US20070124897A1

US20070124897A1 - Clamp for circular objects

Info

Publication number: US20070124897A1
Application number: US11/607,717
Authority: US
Inventors: Eric Wilson; Michael Oh; Raymond Laughlin; Raymond Olle
Original assignee: Individual
Current assignee: Erico International Corp
Priority date: 2005-12-01
Filing date: 2006-12-01
Publication date: 2007-06-07
Also published as: WO2007064955A2; WO2007064955A3

Abstract

A clamp for holding circular objects, such as pipes or conduits, includes a falcate rod portion that engages slots in a bar portion. The rod portion has a circular central section that is between a bent end and a threaded end for engaging respective of the slots. The circular section may have a cylindrical section inner surface, which may be textured, for engaging the circular object. The bar portion also has a circular central portion, for engaging the opposite side of the circular object. The clamp is installed on a circular object by placing the circular section of the bar portion against the circular object, hooking the bent end of the rod portion into one of the slots, inserting the threaded end of the rod portion through the other slot, and tightening a nut on the threaded end to secure the clamp to the circular object.

Description

This application claims priority under 35 USC 119 to U.S. Provisional Application No. 60/741,412, filed Dec. 1, 2005, which is herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention
This invention relates generally as indicated to clamps for circular objects such as pipes or conduits.
2. Description of the Related Art
Clamps for holding circular objects such as pipes or conduit are commonly used in a wide variety of circumstances, such as to secure the objects to structure, to secure other objects or fixtures to the circular objects, or to otherwise limit movement of the circular objects.
One example of a clamp used for holding circular objects is a riser clamp, used to secure vertical pipe runs, such as in a plumbing stack. A stack is a vertical run of pipe through a building, used for example to vent plumbing drain lines. The vertical run may be several stories high, passing through circular floor openings that are greater in diameter than the diameter of the pipe run.
These vertical runs of pipe are secured by riser clamps. An example prior art riser clamp 1 is shown in FIG. 1. The riser clamp 1 has a pair of bar portions 2 of rectangular cross-section bar each having a pair of straight ends 3 with a circular portion 4 between the straight ends 3. The bar portions 2 are clamped onto a pipe or conduit 5, with opposite sides of the pipe 5 engaged by surfaces of the circular portions 4. The bar portions 2 are secured onto the pipe 5 by a pair of bolts 6 that pass through holes 7 in the straight ends 3 on either side of the circular portions 4, and nuts 8 that threadedly engage the bolts 6. The nuts 8 are tightened to clamp the pipe 5 securely between the circular portions 4. The circular portions 4 are configured so that the straight ends 3 of the portions 2 do not come into contact when the riser clamp 1 is installed, but rather there is a spacing between the straight ends 3 of one of the bar portions and the corresponding straight ends 3 of the other bar portion.
A riser clamp such as the riser claim 1 is secured to a vertical run of piping just above a circular floor opening though which the pipe run passes. The riser clamp 1 ordinarily rests on the floor, with the straight ends 3 being long enough to extend beyond the circular floor opening. Thus one function of the riser clamp 1 is to prevent vertical movement of the pipe, since the riser clamp 1 is too large to fit through the circular floor opening.
In addition, the riser clamp 1 prevents torquing or tilting of the pipe run. The spacing between the corresponding straight ends 3 of the portions 2 provides a stable base that resists twisting or torquing of the pipe that would otherwise result in tipping of the clamp 1 over an edge of the straight ends 3 of one of the portions 2. In other words, having the corresponding straight ends 3 of the portions 2 separated from each other provides a base that engages the floor around the circular floor opening to prevent undesirable twisting, tilting, and/or torquing of the pipe run.
Nonetheless, there is room for improvement in that the riser clamp 1 involves a large number (six) of separate parts, and two different threading operations. In addition, some care must be taken to provide at least rough symmetry between the tightening of the nuts 7 on opposite sides of the pipe 5, to have proper installation of the riser clamp 1.
From the foregoing it will be appreciated that improvements would be desirable for pipe or conduit clamps in general, and for riser clamps in particular.

SUMMARY OF THE INVENTION

According to an aspect of the invention, a clamp for holding circular objects includes a bar portion having slots, and a sickle-shape rod portion that is secured within the slots to secure a circular object within a space between the bar portion and the rod portion.
According to another aspect of the invention, a clamp includes: a first portion having a pair of slots therein; a second portion having a bent end and a threaded end, wherein the bent end is in one of the slots and the threaded end is in the other of the slots, and wherein the first portion and the second portion define a space therebetween for securing an object; and a nut threadedly engaging the threaded end to secure the first portion and the second portion together.
According to yet another aspect of the invention, a method of clamping an object includes the steps of: placing a bent end of a rod portion through a first slot of a bar portion; turning the rod portion to enclose the object between the bar portion and the rod portion, and to place a threaded end of the rod portion through a second slot of the bar portion; and securing the portions together by tightening a nut along the threaded end, against the bar portion.
According to still another aspect of the invention, a clamp includes a pair of portions having respective central circular sections that define a round space therebetween for receiving a circular object. The portions mechanically interlock together on one side of the round space. The portions are threadedly coupled together on an opposite side of the round space.
To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the annexed drawings, which are not necessarily to scale:
FIG. 1 is a plan view of a prior art riser clamp secured to a pipe run;
FIG. 2 is a plan view of a clamp in accordance with the present invention;
FIG. 3 is an exploded view of the clamp of FIG. 1;
FIG. 4 is an oblique view of a bar portion of the clamp of FIG. 1;
FIG. 5 is an oblique view of the rod portion of the claim of FIG. 1;
FIG. 6 is a first cross-section configuration for the bar portion of FIG. 4;
FIG. 7 is a second cross-section configuration for the bar portion of FIG. 4;
FIG. 8 is a third cross-section configuration for the bar portion of FIG. 4;
FIG. 9 is a fourth cross-section configuration for the bar portion of FIG. 4;
FIG. 10 is a fifth cross-section configuration for the bar portion of FIG. 4;
FIG. 11 is a sixth cross-section configuration for the bar portion of FIG. 4;
FIG. 12 is a side view of an alternate embodiment clamp in accordance with the present invention;
FIG. 13 is an end view of the clamp of FIG. 12;
FIG. 14 is an oblique view of another alternate embodiment clamp in accordance with the present invention; and
FIG. 15 is a plan view of the clamp of FIG. 14.

DETAILED DESCRIPTION

A clamp for holding circular objects, such as pipes or conduits, includes a falcate or sickle-shape rod portion that engages slots in a bar portion. The rod portion has a circular central section that is between a bent end for engaging one of the slots, and a threaded end for engaging the other of the slots. The circular section may have a cylindrical section inner surface for engaging the circular object. The cylindrical section inner surface may be textured to improve its grip on the circular object. The bar portion also has a circular central portion, for engaging the opposite side of the circular object from that engaged by the inner surface of the rod portion circular central section. The slots in the bar portion are at radius bends at opposite ends of the bar portion circular section, where the bar portion bends back outward into straight extensions that may be co-linear, extending away from the circular section in opposite directions. The straight extensions have bent ends, bent in opposite directions from one another, to provide increased stability for the clamp, for example as the bent ends and outer portion of the straight extensions rest on a floor surface around a circular opening. The clamp is installed on a circular object by placing the circular section of the bar portion against the circular object, hooking the bent end of the rod portion into one of the slots, inserting the threaded end of the rod portion through the other slot, and tightening a nut on the threaded end to secure the clamp to the circular object.
Referring to FIGS. 2 and 3, a clamp 10 includes a bar portion 12 and a falcate or sickle-shape rod portion 14 for securing between them a circular object 16, such as a pipe or conduit. The circular object 16 is secured in a round space 18 between the bar portion 12 and the rod portion 14.
Referring now in addition to FIG. 4, the bar portion 12 includes a central circular section 20 having radiused bends 22 and 24, opposite in direction from the circular section 20, bending back to straight extensions 26 and 28 extending away from the circular section 20. The circular section 20 has an inner surface 30 configured to contact the object 16 when the clamp 10 is installed. The extensions 26 and 28 may be substantially in line with one another, and may be configured to extend outward away from the circular object 16 in opposite, radial and diametrically opposed, directions. With this configuration, the circular section 20 may be substantially a semi-circle. Alternatively, the extensions 26 and 28 may have other configurations, such as being angled at a nonzero angle relative to one another.
The extensions 26 and 28 have respective bent ends 32 and 34 at their distal ends, away from the circular section 20. The bent ends 32 and 34 may be bent at right angles relative to the extensions 26 and 28. The bends 32 and 34 may be in opposite directions relative to one another. The bends 32 and 34 aid in maintaining stability of the clamp 10 when the clamp 10 is used to secure a vertical stack above a floor opening. The bends 32 and 34 increase the effective width of the clamp 10 so as to better resist tilting, torquing, or twisting of the pipe, in a manner analogous to the above-described spacing between corresponding straight ends 3 of the prior art clamp 1 (FIG. 1).
The bar portion 12 has a pair of slots 36 and 38 for receiving and securing ends of the rod portion, as described further below. The slots 36 and 38 are located at the middle of the height of the bar portion 12. In the illustrated embodiment the slots 36 and 38 are elongate slots, having a greater extent along the length of the bar portion 12 than along the height of the bar portion 12. The slots 36 and 38 may be substantially centered about the radiused bends 22 and 24. The slots 36 and 38 may extend fully across the radiused bends 22 and 24, with ends 42 and 44 of the slots 36 and 38 extending into the central circular section 20, and opposite ends 46 and 48 of the slots 36 and 38 extending into the respective straight extensions 26 and 28. The slots 36 and 38 may be substantially identical to one another in shape and relative location. It will be appreciated that many alternative configurations for the slots 36 and 38 are possible.
The bar portion 12 may be made out of a variety of suitable materials, including suitable metals. For example, the bar portion 12 may be made out of cast iron or steel.
With reference now in addition to FIG. 5, the rod portion 14 has a sickle shape, with central curved object-engaging section 60. The curved section 60 may be a substantially circular section that curves inward toward a securing area 62, which is part of the round space 18 when the clamp 10 is assembled. An inner surface 64 bears against and engages the object 16 held by the clamp 10. The inner surface 64 may be a substantially cylindrical section surface, which may be machined from round stock used to make the rod portion 14. Making the inner surface 64 a cylindrical section allows more area to engage the object 16, improving the grip on the object 16. The inner surface 64 may have a circumferential extent of about 120 degrees, although the angular portion with the inner surface 64 may be greater or lesser in extent. Alternatively the inner surface 64 may be rounded or sharp, if desired.
The inner surface 64 may be patterned or textured to improve its grip for example having a stamped crosshatch pattern 66 on the inner surface 64. It will be appreciated that a wide variety of patterns may be used to improve the gripping of the inner surface 64, including various protrusions and/or depressions formed by stamping or other suitable properties. The inner surface 30 of the bar portion 12 (FIG. 2) may also be patterned to improve gripping.
A straight extension 68 extends tangentially away from the curved section 60 at one end of the curved section 60. The extension 68 has a threaded end 70, configured to mate with a nut 72.
At the opposite end of the curved section 60 is an L-shape bent end 74 having a pair of straight legs 76 and 78, with a radiused bend 82 between the legs 76 and 78. The leg 76 extends from the curved section 60, and the leg 78 is a free end of the rod portion 14. The legs 76 and 78 may have a right-angle bend between them, although it will be appreciated that bends of greater or lesser extent may alternatively be used, making the angle between the legs 76 and 78 either obtuse or acute. The leg 78 is an unthreaded rod portion.
The rod portion 14 is configured so that it can be secured to the bar portion 12 by passing parts of the straight extension 68 and the bent end 74 into the slots 36 and 38. Thus the straight extension 68 and the bent end 74 are separated by a distance corresponding to the distance between the slots 36 and 38, with the end leg 78 of the bent end 74 being sufficiently long so that the bent end 74 does not pull out of its slot when the extension 68 is inserted in its slot, and the nut 72 is tightened along the threaded end 70. The end leg 78 may have a length greater than the length of the slots 36 and 38.
The rod portion 14 may be formed from suitable round steel stock, bent and machined to form its shape and structures. Alternatively, the rod portion 14 may be made from other sorts of suitable stock, such as square cross-section bar stock.
To assemble the clamp 10, first the bar portion 12 is put in place, with the inner surface 30 of circular section 20 of the bar portion 12 touching or near the object 16. The leg 78 of the rod portion 14 is then inserted into one of the slots, the slot 36. In order for the leg 78 to be inserted into the slot 36 the rod portion 14 must be turned so that the leg 78 is at a suitable angle relative to the slot 36. The presence of the object 16 provides some limitation on the angle of insertion of the leg 78 of the rod portion 14.
Following insertion of the bent end 74, the rod portion 14 is rotated, pivoting at approximately the radiused bend 82, until part of the threaded end 70 protrudes through the other slot, the slot 38, and until the inner gripping surface 64 is in contact with or close to the object 16. This may bring the leg 78 into contact with material of the bar portion 12 along a radial outboard side of the slot 36. The nut 72 is then threaded onto the threaded end 70, and tightened until the nut 72 is secure against parts of the bar potion 12 that are around the slot 38. The nut 72 may be a shear nut that has a hex portion 84 and a narrowed circular smooth portion 86. The hex portion 84 shears off at a predetermined torque, leaving behind the circular portion 86. This prevents overtightening and/or subsequent removal of the nut 72. Also, the narrower smooth portion 86 threads further onto the threaded end 70, making a more compact engagement with the bar portion 12. Further, the smooth portion 86 has no corners that scratch or otherwise mar the bar portion 12, and the smooth portion 86 provides an offset between the hex portion 84 and the bar portion 12, making engagement of the faces of the hex portion 84 easier. Alternatively, however, the nut 72 may be a conventional hex nut.
The installed clamp 10 is retained in place by the nut 72, and by the cooperation of the bar portion 12 and the rod portion 14. The nut 72 prevents removal of the straight extension 68 from the slot 38. The extension of the leg 78 beyond the outboard edge of the slot 36 prevents the bent end 74 from being disengaged from the slot 36 by moving the bent end 78 in a circumferential direction. The presence of the object 16 prevents disengagement of the bent end 74 from the slot 36 by movement of the bend end 74 in a radially inward direction (toward the center of the object 16). Thus the portions 12 and 14 are maintained mechanically interlocked on one side of the object 16, and threadedly coupled on an opposite side of the object 16.
The clamp 10 advantageously reduces the number of parts, weight, cost, and installation time, all in comparison with prior art clamps such as the clamp 1 (FIG. 1). Installation involves a single threading operation, without the concern for maintaining balance in a pair of threading operations on opposite sides of an object to be clamped.
The clamp 10 has been described above for securing an object 16 having a circular cross-section. It will be appreciated that the clamp 10 may also be used to secure non-circular objects.
The bar portion 12 described above has a rectangular cross-section. It will be appreciated that the bar portion 12 may have other cross-section shapes, which may increase strength, may allow for reduction of material thickness and weight, and/or may improve the gripping between the bar portion 12 and the object 16. FIGS. 6-11 show a few of the many possible alternative cross-section shapes for the bar portion 12. FIG. 6 shows a rectangular cross-section 90, which engages the object 16 (FIG. 2) along a major surface 92. FIG. 7 shows a C-shape cross-section 94, which engages the object 16 at a pair of tips 96 and 97 at ends of the C shape. FIG. 8 shows a rectangular channel shape 98, which engages at top and bottom tips 99 and 100. FIG. 9 shows a modified version of the channel shape 98, a channel shape 98′ have an additional central bend 101. FIG. 10 shows a curved shape 102 having object-engaging tips 104 and 105. FIG. 11 shows a cross-section shape 106 having a central curved portion 107, with top and bottom portions 108 and 109 angling away to engage the object at respective tips. It will be appreciated that these are only a few of the many suitable cross-section shapes for the bar portion 12. The shapes shown in FIGS. 6-11 advantageously engage the object at top and bottom locations, which may provide better gripping in conjunction with a central engagement by the rod portion 14 (FIG. 2).
What follows now is an alternate embodiments of the invention. Many of the features of the alternate embodiment clamp described below may be similar to corresponding features of the clamp 10. Discussion of these similar features is abbreviated or omitted in the below description of the alternate embodiment clamps, although it will be understood that the alternate embodiment clamps may include other features corresponding to those of the clamp 10. In addition, it will be appreciated that various features from the various embodiments may be combinable with one another.
FIGS. 12 and 13 show an alternate embodiment of the present invention, a clamp 110 that is used as a pipe hanger for supporting a horizontal run 116 of pipe or conduit. The pipe clamp 110 includes rod portion 114 that engages slots 136 and 138 of a bar portion 112 in a manner similar to the engagement of the bar portion 12 and the rod portion 14 (FIG. 2). A threaded end 170 of the rod portion 114 is held in place by a nut 172 tightened against the bar portion 112. The pipe or conduit 116 is secured between the bar portion 112 and the rod portion 114.
The bar portion 112 has a pair of extensions 126 and 128 on either side of a central circular section 120. The bottom extension 128 serves to accommodate the slot 138, and to support a bent end 174 of the rod portion 114 within the slot 138. The top extension 126 has a thread form hole 194 and a nail or screw hole 196. The holes 194 and 196 may be used to secure the clamp 110 to a wall or any of a variety of structural members. In the illustrated embodiment a bolt 198 engages the thread form hole 194 is used to secure the clamp 110 to a bracket 200.
The illustrated embodiment is just one possible way of securing the clamp 110 to structure. Various other ways are known for securing vertical extensions to a large variety of structural members, such as purlins of various types, beam flanges, walls, brackets, drop wires, etc. Further information regarding securing to structural members may be found in U.S. Pat. No. 5,740,994, the description and drawings of which are herein incorporated by reference.
It will also be appreciated that many other configurations are possible for clamps for circular or other-shape objects that utilize the basic principle of the clamps described above, that of a rod member that engages slots of a bar member.
FIGS. 14 and 15 show another alternate embodiment, a clamp 210 having a pair of notched bar portions 212 and 214. The bar portions 212 and 214 have respective central circular sections 220 and 221 for holding a circular object 216 clamped in a round space 218 between the portions 212 and 214.
At one side of the circular sections 220 and 221 the portions 212 and 214 have notched sections with angled ends. The portion 212 has a straight extension 226, extending away from the round space 218. The straight extension 226 concludes at a bend 227, where the portion 212 has a notch 229. On the other side of the bend 227 is an angled free end 233 of the portion 212. The angled end 233 is angled away from the circular section 220, toward an opposite side of the round space 218 from that bordered by the circular section 220. The angled end 233 may be angled at a 45-degree angle from the straight extension 226. The notch 229 may extend across the bend 227, into both the straight extension 226 and the angled end 233. The portion 214 may have corresponding features: a straight extension 236, a bend 237, a notch 239, and an angled end 243.
At the other side of the circular sections 220 and 221, the portions 212 and 214 have respective straight extensions 250 and 251. The extensions 250 and 251 run parallel to each other, away from the round space 218 between the circular sections 220 and 221. The extension 250 has a hole 252 in it, for receiving a bolt 254 therethrough. The extension 251 has an open slot 256 at a corresponding location. The slot 256 is open in the same downward direction as the notch 239. The slot 256 is wide enough to allow a shaft 257 of the bolt 254 to enter into it. The bolt 254 is substantially perpendicular to the extensions 250 and 251 when the bolt passes through hole 252 and the slot 256. With the bolt shaft 257 though the hole 252 and in the slot 256, a nut 258 on the shaft 257 can be tightened to secure the extensions 250 and 251.
In installation, the bolt 254 may first be installed through the hole 252 in the extension 250 of the portion 212. The nut 258 may be loosely screwed onto the threaded bolt shaft 257 to aid in keeping the bolt 254 coupled to the portion 212. Then the portion 212 is placed on one side of the circular object 216. After that, the portion 214 is placed on the other side of the circular object 216. During this placement the notches 229 and 239 are engaged, causing the angled ends 233 and 243 to overlap and interlock together. Also, the bolt shaft 257 passes into the slot 256. After engagement of the portions 212 and 214, the nut 258 is tightened to pull the extensions 250 and 251 toward one another. This securely clamps the circular object 216 in the round space 218, between the circular sections 220 and 221.
The angled ends 233 and 243 provide a wide stable footprint for the installed clamp 210. This aids in preventing torquing or tilting of a pipe or conduit run when the clamp 210 is employed as a riser clamp.
Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.

Claims

1. A clamp comprising:

a first portion having a pair of slots therein;

a second portion having a bent end and a threaded end, wherein the bent end is in one of the slots and the threaded end is in the other of the slots, and wherein the first portion and the second portion define a space therebetween for securing an object; and

a nut threadedly engaging the threaded end to secure the first portion and the second portion together.

2. The clamp of claim 1, wherein the first portion is a bar portion.

3. The clamp of claim 1, wherein the second portion is a rod portion.

4. The clamp of claim 1,

wherein the first portion includes a circular central section between the slots;

wherein the second portion includes a curved section between the ends; and

wherein the space is a round space for receiving a round object.

5. The clamp of claim 1, wherein the second portion is falcate.

6. The clamp of claim 5,

wherein the second portion is a rod portion that includes:

a curved central section; and

an extension from one side of the curved section, wherein the extension includes the threaded end; and

wherein the bent end is attached to an opposite side of the central section from the extension.

7. The clamp of claim 6, wherein the curved central section has a cylindrical section inner surface.

8. The clamp of claim 7, wherein the cylindrical section inner surface has an angular extent of about 120°.

9. The clamp of claim 7, wherein the cylindrical section inner surface is patterned to improve gripping.

10. The clamp of claim 9, wherein the cylindrical section inner surface has a stamped cross-hatch pattern.

11. The clamp of claim 7,

wherein the rod portion is formed from round stock; and

wherein the cylindrical section inner surface is a machined portion of the round stock.

12. The clamp of claim 6, wherein the bent end includes a pair of legs angled to one another at an intervening bend.

13. The clamp of claim 12, wherein the legs are substantially at right angles to one another.

14. The clamp of claim 1, wherein the first portion is a bar portion that includes:

a central circular section;

a pair of radiused bends at respective opposite ends of the circular section, bending in an opposite direction from the circular section; and

a respective pair of extensions extending outward from respective of the radiused bends, away from the circular section.

15. The clamp of claim 14, wherein the bar portion further includes respective bar portion bent ends at distal ends of the extensions, wherein the bar portion bent ends are angled at nonzero angles relative to the respective extensions.

16. The clamp of claim 15, wherein the bar portion bent ends are bent in opposite directions from one another.

17. The clamp of claim 16, wherein the bar portion bent ends are at right angles to the extensions.

18. The clamp of claim 14, wherein the extensions are substantially in line with one another.

19. The clamp of claim 14, wherein the slots extend fully across the radiused bends.

20. A method of clamping an object, the method comprising:

placing a bent end of a rod portion through a first slot of a bar portion;

turning the rod portion to enclose the object between the bar portion and the rod portion, and to place a threaded end of the rod portion through a second slot of the bar portion; and

securing the portions together by tightening a nut along the threaded end, against the bar portion.

21. A clamp comprising:

a pair of portions having respective central circular sections that define a round space therebetween for receiving a circular object;

wherein the portions mechanically interlock together on one side of the round space; and

wherein the portions are threadedly coupled together on an opposite side of the round space.

22. The clamp of claim 21, wherein both of the portions are bar portions.

23. The clamp of claim 21, wherein one of the portions is a bar portion, and the other of the portions is a rod portion.

24. The clamp of claim 21, wherein the portions mechanically interlock together by an end of one of the portions being inserted into a slot in the other of the portions.

25. The clamp of claim 21, wherein the portions mechanically interlock together by engagement of respective notches in the portions.

26. The clamp of claim 25, wherein the notches are at respective bends of the portions.