GB2099099A

GB2099099A - Sheet metal nut

Info

Publication number: GB2099099A
Application number: GB8211849A
Authority: GB
Original assignee: Mecano Simmonds GmbH
Current assignee: Mecano Simmonds GmbH
Priority date: 1981-05-26
Filing date: 1982-04-23
Publication date: 1982-12-01
Also published as: NL8201221A; ES272068U; GB2099099B; DE3121771A1; SE8203236L; DE3121771C2; SE449906B; FR2506866A1

Abstract

A sheet metal nut is formed e.g., as an E-shape (as shown) or S-shape Fig. 1, not shown), with three substantially parallel arms of which the first (1) has an opening to receive a bolt or screw; and the second (2) and third (3) have different thread impressions (4) or (4a), of which one (4a) is rigid and the other (4) is flexible. This allows the tensile load to be sustained by more than one course of thread. A detent (16 or 7) (Figures 1d and 2d, not shown) may be provided in the first arm (1) to engage the thread of the screw. The threads 4 and 4a may be staggered axially or radially (as shown in Figure 1) so that the nut is under tension when engaging a screw or bolt. <IMAGE>

Description

SPECIFICATION Sheet metal nut The invention relates to a one-piece clamp-like sheet metal nut with an impressed thread, for the connection of sheet metal parts and the like.

Sheet metal nuts made of sheet metal strips which are bent U-shaped or in the form of a clamp, having on one shank an impressed thread, are known for example from German Gebrauchsmuster Nos: 1946929 and 1926036.

Such known sheet metal nuts are normally provided with an opening for the bolt to pass through and a locking or arresting tongue in the lower shank; they may also have an impressed thread in the upper shank. A disadvantage in known sheet metal nuts is that the entire tensile load of the screw connection is taken by one course of thead of the bolt, so that on overloading, a shearing of the bolt thread can occur.

The present invention seeks to provide a clamplike, one-piece sheet metal nut, which mitigates the above problems, but without increasing the amount of material used. To this end, the invention provides a sheet metal nut having an impressed thread for connecting sheet metal parts, which nut comprises a metal strip bent to form at least three substantially parallel shanks of which the first shank has an opening therein for receiving a bolt or screw; and openings in the second and third shanks have different thread impressions, one constructed rigid and the other flexible. The flexible thread impression is normally provided on the second, or central shank.

The nut of the invention is of simple manufacture, but can provide an improved securing effect, a higher tightening and loosening torque and also an increase in the static tensile load of the bolt thread. Further, by forming the nut in such a way that it is elastically strained merely by the presence of a bolt or screw therein, some vibration-proof security from loss between bolt and nut can be brought about, thus facilitating storage of nut and bolt units.

In the use of a sheet metal nut according to the invention the thread impressions engaged by the bolt are braced independently of each other, and an additional security moment is obtained. In addition, the security moment may be strengthened in that where the fixed thread impression is on the third shank lying away from the bolthead, it is pressed onto the second shank arranged beneath it towards the thread core of the bolt as the bolt is tightened. At the same time the tightening and loosening torque and the static tensile load are increased. The danger of shearing of a course of thread is substantially reduced or is avoided, since the load of the bolt thread is taken up by several courses of thread.

Two embodiments of the invention will now be described by way of example and with reference to the accompanying drawings wherein like references identify like parts and wherein Figure 1 shows a longitudinal section through a sheet metal nut according to a first embodiment of the invention; Figures 1 a, 1 b, and 1 C are perspective views of the nut shown in Figure 1; and Figure 1 d shows a sheet metal nut according to Figure 1, in use with a conventional bolt or screw; Figure 2 shows a longitudinal section through a sheet metal nut according to a second embodiment of the invention; Figures 2a, 2b and 2c are perspective views of the nut shown in Figure 2; and Figure 2d shows a longitudinal section through a sheet metal nut according to Figure 2, in use with a conventional bolt or screw.

Each sheet metal nut shown in the drawings comprises a sheet metal bent twice to form shanks 1, 2 and 3. Shank 1 has a through bore 5 and a detent 6 (Figure 1) or two detents 7 (Figure 2); shank 2 has a thread impression formed by two tongues 4 which are flexible independently of each other; and shank 3 is provided with a thread impression 4a. The axial spacing of the thread impressions 4 and 4a, indicated at 8, in the nontightened state of the nut; i.e., before turning in of the bolt, differs from, and is normally greater than the distance determinable from the pitch of the thread in either impression. Also, the centre axes of the thread impressions 4, 4a in the nontightened state of the nut may be laterally displaced, as indicated at 8'.As a consequence of these characteristics, when the nut is used to secure two workpieces 10 as shown in Figures id and 2d, the shanks 2 and 3 are drawn together as the bolt 9 is tightened.

The nut shown in Figures 1 a to 1 d is formed from a sheet of metal bent twice at spaced parallel folds into a Z-shape. That shown in Figures 2a to 2d however, differs in that the two fold lines are on the same side of the nut. Here, the shank 3 is cut out from the shank 1, thereby saving material and weight, and is bent over from the shank 2. The thread impressions 4 and 4a are the same, but in the shank 1 the through bore 5 is open on one side and provided with two detents 7 in place of the single detent 6 of the Figure 1 embodiment.

1. A sheet metal nut having an impressed thread for connecting sheet metal parts, which nut comprises a metal strip bent to form at least three substantially parallel shanks of which the first shank has an opening therein for receiving a bolt or screw; and openings in the second and third shanks have different thread impressions, one constructed rigid and the other flexible.

2. A sheet metal nut according to Claim 1 wherein the opening in the first shank has at least one detent for engaging the thread of a screw or bolt.

3. A sheet metal nut according to Claim 1 or Claim 2 wherein the axial distance between the thread impressions of the second and third shank deviates from the distance determinable from the pitch of the thread in either impression.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Sheet metal nut The invention relates to a one-piece clamp-like sheet metal nut with an impressed thread, for the connection of sheet metal parts and the like. Sheet metal nuts made of sheet metal strips which are bent U-shaped or in the form of a clamp, having on one shank an impressed thread, are known for example from German Gebrauchsmuster Nos: 1946929 and 1926036. Such known sheet metal nuts are normally provided with an opening for the bolt to pass through and a locking or arresting tongue in the lower shank; they may also have an impressed thread in the upper shank. A disadvantage in known sheet metal nuts is that the entire tensile load of the screw connection is taken by one course of thead of the bolt, so that on overloading, a shearing of the bolt thread can occur. The present invention seeks to provide a clamplike, one-piece sheet metal nut, which mitigates the above problems, but without increasing the amount of material used. To this end, the invention provides a sheet metal nut having an impressed thread for connecting sheet metal parts, which nut comprises a metal strip bent to form at least three substantially parallel shanks of which the first shank has an opening therein for receiving a bolt or screw; and openings in the second and third shanks have different thread impressions, one constructed rigid and the other flexible. The flexible thread impression is normally provided on the second, or central shank. The nut of the invention is of simple manufacture, but can provide an improved securing effect, a higher tightening and loosening torque and also an increase in the static tensile load of the bolt thread. Further, by forming the nut in such a way that it is elastically strained merely by the presence of a bolt or screw therein, some vibration-proof security from loss between bolt and nut can be brought about, thus facilitating storage of nut and bolt units. In the use of a sheet metal nut according to the invention the thread impressions engaged by the bolt are braced independently of each other, and an additional security moment is obtained. In addition, the security moment may be strengthened in that where the fixed thread impression is on the third shank lying away from the bolthead, it is pressed onto the second shank arranged beneath it towards the thread core of the bolt as the bolt is tightened. At the same time the tightening and loosening torque and the static tensile load are increased. The danger of shearing of a course of thread is substantially reduced or is avoided, since the load of the bolt thread is taken up by several courses of thread. Two embodiments of the invention will now be described by way of example and with reference to the accompanying drawings wherein like references identify like parts and wherein Figure 1 shows a longitudinal section through a sheet metal nut according to a first embodiment of the invention; Figures 1 a, 1 b, and 1 C are perspective views of the nut shown in Figure 1; and Figure 1 d shows a sheet metal nut according to Figure 1, in use with a conventional bolt or screw; Figure 2 shows a longitudinal section through a sheet metal nut according to a second embodiment of the invention; Figures 2a, 2b and 2c are perspective views of the nut shown in Figure 2; and Figure 2d shows a longitudinal section through a sheet metal nut according to Figure 2, in use with a conventional bolt or screw. Each sheet metal nut shown in the drawings comprises a sheet metal bent twice to form shanks 1, 2 and 3. Shank 1 has a through bore 5 and a detent 6 (Figure 1) or two detents 7 (Figure 2); shank 2 has a thread impression formed by two tongues 4 which are flexible independently of each other; and shank 3 is provided with a thread impression 4a. The axial spacing of the thread impressions 4 and 4a, indicated at 8, in the nontightened state of the nut; i.e., before turning in of the bolt, differs from, and is normally greater than the distance determinable from the pitch of the thread in either impression. Also, the centre axes of the thread impressions 4, 4a in the nontightened state of the nut may be laterally displaced, as indicated at 8'.As a consequence of these characteristics, when the nut is used to secure two workpieces 10 as shown in Figures id and 2d, the shanks 2 and 3 are drawn together as the bolt 9 is tightened. The nut shown in Figures 1 a to 1 d is formed from a sheet of metal bent twice at spaced parallel folds into a Z-shape. That shown in Figures 2a to 2d however, differs in that the two fold lines are on the same side of the nut. Here, the shank 3 is cut out from the shank 1, thereby saving material and weight, and is bent over from the shank 2. The thread impressions 4 and 4a are the same, but in the shank 1 the through bore 5 is open on one side and provided with two detents 7 in place of the single detent 6 of the Figure 1 embodiment. CLAIMS

4. A sheet metal nut according to any preceding Claim wherein the centre axes of the thread impressions in the non-tightened state of the nut are displaced laterally.

5. A sheet metal nut according to any preceding Claim formed from a strip of metal having a tongue defined therein surrounded by a border, wherein the tongue is bent in one direction to form the third shank, and the border is bent in the other direction to form the first shank.

6. A sheet metal nut according to any preceding Claim wherein the flexible thread impression comprises tongues which are flexible independently of each other.

7. A sheet metal nut according to any preceding Claim wherein the flexible thread impression is formed in the second shank and the rigid thread impression is formed in the third shank.

8. A sheet metal nut substantially as described herein with reference to Figures 1 a to 1 d or Figures 2a to 2dof the accompanying drawings.