US3735621A

US3735621A - Hand operated tube bender

Info

Publication number: US3735621A
Application number: US00188489A
Authority: US
Inventors: H Dodge
Original assignee: Crawford Fitting Co
Current assignee: Crawford Fitting Co
Priority date: 1971-10-12
Filing date: 1971-10-12
Publication date: 1973-05-29
Anticipated expiration: 1990-05-29

Abstract

The specification and drawings disclose a hand operated tube bender. The disclosed bender includes a pair of rigid frame members which are pivotally interconnected for oscillation about an intermediate axis. Portions of the frames on one side of the axis comprise operating handles to allow manual oscillation. Carried on one of the frames on the side of the axis opposite the handles is a forming roller with a peripheral, semi-circular groove sized to closely receive the outer circumference of a tube to be bent. Releasable lock means are carried on the roller for clamping a tube in the groove. Associated with the forming roller and carried on the same frame is a forming shoe having a generally semi-circular groove along one side and mounted to oscillate between a first lock position where it cooperates with the forming roller to closely engage the tube at the point of bend, and a second position where it is spaced from the forming roller to allow the tube to be inserted or removed. The forming roller is driven by a ratchet drive including a ratchet wheel drivingly connected to the forming roller and a pawl which is pivotally connected to the second frame and ocated so that when the frames are oscillated toward one another, a drive force is imparted to the forming roller.

Description

ilnited States Patent 9] Dodge [54] HAND OPERATED TUBE BENDER [75 Inventor: Harry G. Dodge, Painesville, Ohio [73] Assignee: Crawford Fitting Company, Solon,

Ohio

[22] Filed: Oct. 12, 197] Appl. No.: 188,489

Primary Examiner-Milton S. Mehr Attorney-Fay, Sharpe and Mulholland [451 May 29,1973

[S7] ABSTRACT The specification and drawings disclose a hand operated tube bender. The disclosed bender includes a pair of rigid frame members which are pivotally interconnected for oscillation about an intermediate axis. Portions of the frames on one side of the axis comprise operating handles to allow manual oscillation. Carried on one of the frames on the side of the axis opposite the handles is a forming roller with a peripheral, semi-circular groove sized to closely receive the outer circumference of a tube to be bent. Releasable lock means are carried on the roller for clamping a tube in the groove. Associated with the forming roller and carried on the same frame is a forming shoe having a generally semi-circular groove along one side and mounted to oscillate between a first lock position where it cooperates with the forming roller to closely engage the tube at the point of bend, and a second position where it is spaced from the forming roller to allow the tube to be inserted or removed. The forming roller is driven by a ratchet drive including a ratchet wheel drivingly connected to the forming roller and a pawl which is pivotally connected to the second frame and ocated so that when the frames are oscillated toward one another, a drive force is imparted to the forming roller.

7 Claims, 7 Drawing Figures PAIENIEWW 3.735.621

SHEET 1 OF 2 INVENTOR. HARRY G. DODGE ATTORNEYS PATENTEDW29|975 3,735,621

SHEET 2 UF 2 HARRY 6 81 852 2 BY ay 5W 8 Mal/10M ATTORNEYS 1 HAND OPERATED TUBE BENDER The subject invention is directed to the art of tube bending tools and, more particularly, to an improved portable, hand operated tube bender.

Prior tube benders of the general type considered herein were typically rather difficult to operate. Moreover, after bending tubing in the prior benders, the tubing in the area of the bend was often out-of-round by several thousanths of an inch. Also, it was generally difficult to bend the tubing to the precise angle required.

The primary object of the invention is the provision of of a tube bender of the type described wherein the bending is accomplished during actuation of a pair of handles toward one another. This allows the more powerful of the arm and shoulder muscles to be used for applying the bending force. Also, it is generally much easier to control the extent of movement when moving levers or handles together than when moving them apart.

The invention also has for an object the provision of a tube bender wherein the tube is enclosed about substantially all 360 degrees of its circumference at the point of bend during the bending operation, and wherein the tube can be released quickly and easily following the bending operation.

The above objects are achieved by a tube bender which comprises first and second elongated bodies which are pivotally interconnected for oscillation about an intermediate axis. Portions of the bodies on afirst side of the axis serve as operating handles to permitthe bodies to be manually oscillated. Mounted on the first body of the side of the axis opposite the handles is a forming roller having a peripheral, semi-circular groove size to receive a tube to be bent and releasable means to hold the tube in the groove. Associated with the forming roller and carried on the same body is a forming shoe having a generally semi-circular groove along one side and mounted to move between a first lock position where it cooperates with the forming roller to closely engage a tube to be bent, and a second position where it is spaced from the forming roller. A ratchet wheel is drivingly connected to the forming roller and a pawl is pivotally connected to the second body such that when the bodies are moved toward one another, a drive force is imparted to the forming roller. Preferably, the forming shoe is located between the axis of oscillation and the forming roller, andtheforming roller is rotated. in adirection such that-the tube bends away from the operator.

The invention also contemplates that the forming shoe will preferably be mounted for pivotal movement about an axis parallel to, but spaced from, the first mentioned axis. Also, the lock means for the forming shoe is preferably a simple lever carried in the forming shoe and adapted to engage a lock groove carried in the first body. This arrangement permits rapid engagement and disengagement of the forming shoe.

The above and other objects and advantages will become apparent from the following description when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a plan view of the preferred embodiment of a tube bender formed in accordance with the invention;

FIG. 2 is a side view partially in cross-section taken on line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken on line 4-4 of FIG. 1;

FIG. Sis a cross-sectional view taken on line 5-5 of FIG. 1 and showing the forming shoe lock mechanism in detail;

FIG. 6 is a view taken on line 6-6 of FIG. 1 showing the tube clamp mechanism; and,

FIG. 7 is an enlarged cross-sectional view taken on line 77 of FIG. 1.

Referring more particularly to FIGS. 1 and 2, the overall arrangement of the tube bender is shown as including first and second pivotally interconnected

rigid bodies

10 and 12 which are mounted for oscillation about axis 14 which extends transversely through the bodies. Portions of each of the bodies on one side of the axis of oscillation 14 are formed to serve as operating handles. Note that body 10 includes an elongated relatively narrow portion 16 and the body 12 includes a similar portion 18 which serve as manually actuable handles. The bodies can be made from any suitable material and, of course, be one-piece or multiple-piece construction.

Carried from body 10 is a forming roller and tube clamp assembly 20 which cooperate with a pivotally mounted forming shoe assembly 22. The forming roller assembly will subsequently be described in substantial detail; however, for the present, it is sufficient to note that the forming roller assembly 20 is drivingly rotated through a drive ratchet assembly 24 such that rotation of the roller takes place when the

handles

16 and 18 are oscillated toward one another.

As best shown in FIG. 2, the

bodies

10 and 12 are pivotally connected for oscillation about axis 14 by a shaft 28 having a thin, enlarged head 30. The left-hand end of shaft 28 (as viewed in FIG. 2) extends through the body 12 andis provided at its outer end with an enlargedflange or retaining disc 32 releasably connected to the shaft in any convenientmanner such as through the use of a socket head screw 34. The amount of movement which the

bodies

10 and 12 can take toward one another about axis 14 is limited by a stop pin 36 which is press fitted through body 10 and extends outwardly therefrom on both sides. As shown in FIG. 1, the pin engages the body 12 along its right-hand face to prevent further movement of the bodies toward one another.

The forming roll assembly 20 is pivotally mounted at the outer end of body 10 at a location spaced from axis 14 and on the side of the axis opposite the handle portion 16. As best seen in FIG. 2, assembly 20 includes a forming rollmember 40 having a peripheral groove 42 of semi-circular cross-section and of a radius sized to closely receive the outer surface of a tube to be bent. Roll 40 has a laterally extending shaft portion 44 which is carried in a sleeve bearing 46 extending through body 10. A thin, flanged portion serves as a spacer between the body 10 and the under-size of roll member 40. The left-hand end of shaft 44 (as viewed in FIG. 2) is connected with the ratchet assembly 24 in a manner subsequently to be described. For the present however, attention is directed to FIG. 1 where it is shown that a tube clamp 50 is carried on the forming roll 40 for engaging the tube 52. The tube clamp 50 is of the type described and claimed in the commonly assigned US. Pat. No. 3,433,042 which is incorporated herein by reference. Broadly, it includes an arm 54 which is pivotally connected to the roller 40 by a shoulder bolt 56.

It will be noted that the roller 42 has a flat 58formed on the right side thereof (as viewed in FIG. 1) and that the bolt 56 is arranged to hold the clamp arm 54 against the surface of the flat 58. The lower end of arm 54 (as viewed in FIG. 1) has a curved, downwardly extending portion (best shown in FIG. 6). A slot or guide groove 60 is formed through the arm 54 and a lock jaw 62 is mounted therein for selective movement between the solid and dotted line positions shown in FIG. 6. Note that the lock jaw 62 has a total arcuate extent of slightly less than 180. Also, it has an inner contour 64 sized so as to closely engage the outer surface of the tube 52. A guide pin extends from the back surface of the locking jaw 62 through the slot 60 and a flange or shoulder 66 maintains the locking jaw properly positioned in the groove while permitting it to move between the solid and dotted line positions of FIG. 6.

To use the tube clamp, the locking jaw 62 is moved to the dotted line position of FIG. 6 and the arm 54 pivoted upwardly so that the tube can'be inserted adjacent the groove 42 of the forming roller. The tube, at the start of a bending operation, is shown in solid lines in FIG. 1. With the tube inserted, the arm is pivoted back down to the solid line position and the lock jaw 62 pivoted or slid back to its solid line position. The tube is thus loosely clamped in the groove 42.

Associated with the forming roll assembly 20 is the forming shoe assembly 22. Forming shoe assembly 22 serves to support the tube 52 against the forming roll 40 and acts somewhat like an anvil during the bending operation. As best shown in FIGS. 1 and 2, the forming shoe assembly 22 includes a first bar 70 having an arcuate groove 72 formed along one side thereof. Groove 72 has an arcuate extent of slightly less than 180 and a radius substantially corresponding to the radius of the outer surface of the tube 52. The preferred relationship between the groove in the forming shoe and the forming roll is best seen in FIG. 7. Note that the forming roll groove is a perfect circle throughout 180. Tangents of 0.015 inches in length extend out from the end points. The cross-section of the forming shoe groove is also a perfect circle but terminates 0.020 inches beyond the end of the tangents, thus providing 0.005 inches for clearance.

The bar 70 is carried on a second pivotally mounted bar 74 and is releasably connected thereto by machine screws or the like 76. Bar 70 has a tongue portion 78 which is received in a groove 80 formed in bar 74. As best shown in FIG. 1, bar 74 is pivotally connected to the body for movement about an axis 82 which is parallel to the axis of rotation of the forming roll 40. Referring to FIG. 5, it is seen that the bar 74 is connected to body 10 by a shaft 86 having a thin enlarged head 88. A disc or the like 90 is releasably connected to the opposite end of shaft 86 by a socket head screw 92 to maintain the bar 74 on the shaft while permitting free rotation. It should also be noted that a bearing 94 having a thin flange 96 is positioned about the shaft 86 where it passes through body 10.

As shown in FIG. 1, the forming shoe assembly 22 is arranged so that it can be moved between the solid line position where it cooperates with the forming roll 40' for a bending operation, and to the dotted line position wherein the tube can be freely inserted and locked in position on the forming roll or removed after the forming operation. The solid line position of the forming shoe assembly is a lock position and the lock means could take many forms but the preferred embodiment uses a pivotally mounted locking lever best shown in FIGS. 1, 2 and 5. Referring in particular to FIG. 5, it will be seen that a lever 100 is pivotally mounted in bar 74 by a screw or shoulder bolt 102 which extends through bar 74. The lever has an end portion 104 which extends through a slot or groove 106 formed in bar 74. As shown, when pivoted to the solid line position of FIG. 5, the portion 104 extends upwardly through the bar 74 into a slot or groove 107 carried in body 10. In,

the embodiment shown, the groove 107 is formed in a separate element shown as a circular disc 108 carried in body 10. The disc 108 is merely press fitted into an opening formed through the body. This facilitates forming of the groove 107 and allows some adjustment of the groove as needed during assembly of the appara- IUS.

When the lever 100 is pivoted to the dotted line position of FIG. 5, the portion 104 is withdrawn from the groove 107 and the forming shoe can be swung to the dotted line position of FIG. 1 for the insertion or removal of the tube.

The operation of the device thus far described is relatively simple. Note that the solid line showing of FIG. 1 illustrates the relationship of the various parts at the start of a bend. To place the tube in the bender, the forming shoe assembly 22 is released from its lock position and swung to the dotted line position. Also, the clamp arm is released by pivoting the lock member 62 and its pin shoulder 66 to the dotted line position of FIG. 6. The arm 54 is then swung up and the tube placed in position adjacent the forming roll 40. Thereafter, arm 54 is swung down to the solid line position of FIG. 1 and the lock member rotated to the solid line positions of FIGS. 1 and 6. Subsequently, the forming shoe assembly 22 is rotated to the solid line position of FIG. 1 and locked therein. As can be appreciated, rotation of the forming roll 40 in a counter-clockwise direction (as viewed in FIG. 1) causes the right-hand end of tube 52 to be bent upwardly as shown by 52, as it is pulled by the clamp assembly 50. The forming shoe assembly 22 holds the opposite end of the tube against the forming roll while the bend takes place. It should be noted that the bending takes place at point and that at this point, the tube is held substantially completely about its circumference by the groove in the forming roll and the groove in the forming shoe (see FIG. 7). By controlling the amount of rotation of forming roll 40, the extent of the bend can be controlled. In the subject embodiment, indicia in the form of score lines 122 are provided on the top of the forming roll 40 and a datum line 124 similarly provided on the top of the forming shoe assembly. The solid line position illustrates the start of the bend and, as can be appreciated, upon rotation to align different ones of these lines on the forming roll with the datum line 124, the degree of bend can be closely controlled to substantially any desired angle.

The subject invention uses a ratchet drive mechanism for rotating the forming roll 40. The ratchet drive is arranged so that the driving movement takes place when the

handles

16 and 18 are moved toward one another. This makes manual application of the forces required for the bending operation substantially easier than when the force must be exerted by pulling a pair of handles apart. This is so since it uses a set of arm and shoulder muscles which are generally much stronger.

Specifically, the ratchet drive mechanism includes a ratchet wheel 130 which is connected to the shaft 44 in the manner best shown in FIGS. 1 through 4. Note that the ratchet member 130 is received on a reduced diameter outer end portion of shaft 44 and is maintained thereon in driving connection by a cap plate or disc 132 connected to shaft 44 by a machine screw 134. A pin 136 is press fitted into the cap plate 132 and extends into an opening 138 formed at the juncture between the internal bore of the ratchet 130 and the reduced diameter end portion of shaft 44. This effectively keys the ratchet wheel to the shaft but permits easy removal of the ratchet wheel for repair or replacement, if necessary. A spacer washer 140 is positioned between body and the ratchet wheel 130 to maintain the ratchet wheel spaced outwardly a short distance from the body 10.

The ratchet wheel 130 is driven during oscillation of the arms by a pawl 144 best shown in FIG. 3. Note that pawl 144 is pivotally connected to body 12 by a pin 146. It should also be noted that the end of the pawl is received in a slot 148 formed in body 12. The end is bifurcated as best shown in FIG. 2 and a spring 150 is positioned about the shaft 146 and has its end portions bearing respectively against the pawl and the inner wall of the groove 148. This maintains the pawl continually biased in a clockwise direction as viewed in FIG. 3. An adjustable stop pin 152 extends through the pawl and engages the body 12 to limit the extent of clockwise movement of the pawl.

As best shown in FIG. 3, the end of the pawl is provided with a tooth or the like 154 which is adapted to engage the ratchet teeth 156. Note that as the arm 18 is moved to the left (as viewed in FIG. 3), the pawl is moved upwardly through the two dotted line positions until the portion 154 is engaged with one of teeth 156 of the ratchet wheel 130. The spring 150 maintains the pawl in engagement and the movement of arm 18 in a counter-clockwise direction causes a rotating drive force to be applied to the ratchet wheel driving the forming roll 40. At the end of the counter-clockwise movement of arm 18 as determined by the stop pin 36, the stop pin 152 engages body 12 and withdraws the pawl from ratchet wheel 130.

The invention has been described in great detail sufficient to enable one of ordinary skill in the tube bending art to make and use the same. Obviously, modifications and alterations of the preferred embodiment will occur to others upon a reading and understanding of the specification and it is my intention to include all such modifications and alterations as part of my invention insofar as they come within the scope of the appended claims.

What is claimed is:

I. A manually operable tube bender comprising:

first and second elongated rigid bodies pivotally interconnected for oscillation about a first axis having a fixed location with respect to said bodies with portions of the bodies on a first side of the first axis formed to serve as operating handles to allow the bodies to be manually oscillated;

a forming roller having a peripheral, semi-circular groove sized to receive a tube to be bent and rotatably mounted on the first body at a location spaced from the axis on the side opposite the handles for rotation about a second axis extending parallel to the first axis;

a releasable tube clamp means carried on the roller and adapted to clamp a tube in said groove;

a forming shoe carried on the same body as the forming roller and having a generally semi-circular groove along one side and mounted to move between a first lock position to closely engage the tube to be bent, and a second position wherein it is spaced a substantial distance from the roller; and,

drive means for rotating said forming roller comprising a ratchet wheel drivingly connected to said forming roller for rotation therewith about said second axis and a pawl member pivotally connected to the second body at a location such that when the handles are oscillated toward one another, a drive force is imparted to the forming roller.

2. The tube bender as defined in claim 1 wherein the forming shoe is located between the first axis and the second axis.

3. The tube bender as defined in claim 1 wherein the forming shoe is mounted for pivotal movement about a third axis parallel to and spaced from the first axis.

4. The tube bender of claim 3 wherein means are provided for locking said forming shoe in a first position substantially in engagement with said forming roller, said lock means comprising a lever carried in said forming shoe and adapted to engage a groove formed in said first body.

5. The tube bender of claim 1 wherein said forming roller is carried on a shaft extending through said first body and wherein said ratchet wheel is connected to said shaft on the side of said body opposite said forming roller.

6. The tube bender of claim 5 wherein said pawl member is pivotally connected to said second body and spring biased toward said ratchet wheel, and stop means for producing disengagement of said pawl from said ratchet wheel at the inner limit of oscillation of said bodies.

7. The tube bender of claim 6 wherein said releasable clamp means for holding a tube in the groove on said forming roller is pivotally connected to said forming roller for movement about an axis generally perpendicular to said first axis.

k 4 I! l

Claims

1. A manually operable tube bender comprising: first and second elongated rigid bodies pivotally interconnected for oscillation about a first axis having a fixed location with respect to said bodies with portions of the bodies on a first side of the first axis formed to serve as operating handles to allow the bodies to be manually oscillated; a forming roller having a peripheral, semi-circular groove sized to receive a tube to be bent and rotatably mounted on the first body at a location spaced from the axis on the side opposite the handles for rotation about a second axis extending parallel to the first axis; a releasable tube clamp means carried on the roller and adapted to clamp a tube in said groove; a forming shoe carried on the same body as the forming roller and having a generally semi-circular groove along one side and mounted to move between a first lock position to closely engage the tube to be bent, and a second position wherein it is spaced a substantial distance from the roller; and, drive means for rotating said forming roller comprising a ratchet wheel drivingly connected to said forming roller for rotation therewith about said second axis and a pawl member pivotally connected to the second body at a location such that when the handles are oscillated toward one another, a drive force is imparted to the forming roller.