US2695538A - Ratchet and pawl actuated lightweight tube benders - Google Patents

Description

Nov; 30, 1954 w. R. PARKER 2, 3 RLATCHET AND PAWL ACTUATED LIGHTWEIGHT TUBE BENDERS 7 Filed March 19, 1951 2 sheets-sheet 1 lmoentor WILL mm R fine/ 56 (Ittornegs Nov. 30, 1954 w. R. PARKER RATCHET AND- PAWL ACTUATED LIGHTWEIGHT TUBE BENDERS 2 Sheets-Sheet 2 Filed March 19, 1951 Z'mnentor W/u/AM 2.12784645/3 MAL, arm 41% (Ittornegs United States Patent RATCHET AND PAWL ACTUATED LIGHTWEIGHT TUBE BENDERS William R. Parker, Milwaukee, Wis., assignor to Tal Bender, Inc., Milwaukee, Wis., a corporation of Wisconsin Application March 19, 1951, Serial No. 216,369

Claims. (Cl. 81-15) My invention relates to improvements in tube bending devices.

My invention relates particularly to tube bending devices which are light in weight and particularly suited to manual support and manipulation and which may be adjusted to present laterally a wide open throat for the reception of a tube to be bent, with facilities provided to adjust a former bar toward a rotatable or oscillatable former which is subject to easy rotative advancement in small increments.

The objects of my invention are: to provide a tube bending device wherein a frame provided with a fixed handle and a movable handle side by side for hand tool use is provided with an adjustable bar former and a mutilated circular rotatable former, the bar and rotatable formers being secured to one face of the frame so that when the formers are adjusted for the inception of a tube bending operation, a wide open throat is provided for the lateral reception of the tube; to provide a portable hand operated tube bending device wherein a post-like frame provides not only a fixed handle for support of the device during the bending operation, but also provides ways for the adjustable mounting of a bar former, the frame being extended beyond the post-like portion to provide a mounting for a rotatable former; and to provide a portable tube bender with a ratchet action rotatable former whereby in a small light-weight hand supported and operated device a bending operatlon may be performed in small increments with relatively l1ttle effort, but at the same time the tube being bent may be released from its bending tension and readily removed Y from the tube bender.

In the following description it will be understood that in using the term multilated former, I mean that the oscillatable or rotatable former which I use is generally circular in form, but a portion of the periphery is cut away to provide a surface to which a clamping device or book may be mounted, and the fact that this cut away portion is removed makes it possible to provide a wide open throat into which a tube may be laterally inserted. It is not necessary, therefore, to insert the tube endwise into my former. This is especially true because the bar former in my bender is adjustable toward and from my rotatable former, and the throat is thus subject to additional amplitude.

In the drawings:

Fig. 1 is an elevation of my tube bender showing a tube in position for a tube bending operatlon WhlCh has proceeded to the second stage or second ratchet operation.

Fig. 2 is a section on line 22 of Fig. 1.

Fig. 3 is a section on line 33 of Fig. 2.

Fig. 4 is a perspective of my tube bender with a tube in position on the bar former in readiness for ad ustment of the bar former toward the rotatable former.

Like parts are designated by the same reference characters throughout the several views.

The frame of my tube bender includes a relatively centrally disposed post 10, a fixed handle 11 preferably integrally formed with the post 10, and a shell-like mounting 12 for a rotatable former 13. This former 13 is the mutilated former to which I have referred above. It is generally cone-shaped as shown most clearly in Figs. 2 and 4 but it is cut away along lines 14 and 15. The result of the removal of a portion of the body structure of the generally conical former 13 is provision of a smooth face along the plane 15 against which are 2,695,538 Patented Nov. 30, 1954 mounted an appropriate number of tube engaging hooks 16, 17 and 18. These hooks are pivotally mounted, each upon its own cap screw 19, 20 or 21, as shown clearly in Figs. 1 and 2. The appropriate number of hooks is, of course, the number corresponding to the number of grooves 25, 26 or 27 formed in the conical peripheral surface of the former 13. The former 13 is rotatably mounted to the frame 10 and its shell-like mounting member by means of a shoulder stud 30 locked to the shell-like member 12 by nut 31 so that the rotatable former 13 is freely revoluble with reference to the frame 10 and the shell-like member.

Housed within flange 32 of the member 12 is a ratchet wheel 33 secured to the rotatable former 13 so as to rotate positively therewith. It is the ratchet rotation of the former 13 at a time when one of the hooks 16, 17 or 18 is engaged with a tube such as the tube 35 shown in Figs. 1 and 2 which accomplishes the tube bending operation as will be described below. During the bending operation a bar former having straight grooved surfaces supports the tube against the rotatable former.

It will be noted that the lower end of the post-like frame 10 has a forwardly extending bracket 36 at its lower end and that ways 37 are provided in the side walls of the post 10 for sliding and adjustable mounting of bar former 38. The bar former is provided with an adjusting screw 39 in swivel connection with the bar former 38 at 40, the screw 39 being in threaded connection with the bracket 36 under the control of the knurled handle 41.

It will be noted that the fixed handle 11 extends down below theleft side of the frame post 10. At the right side of the post 10 is a flange 45 which not only provides an additional brace for the shell-like member 12, but also provides a mounting for movable handle 46 mounted upon shoulder screw 47. This handle rotates a lever of the first class and the working or loaded end thereof at 48 is fairly short and provides a mounting for a spring actuated pawl 49 mounted upon pawl pin 50. A torsion spring 51 urges the pawl constantly toward the ratchet wheel 33. Thus when the handle 46 is oscillated about shoulder screw 47 the pawl will engage the ratchet and advance the rotation of the former 13 in increments of rotative motion.

As shown most clearly in Fig. 3, frame 10 is provided with a fixed pawl boss 55 which is bored and counterbored at 56 for the reception of a retractable pawl 57 constantly urged by compression spring 58 so as to engage the pawl with the ratchet 33. A knurled handle at 60 may be used to withdraw this rotatable pawl from its position of engagement with the ratchet 33, and a key 61 protruding from the rotatable pawl 57 may be rotated .to a position against the outer end of the boss 55 so as to prevent the spring 58 from urging this pawl into engagement with the ratchet. Thus I provide means for holding the rotatable former 13 in any position of advanced rotation but if the operator wishes to freely rotate the former 13 without interference of the retractable pawl 57 he may withdraw and rotate the key 61 to a position where it will hold the pawl out of engagement with the ratchet 33.

When the operator wishes to freely rotate the former 13 he not only will wish to withdraw the retractable pawl 57 but also clear the pawl 49 from the ratchet. To facilitate this I provide an automatic pawl retractor pin 65 secured to the frame and extending into such position between shoulder pin 47 and the ratchet that the pawl 49 will ride against the pin and will be swingably withdrawn from the ratchet as the handle 46 is swung to 511% extreme position to the right as shown in Figs. 1 an The operation of my tube bender is as follows: the operator will place the retractable pawl in the position shown in Fig. 3, so that it will engage the ratchet automatically as the rotation of the former 13 progresses. Bar former 38 will be threadedly retracted to its lower position on the ways 37 and the rotatable former 13 will be so rotated that the cut away portion will overlie the bar former, thus opening a wide throat for the lateral reception of a tube 35 into position in the particular groove in which the tube 35 fits. The rotatable former will then be adjusted so that surface will be aligned with the right hand margin of the bar former 38. The bar former 38 will then be threadedly adjusted upon the ways 37 by means of screw 39 and the knurled handle 41 until the tube 35 is firmly pressed into the groove mated with the groove of the bar former which is being used. The hook, 16 in this particular instance, as shown in the drawings is then swung into position to engage the tube 35 and the apparatus is then in condition to institute the tube bending operation.

The actual bending of the tubing is accomplished by the repeated oscillation of the handle 46 so as to cause the pawl 49 to repeatedly advance the rotation of the former 13 in increments determined by the spacing of the ratchet teeth. As each increment of rotative motion is accomplished, the pawl 57 will engage then'ex't tooth and hold the former 13 in its position of advanced rotation.

Throughout the bending operation the position of the tube bender in the hands of the operator is such that the degree to which the tube 35 is bent is perfectly obvious, and as soon as the tube is bent to the extreme required, the bar former 38 can be threadedly withdrawn upon its ways 37. The hook 16, 17 or 18 can be disengaged from the bent tube and the tube may be laterally withdrawn from the tube bender.

If a particularly stiff tube is being bent and the stresses are such so as to tend to hold the pawls in engagement with the ratchet, the handle 46 may be swung to an extreme position as shown in Fig. 3 and the pawl 49 will be automatically withdrawn from the ratchet.

An important feature of my tube bender is the relative position of the major structural elements so as to provide a balance of the tool in the hands of the user. The central post 10 with the fixed handle on the one side and the movable handle on the other provides an inherent bracing and balancing action. This is somewhat unbalanced by the relative position of the shell-like member 12 and the rotatable former 13 positioned as shown in Fig. 1, but this imbalance is deliberately set up to counterbalance the weight of the tube 35 which normally extends somewhat to the left as shown in Fig. 1.

I claim:

1. In a tube bender, a frame having a front face upon which the operable members are mounted, said operable members including a slidably adjustable bar former and a rotatable former mounted to the frame upon an axis normal to said face; an operating handle oscillatable upon an axis parallel with the axis for the rotatable former.

and provided with a pawl, ratchet teeth upon the rotatable former engageable with said pawl, said pawl having a path of movement to advance the rotation of the former in increments, a projection upon the frame in a position to interfere with the path of movement of the pawl in an extreme of movement of the operating handle and to force the pawl out of engagement with the rotatable former, and a relatively fixed spring ratchet pawl positioned to engage the teeth of the ratchet on the rotatable former, said relatively fixed ratchet being manually retractable to an inoperative position.

2. A tube bender having a shell-like mounting for a rotatable bending former, a bending former having a ratchet rotatable in said mounting, a handled post forming an extension of said mounting and provided with an oscillatable handle, a pawl controllably connected to the oscillatable handle in position to engage the ratchet for step by step rotation of the bending former, and a relatively fixed resilient pawl mounted to the frame and positioned to hold the ratchet in a particular position of rotation, said post having a bar former slidably adjustable thereon whereby to be positioned between the handle and the rotatable former, said handled post providing a guide for a bar former reciprocably adjustable toward and away from the rotatable former, said rotatable former being exter'iorly cut away to provide an outwardly facing flat surface in certain positions of adjustment of the rotatable former to face the reciprocable bar former and thereby open a throat for lateral reception of a workpiece.

3. In a portable tube bender, a frame including a fixed handle and a post-like portion provided with a former bar adjustably mounted thereon, an extension of the frame shaped to receive a rotatable former thereagainst, a mutilated circular former grooved exteriorly to receive a tube and mounted to said frame whereby in certain positions thereof to present a laterally open throat between the rotatable former and the former bar, the postlike portion being provided with a mounting and an oscillatable handle thereon, and the rotatable former and said oscillatable handle being in ratchet and pawl relationship, the oscillatable handle having a pawl to engage a ratchet on the rotatable former, and a pin disposed in upstanding relationship to the frame in the path of movement of the pawl whereby in extremepo'sition of oscillation of the handle the pawl is withdrawn from the ratchet.

4. In a tube bender, a frame with a central post having a fixed handle at one side thereof, a movable handle at the other side thereof, a bar former mounted for adjustment along the post between the handles, and a rotatable former mounted against the frame with a ratchet surface ad acent the movable handle, the movable handle having a pawl for engagement with the ratchet to move the rotatable handle in increments, a manually retractable resilient pawl mounted to the frame in position to engage the ratchet whereby to hold the rotatable former in advanced rotative position, the frame being provided with a p n to automatically retract the pawl of the movable handle when it is moved to an extreme position by its handle.

5. A tube bender com rising a frame having a handle, a former block having a mounting on said frame on which the former block is rotatable, said former block being provided with a plurality of stepped former grooves and means for releasably clamping tubes in said grooves for rotation of said tubes with said former block, and a former bar having a plurality of stepped grooves respeetively aligned with the grooves in the former block, said frame being provided with a sliding way on which the former bar is reciprocable on arectilinear path of movement toward and away from the axis of former block rotation, screw means for advancing and retracting said former bar on said ways, and lever means for rotating the former block with respect to the former bar.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 844,789 Gardner 1 Feb. 19, 1907 1,119,292 Lawson 1 Dec. 1, 1914 1,155,042 Caron et al. -a -2 Sept. 28, 1915 1,167,983 Davis et al. 1 Jan. 11, 1916 1,353,168 McArthur r Sept; 21, 1920 1,543,338 Neal et al 1 June 23, 1925 1,687,210 Holsclaw et al. Oct.- 9, 1928 1,688,199 Meier v Oct. 16, 1928 1,899,281 Lidseen Feb. 28, 1933 1,949,938 Martin at Mar. 6, 1934 2,171,907 Beehler 'et al. a Sept; 5, 1939 1 FOREIGN PATENTS Number Country Date 8,750 Norway 1 Mar. 31, 1900

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