Patent ID: 6571841
Filing Date: 2003-06-03
Classification: B25B,B27H,B27M,Y10S,Y10T

Abstract:
A unit for bending wood into arcuate shapes comprising:D) a planar magnetically attractive workpiece-supporting surface; E) a plurality of form blocks, each of which includes (1) an aluminum body having (a) a top, (b) a bottom, (c) a longitudinal axis extending between the top and the bottom of the body of each form block, (d) a workpiece-engaging side extending between the top and the bottom of the body of each form block, (e) a second side spaced from the workpiece-engaging side of each form block, (f) a transverse axis extending between the workpiece-engaging side and the second side of each form block, (g) a handle section, (h) a channel defined in the workpiece-engaging side of each form block, and (i) an electromagnet accommodating section defined in the body of each form block adjacent to the bottom of each form block, (2) a magnet-supporting base slidably received in the channel on the workpiece-engaging side of each form block, (3) a plurality of permanent magnets magnetically fixed to the magnet-supporting base in each form block, the permanent magnets being spaced apart from each other along the longitudinal axis of each form block, (4) an electromagnet unit accommodated in the electromagnet accommodating section on each form block, (5) an electric control circuit electrically connecting the electromagnet unit in each form block to a power source, which includes (a) an on/off switch in the electronic control circuit of each electromagnet unit of each form block and mounted on the body of each electromagnet unit of each form block, and (b) an on/off indicator in the electronic control circuit of each electromagnet unit of each form block and mounted on the body of each electromagnet unit of each form block, (6) fasteners fastening the electromagnet unit of each form block to the body of each form block, and (7) a friction unit movably mounted on the bottom of the body of each form block and which includes (a) blind-ended bore defined in the body of each form block and extending from the bottom of the body of each form block along the longitudinal axis of the body of each form block toward the top of the body of each form block, (b) a screw thread defined in the body of each form block adjacent to the blind-ended bore of the friction unit, (c) a friction element having a body with a screw thread thereon that engages the screw thread on the body of each form block adjacent to the blind-ended bore of the friction unit and a friction head on the body of the friction element of the friction unit, (d) a counter-bore defined in the body of each form block adjacent to the blind-ended bore of the friction unit, and (e) the friction head of the friction element of the friction unit being movable in the blind-ended bore and in the counter-bore of the friction unit on each form block between a workpiece-surface engaging position and a stored position and frictionally engaging the workpiece-supporting surface when the friction element is in the workpiece-supporting surface engaging position and the form block on which the friction unit is mounted is located on said workpiece-supporting surface; C) a plurality of aluminum clamp blocks, each clamp block including (1) a body which includes (a) a top, (b) a bottom, (c) a longitudinal axis extending between the top of each clamp block and the bottom of each clamp block, (d) a first side, (e) a second side, (f) a transverse axis extending between the first side and the second side of each clamp block, (g) an electromagnet accommodating section defined in the body of each clamp block adjacent to the bottom of each clamp block, (h) a front surface, (i) a rear surface, (j) a longitudinally extending blind-ended bore defined from the top of the body of each clamp block toward the bottom of the body of each clamp block along the longitudinal axis of the body of each clamp block and which is located between the front surface and the rear surface of the body of each clamp block and near the first side of the body of each clamp block, (k) two transversely extending blind-ended bores defined from the first side of the body of each clamp block toward the second side of the body of each clamp block along the transverse axis of the body of each clamp block and between the front surface and the back surface of the body of each clamp block and intersecting the longitudinally extending blind-ended bore defined in the body of each clamp block and being spaced apart from each other along the longitudinal axis of the body of each clamp block, (l) a width measured between the first side to the second side of the body of each clamp block, (m) a length measured between the top and the bottom of the body of each clamp block, and (n) a thickness measured between the front surface and the rear surface of the body of each clamp block, (2) a rack located in each of the two transversely extending blind-ended bores defined in the body of each clamp block, each rack extending out of the transversely extending blind-ended bore and having a distal end located outside of the transversely extending blind-ended bore and a proximal end located inside the transversely extending blind-ended bore, (3) a workpiece-engaging element mounted on the distal ends of the two racks of each clamp block and including (a) a body having (i) a top end located adjacent to the top of the body of the clamp block on which the workpiece-engaging element is mounted, (ii) a bottom end located adjacent to the bottom of the body of the clamp block on which the workpiece-engaging element is mounted, (iii) a front side located adjacent to the front surface of the body of the clamp block on which the workpiece-engaging element is mounted, (iv) a rear side located adjacent to the rear surface of the body of the clamp block on which the workpiece-engaging element is mounted, (v) a longitudinal axis extending from the top end of the body of the workpiece-engaging element to the bottom end of the workpiece-engaging element, (vi) a length which is essentially equal to the length of the body of the clamp block on which the workpiece-engaging element is mounted, (vi) a thickness that is essentially equal to the thickness of the body of the clamp block on which the workpiece-engaging element is mounted, (vii) a workpiece-engaging surface, (viii) a second surface located adjacent to the first side of the body of the clamp block on which the workpiece-engaging element is mounted, and (ix) two rack distal end receiving blind-ended bores defined in the body of each workpiece-engaging element from the second surface of the body of each workpiece-engaging element toward the workpiece engaging surface of the body of the workpiece-engaging element, the distal ends of each of the racks being accommodated in the one of the rack distal end receiving blind-ended bores to attach each workpiece-engaging element to the body of one clamp block of the plurality of clamp blocks, and (4) a pinion unit associated with each clamp block and having (a) an elongated pinion gear located in the longitudinally extending blind-ended bore defined in the body of each clamp block and intersecting both of the two transversely extending blind-ended bores defined in the body of each clamp block and engaging the rack in each of the two transversely extending blind-ended bores defined in the body of each clamp block, (b) a distal end on.the elongated pinion gear and positioned outside of the longitudinally extending blind-ended bore defined in the body of each clamp block, (c) a handle on the distal end of the elongated pinion gear, (d) the elongated pinion gear meshingly engaging the racks to move those racks into and out of the transversely extending blind-ended bores defined in the body of each clamp block as the handle is rotated to move the workpiece-engaging element toward and away from the body of the clamp block on which the workpiece-engaging element is located, and (e) a lock on the top of the body of each clamp block and engaging the elongated pinion gear to prevent retrograde rotation of the elongated pinion gear when the lock is engaged with the elongated pinion gear, the lock including (i) a gear having gear teeth fixedly mounted on the elongated pinion gear for rotation therewith, (ii) a dog element pivotally mounted on the body of the clamp block and having a distal end, (iii) the dog element being movable between a rotation permitting position with the distal end thereof spaced from the gear teeth of the gear of the lock and a rotation preventing position with the distal end thereof engaging the gear teeth of the gear of the lock, (iv) a biasing element mounted on the body of the clamp block and engaging the dog element and biasing the dog element into the rotation preventing position, and (v) a release element mounted on the body of the clamp block and engaging the dog element to move the dog element into the rotation permitting position when the release element is manually activated, (5) an electromagnet accommodated in the electromagnet accommodating section defined in the body of each clamp block adjacent to the bottom of each clamp block, (6) an electric control circuit electrically connecting the electromagnet in each clamp block to a power source, which includes (a) an on/off switch in the electronic control circuit of each electromagnet of each clamp block and mounted on the body of each clamp block, and (b) an on/off indicator in the electronic control circuit of each electromagnet of each clamp block and mounted on the body of each clamp block, and (7) fasteners fastening the electromagnet of each clamp block to the body of each clamp block; D) a trammel which includes (1) a base having (a) a top section, (b) a bottom section, (c) a rotatable connection connecting the top section to the bottom section so the top section will rotate with respect to the bottom section, (d) a permanent magnet in the bottom section of the base of said trammel, (e) said trammel being mounted on said workpiece-supporting surface by the permanent magnet of said trammel, and (g) a pivot element on the top section of the base of said trammel, (2) a trammel arm having (a) a proximal end pivotally connected to the pivot element of the base of said trammel, (b) a distal end, (c) two side edges that extend from the distal end of said trammel arm to the proximal end of said trammel arm, (d) a width dimension extending between the two side edges of said trammel arm, (e) a multiplicity of markings on the trammel arm, (f) a stop element slidably mounted on said trammel arm to move toward and away from the distal end of said trammel arm and having (i) a rear edge that extends along the width dimension of said trammel arm and has a dimension that is greater than the width dimension of said trammel arm, (ii) ends on the rear edge of the stop element of said trammel that are spaced apart from the side edges of said trammel arm with the rear edge of the stop element of said trammel arm extending away from the side edges of said trammel arm when the stop element is mounted on said trammel arm, (iii) the stop element being frictionally held on the trammel arm of said trammel, (e) a sight gauge slidably mounted on said trammel arm to move toward and away from the distal end of said trammel arm and having a gauge mark thereon which is located to be aligned with one of the markings on the trammel arm when the sight gauge is mounted on said trammel arm, (f) a lock on the sight gauge of said trammel arm to lock the sight gauge in place on said trammel arm, (g) said sight gauge being frictionally held on the trammel arm of said trammel, (h) when said trammel arm is mounted on the base of said trammel and said base is mounted on said workpiece-supporting surface, said trammel arm being rotatable in a plane that is parallel to said workpiece-supporting surface and said trammel arm being pivotable in a plane that is upright with respect to said workpiece-supporting surface; and E) the rear edge of the stop element of said trammel arm being movable with said trammel arm and defining a continuous and uninterrupted path over said workpiece-supporting surface and over said workpiece-supporting surface when said trammel arm is rotated about the base of said trammel arm when said trammel arm is mounted on said workpiece-supporting surface, the stop element of said trammel arm defining a form block location at any location along the continuous and uninterrupted path; and F) a form block at each form block location.