The present invention relates generally to tool attachments for hand-held power tools and, more particularly, to a bending head for attachment to a hand-held power tool for bending the edge of sheet metal and sheets of material.
Bending head attachments for hand-held power tools are known in the art and are useful in metalworking applications such as, for example, automotive body repair work, curtain wall systems installation and air duct assembly. Bending head attachments of the prior art generally consist of an anvil member provided with support means for rigidly fastening the latter to the main body of a hand power tool driving a reciprocating member. A movable hammer member, generally pivotably mounted on the support means of the head attachment, is articulated by the reciprocating member of the power tool such that its hammer head portion performs a reciprocating movement against the comparatively fixed anvil member. The hammer head and anvil members generally have correspondingly-shaped configurations that can be imbricated into one another such as, for example, two elongated members that are both having V-shaped cross-sections, or half-circular cross-sections, or the like, depending on the desired bend along the sheet metal edge.
In use, the hand power tool equipped with the bending head attachment is turned on and the sheet metal engaging portion of the head attachment is progressively engaged along the peripheral edge of a sheet metal to be bent. As the head attachment is moved longitudinally along the edge, the reciprocating action of the hammer head against the anvil member incrementally bends an edge portion of the sheet metal.
Some examples of the prior art are U.S. Pat. No. 3,777,687, to Colman (1973), U.S. Pat. No. 4,145,907, to Barber et Al. (1979), U.S. Pat. No. 4,176,541, to Cooper (1979), and U.S. Pat. No. 6,578,404 B1, to Rousseau (2003).
While these prior art devices generally offer a bending head attachment for hand-held power tools for longitudinally bending the edge of sheet metal, they also entail one or more of the following disadvantages:
Against this background, there exist a need for a new and improved bending head. It is a general object of the present invention to provide a new and improved bending head.
In a broad aspect, the invention provides a bending head for bending the peripheral edge of a sheet of material, the bending head being usable with a power source. The bending head includes an anvil member, the anvil member defining a substantially elongated anvil surface. A hammer member is movable relatively to the anvil member substantially perpendicularly to the anvil surface. An actuator is provided for receiving power from the power source, the actuator being operatively coupled to the hammer member for moving the hammer member relatively to the anvil member when the power source powers the actuator. The hammer member defines a hammer surface, the hammer surface being substantially elongated, the hammer surface substantially opposing the anvil surface so as to define a gap therebetween. The gap defines an entry point and a substantially longitudinally opposed exit point. The sheet of material is movable along the gap between the entry and exit points. The entry and exit points define respectively an entry transversal cross-sectional configuration and an exit transversal cross-sectional configuration. The entry and exit transversal cross-sectional configurations differ from each other. The gap has a transversal cross-sectional configuration that longitudinally transitions substantially smoothly between the entry and exit transversal cross-sectional configurations.
In some embodiments of the invention, the fixed anvil member and movable hammer member are typically implemented by a pair of correspondingly-shaped elongated members defining opposing surfaces having progressively profiled cross-sections that are starting as substantially planar at one end, to a progressively rounded parabolic shape at the opposite end of the pair. The planar end of the pair of elongate members generally defines the entry point, or sheet engaging end, of the bending head attachment, while the rounded parabolic end of the pair defines the exit point.
In some embodiments of the invention, projecting perpendicularly from the opposite side of the sheet engaging side of the of the bending head attachment, there is a rotatable drive shaft that is linked to an internal rotary drive mechanism providing a reciprocating movement to the hammer member within a hammer guiding means. Furthermore, the internal rotary drive mechanism is equipped with resilient cushioning means for allowing the head attachment to perform edge bending operations on sheet material panels having relatively varied thicknesses.
Typically, to attach the bending head attachment to a hand-held rotary power tool, the chuck of the latter is first firmly tightened on the rotatable drive shaft of the head attachment, followed with attachment of the support means of the head attachment to the main body of the hand power tool using an attachment, such as an anchoring screw. To use the bending head attachment, the power tool is turned on and the sheet material engaging portion of the head attachment is straddle-engaged, preferably over an end corner of the edge to bend. The power tool is then progressively moved forwardly along the edge, thus gradually incrementally bending the latter.
It is to be noted that the progressively profiled cross-sections of the correspondingly-shaped anvil and hammer members allow to revert a bent edge to its original planar configuration by simply engaging one end of the bent edge through the exit point of the operating head attachment and move the latter rearwardly along the edge.
The relatively smooth, professionally looking bent edges that can be achieved with the bending head attachment of the present invention are useful, for example, for bending the peripheral edges of aluminium composite panels (ACP) commonly used in decorative curtain wall systems for displaying corporate colors and logos around the exterior walls of gas station franchises, grocery store chains and the like. In such applications, it is advantageous to have a hand-held power tool that can perform on-site edge bending operations on ACP that leaves little or no impact marks, waving schemes or scores on the high-quality surface along the bent edges.
Although the bending head of the present invention is described in reference to bending operations on sheet metal, it is to be understood that the head attachment is applicable to any sheet material having comparable malleability characteristics as metal sheet.
The propose bending head has correspondingly-shaped anvil and hammer members that have progressively profiled cross-sections that create relatively high-quality, professionally looking longitudinal bends along the edge of sheet material, similarly to results that would be obtained if the full longitudinal length of the bend was formed by a substantially larger, stationary press machine using a single punch-press process.
The resilient cushioning elements integrated in the rotary drive mechanism creates bent edges having a cross-section displaying a constant radius, independently of the relatively varied thicknesses of sheet material to be bent.
Typically, the proposed bending head requires a commonly available, and generally relatively inexpensive rotary power tool for its operation, such as a right angle power drill.
The proposed bending head can readily revert a bent edge to its original planar configuration without having to change any component or apply any adjustment to the head attachment. The proposed bending head is also relatively simple and economical to produce.
Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.
Referring to
Referring to
With reference to
Now referring to
Mounting plate 12 is provided with a pair of spaced apart threaded apertures 28 that are in communication with corresponding apertures 30 extending through the entry and exit guiding blocks 14 and 16. Also, apertures 32 are extending through the hammer guide block 20. Each threaded apertures 28 is substantially coaxial with one the apertures 30 and one of the apertures 32 and is provided for receiving therein a threaded clamping screws 34. Thus, clamping screws 34 allow to secure the entry and exit guiding blocks 14 and 16 and the anvil member 18 between hammer guide block 20 and the underside of the mounting plate 12.
Mounting plate 12 is further provided with an attachment for attaching the power tool to the bending head 10. For example, the attachment takes the form of an anchoring aperture 36 adapted to receive a threaded fastener 38 for rigidly fastening the bending head 10 to the hand-held power tool 26, as illustrated in
As seen in
The entry and exit guiding blocks 14 and 16, along with the anvil member 18 and the hammer member 60, are removably mountable to the base 11, which allows for the selection of components having a configuration suitable for bending the sheet of material 54 in a desired shape by exchanging these components.
Referring to
As can be observed in
In some embodiments of the invention, the entry guiding block 14 defines a guiding lip 46 protruding substantially laterally outwardly therefrom substantially adjacent to the entry point 64 for abuttingly engaging the top surface 50 of the peripheral edge 52 of the sheet metal 54 to be bent (as illustrated in
A ridge 100 projecting substantially away from the mounting plate 12 extends longitudinally along the surface of the contiguously assembled entry and exit guiding blocks 14 and 16 and intermediate anvil member 18. The ridge 100 is shaped to be engaged in a correspondingly-shaped, substantially elongated linear slot 102 provided along an edge of the surface of the hammer guide block 20 that faces the ridge 100.
Hammer guide block 20 is provided with a hammer guide for slidably receiving the hammer member 60 thereinto, the hammer guide extending substantially perpendicularly to the anvil surface 40. For example, the hammer guide takes the form of a hammer receiving passageway 106 extending substantially perpendicularly to the anvil surface 40 through the hammer guide block 20 for slidably receiving therein the compatibly-shaped hammer member 60. As seen in
An additional aperture 108 (as best shown in
The portion of the hammer surface 62 provided substantially adjacent to the entry point 64 has a cross-sectional shape generally resembling the pointed portion of an isosceles right triangle, with the sloped side generally pointing inwardly in the bending head 10, while the portion of the hammer surface 62 provided substantially adjacent to the exit point 66 has a substantially uniformly rounded, parabolic cross-sectional shape. Thus, the longitudinally profiled shape of hammer surface 62 gradually and smoothly changes from a substantially angled planar surface to a progressively rounded parabolic shape. Furthermore, compared to a horizontal reference defined by the mounting plate 12, the acute apex of the hammer surface 62 substantially adjacent to the entry point 64 is slightly closer to the mounting plate 12 than the rounded apex of the hammer surface 62 substantially adjacent to the exit point 66.
It is to be understood that the anvil and hammer surfaces 40 and 62 may have any other suitable shapes. For example, instead of bending an edge to a rounded configuration, the exit point 64 of the gap may have a right-angle bend, a V-shaped groove, or the like, along the peripheral edge 52 of the sheet metal 54.
As seen in
The carriage 70 is generally defined by an elongated member defining a pair of substantially U-shaped recesses 72 disposed in a side-by-side configuration, a carriage aperture 74 extending through the carriage 70 between the recesses 72. The pair of U-shaped recesses 72 are opened in a direction leading generally toward the mounting plate 12 and each receive a resilient cushioning elements 76 made of, for example, urethane or the like, that is substantially occupying the space provided therein, except for a portion of the cushioning elements 76 which is protruding away from the carriage 70 towards the mounting plate 12.
In other words, the hammer member 60 is reciprocating between a proximal position, seen in
Carriage aperture 74 is provided for receiving, in a substantially snug fit, a cylindrical anti-friction element such as a needle bearing 78. The assembled carriage 70, including the cushioning elements 76 and needle bearing 78, is adapted to be resiliently slidably inserted in the slot 68 of the hammer member 60.
Referring to
A retaining element such as, for example, a flat washer 112, cooperatively with a pair of set screws 114 and corresponding threaded holes (not shown) in hammer guide block 20, holds drive shaft 22 rotatably mounted within the assembled bending head 10 (as illustrated in
Thus, when a source of rotary power is applied to the tool engaging section 80 of rotatable drive shaft 22, the hammer member coupler 84 engaged in needle bearing 78 of carriage 70 induces a circular movement to the latter around the longitudinal central axis of axially aligned sections 80 and 82 of the drive shaft 22. All the while, the carriage 70 is performing a reciprocating movement within linear slot 68 of hammer member 60 which, consequently, induces a reciprocating movement to the latter within the hammer receiving passageway 106.
The bending head 10 is preferably made of any suitable rigid material such as, for example, steel, aluminium, brass, TeflonĀ®, or the like, or a combination of these, depending on the malleability of the target sheet metal to be bent. Furthermore, it is to be noted that all the components of the bending head 10 may be appropriately sized, with varied relative proportions between the components, to suit a particular application. For example, the correspondingly-shaped anvil surface 40 and hammer surface 62 may be configured to bend a substantially wider peripheral edge of a sheet metal.
To use the bending head 10, a hand-held rotary power tool such as the right angle drill 26 illustrated in
In use, as illustrated in
In a manner readily apparent to one skilled in the art of metalworking, the thickness and malleability of the sheet metal to be bent, in cooperative relation with the resiliency of the cushioning elements 76, will dictate the appropriate modulation of the forward speed and pressure to be applied by the user on the hand-held power tool 26 such that a uniform, professional looking bend is obtained along the peripheral edge 52.
It is to be noted that the bending head 10 can as well be used to flatten, or revert an existing rounded edge 53 to a planar configuration by moving the attachment head 10 in a reverse direction.
Although the above description contains many specificities, these should not be construed as limitations on the scope of the invention but as merely providing one illustration of the presently preferred embodiment of this invention. For example, mounting plate 12, entry and exit guiding blocks 14 and 16 and anvil member 18 may all be molded as a single-piece element using a conventional molding process. Also, a thin layer of material, such as a fabric, TeflonĀ®, or the like, may cover the anvil surface 40 and hammer surface 62 for an even better protection of the sheet metal to be bent. Yet another example is a bending head 10 that would be made an integral part of a dedicated rotary power tool, which may be either a portable or stationary power tool.
Although the present invention has been described hereinabove by way of preferred embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims.
Number | Date | Country | Kind |
---|---|---|---|
0725364.4 | Dec 2007 | GB | national |
Number | Name | Date | Kind |
---|---|---|---|
2783668 | Frolich | Mar 1957 | A |
3213817 | Hunziker | Oct 1965 | A |
3777687 | Colman, Jr. | Dec 1973 | A |
3987740 | Merson | Oct 1976 | A |
4145907 | Barber et al. | Mar 1979 | A |
4176541 | Cooper | Dec 1979 | A |
5090101 | Welty | Feb 1992 | A |
6345526 | Deriaz et al. | Feb 2002 | B1 |
6578404 | Rousseau | Jun 2003 | B1 |
Number | Date | Country | |
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20090165527 A1 | Jul 2009 | US |