US3844149A

US3844149A - Pipe necking apparatus

Info

Publication number: US3844149A
Application number: US00420289A
Authority: US
Inventors: E Hansen
Original assignee: Dako Werkzeugfabriken David Kotthaus GmbH and Co KG
Current assignee: Dako Werkzeugfabriken David Kotthaus GmbH and Co KG
Priority date: 1972-12-04
Filing date: 1973-11-29
Publication date: 1974-10-29
Anticipated expiration: 1991-10-29

Abstract

An elongated drill bit is composed of two longitudinally extending drill bit sections each of which is formed with an outwardly extending pressure face and with a leading end. These sections are pivotally connected to a rotatable support in such a manner that they can be placed into a position in which the leading ends overlap, and into a position in which they are spread apart. A rotatable sleeve is mounted on the support, surrounding the drill bit sections and having a front end face provided with a recess dimensioned to in part accommodate a pipe which is to be necked. The drill bit is used, with the leading ends of the sections overlapping, to drill a hole in a pipe, whereupon the sections are spread apart so that the leading ends are spaced sufficiently for the pressure faces to exert pressure upon the marginal portion of the pipe surrounding the hole, and rotation of the support causes the sleeve to move forwardly against the pipe, thus extracting the drill bit sections from the hole and causing their pressure faces to outwardly displace the marginal portion of the pipe which surrounds the hole and to form a neck on the pipe.

Description

United States Patent Hansen PIPE NECKING APPARATUS Inventor:

13 Elmar Hansen, Munich, Germany Dako-Werkzeugfabriken David Kotthaus KG, Remscheid, Germany Filed: Nov. 29, 1973 Appl. No.: 420,289

Assignee:

Foreign Application Priority Data Dec. 4, 1972 Germany ..2259638 M June 5. 1973 Germany ..23284619 [52] US. Cl 72/71, 72/120, 72/125, 72/325 [5l] Int. Cl BZld 51/38 [58] Field of Search 29/157 T; 72/70, 71, 112, 72/120, 325, 125

[56] References Cited UNITED STATES PATENTS 656,425 8/1900 Schilling, et a1. 72/120 3,081,812 3/1963 Brown 72/125 3,277,683 10/1966 Knoblock.... 72/71 3,592,038 7/1971 Larikka 72/112 Primary Examiner-Lowell A. Larson Attorney, Agent, or FirmMichael S. Striker [57] ABSTRACT An elongated drill bit is composed of two longitudinally extending drill bit sections each of which is formed with an outwardly extending pressure face and with a leading end. These sections are pivotally connected to a rotatable support in. such a manner that they can be placed into a position in which the leading ends overlap, and into a position in which they are spread apart. A rotatable sleeve is mounted on the support, surrounding the drill bit sections and having a front end face provided with a recess dimensioned to in part accommodate a pipe which is to be necked. The drill bit is used, with the leading ends of the sections overlapping, to drill a hole in a pipe, whereupon the sections are spread apart so that the leading ends are spaced sufficiently for the pressure faces to exert pressure upon the marginal portion of the pipe surrounding the hole, and rotation of the support causes the sleeve to move forwardly against the pipe, thus extracting the drill bit sections from the hole and causing their pressure faces to outwardly displace the marginal portion of the pipe which surrounds the hole and to form a neck on the pipe.

15 Claims, 8 Drawing Figures PATENTEU B W4 3,844,149

sum snr 4 PATENIED mm 2 9 I974 3, 44 1 suzem or 4 PIPE NECKING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to a pipe necking apparatus, and particularly to a pipe necking apparatus which can be connected to the chuck of a drill or the like.

Apparatus of this type can be used for heating installations, for air conditioning installations, and generally wherever pipes of relatively soft material are to be necked, such as copper pipes or soft steel pipes.

When a branch pipe must be connected with another pipe, it is conventional to install a so-called T-fitting in the main pipe, and to connect the branch pipe to the fitting. This is a thoroughly conventional approach to the problem of providing a pipe with a branch, but it not only requires the use of the T-fitting itself, but also two connections of the fitting to the main pipe and a further connection of the fitting to the branch pipe. These connections are usually solder connections so that they are relatively time consuming and therefore comparatively expensive, especially when the price of the T-frtting itself is taken into account.

A further approach which is sometimes used is to form the main pipe with a hole, and to use shaping tools to manually shape and end portion of the branch which is to be connected with the main pipe, to form a saddle which is then placed over the hole of the main pipe and soldered to the latter. This not only requires special shaping tools, but a high degree of skill on the part of the installer, so that it is a time consuming, difficult and expensive way to provide a branch pipe on a main pipe.

Still another approach known from the art is to provide an apparatus which drills a hole in the pipe with a drill bit. As soon as the leading end of the drill bit has penetrated through the wall of the pipe, pins are made to extend from the drill transversely of the axis of rotation of the latter, and the drill bit with the pins is then retracted outwardly of the hole and the pipe so that pressure faces formedon these pins will deform the material surrounding the hole and form a neck on the pipe to which a branch pipe can be secured. This priorart apparatus is very complicated and expensive. In addition, moreover, it has the disadvantage that the drill bit itself must have a certain minimum size because it must be formed with at least two diagonally extending bores in which the pressure-exerting pins are retracted during drilling and from which they are subsequently extended outwardly. It stands to reason that the diameter of the drill bit cannot be reduced below a certain value, because otherwise the drillbit would no longer be strong enough to withstand the forces which act upon it during retraction, that is during the actual neck-forming operation.

SUMMARY OF THE INVENTION It is, accordingly, a general object of the present invention to overcome the disadvantages of the prior art.

More particularly, it is an object of the present invention to provide an improved pipe necking apparatus which is not possessed of the disadvantages mentioned above.

An additional object of the invention is to provide such an improved pipe necking apparatus which is particularly simple and uncomplicated construction, and which is therefore inexpensive to produce.

A further object of the invention is to provide such a pipe necking apparatus which can be operated very simply and very easily.

In keeping with the above objects, and with others which will become apparent hereafter, one feature of the invention resides in a pipe necking apparatus which, briefly stated, comprises rotatable support means having longitudinally extending axis and a front end portion. An elongated drill bit is composed of two longitudinally extending drill bit sections each of which is formed with an outwardly extending pressure face and with a leading end. Pivot means mount these sections on the support means for arrestable displacement between one position in which the sections and leading ends overlap and are received in a hole formed in the pipe, and a plurality of other positions in each of which the sections and leading ends are spread apart to a different extent in excess of the diameter of the hole. Actuating means is provided for effecting displacement of the sections to respective ones of the other positions when the sections are received in the hole. A sleeve fittingly surrounds the sections and has a forward end engaging a pipe to be necked so that the sleeve is prevented from' rotation relative to the pipe. Mounting means mounts the sleeve on the support means for rotation of the support means relative to the sleeve, so as to advance relative to the support means and the section towards the pipe in response to rotation ofthe support means, to thereby extract the spreading-apart sections from the hole and neck the pipe. The advance ment of the sleeve towards the pipe is, of course, with reference to the support means only, meaning that the sleeve remains stationary and the support means actually retracts from the pipe within the sleeve so that it is the support means which moves axially of the sleeve.

The construction according to the present invention thus represents a drastic departure from the prior-art apparatus, in that the necessity for providing bores in the ,drill bit, and pins which are shiftable in the bores, is eliminated. Instead, it is the sections of the drill bit itself which provide the pressure faces.

Moreover, the retraction is carried out in the novel apparatus by cooperation of the support means with the sleeve, by comparison to a very complicated retracting mechanism in the prior-art apparatus.

The drill bit in the apparatus according to the present invention can have relatively small diameters if and when it is necessary to form small holes, by contrast to the prior-art apparatus, because it is not weakened by the diagonal bores required in the prior-art apparatus.

Since the drill bit sections can be adjusted to any spread-apart position desired, the apparatus according to the present invention can form holes in a pipe which are of any desired diameter, and can neck the pipe sub sequently to any dimension which is desired or required. Y

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following de- BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view of an apparatus according to the present invention, with the drill bit in drilling position;

FIG. 2 is an axial section through the apparatus of FIG. 1;

FIG. 3 is a view similar to FIG. 2, but illustrating the apparatus during the necking operation;

FIG. 4 is an axial section throughthe pipe being necked in FIG. 3, looking outwardly towards the necking apparatus;

FIG. 5 is a section through the necked pipe, with a branch pipe secured to it;

FIG. 6 is a partly sectioned side view of a support bracket for the apparatus of FIGS. l-4;

FIG. 7 is a side elevational view of the support bracket in FIG.-6; and

FIG. 8 is a partly sectioned plan view in the direction of the arrow X in FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing the drawing now in detail, and referring firstly to FIGS. 1-5, in which latter figure the finished T-branch shaped connection between the necked main pipe and a branch pipe is shown, it will be understood that the apparatus is to be used wherever a branch 28 is to be provided in a main pipe 19. The wall of the main pipe 19 is formed with a neck 26 in that the apparatus according to the present invention is used first as a drill (in the condition shown in FIG. 1) to form a bore in the wall of the pipe 19, whereupon the pipe 19 is then necked as shown in FIGS. 3 and 4.

FIGS. I-3 show that the apparatus is provided with a drill bit 10 which is longitudinally subdivided into two sections 11 and 12 which are pivoted on a pivot 24. A nut together with amounting member or fitting 14 are provided which operate upon arms 22 pivoted at 23, so that by turning the nut 15 (see FIG. 3) the drill bits 11 and 12 can be spread apart in outward direction from the position shown in FIGS. 1 and 2 to the spreadapart position shown in FIG. 3. The degree of spreading can be selected in a manner still to be described, so that the apparatus can be accommodated to the requirements of a particular situation. When the drill bit 10 is to be used for drilling a hole in the pipe preparatory for the necking operation,-then its sections 11 and 12 are moved to the position shown in FIGS. 1 and 2 in which they overlap in their entirety, including at their free ends, so that the bit can be used for drilling purposes.

A further nut 25 is provided which is formed in its circumferential wall with a tapped bore into which a set screw (see FIG. I) is threaded. When the set screw 20 is withdrawn, the nut can be rapidly turned to provide a quick preselection of the desired spreading angle of the sections 11 and I2, and in the selected position the nut can be fixed by tightening the screw 20 so that the latter engages a flat 18 provided on the threaded spindle 29 of the support means 16 which flat l8.extends axially of the spindle 29. An insert of a material which is softer than the material of the spindle 29 may be interposed between the flat l8 and the inner end of the screw 20.

An internally threaded sleeve 17 is threaded onto a thread 32 of the support 16. Assuming that the spindle.

29 is to be turned for drilling and necking purposes in clockwise direction, that is towards the right, the threads of the sleeve 17 are left-hand threads. Evidently, if the spindle 29 were to be rotated in counterclockwise direction, then the threads of the sleeve 17 would have to be right-hand threads.

The opposite axial ends of the sleeve 17 are provided with recesses 31 (only one shown in FIG. 1) Cone sponding to the outer diameter of a particular pipe with which the arrangement is to be used, so that the pipe is partly received in the respective recess 31. The sleeve 17 can be removed and turned end for end if a differently-dimensioned pipe requires that it cooperate with a particular one of the recesses 31.

During the necking operation which is shown in FIG. 3, the pipe 19 is in part received in an associated recess 31 so that the sleeve 17 cannot turn relative to the pipe 19. When the sections 11, 12 and the support 16 are rotated, the support and the sections are retracted outwardly so as to perform an axial movement in and with reference to the sleeve 17, with the result that the outwardly directed pressure faces 10aon the two spreadapart sections ll, 12 press against the marginal pipe portion which surrounds the bore that has previously been formed with the drill bit 10. This pressure during the outward retraction causes the material to be displaced outwardly, that is the pipe 19 is formed with a neck 26 to which, as shown in FIG. 5, a branch pipe 28 can be connected by soldering or the like.

The apparatus is provided with a shaft 21 (see FIG. 3) which can be engaged in a conventional chuck of a drill or the like to perform the necessary rotation.

The control of the movements of the sections 11 and 12 takes place via the nut 15 and the member 14. The nut 15 is turnably connected with the member 14, but the two cannot perform relative axial movements. Thus, axial advancement or retraction of the arms 22 will result due to turning of the nut 15 in requisite direction, and this in turn will cause the sections 11, 12 to be pivoted to a desired angle about the pivot 24. As

' FIG. 3 shows clearly, the rear portions of the sections ll, 12 are angled in direction outwardly away from the longitudinal axis of the spindle 29, as shown at 33, with reference to the front portions of the sections l1, 12. Each end of the arms 22 which is remote from the member 14 is pivoted at 230 to the end of one of the portions 33. FIGS. 2 and 3 show that the nut 15 is formed with a circumferentially extending groove 30 into which spherical members 27 extend which are received in bores of the member 14 (or otherwise fixed) so that they cannot move axially of the member 14.

Thus, the member 14 and the nut 15 are connected so that they can turn relative to one another but cannot become displaced axially relative to one another.

Coming now to FIGS. 6-8, it will be seen that these illustrate a support bracket 34 to' counteract the torque acting upon the apparatus. The bracket 34 is intended for use with the apparatus of FIGS. I3 and permits the front housing portion of a drill (not illustrated) to be connected to the bracket by means of the tensioning arrangement 35 which is known per se in the art. FIG. 6 shows particularly clearly that the apparatus of FIGS. l-3 (which is also not shown in FIGS. 6-8) can be arranged between the two supporting arms 36 which are connected with one another by a transverse portion 37 provided with the tensioning arrangement 35.

Each of the arms 36 is composed of an inner telescopic part 38 and an outer telescopic part 39. The respective inner telescopic part 38 is freely axially displaceable within the associated outer part 39, but is prevented from turning relative to it by a pin, screw or the like 40 which slides in an axial slot 41 formed in the respective part 39. A spring 42 permanently urges the respective outer part 38 to the telescoped-part position shown in the drawing. The lower end of the respective spring 42 is secured by means of a screw 43 which serves the additional function of securing the part 39 to the transverse part 37.

The upper free ends of the respective parts 38 are shown with sickle-shaped portions 44 shown in FlG. 7, which can hold and retain a pipe 19 (not shown) which is to be provided with a hole and subsequently to be necked, to counteract the torque which develops during the drilling and the subsequent necking operation.

FIG. 6 shows particularly clearly that the bracket 34 permits a free and unhindered guidance of the apparatus of FIGS. l-3, while at the same time centering it with respect to the pipe 19. Moreover, the torque is effectively counteracted and this makes the operation of the apparatus of FIGS. l-3 very simple, especially where difficult operating conditions exist, as for instance if the pipe 19 should already be in installed condition on a wall or the like.

The setting of sections ll, 12 in spreadapart position can be predetermined by the use of a gauge provided with respective holes through which the sections ll, 12 must fit in a respective spread-apart position in order to later obtain-at the same setting-a desired necking effort on the pipe.

The number of spherical members which connect the nut and the member 14 with one another may be selected at will, for instance there may be four of them which is a currently preferred number.

The purpose of the nut 25 is, of course, to preselect the angle to which the sections ll, 12 are spread apart. lt is merely necessary to set the nut at the desired position, and then subsequently to screw the nut 15 rearwardly until it abuts the nut 25, whereby the selected angle of spreading for the sections ll, 12 will have been realized.

The thread provided on the outer surface of the spindle and cooperating with the thread of the nut 25'is advantageously circumferentially complete, and the purpose of using an interposed insert of softer material than that of the spindle is to assure that no damage will occur to the thread from the set screw 20. When the thread is so constructed, a particularly precise setting of the screw 25 and thus of the spreading angle of the sections ll, 12 can be obtained, which is very important because different pipe materials tend to spring back to a different degree after the necking operation. Allowance for this spring-back effect can be made by setting the spreading angle for the sections ll, 12 so that it is just slightly larger than the necking diameter required. by that amount by which the material would tend to spring back. The fact that the support arms in the bracket 34 are telescopable is particularly advantageous if the pipe to be necked is for instance installed directly outside a wall or the like. A contact of the arms with the wall is avoided because the arms can be telescoped together against the action of the respective spring. Since the arms can be individually telescoped to different extents, the arrangement even makes it possible even to place the entire apparatus at an angle to the pipe while nevertheless centering it relative thereto, if such angular placement should become necessary due to cramped working conditions.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the type described above.

While the invention has been illustrated and described as embodied in a pipe necking apparatus, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. A pipe necking apparatus, comprising rotatable support means having a longitudinally extending axis and a front end portion; an elongated drill bit composed of two longitudinally extending drill bit sections each formed with an outwardly extending pressure face and with a leading end; pivot means mounting said sections on said support means for arrestable displacement between one position in which said sections and leading ends overlap and are recieved in a hole formed in the pipe, and a plurality of other positions in each of which said sections and leading ends are spread apart to a different extent in excess of the diameter of said hole; actuating means for effecting displacement of said sections to respective ones of said other positions when said sections are received in said hole; a sleeve fittingly surrounding said sections and having a forward end engaging a pipe to be necked so that said sleeve is prevented from rotation relative to the pipe; and mounting means mounting said sleeve on said support means for rotation of the same relative to the sleeve, so as to advance relative to said support means and said sections towards the pipe in response to rotation of said support means, to thereby extract the spread-apart sections from said hole and neck the pipe.

2. An apparatus as defined in claim 1, said support ameans including a screw spindle; said actuating means including an adjusting nut threaded onto said screw spindle, a mounting member coaxial with said nut and connected with the same for movement therewith, and a pair of arms each having one end portion pivoted to said mounting member and another end portion associ ated with one of said sections.

3. An apparatus as defined in claim 2, said sections each having a first end portion which together with the first end portion of the respective other section forms a tip of the drill bit, and a second end portion extending at an angle to said first end portion outwardly from said axis and pivoted to said other end portion of one of said arms.

4. An apparatus as defined in claim 2, one of said nut and mountingmember having a circumferentially extending annular groove, and the other of said nut and mounting member having a plurality of anchored balls which extend partly into said groove, so that said nut and mounting means can rotate with reference to one another. a

5. An apparatus as defined in claim 2; and further comprising a setting nut also threaded onto said spindle and adapted to be moved to selected distances from said adjusting nut, so as to determine the permissible angle of spreading of said sections.

6. An apparatus as defined in claim 1, said sleeve being turnable end for end, and each end of said sleeve being provided with an arcuate recess corresponding to v a different pipe diameter.

7. An apparatus as defined in claim 1, said support means having an external thread, and said sleeve having an internalleft-hand thread.

8. An apparatus as defined in claim 5, said spindle having an axially extending flat; and said setting nut having a circumferentially extending wall provided with a tapped bore, and with a set screw received in spindle; and further comprising an insert of a material softer than that of the spindle, interposed between said screw thread and said set screw.

10. An apparatus as defined in claim 1; and further comprising a bracket for holding said support means in place on a pipe to be necked, including a pair of connected supports located at opposite sides of said support means and beingdisplaceable axially of the same between two spaced-apart end positions, each of said supports having a free end configurated for engaging and holding a pipe to be necked.

11. An apparatus as defined in claim 10, wherein said supports are telescopable together and apart.

12. An apparatus as defined in claim 11; and further comprising biasing means resisting the telescoping together of said supports.

13. An apparatus as defined in claim 11, each of said supports including an outer tube member, an inner member telescopically received in said outer tube member, and a biasing spring accommodated in said outer tube member and permanently biasing said inner member outwardly of said outer tube member.

14. An apparatus as claimed in claim 11; and further comprising a connecting portion connecting said supports to one another. Y

15. An apparatus as defined in claim 11; and further comprising arresting means for arresting said supports against turning movement.

Claims

2. An apparatus as defined in claim 1, said support means including a screw spindle; said actuating means including an adjusting nut threaded onto said screw spindle, a mounting member coaxial with said nut and connected with the same for movement therewith, and a pair of arms each having one end portion pivoted to said mounting member and another end portion associated with one of said sections.

4. An apparatus as defined in claim 2, one of said nut and mounting member having a circumferentially extending annular groove, and the other of said nut and mounting member having a plurality of anchored balls which extend partly into said groove, so that said nut and mounting means can rotate with reference to one another.

6. An apparatus as defined in claim 1, said sleeve being turnable end for end, and each end of said sleeve being provided with an arcuate recess corresponding to a different pipe diameter.

7. An apparatus as defined in claim 1, said support means having an external thread, and said sleeve having an internal left-hand thread.

8. An apparatus as defined in claim 5, said spindle having an axially extending flat; and said setting nut having a circumferentially extending wall provided with a tapped bore, and with a set screw received in said bore and adapted to engage said flat.

9. An apparatus as defined in claim 5, said spindle having an external screw thread extending continguously over the entire circumference over said spindle; said setting nut having a circumferentially extending wall provided with a tapped bore, and with a set screw received in said bore and adapted to press against said spindle; and further comprising an insert of a material softer than that of the spindle, interposed between said screw thread and said set screw.

10. An apparatus as defined in claim 1; and further comprising a bracket for holding said support means in place on a pipe to be necked, including a pair of connected supports located at opposite sides of said support means and being displaceable axially of the same between two spaced-apart end positions, each of said supports having a free end configurated for engaging and holding a pipe to be necked.

14. An apparatus as claimed in claim 11; and further comprising a connecting portion connecting said supports to one another.