GB2111161A

GB2111161A - Joining of metal sheets

Info

Publication number: GB2111161A
Application number: GB08138071A
Authority: GB
Inventors: Paul Adrian Southon Jackson; Andrew Clive Jackson
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-12-17
Filing date: 1981-12-17
Publication date: 1983-06-29
Also published as: GB2111161B

Abstract

To-join the edge of a metal sheet to another sheet for assembly of knock-down furniture tabs 11 and 12 on the edge of sheet 10 are passed through slots 14 and 15 in sheet 13. Notches 19 and 20 allow the tabs to be twisted to secure them in position. Opposed edges 17 and 18 locate the sheets against lateral displacement. Alternatively each notch may be formed in the part of the tab which projects beyond the slot but immediately adjacent the outer face of sheet 13. <IMAGE>

Description

SPECIFICATION Joining of metal sheets The present invention relates to the joining of metal sheets to other sheets by means of tabs on the metal sheet passed through slots in the other sheet. The slotted sheet will commonly, but not necessarily, be of the same or similar metal to the tabbed sheet.

A variety of joining methods of this kind are known. For example a tab, conveniently of semicircular shape, can be passed through a slot and then folded down against the face of the sheet in which the slot is formed. Alternatively the tab may be formed with a barb which passes through the slot and then springs out to prevent retraction. The latter method, though quick and convenient for assembly, can only be used with tempered steel and other appropriately resilient metals.

The present invention has been developed in the context of filing cabinets and other furniture constructed of sheet metal and packed flat for delivery. A rapid and convenient method of assembly using only simple tools is desirable in this case and the existing methods of tab and slot connection are not suitable. After joining the back and sides of cabinets and cupboards together the top has to be joined on and commonly this is in the form of a panel with margins turned down to form a rim and then turned inwards to form a flange parallel to the body of the panel. The flanges are joined to inwardly-turned flaps extending along the top edges of the back and side panels. In this way the fastenings are concealed and a smooth external appearance is obtained.To use a tab and slot connection between the flanges and the flaps presents some difficulty because of restricted access and this again means that a simpler and more convenient method is required.

A further known method is to twist the tab after it has been passed through the slot in order to prevent withdrawal. This is easily carried out using a pair of pliers or a similar tool but it does not have sufficient strength and reliability for use in the assembly of steel furniture.

In accordance with the present invention there is provided a method of joining a metal sheet to another sheet by means of tabs formed on the metal sheet and passed through corresponding slots in the other sheet wherein the tabs have a notch formed in one edge at or close to the root of the tab and after they have been passed through the slots a part of each tab defined by the notch is bent out of the plane of the tab to form a lug which prevents withdrawal of the tab.

The bending can easily be carried out by a twisting action using a pair of pliers or similar gripping tool.

To prevent the movement of the tabs along the slots, which might otherwise be possible because of the presence of the notches, preferably at least one tab and conveniently every alternate tab has its notch on the opposite edge to those of the other tabs. In this way the un-notched edges of two tabs with opposed notched cooperate with the ends of the corresponding slots to locate the one sheet with respect to the other.

The invention will now be described in more detail with the aid of examples illustrated in the accompanying drawing, in which Fig. 1 shows a stage in the production of a junction between two sheets by a method in accordance with the invention, and Fig. 2 shows on a slightly enlarged scale a modification in the shape of the tab.

As seen in Fig. 1, a metal sheet 10 with tabs 11 and 12 is to be joined at right angles to a sheet 13 having slots 14 and 1 5 to receive the tabs 11 and 12, respectively. The tabs 11 and 1 2 project from the edge 16 of the sheet 10. The tab 11 has an abutment edge 1 7 standing perpendicular to the edge 1 6 to abut one end of the slot 14. The tab 12 similarly has an abutment edge 18 to abut the opposite end of the slot 1 5. In this way relative movement of the sheets parallel to the edge 1 6 is prevented.

The tab 11 has a notch 19 bounded on one side by the edge 16 and thus lying at the root of the tab. The tab 12 similarly has a notch 20 facing in the opposite direction. If the notches all faced in the same direction the tabs would be free to move in the slots in a direction parallel to the edge 1 6 but this is prevented if at least one tab has the notch facing the other way so that abutment edges 1 7 and 1 8 operate to restrict such movement.

After the sheets have been assembled as shown, with the tabs 11 and 12 projecting through the respective slots 14 and 15, the part of each tab defined by the notch is bent out of the plane of the sheet 10 by a twisting action with pliers or other gripping tools. The precise axis about which such bending takes place is immaterial but it will be approximately perpendicular to the plane of the sheet 1 3.

In Fig. 2, in which corresponding parts are given the same reference numerals as in Fig. 1, the tab 11, and indeed each of the tabs, has a second abutment edge 21 spaced from the edge 1 7 by a distance corresponding to the length of the slot 14. The notch 1 9A is thus bounded by an edge 22 flush with the outer face of the sheet 13 and lies wholly outside the slot. In this instance the provisions of notches facing in opposite directions is not necessary since each tab fits closely in its slot and prevents movement parallel to the slot.

The joint is completed in the same way by twisting part of the tab out of the plane of the tab.

It will be evident that the edge 22 should not be above but may be below the outer face of the sheet 13.

1. A method of joining a metal sheet to another sheet by means of tabs formed on the metal sheet and passed through corresponding slots in the other sheet wherein the tabs have a notch formed in one edge at or close to the mot of the tab and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Joining of metal sheets The present invention relates to the joining of metal sheets to other sheets by means of tabs on the metal sheet passed through slots in the other sheet. The slotted sheet will commonly, but not necessarily, be of the same or similar metal to the tabbed sheet. A variety of joining methods of this kind are known. For example a tab, conveniently of semicircular shape, can be passed through a slot and then folded down against the face of the sheet in which the slot is formed. Alternatively the tab may be formed with a barb which passes through the slot and then springs out to prevent retraction. The latter method, though quick and convenient for assembly, can only be used with tempered steel and other appropriately resilient metals. The present invention has been developed in the context of filing cabinets and other furniture constructed of sheet metal and packed flat for delivery. A rapid and convenient method of assembly using only simple tools is desirable in this case and the existing methods of tab and slot connection are not suitable. After joining the back and sides of cabinets and cupboards together the top has to be joined on and commonly this is in the form of a panel with margins turned down to form a rim and then turned inwards to form a flange parallel to the body of the panel. The flanges are joined to inwardly-turned flaps extending along the top edges of the back and side panels. In this way the fastenings are concealed and a smooth external appearance is obtained.To use a tab and slot connection between the flanges and the flaps presents some difficulty because of restricted access and this again means that a simpler and more convenient method is required. A further known method is to twist the tab after it has been passed through the slot in order to prevent withdrawal. This is easily carried out using a pair of pliers or a similar tool but it does not have sufficient strength and reliability for use in the assembly of steel furniture. In accordance with the present invention there is provided a method of joining a metal sheet to another sheet by means of tabs formed on the metal sheet and passed through corresponding slots in the other sheet wherein the tabs have a notch formed in one edge at or close to the root of the tab and after they have been passed through the slots a part of each tab defined by the notch is bent out of the plane of the tab to form a lug which prevents withdrawal of the tab. The bending can easily be carried out by a twisting action using a pair of pliers or similar gripping tool. To prevent the movement of the tabs along the slots, which might otherwise be possible because of the presence of the notches, preferably at least one tab and conveniently every alternate tab has its notch on the opposite edge to those of the other tabs. In this way the un-notched edges of two tabs with opposed notched cooperate with the ends of the corresponding slots to locate the one sheet with respect to the other. The invention will now be described in more detail with the aid of examples illustrated in the accompanying drawing, in which Fig. 1 shows a stage in the production of a junction between two sheets by a method in accordance with the invention, and Fig. 2 shows on a slightly enlarged scale a modification in the shape of the tab. As seen in Fig. 1, a metal sheet 10 with tabs 11 and 12 is to be joined at right angles to a sheet 13 having slots 14 and 1 5 to receive the tabs 11 and 12, respectively. The tabs 11 and 1 2 project from the edge 16 of the sheet 10. The tab 11 has an abutment edge 1 7 standing perpendicular to the edge 1 6 to abut one end of the slot 14. The tab 12 similarly has an abutment edge 18 to abut the opposite end of the slot 1 5. In this way relative movement of the sheets parallel to the edge 1 6 is prevented. The tab 11 has a notch 19 bounded on one side by the edge 16 and thus lying at the root of the tab. The tab 12 similarly has a notch 20 facing in the opposite direction. If the notches all faced in the same direction the tabs would be free to move in the slots in a direction parallel to the edge 1 6 but this is prevented if at least one tab has the notch facing the other way so that abutment edges 1 7 and 1 8 operate to restrict such movement. After the sheets have been assembled as shown, with the tabs 11 and 12 projecting through the respective slots 14 and 15, the part of each tab defined by the notch is bent out of the plane of the sheet 10 by a twisting action with pliers or other gripping tools. The precise axis about which such bending takes place is immaterial but it will be approximately perpendicular to the plane of the sheet 1 3. In Fig. 2, in which corresponding parts are given the same reference numerals as in Fig. 1, the tab 11, and indeed each of the tabs, has a second abutment edge 21 spaced from the edge 1 7 by a distance corresponding to the length of the slot 14. The notch 1 9A is thus bounded by an edge 22 flush with the outer face of the sheet 13 and lies wholly outside the slot. In this instance the provisions of notches facing in opposite directions is not necessary since each tab fits closely in its slot and prevents movement parallel to the slot. The joint is completed in the same way by twisting part of the tab out of the plane of the tab. It will be evident that the edge 22 should not be above but may be below the outer face of the sheet 13. CLAIMS

1. A method of joining a metal sheet to another sheet by means of tabs formed on the metal sheet and passed through corresponding slots in the other sheet wherein the tabs have a notch formed in one edge at or close to the mot of the tab and after they have been passed through the slots a part of each tab defined by the notch is bent out of the plane of the tab to form a lug which prevents withdrawal of the tab.

2. A method as claimed in claim 1 in which at least one tab has its notch on the opposite edge to those of the other tabs.

3. A method as claimed in claim 2 in which every alternate tab has its notch on the opposite edge to those of the other tabs.

4. A method as claimed in any of the preceding claims in which the root of each tab is the full width of the slot over a height substantially equal to the thickness of the slotted sheet.