SCAFFOLDING TUBE CLAMPS
A clamp for securement to a cylindrical body such as scaffold tubing has first and second curved body portions hinged to each other to form a generally circular enclosure. A clasp for coupling the first and second curved body portions has a bolt fixed to one curved body portion and a rotatable housing. The housing has a peripheral groove to slidingly receive the bolt and is coupled to the other curved body portion. The housing has an access opening to receive the bolt into the peripheral groove and the bolt is captured in the peripheral groove when the housing is rotated. The housing is rotatable about a post which is fixed to the other curved body portion and has an opening to receive the post that is eccentric to the geometric center of the housing so that a passage formed between the peripheral groove and the post varies in width about the periphery of the housing. This variable width allows the housing to be tightened gradually on the bolt.
This application claims priority under 35 U.S.C. 371 to International Patent Application Serial Number PCT/CA2007/000277, filed 22 Feb. 2007, claiming priority to Canadian Patent Application Number 2,537,674 filed 27 Feb. 2006, entitled “SCAFFOLDING TUBE CLAMPS,” the entirety of which is incorporated herein by reference.
FIELD OF INVENTIONThis invention relates to clamps used to couple cylindrical bodies, more particularly, cylindrical bodies in the form of tubes used to erect scaffolding at building sites.
BACKGROUND OF THE INVENTIONMany styles of clamps are known for coupling scaffold tubes. The main styles are known as “nut and bolt” as exemplified by U.S. Pat. No. 6,786,302, and “wedge clamp” as exemplified by U.S. Pat. No. 6,789,647. Each of the aforementioned clamp styles suffers from specific disadvantages which this invention is intended to overcome.
An object of this invention is to provide a secure means of coupling to a cylindrical body which is easy to use and reliable but which also will accommodate small variations in the outer diameter of scaffold tubes from different suppliers.
SUMMARY OF THE INVENTIONIn accordance with this invention, there is provided a clamp for securement to at least one cylindrical body, the clamp having first and second curved body portions hinged to each other to form a generally circular enclosure to receive the cylindrical body and a clasp for releasably coupling the first and second curved body portions. The clasp has a bolt fixed to one curved body portion and a rotatable housing defining a peripheral groove to slidingly receive the bolt is coupled to the other curved body portion. The housing has an access opening to receive the bolt into the peripheral groove and the bolt is captured in the peripheral groove when the housing is rotated. The housing is rotatable about a post which is fixed to the other curved body portion and has an opening to receive the post that is eccentric to the geometric center of the housing so that a passage formed between the peripheral groove and the post varies in width about the periphery of the housing. This variable width allows the housing to be tightened gradually on the bolt. To minimize any slipping, the post itself is eccentric to the opening in the housing.
The clamp may be used as a fence clamp for securing to a single cylindrical body or tube, or it may be used in pairs to couple more than one tube in which case, the clamp pairs may be secured by welding or rotatably coupled together to vary the angle therebetween and accommodate tubes or other cylindrical bodies which are not orthogonal.
In order to better understand the invention, a preferred embodiment is described below with reference to the accompanying drawings, in which:
Referring to
The first clamp 24 will now be described in detail. It will be seen that the clamp 24 has a first curved body portion 28 and a second curved body portion 30 hinged to the first curved body portion 28 to form a generally circular enclosure for receiving the cylindrical body 22. Each of the first and second curved body portions 28, 30 are formed from a continuous loop of forged mild steel and they are coupled at one end of the clamp by a hinge 32 and at the other end by a releasably clasp 34. The radius of curvature of the first and second curved body portions 28, 30 is selected to approximate the outer diameter of the cylindrical body 22 received therebetween and additionally includes gripping portions on an interior surface thereof such as flat lands 36 cut from the steel for mating contact with the cylindrical body 22.
The hinge 32 has a C-shaped body with a medial separation 38 that spaces the first and second curved body portions 28, 30 with the respective continuous loops received in the C-shaped body so that each curved body portion may rotate in the C-shaped body independently of the other. In use, the medial separation 38 bears upon the cylindrical body 22 throughout its length thereby reducing the amount of bending moment on the hinge 32.
The clasp 34 consists of a bolt 40 fixed to the second curved body portion 30 with a mounting block 42 and a housing 44 that is rotatably coupled to the first curved body portion 28 with a mounting block 46 supporting a post 48.
The clamp assembly 20 is shown in a latched configuration in
The structure of the housing 44 will now be described with particular references being made to
The housing 44 has a peripheral wall 52 which depends from the top side 49 and that defines an access opening 54 through which the bolt 40 is received into the housing. A bottom lip 56 is co-extensive with the peripheral wall 52 and together they define a peripheral groove 58 for the housing which is adapted to capture the bolt 40 upon rotation of the housing 44. The housing 44 rotates as indicated by arrow 60 in
In addition, it will be observed that the post 48 has a smaller diameter than the opening 50 and the centre-line of the post 48 is eccentric to the opening 50 to thereby further secure the clasp 34 and significantly minimize the likelihood of the clasp releasing during vibration of the clamp assembly 20.
As illustrated in
In an alternative embodiment of the invention shown in
In yet another embodiment of the invention drawn in
In
In use, the clamp assembly is positioned about a cylindrical body so that the cylindrical body is positioned between the first and second curved body portions 28, 30 of the clamp 24. The second curved body portion 30 is then brought into engagement with the cylindrical body 22 by aligning the bolt 40 with the receiving access opening 54 of the housing 44 and the second access opening 62 of the post 48. The housing 44 is then rotated so as to capture the bolt 40 in the peripheral groove 58 thereby securing the first and second curved body portions 28, 30 in frictional engagement with the cylindrical body 22.
It will be appreciated that the clamp assembly made according to the invention is more compact in size than prior art devices and therefore a large number of clamp assemblies may more easily be stored without accidental tangling of the assemblies with each other. The design of the first and second curved body portions 28, 30 allows the clamp 24, 26 to adjust for changes in the diameter of the enclosed cylindrical body 22, 23 so as to accommodate tubular scaffolding having different tolerances and originating from different sources having somewhat different diameters. In addition, the hinge 32 permits the first and second curved body portions 28, 30 to change their relative positions so as to enclose larger or smaller scaffolding tubes 22, 23 as the case may be. The compact design of the curved body portions 28, 30 results in less stretching of the material so that the clamp assembly will have a prolonged life. In the event that damage occurs to the housing 44, it may easily be replaced, particularly if the housing is attached to the second curved body portion 30 in the case of a dual clamp assembly so that it is independent of the second clamp forming part of the assembly 20.
Other variations to the clamp assemblies described may be made within the scope of the appended claims as will be apparent to those skilled in the art. In particular, the clasp comprising a bolt captured in a rotatable housing may be used to secure first and second body portions having different configurations than those shown in the accompanying drawings.
Advantageously, the housing for the clasp has a peripheral wall 77 with a fluted external surface 78 as illustrated in
Like the housing 40, an access opening 54 is formed in the peripheral wall 77 to allow the bolt 40 to be introduced into the housing and a bottom lip 56 which is co-extensive with the peripheral wall 77 defines a peripheral groove 50 for the housing 80 in order to capture the bolt 40 upon rotation of the housing 80.
In the embodiment illustrated, the housing 80 has a circular opening 86 formed in a top side of the housing which is positioned in a quadrant of the housing to receive the post 48. As a result, the passage formed between the peripheral groove 58 and the post 48 is wider on one side of the access opening 54 than the other. Thus, rotation of the housing 80 in the direction indicated by arrow 88 in
A specialized tool 90 is shown in
It will be observed in
A smoother, rounder profile for the flanges 104, 106 is shown by the hinge 108 in
Still other variations to the clamp according to the invention will equally be understood to be within the scope of the appended claims.
Claims
1. A clamp for securement to at least one cylindrical body, the clamp comprising:
- a first curved body portion,
- a second curved body portion hinged to the first curved body portion to form a generally circular enclosure for receiving the cylindrical body, and
- a clasp for releasably coupling said first and second curved body portions, the clasp having a bolt fixed to one of said first and second curved body portions, and a rotatable housing defining a peripheral groove for slidingly receiving said bolt coupled to the other of said first and second curved body portions, the housing having an access opening for receiving the bolt into said peripheral groove and being adapted to capture the bolt in said groove upon rotation of the housing thereby securing said first and second curved body portions in frictional engagement with said cylindrical body.
2. Clamp according to claim 1 in which the housing is rotatable about a post fixed to the other said first and second curved body portions, the housing having an opening for receiving the post that is eccentric to the geometric centre of the housing so that a passage formed between the peripheral groove and the post varies in width about the periphery of the housing.
3. A clamp according to claim 2 in which the post is circular and has a diameter commensurate with the diameter of the opening in the housing.
4. A clamp according to claim 3 in which the post has a smaller diameter than the diameter of the opening in the housing, the opening in the housing being eccentric relative to the geometric center of the post.
5. A clamp according to claim 1 in which the first and second curved body portions are each formed from a continuous loop forged from mild steel.
6. A clamp according to claim 5 in which the first and second curved body portions each have gripping portions shaped from the continuous loop on an interior surface thereof for mating contact with a cylindrical body received in the clamp.
7. A clamp assembly for coupling first and second cylindrical bodies to each other having a clamp according to claim 1 and a tube receiving member shaped to receive said second cylindrical body, the tube receiving member being coupled to the first curved body portion of said clamp.
8. A clamp assembly according to claim 7 in which the tube receiving member is a second clamp comprising:
- a first curved body portion,
- a second curved body portion hinged to the first curved body portion to form a generally circular enclosure for receiving the cylindrical body, and
- a clasp for releasably coupling said first and second curved body portions, the clasp having a bolt fixed to one of said first and second curved body portions, and a rotatable housing defining a peripheral groove for slidingly receiving said bolt coupled to the other of said first and second curved body portions, the housing having an access opening for receiving the bolt into said peripheral groove and being adapted to capture the bolt in said groove upon rotation of the housing thereby securing said first and second curved body portions in frictional engagement with said cylindrical body.
9. A clamp according to claim 7 in which the tube receiving member is rotatably coupled to the first curved body portion.
10. A clamp assembly according to claim 9 in which the tube receiving member is a second clamp comprising:
- a first curved body portion.
- a second curved body portion hinged to the first curved body portion to form a generally circular enclosure for receiving the cylindrical body, and
- a clasp for releasably coupling said first and second curved body portions, the clasp having a bolt fixed to one of said first and second curved body portions, and a rotatable housing defining a peripheral groove for slidingly receiving said bolt coupled to the other of said first and second curved body portions, the housing having an access opening for receiving the bolt into said peripheral groove and being adapted to capture the bolt in said groove upon rotation of the housing thereby securing said first and second curved body portions in frictional engagement with said cylindrical body.
11. A clamp assembly according to claim 7 in which the rotatable housing of the clamp is rotatable about a post fixed to the second curved body portion of the clamp to facilitate replacement of spare parts.
12. A clamp according to claim 1 in which the housing has a peripheral wall with a hexagonal external surface to facilitate tightening and release of the housing from the bolt using a conventional wrench.
13. A clamp according to claim 1 in which the housing has a peripheral wall with a fluted external surface to facilitate tightening and release of the housing from the bolt using a specialized tool.
14. A clamp according to claim 1 in which the housing has a peripheral wall with a scalloped internal surface for step-wise adjustment of the clasp.
15. A clamp according to claim 5 having a hinge to couple said first and second curved body portions, the hinge having a C-shaped body with a medial separation spacing said first and second curved body portions with the respective continuous loops received in said C-shaped body so that each said curved body portion may rotate in the C-shaped body independently of the other.
Type: Application
Filed: Feb 22, 2007
Publication Date: Oct 8, 2009
Inventor: Jonathan Jonny Melic (Stoney Creek)
Application Number: 12/280,612
International Classification: A44B 21/00 (20060101);