US3913370A

US3913370A - Supplemental bending attachment for portable sheet material bending brake

Info

Publication number: US3913370A
Application number: US403816A
Authority: US
Inventors: Douglas G Break
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-10-05
Filing date: 1973-10-05
Publication date: 1975-10-21
Anticipated expiration: 1992-10-21

Abstract

A horizontally-elongated upstanding stationary clamping member having a horizontal base portion adapted to be fixedly mounted in the jaws of a conventional portable bending brake has a forward workpiece-engaging face thereon and intermediate its upper and lower ends has a horizontal pivotal connection with a horizontally-elongated upstanding movable workpiece clamping member having a rearward workpiece-engaging face swingable around the pivot axis toward and away from the stationary clamping member into and out of clamping engagement with an elongated portion of a previously-partially-bent workpiece of sheet material inserted therebetween. Near its upper end the movable workpiece-clamping member has a movable locking member pivotally connected thereto in spaced relationship to the horizontal pivotal connection thereof with the stationary clamping member and movable into and out of locking engagement with a locking abutment on the upper portion of the stationary clamping member to lock said clamping member into clamping engagement with the previously-bent workpiece portion inserted therebetween.

Description

United States Patent 1191 Break 1451 Oct. 21, 1975 SUPPLEMENTAL BENDING ATTACHMENT FOR PORTABLE SHEET MATERIAL BENDING BRAKE Douglas G. Break, 30262 Astor, Farmington, Mich. 48024 22 Filed: Oct. 5, 1973 21 Appl. No.: 403,816

[76] Inventor:

Primary Examiner-Michael J. Keenan Attorney, Agent, or Firm-Willis Bugbee [57] ABSTRACT A horizontally-elongated upstanding stationary clamping member having a horizontal base portion adapted to be fixedly mounted in the jaws of a conventional portable bending brake has a forward workpieceengaging face thereon and intermediate its upper and lower ends has a horizontal pivotal connection with a horizontally-elongated upstanding movable workpiece clamping member having a rearward workpieceengaging face swingable around the pivot axis toward and away from the stationary clamping member into and out of clamping engagement with an elongated portion of a previous]y-partially bent workpiece of sheet material inserted therebetween. Near its upper end the movable workpiece-clamping member has a movable locking member pivotally connected thereto in spaced relationship to the horizontal pivotal connection thereof with the stationary clamping member and movable into and out of locking engagement with a locking abutment on the upper portion of the stationary clamping member to lock said clamping member into clamping engagement with the previouslybent workpiece portion inserted therebetween.

10 Claims, 8 Drawing Figures US. Patent} 0r.21, 1975 Shetlof3 3,913,370 I U.S Patent Oct. 21, 1975 Sheet2 of3 3,913,370

US. Patent Oct. 21, 1975 Sheet30f3 3,913,370 r SUPPLEMENTAL BENDING ATTACHMENT FOR PORTABLE SHEET MATERIAL BENDING BRAKE BACKGROUND OF THE INVENTION Portable bending brakes have previously been provided for bending workpieces of sheet material through a range of angles varying from substantially to 120. Such conventional portable bending brakes possess the advantages of manual operation, simplicity of design, ease of transportation and handling and low cost of maintenance. Nevertheless, such portable bending brakes have the disadvantage of being limited to the above-mentioned range of angles not exceeding approximately l. Stationary bending brakes, having bending ranges greater than approximately I20 are too heavy, unwieldy and mechanically complicated to be hauled to the job where the bending is to be done, such as, for example, the bending of sheet material siding, roofing, flashing or gutters of building structures.

SUMMARY OF THE INVENTION The present supplemental bending attachment, when installed in a conventional portable bending brake, enlarges the bending range thereof by enabling the supplemental bending of a sheet material workpiece previously bent to the maximum angle permitted by the conventional portable bending brake. The present invention particularly resides in the upstanding stationary clamping member having a horizontal base portion for mounting in the conventional portable bending brake jaws, and also in a movable workpiece clamping member pivoted to the stationary clamping member intermediate the upper and lower ends thereof and movable toward and away from the stationary clamping member. Pivoted to one of these clamping members near its upper end above the pivotal connection between the clamping members is a movable locking member movable into and out of locking engagement with the upper portion of the other clamping member so as to hold one part of the previously-bent workpiece immovably therebetween while performing a supplemental bending operation upon another part of the workpiece by manual upward swinging of the bending member of the conventional portable bending brake. In the drawings,

FIG. 1 is a fragmentary perspective view of a first form of the supplemental bending attachment of the present invention;

FIG. 2 is a vertical cross-section taken along the line 22 in FIG. 1, with the attachment in its closed position without a workpiece therein;

FIG. 3 is a vertical cross-section similar to FIG. 2 but with the attachment in its open position ready to receive one part of a previously partially-bent workpiece;

FIG. 4 is a vertical cross-section similar to FIGS. 2 and 3 but with one part of a sheet material workpiece clamped between the clamping members of the attachment ready for bending of the other part thereof;

FIG. 5 is a fragmentary perspective view of a conventional portable bending brake with the supplemental bending attachment of the present invention mounted therein and with one part of a workpiece mounted in the supplemental bending attachment between the clamping members thereof, with the other part of the workpiece ready to be bent further by the manual upward-swinging of the bending member of the conventional portable bending brake;

FIG. 6 is a cross-section similar to FIGS. 2, 3 and 4 but showing a second form of the invention;

FIG. 7 is a vertical cross-section through the second form of the invention shown in FIG. 6, with the clamping members thereof in a closed position without a workpiece therein; and

FIG. 8 is a vertical cross-section similar to FIG. 7 but with the modified attachment in its open position ready to receive one part of a previously partially-bent workpiece.

Referring to the drawings in detail, FIGS. I to 4 inclusive show an inclined embodiment of the supplemental bending attachment of the present invention, generally designated 10, removed from the conventional sheet material bending brake 14, in which FIG. 5 shows the attachment l0 and workpiece mounted. The inclined supplemental bending attachment 10 includes an upstanding rearwardly-inclined stationary clamping member 12 having at its lower edge a rearwardly-bent horizontal mounting flange 16. The stationary clamping member 12 includes a rearwardly inclined lower stationary workpiece clamping portion 18 integral at its lower end with the horizontal mounting flange 16. A substantially horizontal intermediate portion 20 extends rearwardly from the upper end of the lower stationary workpiece clamping portion 18. An upper locking abutment portion 22 projects upward from the rearward end 24 of the intermediate portion 20. The mounting flange 16 is joined to the lower end of the stationary workpiece clamping portion 18 at an acute-angled corner edge 28 above which is a rearwardly-projecting horizontal rib 26 having a substantially horizontal lower surface 30 spaced a short distance above the upper surface 32 of the horizontal mounting flange 16. An internal pivot groove 34 of arcuate cross-section is formed in the rearward end 24 of the intermediate portion 20 of the stationary clamping member 12 below the substantially vertical forward abutment face 36 of the upstanding locking abutment portion 22. Horizontally spaced

ribs

38 and 40 project upward from the upper face 42 of the intermediate portion 20 near the forward and rearward ends thereof. Pivotally connected to the stationary clamping member 12 at the pivot groove 34 and swingable upward and downward relatively thereto is a movable clamping member 50 having a movable lower workpiececlamping portion 52 integral at its upper end with a rearwardly-extending pivot arm portion 54. The movable clamping member 50 terminates at its lower end in a bending fulcrum edge 56 around which the material is bent. Its movable lower workpiece clamping portion; 52 is swingable into and out of workpiececlamping engagement with the support portion 18 to hold one part of a previously partially-bent sheetmaterial workpiece 100 therebetween while another part thereof is subjected to the bending operation around the workpiece-bending edge 56 described more fully below.

The movable clamping member 50 also has an upper edge 58 spaced upward away from the rearwardlyextending pivot arm portion 54 which has at its rearward end a hollow external pivot portion 60 of arcuate cross-section disposed in mating pivotal engagement with the internal pivot groove 34 of arcuate crosssection so as to enable the swinging of the movable clamping member 50 inward and outward therearound relatively to the stationary clamping member 12. The

lower surface 62 of the rearwardly-extending pivot arm portion 54 is limited in its downward swinging around the

pivot portions

34, 60 by the upstanding ribs 38 and 40 (FIG. 2) on the upper surface 42 of the intermediate portion 20 of the stationary clamping member 12 (FIG. 2).

Formed at the junction between the lower portion 52, an upstanding rib 65 on the rearwardly-extending pivot arm portion 54 and an upwardly-projecting portion 66 terminating in the upper edge 59 is a horizontal pivot groove 64 of arcuate cross-section which pivotally supports the forward end of the forward arm portion 72 of a locking member 70 having at its rearward end an upstanding arcuate handle portion 74. Disposed at the junction of the handle portion 74 and the forward portion 72 of the locking member 70 is a locking cam edge 76 of arcuate cross-section engageable with the abutment surface 36 of the locking abutment portion 22 in the locked position (FIG. 2) of the attachment 10 (FIGS. 2 and 4). The stationary clamping member 12, the movable clamping member 50 and the locking member 70, together with their component parts, extend horizontally the entire length of the attachment 10, as shown in FIGS. 1 and 5.

Formed along the forward edge of the forward portion 72 of the locking member 70 is a pivotal connection 77 consisting of a hollow pivot rib 78 of arcuate cross-section disposed in mating pivotal engagement with the groove 64 of arcuate cross-section adjacent the rib 65 on the rearwardly-extending portion 54, and having an internal surface of arcuate cross-section. The lower surface 80 of the handle portion 74 is of approximately semi-cylindrical configuration for ease of grasp by the fingers when the thumb engages the upper surface thereof to lock or unlock the movable clamping member 50 and the stationary clamping member 12 to one another (FIG. 4). The

clamping members

50 and 12 and the locking member 70 are preferably made of extruded aluminum. The upward swinging of the locking member 70 is limited by engagement of the upper surface 82 of its rearwardly-extending portion 72 with the rearward surface 84 of the upper portion 66 of the movable clamping member 50 upon which the locking lever 70 is pivotally mounted.

In the operation of the first form of the supplemental bending attachment 10 of FIGS. 1 to inclusive, the attachment is installed in the conventional portable bending brake 14 by moving the operating lever 94 of the brake actuator 90 (FIG. 5) to the right, thereby releasing the movable upper clamping jaw 92 to move upward away from the lower clamping jaw thereof (not shown). The mounting flange 16 of the attachment 10 is then placed upon the lower clamping jaw with the workpiece bend engaging the bending edge 56 and both are then placed adjacent the pivot axis of the bending member 108 and immovably clamped at 92 between said upper and lower clamping jaws by swinging the handle 94 to the left to force said upper clamp ing jaw 92 downward against the mounting flange l6 resting upon said lower clamping jaw. The construction and operation of the conventional portable brake 14 are so well known to those skilled in the sheet metal working art that they are believed to require no further description.

With the supplemental bending attachment 10 thus mounted in the conventional portable bending brake 14 (FIG. 5), the attachment 10 is opened from its closed position of FIG. 2 to its open position of FIG. 3 by swinging the locking member upward and then pulling it upward to raise the movable clamping member 50 into its open position (FIG. 3). One part of the already partially bent sheet material workpiece is then inserted between the stationary and

movable clamping members

12 and 50 as shown in FIGS. 4 and 5, with the apex of the previously-formed bent part firmly abutting the lower edge 56 of the lower portion 52 of the movable clamping member 50 (FIG. 4). The operator now swings the handle portion 74 of the locking member 70 downward so that its locking cam edge 76 tightly engages the forward abutment face 36 and locks the movable clamping member 50 in firmly gripping engagement with the part of the workpiece abutting the forward surface of the stationary clamping member 12. The operator then grasps the movable bending member 108 of the conventional portable bending brake 14 and swings its plate-shaped inner portion upward (FIG. 5), thereby further bending the already partially bent exposed portion of the workpiece 100 around the bending edge 56 of the movable clamping member 50 to the desired final angle relatively to the portion thereof held between the stationary clamping member 12 and the movable clamping member 50. The operator continues his upward swinging of the bending member 108 until the desired angle is achieved between the two above-mentioned parts of the workpiece 100.

To remove the now completely bent workpiece 100 from the supplemental bending attachment 10, the operator reverses the foregoing procedure by lifting the handle portion 74 of the locking member 70 so as to swing its locking cam edge 76 upward out of engagement with the forward abutment surface 36 of the upstanding locking abutment portion 22 (FIG. 3). A further upward pull upon the handle portion 74 of the locking member 70 raises the movable clamping member 50 out of engagement with the workpiece 100 and enables the latter to be removed from its abutting engagement with the lower support portion 18 of the stationary clamping member 12.

The second or modified supplemental bending attachment, generally designated 110 and shown in FIGS. 6, 7 and 8, includes a vertically-upstanding stationary clamping member 112 provided with a lower supporting portion 118 from the lower edge 128 of which (FIG. 8) a horizontal mounting flange 116 extends rearwardly. As with the supplemental bending attachment 10 of FIGS. 1 to 5 inclusive, the modified supplemental bending attachment 110 extends horizontally the length of the device, similar to that of the attachment 10 shown in FIGS. 1 and 5. From the enlarged or bulbous intermediate portion 120 disposed at the upper edge of the support portion 118, an inclined upstanding locking portion 122 extends rearwardly. Disposed near the lower end of the rearward side of the vertical support portion 118 is a rearwardly-projecting rib 126 spaced above the corner edge 128 and upper surface 130 of the mounting flange 116.

Also formed in the bulbous intermediate portion 120 at the top of the vertical support portion 118 is a pivot groove 134 of arcuate cross-section. Pivotally engaging the pivot groove 134 is a movable clamping member having a lower clamping portion 152 and an upper lock-carrying portion 154 (FIGS. 6, 7 and 8). Pivotally and matingly engaging the pivot groove 134 is a hollow pivot portion rib 160 of corresponding cross-section. Disposed within the hollow pivot portion 160 and internally engageable therewith is an upwardly-projecting rib 163 of arcuate cross-section inside which is a reversely-extending rib 167 of arcuate cross-section connected to and integral with the hollow pivot portion rib 160 of arcuate cross-section and spaced radially inward therefrom toward a rib 165 of arcuate cross-section integral with the bulbous intermediate portion 120 of the upstanding stationary clamping member 112 (FIG. 8). A hollow rib 164 of arcuate cross-section extends upward and rearward from the upper lock-carrying portion 154 of the movable clamping member 150.

Pivotally mounted upon the upper lock-carrying portion 154 is a locking member 170 having a forward portion 172 and a rearward handle portion 174 with a rearwardly and downwardly-projecting cam rib 176 movable into and out of tight locking engagement with the abutment surface 136 of the upper portion 122 on the stationary clamping member 112. The pivotal connection 177 of the locking member 170 with the upper lock-carrying portion 154 of the movable clamping member 150 includes an arcuate hollow cylindrical rib 172 matingly engageable with the internal surface of the rib 164 of arcuate cross-section. Formed concentric with the hollow cylindrical rib 164 and spaced radially therefrom is a rib 179 of arcuate cross-section which is externally matingly-engaged by a hollow rib 181 of arcuate cross-section coaxial therewith and spaced radially inward from, but connected to and extending reversely from, the hollow cylindrical rib 178. The external surface of the rib 181 matingly engages the internal surface of an upstanding rib 183 of arcuate cross-section matingly fitting into the space between the external surface of the rib 181 and the internal surface of the rib 178.

The modified supplemental bending attachment 110 shown in FIGS. 6, 7 and 8 is mounted in the conventional portable bending brake 14 shown in FIG. 5 in a manner similar to the form of the invention shown in FIGS. 1 to 5 inclusive with the exception of the fact that the upper jaw corresponding to the upper jaw 92 engaged by the rib 126 now has a vertical forward surface instead of the inclined forward surface shown at 92 in FIG. 5.

The operation of the modified supplemental bending attachment 110 shown in FIGS. 6, 7 and 8 is also similar to the operation of the attachment 10 shown in FIGS. 1 to 5 inclusive. The workpiece 100 is initially bent in the conventional portable bending brake 14 to approximately L-shaped cross-section with the two parts thereof bent approximately perpendicular to one another before the attachment 110 is inserted and clamped beneath the movable jaw 92 of the conventional portable bending brake 14. The final bending of the workpiece 100 after it has been clamped between the stationary and

movable clamping members

112 and 150 is carried out in the manner described in connection with the operation of the attachment 10 shown in FIGS. 1 to 5 inclusive.

1 claim:

1. A supplemental bendingattachment for installation in the jaws of a conventional portable bending brake to additionally bend a previously-partially bent sheet material workpiece, said attachment comprising a horizontally-elongated upstanding stationary workpiece-clamping member having a forward workpiece-engaging face thereon,

means on said stationary workpiece-clamping member for mounting said stationary clamping member in the jaws of the conventional portable bending brake.

horizontally-elongated movable workpiececlamping member having thereon a rearward workpiece-engaging face and a lower workpiecebending edge swingable toward and away from said stationary clamping member into and out of clamping engagement with a portion of a previouslypartially-bent sheet material workpiece abutting said forward workpiece-engaging face,

pivot means pivotally connecting said movable clamping member to said stationary clamping member at a location spaced above and remote from said workpiece-bending edge,

one of said clamping members having locking abutment thereon spaced away from said pivot means and disposed at a location spaced above and remote from said workpiece-bending edge of said movable clamping member,

and a movable locking member having a pivotal connection to the other clamping member disposed in spaced relationship to said pivot means and movable into and out of locking engagement with said locking abutment whereby to lock said clamping members into closed clamping engagement with the said inserted workpiece portion.

2. A supplemental bending attachment, according to claim 1, wherein said locking member has a locking portion disposed rearwardly of said pivotal connection, and wherein said stationary clamping member has a locking abutment engageable by said locking portion.

3. A supplemental bending attachment, according to claim 2, wherein said locking abutment is disposed approximately on the level of the upper end of said forward workpiece-engaging face of said stationary clamping member.

4. A supplemental bending attachment, according to claim 1, wherein said mounting means comprises a substantially horizontal flange extending rearwardly from the lower portion of said stationary clamping member.

5. A supplemental bending attachment, according to claim 2, wherein said locking abutment is disposed rearwardly of said pivot means and below said pivotal connection.

6. A supplemental bending attachment, according to claim 2, wherein said pivotal connection is disposed above said pivot means in vertically-spaced relationship therewith.

7. A supplemental bending attachment, according to claim 1, wherein said pivotal connection is disposed upon substantially the same horizontal level as said pivot means in the closed positions of said clamping members upon the workpiece.

8. A supplemental bending attachment, according to claim 1, wherein said forward workpiece-engaging face is disposed at an acute angle to said mounting means.

9. A supplemental bending attachment, according to claim 1, wherein said forward workpiece-engaging face ship therewith.

Claims

1. A supplemental bending attachment for installation in the jaws of a conventional portable bending brake to additionally bend a previously-partially bent sheet material workpiece, said attachment comprising a horizontally-elongated upstanding stationary workpiececlamping member having a forward workpiece-engaging face thereon, means on said stationary workpiece-clamping member for mounting said stationary clamping member in the jaws of the conventional portable bending brake. a horizontally-elongated movable workpiece-clamping member having thereon a rearward workpiece-engaging face and a lower workpiece-bending edge swingable toward and away from said stationary clamping member into and out of clamping engagement with a portion of a previously-partially-bent sheet material workpiece abutting said forward workpiece-engaging face, pivot means pivotally connecting said movable clamping member to said stationary clamping member at a location spaced above and remote from said workpiece-bending edge, one of said clamping members having locking abutment thereon spaced away from said pivot means and disposed at a location spaced above and remote from said workpiece-bending edge of said movable clamping member, and a movable locking member having a pivotal connection to the other clamping member disposed in spaced relationship to said pivot means and movable into and out of locking engagement with said locking abutment whereby to lock said clamping members into closed clamping engagement with the said inserted workpiece portion.

9. A supplemental bending attachment, according to claim 1, wherein said forward workpiece-engaging face is disposed substantially perpendicular to said mounting means.

10. A supplemental bending attachment, according to claim 1, wherein said stationary clamping member has a rearwardly-extending projection disposed adjacent said mounting means in vertically-spaced relationship therewith.