torque exerted by the input on the motorized driver. The strut can include a hook end configured to engage a handle of the motorized driver.
While the present invention is advantageous in connection with portable, motor driven tube benders, it will be appreciated that the invention is applicable to bending other workpieces such as rods.
Numerous other advantages and features of the present invention will be become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.
While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred features of the invention. It will be understood, however, that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific form of the combination of features that are illustrated and described.
The apparatus includes a frame 28 comprising a base bar 32, a vertical column 36, and an angular brace 38. The members 32, 36, 38 can be rectangular cross section members, solid or hollow. The members can be composed of steel or aluminum, or other material. The members 32, 36, 38 can be fastened together, cast together, welded together, or otherwise formed as a single unit. Four rubber feet 32a can be mounted to the base bar to support the frame 28 off of a horizontal surface.
A tube guide 42 is fixed to the base bar 32, such as by fasteners 43. Fastening is advantageous in that different guides for different size conduits or tubes can be attached as desired. A main gear 50 and a gear mechanism 54 are mounted to the column 36. The main gear 50 is rotatably mounted to the column 36 by a bearing 55 about a bending axis 56. The vertical column 36 can include widened portions or plates 36a, 36b (
The main gear 50 can include a bending angle scale 51 that indicates the degree of bending of a workpiece during operation of the apparatus.
A strut 62 (
The strut 62 resists opposite reaction torque on the drill handle 24a exerted by the gear mechanism 54 due to the drill driving the apparatus 20 and bending the tube T. This reduces the exertion required by an operator of the drill 24 and avoids a sudden twisting torque on the operator's wrist. Also, the strut supports the drill handle 24a vertically to resist the torque caused by gravity, i.e. the overhanging load of the weight of the drill about the drill chuck connection to the gear mechanism. This support also relieves the operator the exertion of holding up the drill.
The shoe 58 includes one or more forming surfaces. In the illustrated embodiment two forming surfaces 80, 82 are provided. The forming surfaces are generally oriented with a concavity facing away from the bending axis 56. The forming surface 80 is behind the forming surface 82 in
At an end of each bending surface 80, 82 a restraint 84, 86 is fixed to rotate with the bending surface 80, 82. Preferably, the restraints 84, 86 are formed in unitary fashion with the shoe 58. The restraints 84, 86 are open, hook-like portions (
Also,
In operation, the shoe 58 is rotated to a start position as shown in
As shown in the alternate section of
The apparatus 20 provides a portable tube bending apparatus that is configured in an easy to use upright configuration. The apparatus can be driven by a portable electric drill that is also oriented in an easy to use orientation, inclined upwardly toward the user. The apparatus illustrated uses a minimal frame that can be supported and/or attached to scaffolding or lift baskets of construction equipment so that electrical work can proceed effectively at hard to access locations. For attaching to external supports, the base bar 32 can be a channel as shown in
From the foregoing, it will be understood that numerous variations and modifications may be effected without departing from the true spirit and scope of the novel concept of the invention. It is to be understood that no limitation with respect to the specific method, apparatus, and product illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.
Claims
1. A portable bending apparatus for bending tubes, comprising:
- a frame;
- a major gear mounted rotatably to said frame about a bending axis, said major gear having gear teeth on an outer perimeter thereof;
- a forming member carried on a front side of said major gear, said forming member having an arcuate forming surface and a restraint;
- a tube guide mounted to said frame;
- a gear mechanism having an input connected to a geartrain connected to an output gear, said geartrain providing a speed reduction between the input and the output gear, wherein said input is configured to receive rotary input from a motor;
- said output gear enmesh with said gear teeth of said major gear; and
- wherein when a tube to be bent is placed on said tube guide and within said restraint and against said forming surface and when said input receives rotary motion from a motor, said restraint and said forming surface are driven to orbit about said bending axis and said forming surface bends said tube between said restraint and said tube guide.
2. The portable bending apparatus according to claim 1, wherein said frame comprises a base bar, a vertical column, and an angular brace, said vertical column fixed at a base end to said base bar and at an elevated end to said gear mechanism support plate, said angular brace fixed at a base end to said base bar and at an elevated end to said vertical column, said tube guide mounted to said base bar.
3. The portable bending apparatus according to claim 2, further comprising a strut attached to said frame and extending to a position to engage a body of said motor to resist torque.
4. The portable bending apparatus according to claim 3, wherein said strut includes a U-shaped end configured to engage a handle of said motor.
5. A portable bending apparatus for bending workpieces, comprising:
- a frame;
- a major gear mounted rotatably to said frame about a bending axis, said major gear having gear teeth on an outer perimeter thereof;
- a forming member carried on a front side of said major gear, said forming member having an arcuate forming surface and a restraint;
- a gear mechanism having an input connected to a geartrain connected to an output gear, said geartrain providing a speed reduction between the input and the output gear, wherein said input is configured to receive rotary input from a motor;
- said output gear enmesh with said gear teeth of said major gear; and
- wherein when a workpiece to be bent is placed within said restraint and against said forming surface and said workpiece is restrained at a reaction force position located along said workpiece on a side of said forming surface opposite said restraint and said input receives rotary motion from a motor, said restraint and said forming surface are driven to orbit about said bending axis and said forming surface bends said workpiece between said reaction force position and said restraint.
6. The portable bending apparatus according to claim 5, wherein said frame comprises a base bar, a vertical column, and an angular brace, said vertical column fixed at a base end to said base bar and at an elevated end to said gear mechanism support plate, said angular brace fixed at a base end to said base bar and at an elevated end to said vertical column.
7. The portable bending apparatus according to claim 5, wherein said workpiece comprises a tube and said apparatus comprises a tube guide at said reaction force position, mounted to said frame.
8. The portable bending apparatus according to claim 5, further comprising a strut attached to said frame and extending to a position to engage a body of said motor to resist torque.
9. The portable bending apparatus according to claim 8, wherein said strut includes a U-shaped end configured to engage a handle of said motor.
10. A portable bending apparatus for bending workpieces, comprising:
- a frame;
- a major gear mounted rotatably to said frame about a bending axis, said major gear having gear teeth on an outer perimeter thereof;
- a forming member fixed to a front side of said major gear, said forming member having an arcuate forming surface and a restraint;
- a gear mechanism having an input shaft connected to a geartrain connected to an output gear, said geartrain providing a speed reduction between the input shaft and the output gear, wherein said input shaft is configured to receive rotary input from a portable handheld motorized drill;
- a portable handheld motorized drill having a chuck to engage said input shaft;
- said output gear enmesh with said gear teeth of said major gear; and
- wherein when a workpiece to be bent is placed within said restraint and against said forming surface and said workpiece is restrained at a reaction force position located along said workpiece on a side of said forming surface opposite said restraint and said input receives rotary motion from a handheld motorized drill, said restraint and said forming surface are driven to orbit about said bending axis and said forming surface bends said workpiece between said reaction force position and said restraint.
11. The portable bending apparatus according to claim 10, wherein said frame comprises a base bar, a vertical column, and an angular brace, said vertical column fixed at a base end to said base bar and at an elevated end to said gear mechanism support plate, said angular brace fixed at a base end to said base bar and at an elevated end to said vertical column.
12. The portable bending apparatus according to claim 10, wherein said workpiece comprises a tube and said apparatus comprises a tube guide at said reaction force position, mounted to said frame.
13. The portable bending apparatus according to claim 10, further comprising a strut attached to said frame and extending to a position to engage a handle of said drill to resist reaction torque.
14. The portable bending apparatus according to claim 13, wherein said strut includes a hook end configured to engage a handle of said drill.
15. The portable bending apparatus according to claim 10, wherein said frame comprises a base bar, a vertical column, and an angular brace, said vertical column fixed at a base end to said base bar and at an elevated end to said gear mechanism support plate, said angular brace fixed at a base end to said base bar and at an elevated end to said vertical column and where said base bar comprises a clamp mechanism to secure said frame to external structure.
Type: Application
Filed: Feb 9, 2007
Publication Date: Aug 14, 2008
Inventors: Christopher J. Boon (Oswego, IL), Robert A. Kolarits (Oswego, IL)
Application Number: 11/704,406
International Classification: B21D 7/02 (20060101);