US3777527A

US3777527A - Jig for setting resistance stops in a rotary bending machine

Info

Publication number: US3777527A
Application number: US00243971A
Authority: US
Inventors: J Lohman
Original assignee: Alamo Iron Works
Current assignee: Alamo Iron Works
Priority date: 1972-04-14
Filing date: 1972-04-14
Publication date: 1973-12-11
Anticipated expiration: 1990-12-11

Abstract

A jig for aiding in the setting of resistance stops in a rotary bending machine set up, in particular, for forming reinforcing bars with offsets as used in reinforced concrete beams.

Description

United States Patent 1191 Lehman 1 Dec. 11, 1973 4] JIG EOR SETTING RESISTANCE STOPS IN 1,740,091 12/1929 Hessenbruch 72/010. 21 A ROTARY BENDNG MACHINE 1,559,386 10/1925 Valentine 33/102 1,524,392 1/1925 East 33/75 R Inventor: J Lohman, San Ant9n10.Tex- 2,580,263 12/1951 Wooten 33/94 [73] Assigneez Alamo Iron works, San Antonio 2,265,234 12/1941 Jensen 72/D1G. 21

, Tex. [22] Filed: Apr. 14, 1972 Primary Examinef-Chzirles W. Lanham Assistant Examiner-M. J. Keenan [21] Appl' 243371 Att0rney--Bertram H. Mann et a1.

[52] US. Cl 72/36, 72/217, 72/446, 72/461, 72/D1G. 21 51 1nt.C1 B2111 11/22 ABSTRACT [58] Field of Search 72/36, 219, 446,

72/448, 461, DIG. 21, 217; 33/75 R, 75 C, A jig for aiding in the setting of resistance stops in a 79 R, 79 A, 94, 102, 174 TB rotary bending machine set up, in particular, for forming reinforcing bars with offsets as used in reinforced [56] References Cited concrete beams.

UNITED STATES PATENTS 755,588 3/1904 Vanderlinden 72/461 5 Claims, 10 Drawing Figures PATENTEDnEc 11 1915 3777527 sum 2 BF 3 JIG FOR SETTING RESISTANCE STOPS IN A ROTARY BENDING MACHINE FIELD OF THE INVENTION This invention relates to jigs for assistance in propthereby.

BACKGROUND OF THE INVENTION Long concrete beams are provided with reinforcing bars(called re-bars)which may have hooked orangled endsand offset intermediate portions formedswith complementary,double-angle bends. In order to manufacture large quantities of such bars of identical configuration, a typical rotary bending machine is provided with a pair of bending elements on its rotary head or table, positioned to provide the desired offset and angles, and stationary resistance stops mounted adjacent the periphery of the head. The operator merelyadvances his initially straight bar stock to predetermined positions wherein the bender is manually or automatically manipulated to form the desired bends. The placement of the bending pins in the proper pairs of holesin the rotary head is relatively simple, but the establishment of the locations for the resistance stopsby means of geometric measurements is relatively difficult and time-consuming.

I BRIEF SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to provide anadjustable jig which greatly facilitates "the positioning of the resistance stops in a rotary bending machine set up for forming reinforcing bars of the type described. In accordance with this invention, the jig is constructed of parallel ruling bars slidably mounted on parallel, nonrectangularly disposed rodsso that the bars may be variably spaced in order to accommodate different re-bar offset dimensions. Complementary slider members are mounted interrnediately on each parallel bar for seating against the bender pins,

when in their end of bend positions. The sliders are adjustable to accommodate reinforcing bars of varying thicknesses. In the seated position of the jig, as explained, the inner edges of the parallel bars form rules with linear markings which guide the placement of markings on thestationary table to mark the positioning of the working ends of the mentioned resistance stops.

BRIEF DESCRIPTION OF THE DRAWINGS type FIGS. 4, 5,6, and 7 are more-or-less schematic plan views of a bendingmachinqas in FIG. 1, in different operative relationships in the formation of the re-bar of FIG. 3.

FIG. 8 is a plan view of the rotary table or head showing the novel jig in use for positioning the resistance stops utilized in FIGS. 4-7.

FIG. 9 isanisometric view of the jig.

FIG. 10 is an enlarged detail section taken substantially on line 10l0 of FIG. 9.

DETAILED DESCRIPTION OF THE DRAWINGS at 18. The rotary head is driven by a motor 19 and suitable transmission means including vertical shaft 20. Suitable bearings and supports for the rotary head will be provided, but are here omitted. In the present instance, the rotary head is automatically operated with respect to direction, extent, and timing by properly adjusted automatic controls, including conveniently located control box 21. Drilled in table 16 are diametri cal rows of holes 22 which are judiciously arranged, as is understood by those skilled in this art, for maximum versatility. Table portion 14 is also provided with transverse, inverted-T-section grooves 23 and24 for mounting adjustable resistance stops, as indicated at 25-28 in FIGS. 4-7. Subtable 17 is also provided with holes in rows or otherwise, as at 29, which provide for still further versatility of the machine and for lowering the rotary plate, when upper turntable 16 is removed.

The truss re-bar shown in FIG. 3 is of a conventional configuration for use in long reinforced concrete bridge beams or joists, the special shape being as calculated by the architect or engineer to best resist the stresses to which such beams are subjected. The bar has

hooks

32 and 33 at its extremities and offset-forming, intermediate, 45

slants

34 and 35, each formed by a pair of angles as 36 and 37. The over-all length as well as the intervening dimensions and angles, including the offset H, are all carefully determined in advance and are to be duplicated by the supplier of the reinforcing bars.

FIGS. 4-7 illustrate the operation of the bending machine,set up with the use of the novel jig as described hereafter, in forming this reinforcing bar. For forming the terminal bend 32, table 16 is provided with a central stop resistance 40 and a single bending pin ele ment 41 properly positioned in the appropriate one of theholes 22. Bar stock42 is then positioned as shown, extending between pin members40 and 41 and bearing against resistance stop 25. Clockwise rotation of the turntable then forms the hook, as indicated at 32a. It is important, of course, that resistance stops 26 and 28 be positionedoutwardly sufficiently to clear the end of bar 42in its hook-forming motion.

Next, as shown in FIG. 5, central stop member 40 is removed and a second bending member a pin 43, is inserted in a hole 22 in complementary relationship with respect to bending pin 41. With

pins

41 and 43 re- In order to form slant 35 opposite to slant 34,

bend pins

41 and 43 are again returned to their neutral positions of FIG. and rod 42 is slid further rightwardly to the position in which

pins

41 and 43, upon controlled clockwise motion, will form the double bends at the ends of slant 35, corresponding to

angles

36 and 37. The' final hook 33 at the opposite end of the bar is formed by the procedure of FIG. 4, but reversed. If the bar as so formed checks out as accurate, its formation can be repeated quickly and indefinitely.

While

bend pins

41 and 43 are located with the assistance of properly selected pairs of holes 22, the proper location of resistance stops 25-28 is facilitated with the use of the novel parallel ruling jig illustrated in FIGS. 8-10. FIG. 8 shows the jig, generally designated 46, resting in its ruling and gauging position upon turntable 16 having

bend pins

43 and 41 rotated to their end of bend positions, as in FIG. 7. The jig consists of

parallel bars

47 and 48 through which

parallel end rods

49 and 50 slidably extend. These rods preferably are nonrectangular with respect to the parallel bars, in this instance being disposed at 45 degrees thereto to form the nonrectangular paralleogram, as shown. The central portions of

bars

47 and 48 are recessed, as at 51 and 52, for receiving

slider blocks

53 and 54. The surfaces of these blocks facing

bar recesses

51 and 52 are, in turn, cutout as at 55 and 56 for receiving

seating members

57 and 58.

Blocks

53 and 54 are secured in position by means of bolts or pins 59. The side walls of

block recesses

51 and 52 are inclined, as shown in FIG. 10, and the seating members have slots, as at 60 in FIG. l0, receiving locking bolts extending through nonthreaded bores in the blocks and into threaded bores in the underlying parallel bars. Thus,

seating members

57 and 58 are subject to adjustment in the direction of the inclined sides of

block cutouts

55 and 56 and may be locked in their adjusted positions by means of bolts 61 having Allen key recesses at their upper ends (FIGS. 8 and 9).

Blocks

57 and 58 have angled or recessed opposing faces 63 and 64 for stable lodgment against the bend pins.

USE OF THE .IIG

In order to establish the proper positioning of the resistance stops, for forming re-bars 42 according to the exact configuration specified, after setting of the bending machine and automatic controls to perform the work at hand, bending

pins

41 and 43 are placed in their end of bend positions (FIGS. 7 and 8). The inner faces of

parallel bars

47 and 48 of the jig are then spaced apart by the exact dimension H of the desired re-bar offset (FIG. 3) and the jig laid upon turntable 16, as in FIG. 8, with the opposed annular faces 63 and 64 of

seating members

57 and 58 stably nested against

bender pins

41 and 43. Lines are then drawn on the turntable following the inner edges of the portions of

parallel bars

47 and 48 bearing the designation L for Left or the like, as at 65. These portions of the parallel bars also bear linear index markings 66 and the two parallel lines thus made are intersected by short lines adjacent the same index marking on each side. It is simply necessary that these intersections are far enough outwardly from the centers of the parallel bars so tha the end of the bar stock 42 during the formation of hook 32, as in FIG. 4, will clear the resistance stops. The jig is then turned upside down and end for end, and similar intersecting parallel lines and crossing marks are applied to the turntable. These four intersections, then, designate the centers of the bar stock-abutting inner ends of the resistance stops 25-28. The resistance stops are positioned accordingly, being laterally moved along T-

slots

23 and 24 and extended or retracted as necessary with the use of angular tightening bolts 67.

The jig is subject to considerable adjustment, for instance, by varying the transverse spacing of

parallel bars

47 and 48 where the dimension H of the re-bar is varied, or even providing longer

angled end rods

49 and 50. Varying thicknesses of bar stock are compensated for by adjustment of

slider members

57 and 58. Accordingly, the jig can be used easily and expeditiously to position the resistance stops, even by a relatively inexperienced workman. Various details may be modified as will occur to those skilled in the art, and the exclusive use of all modifications as come within the scope of the appended claims is contemplated.

I claim:

1. A jig for aid in positioning outer resistance stops in a rotary bender having a pair of bending pins set for simultaneously double bending an offset in a truss rebar, said jig comprising a nonrectangular frame including parallel side and end bars, said side bars being slidable on said end bars for accommodating bender settings for re-bars with variable offsets, seating elements mounted intermediately on said side bars and shaped to nest against bender pins in their final bending positions so as to cause the inner edges of said side bars to traverse lines including optimum resistance stop positions, and index markings on said edges for complementary positioning of diagonally opposite resistance stops.

2. A jig for establishing the positioning of a fixed resistance stop in a bending machine of the type having a pair of bending elements set up to cooperate with the stop in forming stock of predetermined angularity, at least one of said bending members being movable, said jig comprising a frame having side and end members and seating members on said side members disposed, with relation to a first of said side members, for seating said bending members with said first side member marking a line along which said stop is to be placed.

3. A jig as described in claim 2 in which said frame is in the form of a nonrectangular parallelogram and the side members thereof are slidable on the connecting end members for adjusting the jig to form stock bends of varying dimensions.

4. A jig as described in claim 2 in which said seating members are adjustably mounted on said side members for accommodating stock of varying thicknesses.

5. A jig as described in claim 2 in which both of said side members are disposed with respect to said seating members, when said bending members are seated therein, to mark lines for placement of a pair of fixed resistance stops in a rotary bending machine.

Claims

1. A jig for aid in positioning outer resistance stops in a rotary bender having a pair of bending pins set for simultaneously double bending an offset in a truss re-bar, said jig comprising a nonrecTangular frame including parallel side and end bars, said side bars being slidable on said end bars for accommodating bender settings for re-bars with variable offsets, seating elements mounted intermediately on said side bars and shaped to nest against bender pins in their final bending positions so as to cause the inner edges of said side bars to traverse lines including optimum resistance stop positions, and index markings on said edges for complementary positioning of diagonally opposite resistance stops.