US3236082A

US3236082A - Tube bending tools

Info

Publication number: US3236082A
Application number: US127447A
Authority: US
Inventors: Beck Edward; Edward J Cator
Original assignee: Crawford Fitting Co
Current assignee: Crawford Fitting Co
Priority date: 1961-07-24
Filing date: 1961-07-24
Publication date: 1966-02-22
Anticipated expiration: 1983-02-22

Description

Feb. 22, 1966 B'ECK ETAL 3,235,032

TUBE BENDING TOOLS Filed July 24. 1961 2 Sheets-Sheet 1 INVENTORS EDWARD BECK 8 EDWARD J. CATOR FIG. 2 ,9

ATTORNEYS Feb. 22, 1966 E. B-ECK ETAL 3,236,082

TUBE BENDING TOOLS Filed July 24. 1961 2 Sheets-Sheet z FIG. 3

INVENTORS 5 EDWARD BECK 8 BY EDWARD J. CATOR ATTORNEYS United States Patent 3,236,082 TUBE BENDING TOOLS Edward Beck, Cleveland, Ohio, and Edward J. Cator,

Rochester, N.Y., assignors to Crawford Fitting Company, Cleveland, Ohio, a corporation of Ohio Filed July 24, 1961, Ser. No. 127,447 4 Claims. (Cl. 72-149) This invention relates to improvements in hand operated tube bending tools and consists of the combination, construction and arrangements herein described and claimed.

With prior tube or conduit benders of the type herein described it has been found that the tube after bending has an ovality of as much as .050 inch. This was noted with copper tubing. It also was noted that steel tubing would buckle during bending.

It is a prime object of this invention to provide a hand operated tube bending tool which will operate to minimize ovality in the tube shape, as well as to eliminate buckling in the tube wall, during bending operations.

A further object of the invention is to provide a device by which tubes may be bent Without friction on the outer diameter thereof.

It is also an object of the invention to provide a tube bending tool by which the man power required for operating the tool for bending operations may be reduced to a minimum.

Other objects relating to the advantages obtained in the structure and operation of the tube bending tool constituting this invention Will become apparent in the description to follow.

The invention is illustrated in the accompanying drawings forming a part of this application, in which:

FIG. 1 is a perspective view of the tube bending tool constituting this invention, shown in the loading or threading position;

FIG. 2 is an enlarged top plan view of the tool shown in an alternative position or operating position;

FIG. 3 is a vertical sectional view on the line 3-3 of FIG. 2 looking in the direction of the arrows;

FIG. 4 is a fragmentary view in partial elevation and partially in cross-section on the line 4-4 of FIG. 3;

FIG. 5 is a detail sectional view on the line 5-5 of FIG. 3 and looking in the direction of the arrows, and

FIG. 6 is a detail vertical sectional view illustrating the construction of the U-frame which carries the idler rollers for tube bending operations.

Referring further to the drawings, and more particularly to FIGS. 1 and 2, 10 indicates in general a case construction for housing gears for hand operation of the tool. The gear case comprises a cup-shaped base 11, and a cover plate 12 which is secured to the base by the socket head cap screws 13, or the like.

The base 11 has depending from its bottom, centrally thereof, a block 14 with fiat faces 15 suitable for apply-. ing the jaws of a vise (not shown) for holding the tool on a bench or preferably, on a single column to provide space for compound angle bending. The base member 11 and the cover plate 12 provide an annular space 16 for housing the

bevel gears

17 and 18 as best seen in FIG. 3. The cover plate 12 has a depending annular flange 12' which fits in an annular recess formed in the ice adjacent inner edge of the base member 11. The gear 17 is fixed to the inner end of the stub shaft or crank shaft 19 by a pin 20. The shaft 19 is journaled in the side wall of the base member 11 as best shown in FIG. 3; its outer end is axially recessed for removably receiving the free end of the squared crank arm 21 which carries a hand grasp roller 22 at its outer end.

Gear 1 8 is rotatably supported by the stub shaft 23 which has its lower end journaled in the bottom of the base member 11, as indicated at 24. The hub 25 of the gear 18 is fixed upon the shaft 23 by a pin 26, and the hub is journaled in the cover plate 12 as indicated at 27.

The shaft 23 extends above the cover plate 12 and the forming roll 28 is fixed thereon by a spline or key 29. The plate 30, screw 31, and spline 29 lock the forming roll against movement on the upper end of the shaft 23.

Near the outer edge on the upper surface of the circular cover late 12 is provided a degree scale 32 from zero to 180 degrees. The gear case member 11 and the lower surface of the cover plate 12 are provided with registrating

grooves

33 and 34 respectively which correspond in length to the degree scale 32.

The upper edge of the gear case member 11 is provided with an outer recess or ledge which affords an annular slot 35 with the registering lower edge surface of the cover plate 12 in which bolt 36 can freely slide. Bolt 36 has fixed on its inner end a head adapted to slide in the arcuate slot or channel formed by the

grooves

33 and 34. The outer end of the bolt 36 has threaded thereon a knurled head 37 which can be used for locking the pointer 38 carried by the bolt 36 at the desired degree on the scale 32.

The forming roll 28 is formed with an arcuate peripheral groove which terminates at its ends in a flat section or length 40 (FIG. 4). The flat section is provided with a central threaded bore for receiving the reduced threaded end 41 of the tube clamp bar 42. The inner end of the bar 42 is also reduced for pivotally supporting the arcuately shaped tube clamping jaw 43. The bar 42 also carries a stop 44 which constitutes a plug threaded into a suitable bore in the lower surface of the bar and adapted to form a stop with the pointer member 38 for the scale 32.

The bar 42 has an extension 45 threadedly secured to its outer end. The extension and base are provided with a graduated continuous scale 46 which begins at the inner end of the bar 42.

The bar extension 45 carries an adjustable tube stop 47 comprising a pair of hinged jaws 48 which may be clamped at any point on the scale 46 by the thumb screw 49. The threaded hole 50 in the jaw 47 is provided to receive exchangeably a tube abutment 50' which has a centering tip 51. To adapt tube abutment 50' to various wall thicknesses of available tubing material, several of said tube abutments 58' can be employed with varying diameters of the centering tip 51.

The cover plate 12 supports a U-frame member 52 Which carries the

idler tube rollers

53 and 54. The roller 53 is journaled by the shoulder screw which also serves for pivotally securing the same end of the frame member 52 to the cover plate 12 (FIG. 6). The roller 54 is supported rotatably by a sleeve 55' which in turn encloses a spring loaded plunger 56 adapted to seat in a sleeve lined bore 57 in the cover plate 12 for holding the roller 54 in operative position with respect to the forming roll 28 for tube bending operations.

The plunger head 58 threaded on the outer end of the plunger 56 serves for releasing the roller from its operative position, and permits the frame member 52 to be swung to the position illustrated in FIG. 2. The last named position of the frame 52 permits easy placement of a tube in the bending tool as well as easy withdrawal of the tube after being bent.

It should be noted that the peripheral groove formed in each of

rollers

53 and 54 is the same in shape and depth as the groove 39 of the forming roll 28. As illustrated in FIGS. 2 and 3 the tube 60 is fully enclosed within the peripheral complementary grooves of the mandrel 28 and the roller 54. This is important in the operation of the tool disclosed herein for minimizing ovality or buckling of the tube during bending operations.

It should be noted also that the

rollers

53 and 54 as well as the mandrel 28 can be replaced easily with others which have peripheral grooves suitable for the outside diameter of the large or smaller tubes to be bent.

Before the tube bending tool described herein can be used it must, of course, be solidly secured by a vise, i.e., the jaws of the vise clamping the depending block 14. The block permits the tool to be arranged in the best posi tion for operating the handle 21, or for other working purposes of the operator.

Assuming it is desired to fashion a tube pattern for mass production, the plunger 56 is operated to free the frame 52 on its shoulder screw 55 and the frame is pivoted thereabout to the outward position shown in phantom in FIG. 2. The crank arm 21 is operated to bring the forming roll 28 into posiiton for placing the stop 44 carried by bar 42 at zero point on scale 32, as shown in FIG. 1. A tube is then positioned in the groove 39 of the forming roll with the leading end of the tube being brought past the idler roll 53 and forming roll 28 a sufficient degree so that it will be held in the groove 39 of the forming roll 28 upon engagement by the arcuate clamping jaw member 43. The frame 52 is swung inwardly on its shoulder screw 55 until the spring-loaded plunger 56 seats itself in the detent socket 57 and thus the roller is brought into operating relation with the forming roll 28, i.e., the forming roll and associated idler grooves fully surround and support the tube wall as shown in FIG. 3.

The pointer 38 is set for the angle the tube is to be bent. For example, if a 90 angle is desired, the setting would be as shown in FIG. 1. With the positioning of roller 54, the roller 53 also is in position for a pipe bending operation.

The crank 21 is then rotated, rotating bevel gear 17, thereby imparting rotation to bevel gear 18. The forming roll 28 and bevel gear 18 are attached to the shaft 23 so that rotation thereof imparts rotation to the bar member 42, thus rotating the tube carried by the tube abutment 50 to impart a bending motion thereto. The crank is rotated until the stop means 44 abuts the pointerstop member 38, as best seen in FIG. 2. At this point .a 90 bend will be produced in the end of the tube which will be free of buckling and the ovality thereof minimized. The spring loaded plunger 56 is next lifted to free the frame 52 for outward swinging movement of the roller 54, and after the clamping jaw 43 has been swung free of engagement with the tube end, the tube may be easily withdrawn from the tool. The straight end of the tube now can be cut the desired length from the center of the bend, i.e., to form the tube pattern-desired, and the pattern can be returned to the tool with its straight portion providing a leading end.

The stop 47 now is set at a point on the scale 46 which will bring its abutment member 50' against the end of the tube 60 as shown in FIG. 2. The tool now is ready for mass production of the pattern described above without resetting.

In tube bending operations the guide shoe or roller 54 in conjunction with the mandrel 28 and the roller or idler 53 operate to minimize ovality in the tubes bent, and to prevent buckling in the bend Zone by supporting the tube Wall substantially completely about its periphery. The bevel gears 17 and 18 in the ratio illustrated show operation of the tool for bending purposes without the expenditure of large amounts of manpower, even where used with heavy wall tubes. The tool as a whole, including the bend setting means, as well as the tube stop means to be used for mass production, are simple in construction and operation with the result that .a highly efficient tool is provided, particularly for mass production purposes. Also, the tool is relatively inexpensive to manufacture and sufficiently rugged to withstand long usage,

While the preferred construction and operation of this invention are set forth herein, it is to be understood that said invention is not to be so limited as indicated by the appended claims.

We claim:

1. A tube bending tool comprising a gear case forming a cup shaped base, cover plate means fixedly attached to said base, shaft means rotatably supported in said case and extending through said cover plate, first gear means on said shaft, said first gear means having an axially extending hub portion journalled in said cover plate, second gear means journalled in said cup shaped base and cooperating with said first gear means, crank means interfitted with said second gear to allow manual rotation thereof, a forming roll carried by the end of the shaft extending through said plate, a pivotable U frame carried by said cover plate and being attached thereto by pivot means, said U frame being spaced from said forming roll, a pair of idler rollers carried by said U frame, one of said rollers being rotatable about a sleeve, a spring biased plunger means carried by said sleeve and having a plunger head attached at one end thereof, bore means in said cover plate to receive the other end of said plunger when said U frame is pivoted towards said forming roll, said plunger being removable from said bore thereby to allow pivoting of said U frame to release the other roller from its operative position, marking means on said cover plate to indicate the angle of bend, pointer means slidably carried about the periphery of said case to cooperate with said marking means, bar means carried by said forming roll, said bar means having stop means thereon to cooperate with said pointer means whereby overbending will be avoided.

2. The tube bender of claim 1 wherein said bar means carried by the forming roll has tube abutment means thereon, said abutment means including a centering tip adapted to receive a free end of a tube.

3. The tube bender of claim 2 wherein the tube abutment means is adjustable on said bar means, and marker means on said bar means cooperating with said adjustable tube abutment means whereby the length of tube from said bend may be readily set.

4. A manually operable tube bending tool comprising a cup shaped base member having a clamping block fixedly secured to and depending therefrom, cover plate means overlying said cup shaped base member, means releasably securing said cover plate to said base member thereby to form a hollow compartment therebetween, shaft means rotatably supported by said base and cover plate, said shaft extending above said cover plate, gear means mounted for rotation on said shaft, said gear means being disposed below said cover plate and having a hub portion journalled therein, a forming roll having a concavity formed in the side thereof, said forming roll being fixedly secured to the end of the shaft extending through said cover plate for rotation therewith, a U shaped frame member pivotably secured to said cover plate, said U shaped frame member carrying a first idler roll which is rotatable about the pivot of the U frame, a second idler roll carried by said U shaped frame member spaced from said first idler roll and said forming roll, plunger means passing through said second idler roll and having an end thereof received in a bore in said cover plate, said plunger means being retractable from said bore whereby said U shaped member may be pivoted to increase the distance between said second idler roll and said forming roller, an extension bar carried by said forming roll for rotation therewith, tube clamp means pivotable about said bar to engage said tube, means on said bar to releasably receive the leading end of a conduit, said means including a conduit abutment for engagement with the leading end of said conduit, means releasably securing said abutment member on said bar, said means cooperating with a slidable pointer means carried by said case to form a stop means to limit the degree of rotational movement of said bar.

References Cited by the Examiner UNITED STATES PATENTS 749,029 1/ 1904 Condon 15340 2,762,415 9/1956 Franck 15340 3,004,583 10/1961 Zuccala et a1 15346 10 CHARLES W. LANHAM, Primary Examiner.

WHITMORE A. WILTZ, Examiner.

Claims

1. A TUBE BENDING TOOL COMPRISING A GEAR CASE FORMING A CUP SHAPED BASE, COVER PLATE MEANS FIXEDLY ATTACHED TO SAID BASE, SHAFT MEANS ROTATABLY SUPPORTED IN SAID CASE AND EXTENDING THROUGH SAID COVER PLATE, FIRST GEAR MEANS ON SAID SHAFT, SAID FIRST GEAR MEANS HAVING AN AXIALLY EXTENDING HUB PORTION JOURNALLED IN SAID COVER PLATE, SECOND GEAR MEANS JOURNALLED IN SAID CUP SHAPED BASE AND COOPERATING WITH SAID FIRST GEAR MEANS, CRANK MEANS INTERFITTED WITH SAID SECOND GEAR TO ALLOW MANUAL ROTATION THEREOF, A FORMING ROLL CARRIED BY THE END OF THE SHAFT EXTENDING THROUGH SAID PLATE, A PIVOTABLE U FRAME CARRIED BY SAID COVER PLATE AND BEING ATTACHED THERETO BY PITOT MEANS, SAID U FRAME BEING SPACED FROM SAID FORMING ROLL, A PAIR OF IDLER ROLLERS CARRIED BY SAID U FRAME, ONE OF SAID ROLLERS BEING ROTATABLE ABOUT A SLEEVE, A SPRING BIASED PLUNGER MEANS CARRIED BY SAID SLEEVE AND HAVING A PLUNGER HEAD ATTACHED AT ONE END THEREOF, BORE MEANS IN SAID COVER PLATE TO RECEIVE OTHER END OF SAID PLUNGER WHEN SAID U FRAME IS PIVOTED TOWARDS SAID FORMING ROLL, SAID PLUNGER BEING REMOVABLE FROM SAID BORE THEREBY TO ALLOW PIVOTING OF SAID U FRAME TO RELEASE THE OTHER ROLLER FROM ITS OPERATIVE POSITION, MARKING MEANS ON SAID COVER PLATE TO INDICATE THE ANGLE OF BEND, POINTER MEANS SLIDABLY CARRIED ABOUT THE PERIPHERY OF SAID CASE TO COOPERATE WITH SAID MARKING MEANS, BAR MEANS CARRIED BY SAID FORMING ROLL, SAID BAR MEANS HAVING STOP MEANS THEREON TO COOPERATE WITH SAID POINTER MEANS WHEREBY OVERBENDING WILL BE AVOIDED.