Pipe cutting and beveling tool

Abstract

An apparatus for working pipes has a pair of hinged semicircular rings each having a uniform cross section interior channel. Clamp means permit joining the free ends of the rings to form a hoop clamping onto the outer circumference of a pipe. A continuous slot cut through the outer circumferential surface of each ring communicates with the interior channel therewithin. A wheeled bar rollable circumferentially within the interior channels has a rod extending radially outward through the slot, a tool support mounted on the upper end of the rod permits pipe working tools to be moved orbitably around a pipe.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to tools for cutting metal pipes. More particularly, the invention relates to tools for rotatably supporting a cutting torch to facilitate producing a uniform, beveled cut at right angles to the longitudinal axis of a pipe.

[0003] 2. Description of Background Art

[0004] Several issued United States patents disclose apparatus for performing functions related to those accomplished by the present invention. These are: Dag U.S. Pat. No. 1,922,529, “Guide for Cutting Torches”, Aug. 15, 1933; Livesay U.S. Pat. No. 2,623,742, “Pipe Cutting Machine”, Dec. 30, 1952; Livers U.S. Pat. No. 3,409,282, “Pipe Cutting Apparatus”, Nov. 5, 1968; Frederick U.S. Pat. No. 3,575,364, “Flexible Track”, Apr. 20, 1971; Elliott U.S. Pat. No. 3,700,223, “Self-Aligning Band for Beveling Machine”, Oct. 24, 1972; Stunkard U.S. Pat. No. 3,819,163, “Self-Centering Pipe Working Machine”, Jun. 25, 1974; Mighton U.S. Pat. No. 4,029,301, “Connective Means For Providing Variable Attitude”, Jun. 14, 1977.

[0005] The Dag patent discloses a guide for cutting torches which has complementary, semicylindrical sections adapted to clamping around a pipe and connected by hinges. Semicircular ribs concentric with the inner surfaces of the semicylindrical sections engage the outer surface of a pipe. Semicircular flanges extending radially outward from both ends of the semicylindrical sections have flat outer surfaces forming circular support tracks coaxial with the pipe. A cutting torch is clamped to a carriage provided with a pair of arcuate shoes each having downward-extending flanges for straddling the outer surfaces of the semicircular flanges and sliding on the support tracks.

[0006] The Livesay patent discloses a pipe cutting machine having a continuous, fixed stator ring and a rotatable rotor ring integrally secured to a ring gear supported on circumferentially spaced roller bearings. A cutting torch is secured to the rotor ring by means of a sliding support block adapted to reciprocate radially with respect to the rotor ring. The support block may be secured in a desired radial position for a particular diameter pipe by means of thumb screws.

[0007] The Livers patent discloses a pipe cutting apparatus in which a cutting torch is mounted pivotably on a torch holder. The torch holder is slidably mounted parallel to the longitudinal axis of a pipe, in an elongated hollow slide support having a triangular cross-sectional shape.

[0008] The Frederick patent discloses a flexible track which may be made in a circular shape and fastened to the outer surface of a pipe by means of vacuum cavities in the base of the track. A carriage for torches or other implements is mounted on the track by engagement of carriage rollers with rails extending laterally from the track base.

[0009] The Elliott patent discloses an adjustable hoop comprised of two semicircular bands for supporting a bevel cutter carried on a dolly adapted for movement around the circumference of a pipe. The hoop bands comprises elongated metal strips each having a pair of parallel side guide edges, and a toggle for fastening free ends of the bands into a circumferential clamping configuration around the outer circumferential surface of a pipe. Rollers having pairs of wheels are fastened to the under sides of the bands, facilitating coaxial alignment of the bands with the pipe before the toggle is tightened. The underside of the dolly supporting the bevel cutter has wheels permitting the dolly to roll circumferentially on the upper sides of the bands circling the pipe.

[0010] The Stunkard patent discloses a pipe working machine for orbitably supporting cutting torches or other tools to be moved circumferentially around the outer surface of a pipe. The machine has an openable ring member comprised of two semicircular ring portions. The ring member is rotatably mounted coaxially on the outer surface of a smaller diameter circular ring-shaped frame member. The ring-shaped frame member is secured coaxially around a smaller diameter pipe by means of self-centering clamping members which extend radially inward from the ring-shaped frame member and partially encompass and clamp against the outer circumference of the pipe.

[0011] The Mighton patent discloses a variable attitude torch holder for use with pipe beveling machines. The holder has a rectangular plate having an outer slot disposed parallel to one side of the plate, and a central slot disposed perpendicularly to the outer slot. A pin and bolt fastened to a torch mounting saddle are slidably mounted within the central and outer slots, respectively.

OBJECTS OF THE INVENTION

[0012] An object of the present invention is to provide an apparatus which may be used to guide a manually operated torch in squarely cutting off the end of metal pipe.

[0013] Another object of the invention is to provide an apparatus which facilitates making a square cut through a pipe at a desired bevel angle.

[0014] Another object of the invention is to provide a pipe cutting and beveling apparatus which may be easily attached to and removed from a pipe by a single operator.

[0015] Another object of the invention is to provide a pipe cutting and beveling apparatus which is easily portable.

[0016] Another object of the invention is to provide a pipe cutting and beveling apparatus which may be used in field applications where working clearances around a pipe are limited, as well as in more benign shop environments.

[0017] Various other objects and advantages of the present invention, and its most novel features, will become apparent to those skilled in the art by a reading of the accompanying specification and claims.

[0018] It is to be understood that although the invention disclosed herein is fully capable of achieving the objects and providing the advantages mentioned, the structural and operational characteristics described herein are merely illustrative of the preferred embodiments. Accordingly, I do not intend the scope of my exclusive rights and privileges in the invention to be limited to the details of construction described. I do intend that reasonable equivalents, adaptations and modifications of the various embodiments and modifications of the present invention which are described herein be included within the scope of this invention as defined by the appended claims.

SUMMARY OF THE INVENTION

[0019] Briefly stated, the present invention comprehends a tool for clamping around the outer circumference of a pipe, and orbitably supporting a pipe working tool such as an oxyacetylene torch. The pipe cutting and beveling tool according to the present invention has two semicircular rings joined at one end by a hinge. Each ring contains a uniform cross-section channel concentric with the curvature of the rings. Thus when the free ends of the rings are joined together and clamped around a pipe, the semicircular channels contained within the two rings join together to form a continuous, circular channel concentric with the rings and pipe.

[0020] Before the two rings are clamped together, an arcuate bar having wheels on its bottom, concave surface is inserted into one of the channel openings at the free end of either ring. Once the rings are clamped together, the wheeled bar is free to move orbitably around the pipe, but is confined within the channel.

[0021] A continuous slot is cut through the outer circumferential surface of each ring, and communicates with the channel within the ring. A rod extending upward from the top of the bar protrudes radially outward from the slot. Fastened to the top end of the rod is an angle plate that slidably supports a rotatable bushing adapted to holding the head of a cutting torch. The angle of the upper surface of the plate is chosen to correspond to the desired bevel cutting angle. With the torch contained within the bushing, the slide mount containing the bushing is slid so as to place the torch head at the desired distance from the pipe, and locked in place. Then the torch holder may be manually moved orbitably around the pipe to effect the desired circumferential cut, the wheeled bar facilitating the circumferential motion of the bar within the channel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 is a front elevation view of the pipe cutting and beveling tool according to the present invention, in an open position preparatory to attaching the tool to a pipe.

[0023] FIG. 2 is a fragmentary bottom plan view of the apparatus of FIG. 1.

[0024] FIG. 3 is a fragmentary front elevation view of a detail of the apparatus shown in FIG. 2.

[0025] FIG. 4 is a front elevation view of the apparatus of FIG. 1 secured to a pipe.

[0026] FIG. 5 is a fragmentary side elevation view of the apparatus of FIG. 1.

[0027] FIG. 6 is a side elevation view of the torch holder portion of the apparatus of FIG. 1.

[0028] FIG. 7 is a fragmentary sectional view of the torch holder of FIG. 6, taken along line 7-7 of FIG. 6.

[0029] FIG. 8 is a rear elevation view of the torch holder portion of the apparatus shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0030] Referring now to FIGS. 1 through 8 and especially to FIGS. 1 through 4, a pipe cutting and beveling tool 10 is shown. Tool 10 is adapted to clamping onto the outer circumference of a pipe A and rotatably supporting a torch B which is used for cutting the pipe.

[0031] As may be seen best in FIGS. 1 and 4, tool 10 includes a pair of semicircular rings 11 and 12 joined by a hinge 13. Rings 11 and 12 are preferably made of a rigid, durable material such as steel. As shown in FIGS. 1 and 4, rings 11 and 12 are joined together at two radial end surfaces by hinge 13 comprising U-shaped sheet metal stirrups 14 and 15 extending outward from one end of each ring, and a cylindrical pin 16 extending transversely through holes 17 in both sides of stirrups 14 and 15. Sufficient clearance is provided between the outer diameter of pin 16 and holes 17 to allow rings 11 and 12 to pivot in a common plane about the cylindrical axis of pin 16. Thus, as shown in FIG. 1, the radial ends of rings 11 and 12 may be pivoted outward from one another to permit a pipe A to be encompassed by the rings. Then, as shown in FIG. 4, rings 11 and 12 may be pivoted towards one another to form a continuous annular ring which conforms to the outer circumference of pipe A.

[0032] As may be seen best in FIG. 7, rings 11 and 12 each have continuous semicircular, rectangular cross-section channels 18 disposed annularly through the entire arc length of the ring, concentric with the curvature of the ring. When the free ends of rings 11 and 12 are butted together to form a circular hoop, semicircular channels 18 form cooperatively a continuous circular channel concentric with the hoop.

[0033] As may be seen best by referring to FIGS. 1 through 3, toggle fasteners 19 are used to lock the free ends of rings 11 and 12 together after the rings are conformed to the outer circumference of a pipe A.

[0034] As may be seen best in FIG. 2, identical toggle fasteners 19 are fastened to either side of the free end of ring 12. Each toggle fastener 19 has a guide pin 20 having a flat side base which is fastened to a side of the free end of ring 12. Guide pin 20 is fastened to ring 12 by spot welding or other suitable joining means. One end of guide pin 20 has a circular cross-section and extends tangentially beyond the free end of ring 12. A guide block 21 is fastened to the facing side of the free end of ring 11, flush with the transverse outer face of the free end. A blind cylindrical hole 22 tangentially disposed inward from the outer face of guide block 21 is adapted to insertably and securely receive guide pin 20 when the free ends of rings 11 and 12 are brought together.

[0035] Guide pin 20 is held in fixed relationship to guide block 21 by clamping elements of toggle fastener 10, as will now be described.

[0036] Referring to FIGS. 2 and 3, it may be seen that an elongated, essentially flat, toggle lever 23 is pivotably mounted parallel to the outside face of guide pin 20 by means of pivot pin 24. The shank of pivot pin 24 extends inward through a hole provided in one end of toggle lever 23. The hole has a larger diameter than the shank of pivot pin 24, permitting toggle lever 23 to rotate freely around the pivot pin. The end of the shank of pivot pin 24 is securely anchored in a smaller diameter hole provided in the outer face of guide pin 20.

[0037] As shown in FIGS. 2 and 3, a toggle hasp 25 is pivotably fastened to toggle lever 23. Toggle hasp 25 is preferably fabricated from heavy steel wire stock which resists bending after it has been tempered. Toggle hasp 25 has a straight section lying in a plane parallel to the sides of ring 12. One end of the hasp bends inwards at right angles and extends through a larger diameter hole provided through toggle lever 23 back some distance from the hole provided near one end of the toggle lever for pivot pin 24. The end of hasp 25 extending through toggle lever 23 has an enlarged portion to prevent the hasp from being pulled outward through the hole in the toggle lever. The opposite end of hasp 25 extends inward at right angles from the straight section of the hasp. That end of hasp 25 is adapted to fitting in the bottom of a shallow, arcuate cross-section groove 26 cut in the back face of guide block 21 perpendicularly from the outer side face to the inner side face of the guide block.

[0038] To use the clamping elements of each toggle fastener 19, toggle lever 23 is pivoted towards ring 11 and away from ring 12, and the ends of rings 11 and 12 brought close together. Guide pin 20 is next partially inserted into the hole in the front face of guide block 21. The free end of toggle hasp 25 is then placed in parallel alignment with the bottom of guide block groove 26.

[0039] Finally, toggle lever 23 is pivoted away from ring 11 and towards ring 12, pulling the free end of the toggle hasp down forcibly on the bottom of guide block groove 26, forcing guide pin 20 and guide block 21 to move towards one another into a locking configuration. In this locking configuration, the free ends of rings 11 and 12 and the annular channels 18 there within are brought into conformal alignment.

[0040] As may be seen best in FIGS. 1 and 4, semicircular rings 11 and 12 have liners 27 conformally fastened to the inner surfaces of the rings. Ring liners 27 are fabricated from flat strips of rubber, cork or similar material which has both resilience and a relatively high coefficient of friction. Ring liners 27 are preferably bonded to the inner surfaces of rings 11 and 12 with an adhesive. The purpose of ring liners 27 is to provide a resilient, non-slip frictional contact with the outer circumferential surface of a pipe A when rings 11 and 12 are locked together by toggle fasteners 19. Maintenance of rings 11 and 12 in a fixed position relative to pipe A facilitates the operation of tool 10, as will be described below.

[0041] As has been previously described, semicircular rings 11 and 12 each contain continuous, semicircular, rectangular cross-section channels disposed annularly through the entire arc length of back ring. Referring now to FIG. 7, it may be seen that semicircular rings 11 and 12 also contain a continuous slot 28 cut through the outer circumferential surface of the rings. Slot 28 is formed by two parallel cuts extending perpendicularly inward through the outer circumferential surface of the rings. The cuts are equidistant from and parallel to the medial plane of the rings, and are spaced closer to one another than are the inner side walls of channel 18. Thus, as shown in FIG. 7, slot 28 is a rectangular cross-section slot which communicates with the interior of channel 18, which channel has a greater internal width than the width of the slot. This structure results in the formation of opposed inwardly extending flat annular flanges 29 defining the edges of slot 28. Flanges 29 overlying channel 18 forms a partially closed annular track for supporting an orbitally movable torch support, as will now be described.

[0042] Referring now to FIGS. 6 and 8, a torch support 30 is shown. Torch support 30 has a base fabricated from an elongated arcuate metal bar 31 having a uniform, essentially rectangular cross-sectional shape. Radial slots 32 are cut through either radial face of bar 31. Wheels 33 mounted on axles 34 pinned through holes 35 on opposite walls of slots 32 of bar 31 are mounted at either end of bar 31. Wheels 33 extend downward beyond the bottom surfaces of the slots. As may be seen best in FIG. 7, the width of base bar 31 is slightly less than the width of channel 18. Also, the height of the assembly comprising wheels 33 and bar 31, measured from the bottom surface of the wheels to the top surface of the bar, is slightly less than height of channel 18, measured from the bottom surface of the channel to the lower inner surface of flanges 29. Thus, the bar and wheel assembly may be inserted into the open end of channel 18 in ring 11 or 12 before the ends are clamped together. After the bar and wheel assembly have been inserted into the track defined by channel 18 and flanges 29, the rings may be clamped together around pipe A as was described above. Once inside the continuous circular track, the bar and wheel assembly are held captive from all but circumferential motions within the track. In that position, the bar and wheel assembly may be moved in a direction describing an orbital motion around pipe A.

[0043] As shown in FIG. 6, 7 and 8, a vertically disposed support rod 36 extends upward from the top surface of bar 31. The diameter of support rod 36 is smaller than the spacing between the inner facing surfaces of flanges 29 defining slot 28. Therefore, orbital movement of wheeled bar assembly 31 is not impaired.

[0044] Fastened to the upper end of support rod 36 is a flat steel plate 37 whose elevation cross-sectional shape is that of a right triangle with horizontal and vertical sides. The hypotenuse of the triangle slopes downward to intersect the horizontal surface of pipe A at an acute angle, typically 37½ degrees. As may be seen best in FIG. 8, a rectangular cross-section tube 38 is fastened to the sloping upper side of plate 37. The flat bottom of tube 38 is congruent with the sloping upper side of plate 37. A rectangular cross-section slot 39 is cut through the upper surface of tube 38 and communicates with the interior channel 40 of the tube. Slot 39 is symmetrically and longitudinally disposed along the transverse medial plane of tube 38.

[0045] As may be seen best in FIGS. 6 and 8, a guide plate 41 is fastened to the front side of tube 38. Guide plate 41 is a rectangular steel plate. An elongated rectangular slot 42 cut through plate 41 is disposed parallel to the long axis of the plate, and is located near the upper edge of the plate. Slot 42 is disposed parallel to the longitudinal axis of tube 38, and extends nearly to either side of plate 41.

[0046] Referring now to FIGS. 6, 7 and 8, a torch support slide 43 is shown mounted within channel 40 of tube 38. Torch support slide 43 has a uniform transverse cross sectional shape. That shape is essentially an inverted “T” with an annular ring mounted on top of the inverted foot of the “T”. The horizontal bar of the “T” is slidably mounted within the interior rectangular channel 40 of tube 38. The leg of the “T” extends upwards through slot 39 in tube 38. A tapped cylindrical boss 44 extends forward from the front side of the leg of the “T”, almost to the back surface of guide plate 41. Torch support slide is secured in a desired position by means of bolt 45 screwed into threaded hole 46 in boss 44 and tightened down to lock the front surface of the boss to the rear surface of guide plate 41.

[0047] Rotatably fastened to the interior of the upper end of torch support slide 43 is a hollow cylindrical bushing 47. Bushing 47 has a metal exterior and resilient interior adapted to receiving and securing by an interference fit the cylindrical outer barrel of a standard oxygen-acetylene cutting torch. The exterior of bushing 47 is provided with a bearing surface which permits the bushing to rotate freely within the upper cylindrical interior of torch support slide 43.

[0048] Pipe cutting and beveling tool 10 according to the present invention is used to make a uniform bevel cut through the entire circumference of a pipe as follows.

[0049] First, a standard oxygen-acetylene cutting torch B is inserted into the upper end of torch support slide 43 and pushed inward until the outer cylindrical body of the torch is secured by an interference fit within the interior surface of torch support bushing 47. Next, torch support slide 43 is slid diagonally up or down within tube 38 until the end of cutting torch B is at the desired working distance from pipe A. Torch support fastener bolt 45 is then tightened to secure the torch support slide. After igniting torch B, the welder using the apparatus grasps the handle of the torch and moves the wheeled torch support 30 and torch B circumferentially around pipe A until a complete, 360-degree bevel cut has been made through the cylindrical wall of the pipe. Hoses supplying gases to torch B are prevented from twisting during the orbital motion of the torch around pipe A by the freedom of torch support bushing 47 to rotate within torch support slide 43.

Claims

1. An apparatus for working pipes comprising:

(a) a plurality of annular sector rings conformable around a circular cross-section pipe, each ring having a uniform cross-section internal channel concentric with the inner surface of said ring,

(b) means for fastening said rings together into a locking configuration concentric with a pipe, and

(c) means orbitably movable within said channels for supporting a holder for a pipe working tool.

2. The apparatus of claim 1 wherein said means for orbitably supporting a pipe working tool in said channels inhibits radial motion of said pipe working tool.

3. The apparatus of claim 1 wherein each said ring hsa a slot cut through its outer circumferential wall, said slot extending the entire arc length of said ring and communicating with said internal channel therewithin.

4. The apparatus of claim 4 wherein said slot is narrower than the width of said channels.

5. The apparatus of claim 4 wherein said means for orbitably supporting a holder for a pipe working tool in said channels comprises:

(a) an elongated arcuate bar, and

(b) an upwardly extending support post fastened to the upper, convex surface of said bar, whereby the outer transverse cross-sectional perimeter of said bar permits circumferential movement of said bar within said channels, with said post extending outward through said slot.

6. The apparatus of claim 5 wherein said elongated arcuate bar contains roller means facilitating circumferential movement of said parallel to the upper edge of said bar and tube,

(b) a boss extending outward from the support section of said tool support nearly to the flat inner side of said flat rectangular member, said boss having a concentric, blind tapped hole extending inward from the outer face, and

(c) a bolt adapted to insertion through the outer surface of said slot, whereby securing said bolt through said slot into said tapped hole in said boss secures said boss and integral tool support to said flat rectangular member.

11. The apparatus of claim 8 wherein said tool support clamp is further defined as comprising:

(a) a hollow cylindrical upper section,

(b) a bushing rotably mounted within said hollow cylindrical upper section, and

(c) means for securing part of a tool within said bushing.

12. An apparatus for working pipes comprising:

(a) a pair of semicircular rings each having a uniform cross-section channel concentric with the curvature of said rings, said channels extending the entire arc length of each ring,

(b) hinge means joining two ends of said rings permitting pivoting said rings into a circular ring configuration,

(c) clamp means for locing the two free ends of said rings in said circular ring configuraton, and

(d) means orbitably movable within said channels for supporting a holder for a pipe working tool.

13. The apparatus of claim 12 further comprising resilient semicircular liner rings conformally fastened to the inner, concave surfaces of said rings, said liner rings having an inner concave surface with a relatively high coefficient of friction.

14. The apparatus of claim 12 wherein each said ring hsa a uniform width opening cut through the outer circumferential wall of said ring, said opening extending the entire length of said ring and communicating with the channel therewithin.

15. The apparatus of claim 14 wherein said means orbitably movable within said channels for supporting a pipe working tool comprises:

(a) an elongated, arcuate bar having rolling means facilitating orbital movement of said bar within said channels, and

(b) an upwardly extending support member for holding a pipe working tool.

16. The appartus of claim 15 wherein said rolling means comprises at least one wheel rotatable with respect to said elongated bar.

17. The apparatus of claim 15 further comprising a tool support structure fastened to the upper end of said upwardly extending member, said tool support structure having a rotatable bushing adapted for holding essentailly cylindrical-body tools.

18. The apparatus of claim 17 wherein said rotatable bushing is slidably mounted on a track positioned at a desired acute angle relative to the center line of said rings.