GB2376029A

GB2376029A - Frame cramp

Info

Publication number: GB2376029A
Application number: GB0209532A
Authority: GB
Inventors: Robert Michael Kerr
Original assignee: ACS Stainless Steel Fixings Ltd
Current assignee: ACS Stainless Steel Fixings Ltd
Priority date: 2001-05-03
Filing date: 2002-04-26
Publication date: 2002-12-04
Anticipated expiration: 2022-04-26
Also published as: GB0110850D0; GB0209532D0; GB2376029B

Abstract

A frame cramp (1) comprises a substantially L-shaped member defining a slotted foot (2) capable of being bolted to a substrate and a leg (3) which is adapted for incorporation into a bedding material. The leg (3) is turned through 90{ with respect to the foot (2) at a neck (4) and defines a curved or angled transverse cross-sectional profile to increase the strength of the cramp with respect to tensile and compressive forces. The neck (4) of the cramp (1) also defines a curved or angled cross-sectional profile on each side of which is a ridged stiffening portion (7). Preferably, the ridged portions (7) join together in a loop (9) which passes around the slot (8) in the foot through which the cramp (1) can be secured to the substrate by a fastener.

Description

A FRAME CRAMP The present invention relates to a frame cramp.

Frame cramps are used in the construction industry to provide an adjustable restraint fixing between concrete, brickwork, steel or timber substrates and an adjacent wall.

Conventionally, a frame cramp comprises an L-shaped member with a slotted foot or upstand that can be fastened to the substrate and a leg at 900 to the foot that is bedded into a mortar joint of the wall, typically the outer skin of a cavity wall.

As the frame cramps must withstand tensile and compressive forces, they are usually manufactured from stainless sheet strip which is 25 mm wide and at least 2.5 mm thick in order that the cramps exhibit the required strength.

This means that the cost of frame cramps is relatively high as compared to other comparable metal fittings used in the construction industry.

It is an object of the present invention to provide a frame cramp which can be produced more economically than a conventional cramp as described and yet which still retains the required strength.

According to the present invention there is provided a frame cramp comprising a substantially L-shaped member defining a slotted foot capable of being bolted to a substrate, and a leg which is adapted for incorporation into a bedding material and which is turned through 900 with respect to the foot at a neck, the leg defining a curved or angled transverse cross-sectional profile and the neck of the cramp also defining a curved or angled cross-sectional profile on each side of which is a ridged stiffening portion.

The deformation of the leg and the neck of the cramp where the leg joins the foot into the angled or curved profile increases the strength of the cramp with respect to tensile and compressive forces. This means that the cramp can be made of metal strip material which is thinner than the conventional 2.5 mm thickness. Advantageously, the thickness of the material from which the frame cramp is made is between 1.0 mm and 1.2 mm. Preferably also, the strip material from which the cramp is made has a width between 17 mm and 20 mm inclusive prior to being pressed to define the angled or curved transverse cross-sectional profile.

Preferably, the cross-sectional profile of the leg and the neck comprises a V-shaped or a channel-shaped profile Preferably also, the ridged portions are joined together in a loop which passes around the slot in the foot through which the cramp can be secured to the substrate by a fastener.

Preferably also, the ridged portions define a depression in which a washer can be located.

In a first embodiment, the ridged portions define an open loop around the slot in the foot. Alternatively, in a second embodiment the ridged portions define a closed loop around the slot in the foot.

Preferably also, the loop defines a depression which can accommodate a 16 mm circular washer.

Preferably also, the ridged portions defining the loop project from the foot on the side thereof which is apposed to the leg.

Preferably also, the leg is angled or curved outwards in the same direction as that in which the foot projects from the neck.

Preferably also, the leg is adapted for incorporation into a bedding material by the provision of at least one hole at its end remote from the foot, through which hole the bedding material can pass to anchor the frame cramp to a wall.

Preferably also, the frame cramp is pressed from a stainless steel or galvanized steel strip.

The present invention will now be described by way of example with reference to the accompanying drawings in which :- Fig. 1 is a perspective view of a first embodiment of frame cramp according to the present invention; Fig. 2 is transverse cross-sectional view along the line II-II in Fig. 1 ; Fig. 3 is a view similar to Fig. 2 but along the line III-III in Fig. 1 ; Fig. 4 is a longitudinal cross-sectional view along the line IV-IV in Fig. 1 ; Fig. 5 is a side view of a foot forming part of a second embodiment of frame cramp; and Fig. 6 is a transverse cross-section through a leg of the frame cramp shown in Fig. 5

A frame cramp 1 according to the invention comprises an L-shaped member defining a slotted foot 2 capable of being secured to a substrate, typically a timber window or door frame, and a leg 3 which is adapted for incorporation into a bedding material such as a mortar course of a wall. The leg 2 is turned through 90 with respect to the foot 2 at a neck 4 of the cramp 1.

In a first embodiment, as shown in Figs. 1 to 4, the leg 2 defines an angled transverse cross-sectional profile as shown in Fig. 2, in this case a v-shaped profile, to increase the strength of the cramp with respect to tensile and compressive forces. The neck 4 of the cramp also defines a similar v-shaped cross-sectional profile, the ridge 5 formed by the apex of the v-shaped profile running longitudinally along the leg and terminating as the neck 4 merges into the foot 2 with the ridge 5 pointing in the same direction as the foot 2. However, in a second embodiment of the cramp, as shown in Figs. 5 and 6, the leg 2 and the neck 4 define an angled profile which defines a channel section.

Here, the central part of the channel-shaped profile is at least as wide as each of the side portions. It would also be possible for the leg 2 and neck 4 to be strengthened by being curved or radiused. However, in all the embodiments, the leg 2 is angled or curved outwards in the same direction as that in which the foot 2 projects from the neck 4.

The leg 2 is adapted for incorporation into a bedding material by the provision of a hole 6 at its end remote from the foot 3. Bedding material such as mortar can form a bridge through the hole 6 to anchor the frame cramp 1, for example to one leaf of a cavity wall or similar. In order to ensure a good bond in the bedding material, the depth d of the profiled leg 2 should be around 5 mm to 6 mm but not significantly more than this. Typically, it is expected that the depth of the leg 2 of the first embodiment will be of the

order of 5 mm whereas the depth of the leg 2 of the second embodiment, which is wider, will be around 6 mm.

As indicated above, the neck 4 of the cramp 1 is also profiled and in addition comprises a pair of ridged portions 7 which are located respectively on either side of the central ridge 5 of the profiled shape. The ridged portions 7 are pressed from the foot 2 to project on the same side thereof as the end of the ridge 5, which is the side of the foot 2 apposed to the leg 3.

The foot 2 defines a circular or oval slot 8 by means of which the cramp 1 can be secured to the substrate by a bolt or other similar fastener. The ridged portions 7 on either side of the ridge 5 at the neck 4 join together in a loop 9 which passes around the slot 8. In the first embodiment, as shown in Fig. 1, the loop 9 is open and the ridged portions 7 are conjoined by the loop 9. However, in the second embodiment, as shown in Fig. 5, the loop 9 is closed and adjoins the two linear parts of the ridged portions 7 at an angle. In both cases the loop 9 defines a depression 10 in which a washer can be located. Advantageously, the loop 9 defines a substantially circular or oval depression 10 which can accommodate a 16 mm circular washer.

The cramp 1 is preferably formed by being cut or stamped from a metallic strip, preferably a stainless steel or galvanized steel strip, and is then pressed into the L-shape. Further pressing is then carried out to produce the angled or curved cross-sectional profile and the looping ridged portions 7. However, it is possible for the cramp to be made from a synthetic material such as a plastics material, dependent on the particular application of the cramp 1.

It will be appreciated that the deformation of the leg 3 and the neck 4 of the cramp 1 where the leg 3 joins the foot

4 increases the strength of the cramp 1 with respect to tensile and compressive forces. This means that the cramp 1 can be made of metal strip material which is thinner than the conventional 2.5 mm thickness. Advantageously, the thickness of the metallic strip from which the frame cramp 1 is made is between 1.0 mm and 1.2 mm with a width of between 17 mm and 20 mm inclusive prior to being pressed to define the angled or curved transverse cross-sectional profile. However, the cramp 1 can be made with any suitable dimensions to suit particular applications.

The deformation of the neck 4 to produce the angled or curved ridge 5 and the projecting portions 7 strengthens the neck 4 against leverage forces so that foot 2 and the leg 3 are less likely to be bent away or towards one another in use than a cramp made of the same strip material but which is not provided with the same features 5 and 7.

In use the foot 2 is bolted to a substrate through the slot 8, a washer being located in the depression 10.

Preferably, the cramp 1 is located so that the foot 2 points upwards and the ridge 5 of angled or curved cross-sectional profile of the leg 3 also points upwards so that moisture is not retained in the channel therebeneath. The projecting end of the leg 3 is then embedded into a joint of bedding material, typically mortar, of an adjacent wall.

Claims

CLAIMS 1. A frame cramp comprising a substantially L-shaped member defining a slotted foot capable of being bolted to a substrate, and a leg which is adapted for incorporation into a bedding material and which is turned through 900 with respect to the foot at a neck, the leg defining a curved or angled transverse cross-sectional profile and the neck also defining a curved or angled cross- sectional profile on each side of which is a ridged stiffening portion.
2. A cramp as claimed in Claim 1, wherein the cross- sectional profile of the leg and the neck comprises a V- shaped or a channel-shaped profile
3. A cramp as claimed in Claim 1 or Claim 2, wherein the ridged portions are joined together in a loop which passes around the slot in the foot through which the cramp can be secured to the substrate by a fastener.
4. A cramp as claimed in any of Claims 1 to 3, wherein the ridged portions define a depression in which a washer can be located.
5. A cramp as claimed in any one of Claims 1 to 4, wherein the ridged portions define an open loop around the slot in the foot.
6. A cramp as claimed in any one of Claims 1 to 4, wherein the ridged portions define a closed loop around the slot in the foot.
7. A cramp as claimed in Claim 5 or Claim 6, wherein the loop defines a depression which can accommodate a 16 mm circular washer.

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8. A cramp as claimed in any of Claims 1 to 7, wherein the ridged portions project from the foot on the side thereof which is apposed to the leg.
9. A cramp as claimed in any one of Claims 1 to 8, wherein the leg is angled or curved outwards in the same direction as that in which the foot projects from the neck.
10. A cramp as claimed in any on of Claims 1 to 9, wherein the leg is adapted for incorporation into a bedding material by the provision of at least one hole at its end remote from the foot, through which hole the bedding material can pass to anchor the frame cramp to a wall.
11. A cramp as claimed in any one of Claims 1 to 10, which is made of metal strip material that has a thickness between 1.0 mm and
1.2 mm 12. A cramp as claimed in any one of Claims 1 to 11, which is made of metal strip material that has a width of between 17 mm and 20 mm inclusive prior to being pressed to define the curved or angled transverse cross- sectional profile.
13. A cramp as claimed in any one of Claims 1 to 12, which is made from a stainless steel or galvanized steel strip material.
14. A frame cramp substantially as described herein with reference to Figs. 1 to 4 or Figs. 5 and 6 of the accompanying drawings.