GB2316103A

GB2316103A - A two piece joist hanger

Info

Publication number: GB2316103A
Application number: GB9713481A
Authority: GB
Inventors: Donald Furr; Paul John Furr
Original assignee: Furfix Products Ltd
Current assignee: Furfix Products Ltd
Priority date: 1996-08-10
Filing date: 1997-06-27
Publication date: 1998-02-18
Anticipated expiration: 2017-06-27
Also published as: GB2316103B; GB9713481D0

Abstract

A two piece joist hanger comprises a joist support member or shoe 12 for supporting the end of a joist and a back support member or bracket 13 for attachment to a wall, the support member 12 and bracket 13 having interengagable elements 43, 44 for disconnectably securing them together, preferably at a plurality of height postions. The connecting elements comprise apertures 44 in one member and projections or hooks 43 on the other member. The joist support member 12 is formed from a metal blank by bending side portions 15, 16 upwards from base 14 and bending parts 18 inwardly from the side portion 15, 16 to form the back portion. The side portion 15, 16 may not be bent quite as far as the vertical allowing them to be flexed inwards, moving the parts 18 of the back portion towards one another, facilitating fitment of the support member 12 to the bracket 13 and providing tension to enhance the security of the engagement of the member 12 and bracket 13.

Description

JOIST HANGERS This invention relates to joist hangers. A joist hanger is conventionally used in buildings for supporting an end of a generally horizontal beam member (a joist) from a vertical support such as a load bearing wall.

Most conventional joist hangers have a generally lazy Z-section of metal to provide an upper bearing portion to rest on the vertical support, a central abutment portion to rest against the vertical face of the vertical support and a lower support portion for supporting the end of the joist. The abutment portion and lower support portion are normally connected by vertical side straps which may be seam welded or spot welded thereto. In another form as described in GB-A-2178086 a joist hanger is made from a single metal blank bent to an appropriate shape. The joist hangers of GB-A 21 78086 have wide flanges on the bearing portions which have the advantage of spreading the load. This is particularly desirable where the support wail is made from less dense material.

Some joist hangers may not have the upper bearing portion if the abutment member is intended to be secured to the vertical surface of the support wall by screws or other fixing members.

Because joists come in a variety of sizes, both width and depth, and are for use with support walls of different qualities, it may be necessary to stock up a considerable range of different one-piece joist hangers to cover all needs. However, joist hangers are conventionally made as one piece.

An object of the present invention is to provide a joist hanger which is more adaptable so that less different parts need to be stocked to cover the needs of builders.

In one aspect the present invention provides a joist hanger formed in two pieces having disconnectable connecting means for securing them together, preferably in a plurality of different relative height positions.

With such an arrangement less basic stocks are required to cover the different shapes and sizes of joist.

The two pieces preferably comprise a joist support piece or shoe and a back plate adapted to be secured together by interengageable elements, preferably the elements comprising a series of apertures in one of the pieces for receiving projections, which may be hook shaped, on the other of the pieces. An additional advantage is that the back plates can be incorporated in the wall as it is built and the joist support pieces fixed later so that they do not project outwardly from the wall during the building thereof. Since different joist support pieces can be attached to the back plate in different relative positions errors in selecting the correct joist hanger for building into the wall are reduced.

Preferably both pieces are formed from sheet metal simply by bending, stamping and/or pressing without any welding. The back plate is preferably substantially right-angled with a horizontal support arm adapted to rest on the horizontal face of the wall incorporated between courses of bricks or the like and a vertical abutment arm incorporating connecting elements.

Preferably the horizontal bearing arm is wider than the upright abutment arm so as to spread the load. Alternatively the back plate piece may be substantially planar and incorporate apertures for receiving fixing means by which it may be screwed or the like to the vertical surface of the support wall.

The joist support member or shoe preferably comprises a substantially horizontal base portion (not necessarily extending the full width of the base), two upright side portions and an upright back portion carrying the connecting elements. The shoe is preferably formed from a blank of sheet metal by bending the side portions upwardly from the central base portion and bending the two parts forming the back portion inwardly towards one another from the back edges of the side portions. Alternatively, it could be formed by bending the side portions forwardly from the side edges of the back portions and bending the two parts forming the base portion towards one another from the lower edges of the side portions.

The connecting elements preferably comprise a series of pairs of apertures, with the pairs one above the other, in one of the pieces and at least one pair of hook shaped projections on the other of the pieces pressed out from the blank metal sheet from which the piece is formed. If the hook shaped connecting elements are on the back plate the hooks will extend upwardly. If the hook shaped elements are formed on the shoe then they will be hooked downwardly and the apertures on the vertical arm of the back plate need to be spaced from the vertical face of the support wall to accommodate the hook elements. Preferably this spacing is achieved by projections pressed out from the sheet in the process of forming the apertures.

The shoe member in its unconnected condition preferably has its upright side portions extending slightly away from one another so that the connecting elements can only be inter-fitted by squeezing in the side portions to the parallel condition, or slightly beyond parallel so that they open out when connected to the parallel condition. The natural spring in the metal material which allows this inward flexing then acts to retain the pieces together. If desired the apertures may be formed with sideways extensions to allow the side portions to flex outwardly after connection and positively lock the pieces together so that they can only be disconnected by again inwardly squeezing the side portions of the shoe.

Embodiments of joist hanger in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings of which: Figure 1 is an exploded view of a first embodiment of joist hanger with the back plate built into a wall, the shoe piece about to be connected to the back plate and showing a joist for support by the shoe. Parts of the drawing are shown enlarged in detailed views as circled; Figure 2 shows an alternative back plate for use with the shoe piece of Figure 1; Figures 3 and 4 are views similar to those of Figures 1 and 2 showing a further embodiment of joist hanger; Figures 5 and 6 are views similar to those of Figures 1 and 3 showing further embodiments of joist hanger; Figures 7 and 8 are rear views, on an enlarged scale, showing a preferred feature of a shoe piece in accordance with the invention; Figure 9 shows a modified form of hook connecting element and aperture; Figure 10 shows a further modified back plate (fixing holes omitted); and Figure 11 shows modified apertures in the back portion of a joist support member.

The joist hanger of the invention is formed in two separate connectable and disconnectable pieces comprising a shoe or joist support piece 12 and a back plate 13. In each embodiment the shoe 12 is formed from a metal sheet by bending and pressing or stamping so that it has a horizontal base 14, upright sides 15, 1 6 extending upwardly from the side edges of the base and an upright back 17, formed by flanges 18 turned inwardly from the back edges of the sides. In a modified arrangement the back is formed from the centre of the blank strip and the base by the two ends. In each of the embodiments of Figures 1, 3, 5 and 6, the back plate 13 is formed from metal sheet bent to a substantially right-angled configuration so that it has a horizontal support arm 20 and a vertical abutment arm 21. The horizontal support arm is supported on the top surface of a support wall 22 incorporated between courses of bricks in a support wall 22 with the vertical abutment arm 21 abutting the vertical face of that wall. In the arrangement of Figures 1 and 3 the support arm 20 and the top of the abutment arm are wider, substantially twice as wide, as the abutment arm so as to spread the load. The support arm is formed with ribs 23 and the abutment arm with a rib 24. In the arrangements of Figures 5 and 6 the support arms are the same width as the abutment arms and two back plates are located side by side to receive two side-by-side shoes for supporting side-by-side joists 26. A separate spreader plate 25 (shown in broken line) can be placed under the support arms to spread the load as seen in Figures 5 and 6. Corners 27 may be swaged as seen in the detailed view.

In all embodiments the shoe 12 and back plate 13 are formed with interengageable connecting elements, these elements preferably taking the form of pairs of side-by-side apertures, one above the other, in one piece and pairs of side-by-side hook shaped projecting elements pressed out of the sheet material on the other piece. As seen in Figures 1, 2 and 5 the connecting elements on the back plate comprise a series of, in this example, five pairs, one above the other, of upwardly directed hooks 30. The shoe member 1 2 intended to be connected with such back plate has two pairs of apertures 31 one above the other and separated by the same spacing as the pairs of hook members. The apertures in the shoe can be engaged over one or more, preferably any two, selected pairs of hook members to engage and retain the shoe in contact with the back plate so as to form the joist hanger.

The joist as seen at 26 can then have its end secured in the shoe and connected thereto by nails extending through the holes 34 in the sides of the shoe. The shoe can be connected with the back plate in four different vertical positions relative thereto and therefore the same shoe can be used to support joists of different heights or joists at a different height relative to the back plate. The same back plate could be used to support shoes of different depths or different widths.

In the arrangement of Figures 3 and 6 the connecting elements in the back plate 13 comprise a series of pairs of side-by-side apertures 35, arranged one above the other, pressed out from the sheet metal so that projections 36 abut the vertical face of the wall 22 and space the apertures from the wall. The connecting members on the shoe comprise two side-byside pairs, one above the other, of downwardly extending hook members 38, again pressed out from the sheet material. As before these hook members 38 can be engaged in the apertures 35 of the back plate after the back plate has been built into the wall, so as to connect the pieces 12, 13 and form a joist hanger.

Figures 2 and 4 show alternative back plates 40 and 41, each being substantially planar and including apertures 42 for fixing means for securing it directly onto the vertical face of the wall 22. Plate 40 is formed with a series of upwardly directed hooks 30, similar to the hooks of Figure 1 while plate 41 is formed with a series of apertures 43 for receiving hooks 38.

Figures 7 and 8 show a preferred feature of all the shoes, which is not shown in the other Figures. In the unconnected and undistorted form of the shoe the upright sides 1 5 and 16 are not exactly vertical but slope upwardly and outwardly away from one another at a small angle. However the spring in the metal material from which the shoes are made allows the sides to be pushed towards one another until they are parallel or past parallel and in this position the connecting elements on the back flanges of the shoe will be spaced a similar distance from one another as the connecting elements on the back plate so that they can be interengaged. The spring in the material will then tend to retain the connecting elements and thus the pieces connected together. In the connected position the side portions are parallel.

If desired the apertures on the shoe or plate can be formed with a side extension as seen at 44 to provide a positive interlocking of the hooks and apertures so that the shoe cannot be disconnected from the back plate without again flexing the sides towards one another.

Figure 9 shows a modified form of hook connecting element 43 pressed out sideways from the sheet material and a modified form of aperture 44 to accommodate such element. Such tags and apertures could be used in any of the embodiments. The gap 45 allows for compression of the sides towards one another for interfitting and then springing back to the parallel in the connected state.

In order to ensure that the connection between the back support member and the joist support member is sufficiently strong it may be necessary to ensure that the members cannot be interconnected without at least two pairs of projections on one member interengaging with two pairs of apertures on the other member. To ensure this it is necessary to ensure that the upper connecting element of the joist support member cannot be engaged with the lower connecting element on the back support plate.

It may be desirable to ensure that all the projections on one member engage with apertures on the other member. For this purpose the sizing of the apertures may be varied for example the upper aperture or pair of apertures on the joist support hanger may be smaller than the lowest projection or pair of projections on the back support plate.

An example is shown in Figures 10 and 11. In this example a back support plate 13 is formed with three pairs of upwardly hooked projections 43 of slightly different heights and shapes from one another (as seen from the cut outs from which they are pressed). Corresponding apertures 44 in the parts 18 of the back portion 17 of the joist support member have portions of major height corresponding to the heights of the projections and portions of minimum height corresponding to the minimum dimensions of the hook shaped projections.

Claims

1. A joist hanger formed in two pieces comprising a joist support member for supporting the end of a joist and a back support member for attachment to a wall, the members having interengagable elements for disconnectably securing them together.

2. A joist hanger according to claim 1 in which the connecting elements are such as to allow the members to be connected at a plurality of different relative height positions.

3. A joist hanger according to claim 1 or claim 2 in which the connecting elements comprise a series of apertures in one of the members for receiving projections on the other of the members.

4. A joist hanger according to claim 3 in which the projections are hook shaped.

5. A joist hanger according to claim 3 in which the projections are formed on the back plate and are upwardly hooked.

6. A joist hanger according to any of claims 1 to 5 in which both members are formed from sheet metal by bending, stamping and/or pressing without any welding.

7. A joist hanger according to claim 7 in which the projections are formed by being pressed out of the sheet metal.

8. A joist hanger according to any of claims 1 to 7 in which the back support member includes a horizontal support arm adapted to rest on the horizontal face of part of a wall between courses of bricks or the like and a vertical abutment arm incorporating the connecting elements.

9. A joist hanger according to claim 8 in which the support arm is wider than the abutment arm.

10. A joist hanger according to any of claims 1 to 6 in which the back support member is planar and incorporates apertures for securing it to the vertical face of a wall.

11. A joist hanger according to any of claims 1 to 10 in which the joist support member comprises a base portion, upright side portions and an upright back portion, the back portion carrying the connecting elements.

1 2. A joist hanger according to claim 11 in which the joist support member is formed from a blank of sheet metal by bending the side portions upwardly from the base portion and bending the two parts forming the back portion inwardly towards one another from the back edges of the side portions.

1 3. A joist hanger according to claim 11 or claim 1 2 in which the back portion is formed in two parts spaced from one another which parts can be flexed together elastically through the spring of the material.

14. A joist hanger according to claim 1 3 in which the side portions extend slightly away from one another towards the back portion unless subjected to a force pressing them towards one another.

15. A joist hanger according to claim 13 or claim 14 in which the connecting elements can only be interfitted when the parts of the back portion are moved towards one another.

1 6. A joist hanger according to claim 1 5 in which the apertures are formed with side extensions of lesser height such that the back portions can flex outwardly after interconnection with the projections and thus positively lock the members together so that they can only be disconnected by again flexing the two parts of the back portion towards one another.

1 7. A joist hanger according to claim 3 or any claim dependent thereon in which each member has a plurality of connecting elements or pairs of connecting elements spaced one above the other, there being more apertures on one member than there are projections on the other member.

1 8. A joist hanger according to claim 17 in which some of the projections and apertures are shaped, sized or spaced such that the members cannot be interconnected without at least two pairs of projections, one above the other, are interengaged with two pairs of apertures, one above the other.

19. A joist hanger according to claim 3 or any claim dependent thereon in which each member has a plurality of pairs of projections spaced one above the other and a plurality of pairs of apertures spaced one above the other and the apertures and projections are shaped, sized or spaced such that the members cannot be interengaged unless all of the projections on one of the members are engaged in an aperture on the other of the members.

20. A joist hanger substantially as described herein with reference to or as illustrated in the accompanying drawings.

21. A method of providing a joist hanger using back support members and joist support members according to any of claims 1 to 20 in which a back support member is incorporated into a wall during building when unconnected to a joist support member, and later selecting a joist support member suitable for the required joist and interengaging its interfitting elements with those of the back support member so as to disconnectably suspend the joist support member from the back support member.