US2955639A

US2955639A - Article bending and ejecting method and apparatus

Info

Publication number: US2955639A
Application number: US806896A
Authority: US
Inventors: David W Brown
Original assignee: Blackhawk Manufacturing Co
Current assignee: Blackhawk Manufacturing Co
Priority date: 1959-04-16
Filing date: 1959-04-16
Publication date: 1960-10-11
Anticipated expiration: 1977-10-11

Description

Oct. 11, 1960 ngw. BROWN ARTICLE BENDING AND EJECTING METHOD AND APPARATUS Filed April 16, 1959 INVENTOR. D/9u/0 14/. Bean/M Patented Oct. 1 1, 1960 2,955,639 ARTICLE BENDING ANn EJECTING METHOD AND APPARATUS The present invention relates generally to improvements in the art of bending metal and especially tubes, rods or pipes, and it relates more particularly to improvements in the construction and the. method of operating such article benders to accurately form the desired bends while permitting efiicient ejection of the bent articles from the forming shoe.

It is a principal object of the invention to provide an improved method of and apparatus. for bending pipes, tubes, or the like and for effecting removal of the bent articles from the bending device after completion of the bending operation.

It is, of course, well known in commercial practice to bend tubes, rods or pipes with the aid of bending apparatus having a bending shoe provided with a relatively deep arcuate groove for constraining the pipe to cause it to retain an approximately circular cross section during bending, the shoe being actuated under pressure by a fluid pressure device consisting of a cylinder and ram. In this prior bending apparatus, it is also common practice to provide the frame of the pipe bender With a pair of laterally spaced reaction blocks which coact with the article to be bent outwardly beyond the shoe so that as pressure is applied to the shoe to move the same the reaction blocks coact with the pipe or tube and cause the same to be bent to the desired configuration abou the bending shoe.

While such prior bending equipment is capable of producing satisfactory bends in elongated articles such as pipe or tubing, the bending operation causes the articles being operated upon to spread laterally and thereupon become jammed within the relatively deep groove of the forming shoe. It therefore becomes very difficult in most instances to remove the bent article from the shoe after completion of the bending operation without marring the article and without injuring or damaging the bend.

To remove the pipe, tube or other article operated upon from the shoe, it has previously been proposed to re-position the reaction blocks carried by the frame so that the blocks will coact with the pipe on the inside of the bend and to then reverse the pressure application so as to withdraw the shoe from the pipe as the pipe is forced against the reaction blocks in a manner exactly the reverse of the initial bending operation. However, devices incorporating such means for withdrawing the bent article require the use of a double acting cylinder and ram which increases the expense, size and weight of the unit.

It has also been previously proposed to lock the shoe in the frame so that the shoe is held against movement and to back the actuating plunger away from the shoe while an ejecting pin is inserted in a hole provided therefor and extending axially of the plunger through the shoe and opening into the article receiving groove thereof. The plunger is thereafter again actuated under pressure to press the insert pin directly against the concave side of the bend of the jammed article within the groove while the reaction blocks. are released. This action thereby ejects the article but the pressure of the pin against the bent pipe or tube not only tends to mar and destroy the accuracy of the bend but also frequently dents the' article being formed or worked upon since the pressure is applied locally and directly against the article. p

More recently, it has also been proposed to eject the bent article by backing olf' the plunger and then reversing the bending shoe in the frame, ejector means in the form of a U-shape member being then applied between the end ofthe force applying plunger and the bending shoe. Thus, when pressure is applied from the plunger to the ejector means and then to the shoe, the pipe is caused to engage the stationary reaction blocks on the reverse side of the bend and further pressure and movement of the shoe causes the pipe to be ejected from the groove of the shoe. While this apparatus and method has proven highly satisfactory, it is nevertheless necessary to reverse the position of the heavy shoe with the pipe engaged in the groove thereof, and this necessitates rather heavy work in some instances. Also, it is cumbersome in some instances to reverse the shoe with the pipe carried thereby, especially in cases in which the pipe is rather long.

It is therefore an important object of the present invention to provide an improved method and apparatus for removing jammed articles from the shoe of a bending unit in a most convenient manner While obviating the objections of prior art methods and devicesof this type.

Another important object of this invention is to pro vide improvements in the art of bending articles such as pipe and for subsequently ejecting the pipe from the bending shoe without denting or otherwise marring the pipe or the bend therein.

A further object of the invention is to provide an improved pipe or tube bender and a method for ejecting the pipe or tube subsequent to the bending operation in which there is no need for removing the shoe and the bent pipe from the bender frame to effect the ejection thereof.

Still another object of the invention is to provide an improved article bender and method in which a single acting power cylinder and ram may be utilized to effect the bending operation as well as to remove or eject the pipe from the shoe subsequent to'the bending operation.

A further object of the invention is to provide improvements in the art of bending and ejecting bent pipe or tubing in which the ejection or removal of the pipe from the bending shoe is accomplished by causing the bending shoe and pipe to rotate relative to each other to thereby pry the pipe from the groove of the bending shoe.

These and other specific objections and advantages of the invention will be apparent from the following detailed description.

A clear conception of the features constituting the present improvement and of the construction and mode of utilizing one of my improved pipe benders as well as the steps of the improved method of bending and ejecting the pipe or tubing, may be had by referring to the drawing accompanying and forming a part of this specification in which like reference characters designate the same or similar parts and the various views.

Fig. l is a part sectional plan view of one of the improved fluid pressure actuated. pipe benders showing the same in the act of producing a bend, a part of the frame and one of the reaction blocks having been broken away thereof;

Fig. 2 is a somewhat similar part sectional view of the Same pipe bender as shown in Fig. 1 but with the parts positioned just prior to the ejection of the pipe, parts of the frame and reaction blocks having been broken away to a greater extent than in Fig. l and the pipe ejecting action being illustrated by means of dot and dash lines;

Fig. 3 is a transverse section through the bender taken along the line 33 of Fig. 2;

Fig. 4 is another part sectional plan view of a somewhat modified fluid pressure actuated pipe bender with the parts positioned in pipe ejecting condition and with the pipe being illustrated in its final ejected position, a portion of the frame and the reaction blocks again having been broken away for the sake of clarity with the section through the bending shoe being taken central ly therethrough.

While the invention has been shown and described herein as having been applied to a fluid pressure actuated pipe bender of a particular type, it is not intended to thereby unnecessarily restrict the use of the improved features by reason of such restricted embodiment, and it is also contemplated cetrain specific terms employed herein shall be given the broadest possible description and interpretation consistent with the disclosure.

Referring to the drawing, the portable pipe or tube bender shown therein as embodying the invention comprises, in general, power operated means such as a hydraulic cylinder 6 or the like having an axially movable actuator or ram 7 movable therein and extending from one end thereof; a frame consisting of a pair of parallel laterally spaced

rigid plates

8, 9 detachably but firmly secured to the open end of the pressure cylinder 6 and provided with two series of aligned holes 10, 11 diverging away from the point of attachment of the plates to the cylinder; a pipe bending shoe 12 provided with a relatively deep pipe engaging groove 13 along the longitudinally curved work engaging face thereof, the shoe 12 being detachably secured in a suitable manner to the extreme outer end 14- of the ram or plunger 7 for movement thereby between the

spaced plates

8, 9 forming the frame; and pipe engaging reaction blocks 15, 16 pivotally cooperable with selected ones of the aligned holes 10, 11 respectively on opposed sides of the ram 7 so as to cooperate with the ram and the bending shoe as they are moved outwardly of the cylinder 6 to effect bending of a pipe 17 or similar article having a portion thereof extending across the reaction blocks within the frame formed by the

plates

8, 9.

The general assemblage thus far described has heretofore been proposed and is, in fact, typical of one commercially available line of pipe benders. In operation of ths device in bending the pipe 17, pressure is admitted to the rear of the cylinder 6 causing the ram 7 to move outwardly from the cylinder. The ram 7 carries with it the shoe 12 which in turn acts on the medial portion of the pipe 17 causing it to seat in the bottom of the groove 13, and further movement of the ram 7 and shoe 12 forces the pipe to bear upon the

fixed reaction shoes

15, 16 and under force causes the pipe to assume the curvature of the bending face of the shoe. Upon completion of the bend, the pressure in the cylinder 6 is suitably released, but the pipe 17 during the bending operation has a tendency to assume an elliptical cross section and accordingly invariably becomes jammed or stuck within the arcuate groove 13 of the bending shoe thus presenting the problem of removing or ejecting the same.

In the present instance, the pipe 17 is ejected from the groove 13 of the shoe by providing a lateral fixed pivot for the shoe so that the rotation of the shoe under pressure about the pivot will swing the jammed pipe into contact with one of the reaction blocks and thereby cause the pipe to be pried from the groove of the shoe as the shoe is rotated. To accomplish this pipe removal or ejection step, the pin 18 which secures the outer end 14 of the pressure plunger 7 to the bending shoe 12 is first removed and the plunger 7 may then be backed out of the receiving socket or recess 19 of the bending shoe 12 and away from the shoe. Then, in the device shown in Figs. 1 to 3 inclusive, the bending shoe 12 together with the pipe 17 is moved laterally of the plunger axis with the hole 20 provided in the shoe in axial alignment with one of the innermost holes 10 of the frame side plates. A pivot pin 21 is then inserted through the aligned

holes

20, 10 so that the shoe will swing about its pivot upon application of pressure by the plunger 7 to a bearing ledge or abutment 22 formed on the shoe adjacent to the socket or recess 19 therein. Fluid under pressure may then be admitted once again to the cylinder 6 to advance the ram 7 which swings the shoe 12 about the pivot pin 21 and causes the pipe '17 to bear against the reaction shoe 16 which causes relative rotation of the shoe 12 and pipe 17 and the resultant prying of the pipe 17 from the groove 13 of the bending shoe.

As shown in Fig. 4, a similar result may be obtained without need for re-positioning the shoe 12 and the jammed pipe 17 by means of a somewhat modified device. In the device shown in Fig. 4, additional axially aligned holes 23 may be formed in the

frame side plates

8, 9, and these aligned holes 23 are adapted to be axially aligned with the lateral pivot pin receiving hole 20 of the bending shoe to thereby permit reception of the pivot pin 21. The holes 23 in this case are so located as to permit free working space between the pipe and the reaction blocks 15, 16 without need for moving the shoe 12 laterally as in the device of Figs. 1 to 3. However, to provide a bearing surface for the end of the ram plunger 7, a mushroom-shaped insert 24 is provided for the socket or recess 19 of the bending shoe. Thus, after the

holes

20, 23 have been properly aligned and the pivot pin 21 inserted therein, movement of the ram 7 by fluid pressure will cause the same to bear upon the conical bearing surface of the mushroom-shaped insert 24 and swing the bending shoe 12 about the pivot 23 in exactly the same manner as previously described with reference to Figs. 1 to 3. Further application of pressure will cause the pipe to bear against the reaction shoe 16 and be rotated and pried out of the groove 13 of the bending shoe.

It is believed obvious from the foregoing that the steps of the improved method consist generally in the application of pressure to a medial portion of the pipe 17 while resisting movement of the pipe at two laterally spaced points, then releasing the pressure and pivotally fixing the pipe carrying member or work piece at a point laterally offset from the axis of pressure application, subsequently applying pressure to swing the work piece and pipe about the pivot, and simultaneously resisting swinging movement of the pipe remote from the pivot to thus cause the same to be removed from the work piece.

, From the foregoing detailed description, it is believed apparent that the bent pipe may be readily removed from the groove of the bending shoe by means of a single acting ram and without need for directly contacting the bent pipe with an ejector pin or other means which may tend to dent or otherwise mar the pipe. Furthermore, the only modification necessary in a standard commercially available pipe or tube bender is the provision of a pivot pin receiving hole 20 in the bending shoe and, in the case of the modification of Fig. 4, in the bending frame side plates and the provision of the pivot pin 21. The ejecting operation may obviously be accomplished quickly with little or no re-positioning of the pipe and the bending shoe and without danger of damaging the pipe. In the instant case, all of the force required to remove the pipe from the groove of the bending shoe is obtained from the bender ram without need for external force, and the ejection or removal of the pipe is obtained by a prying action in which the pipe and shoe are caused to rotate with respect to each other as distinguished from a forcing action in which the pipe is pressed directly out of the shoe with considerable pressure being applied to the pipe at a local point.

It should be understood that it is not desired or intended to limit this invention to the exact details of construction or to the precise mode of details of the apparatus herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the packaging art.

I claim:

1. Apparatus for bending an article about a grooved shoe in which it has a tendency to stick and for thereafter releasing the article from within the groove, comprising, a frame, power operated means mounted on said frame and including an axially movable actuator, reaction blocks mounted on said frame on each side of said actuator, a bending shoe movable between said reaction blocks by said actuator and having a work engaging groove and a curved bending surface cooperable with an elongated article supported on said reaction blocks to bend the same, and means laterally offset from the axis of said actuator for pivot-ally securing said bending shoe to said frame upon completion of the bending operation, whereby subsequent movement of said shoe by said actuator causes the bent article to coact with only one of said reaction blocks to release said article from said shoe. 7

2. Apparatus as set forth in claim 1 in which the laterally offset pivot means consists of a pin removably receivable in alignable holes in said frame and said bending shoe.

3. Apparatus as set forth in claim 1 in which pressure is applied to the shoe from one side of a plane extending through the axis of said reaction blocks and the laterally offset pivot means is located on the pressure applying side of said plane.

4. Apparatus as set forth in claim 1 in which the bending shoe is provided with a socket for receiving the actuator during the bending operation and with an adjacent flat bearing shoulder for said actuator during the releasing operation.

5. Apparatus as set forth in claim 1 in which the bending shoe is provided with a socket for receiving the actuator during the bending operation and with a plug insertable within said socket and having a bearing surface for said actuator during the releasing operation.

6. The method of bending an elongated transversely cylindrical article with the aid of a grooved bending shoe and for thereafter releasing the article from within the groove, which comprises, applying pressure through the bending shoe to a medial portion of the article to be bent while resisting movement of the article at laterally spaced points to thereby bend the article, and thereafter rotating the shoe and the article relative to each other to release the bent article from the shoe.

7. The method of bending an elongated transversely cylindrical article with the aid of a grooved bending shoe and for thereafter releasing the article from within the groove, which comprises, moving the bending shoe into contact with a medial portion of the article to be bent, resisting movement of the article at laterally spaced points outwardly beyond opposite sides of the shoe while continuing the movement thereof under pressure to thereby bend the article, and thereafter arcuately swinging the shoe under pressure while simultaneously resisting movement of the article beyond the arcuate path defined by the shoe to release the article therefrom.

8. The method of bending an elongated transversely cylindrical article with the aid of a grooved bending shoe and for thereafter releasing the article from within the groove, which comprises, moving the'bending shoe into contact with a medial portion of the article to be bent, resisting movement of the article at laterally spaced points outwardly beyond opposite sides of the shoe while continuing the movement thereof under pressure to thereby bend the article, and thereafter arcuately swinging the shoe under pressure about a laterally offset pivot point while simultaneously resisting movement of the article beyond the path of movement of the shoe remote from the .pivot point .to release the article from the shoe.

References Cited in the file of this patent UNITED STATES PATENTS 1,865,025 Lidseen June 28, 1932 2,464,459 Newlon Mar. 15, 1949 2,477,910 Tal Aug. 2, 1949 2,871,908 Flessate Feb. 3, 51959