GB2171145A - Press button type fastener - Google Patents

Abstract

There is disclosed press button type fastener having a plug assembly 11 such that when the fastener is in the locked state the upper surface of said plug assembly attached to a movable panel 12A is in the same plane as the surface of said movable panel, and a socket assembly 13 constructed so as to be adjustable according to the necessary grip length of said movable panel and a fixed panel 14 to be mutually fastened by said fastener. <IMAGE>

Description

SPECIFICATION Press button type fastener This specification relates to an adjustable fastener allowing a panel or door to be opened and closed rapidly and attached in the same plane.

An example of a conventionally known press button type fastener is disclosed in U.S. Patent No.

3,152,822 issued to Edward G. Griffiths on 13th October 1964.

Since this type of conventional fastener is only applicable to one fitting thickness, there is the problem that in order to respond to customers' demands for fasteners of different dimensions it is necessary to manufacture and stock a number of sizes.

Furthermore, when the conventional press button fastener is in the locked position, the upper portion of the plug assembly projects above the surface of the panel, and there is the defect that by being erroneously pressed the panel or door will be opened when it should not have been.

In the present invention, within a predetermined grip range (that is fastening thickness) of the fastener, it can be adjusted to accommodate any panel thickness. A screw thread is cut on the inside of a grommet which is part of the socket assembly, and on to this is screwed a socket auxiliary assembly on the outside of which is cut a thread.

The socket auxiliary assembly incorporates a cam mechanism for fixing the plug assembly within it. By means of a thread portion on the outside of the cam housing which forms part of the socket auxiliary assembly, the socket auxiliary assembly is enabled to rotate within the grommet, and thus can be positioned at any point along the longitudinal direction of the thread portion ofthe grommet, and thus can be adjusted for differences in thickness of the panel to which the fastener is to be applied (in other words differences in the grip).

The plug assembly is constructed in such a way that when fixed within the socket assembly, the upper surface of the plug assembly is positioned in the same plane as the surface ofthe panel. Thereby, there is no longer the possibility of erroneously pressing the button.

In order to increase the reliability of the fastener, plug insertion guide protuberances are provided on a portion of the detent cam within the socket auxiliary assembly. By means of these plug insertion guide protuberances the stud which forms part of the plug assembly is inserted appropriately into the socket auxiliary assembly, and erroneous operation of the assemblies is prevented.

Furthermore, the lower surface of the indexing cam is formed so that the cam contacts with low friction so as to be easily rotatable with respect to the inserted stud.

The invention will be further apparent from the following description, with reference to the several figures of the accompanying drawings, which show by way of example only, fasteners embodying same.

Of the drawings:- Figure 1 is a perspective drawing of a fastener of the present invention, and shows a representative characteristic of the present invention, showing a separated plug assembly and socket assembly, Figure 2 is a side elevation of a fastener of the present invention, showing the two assemblies fastened together, Figure 3 is a plan view of the fastener of the present invention shown in Figure 2, Figure 4 is a section along the line of 4--4 in Figure 3, Figure 5 is a plan view of the socket assembly of the fastener of the present invention shown in Figure 1, Figure 6 is a section of the fastener of the present invention of the same construction as the construction of Figure 4 except in that a thick movable panel is used in order to illustrate the case of using the maximum grip, and Figure 7 is an expanded diagram illustrating the positional relationship of the two cams and the cross pin.

The present invention is indicated by numeral 10 in Figure 1, Figue 2 and Figure 6 and comprises two main components, which are a plug assembly 11 and a socket assembly 13.

The socket assembly 13 is attached to a fixed panel or frame 14. An opening of a fixed panel for receiving the socket assembly 13 widens on the side opposing a movable panel 12A. The socket assembly 13 is provided with a grommet 22, retaining nut 25, and adjustable socket auxiliary assembly 21. The grommet 22 is constructed so that its one end is fixed to the enlarged portion of the opening of the fixed panel 14. The other end of the grommet 22 extends downwards as seen in the drawing from the fixed panel 14. The grommet 22 has a thread formed in the outer surface of a portion adjacent to the end incorporated in the fixed panel 14. The retaining nut 25 is screwed on to this threaded portion of the grommet 22, and fastens the grommet 22 in the opening in the fixed panel.

On the opposite free end of the grommet 22, a thread is formed in the inner wall. Within this portion of the inner threaded grommet 22 is disposed the adjustable socket auxiliary assembly 21. This socket auxiliary assembly 21 has a cam housing of cylindrical shape provided with an outer thread formed so as to engage with the inner thread of the grommet 22. With reference to Figure 4 and Figure 6, within the cam housing are disposed a detent cam 26 and an indexing cam 32. These cams are of a conventional construction well-known to those skilled in the relevant art. Each of the cams 26 and 32 has one surface opposing a similar surface of the other cam. These surfaces are of sufficient extent that when a press button 15 is pressed, a cam follwer or stud cross pin 19 causes both of the cams to rotate through 90 degrees, or in other words to allow indexing.

When the eross pin 19 enters the socket auxiliary assembly 21 a central hole 30 of the detent cam 26 receives this cross pin 19. The central hole 30 has a pair of slots which accept both ends of the cross pin 19. The topmost portion of the detent cams 26 has a pair of mutually displaced guide protuberances 28 and 29. With reference to Figure 5, since the guide protuberances 28 and 29 are displaced, the cross pin 19 always opposes the ramp surfaces of the detent cam 26, and then proceeds downwards into the central hole 30 so that the cross pin 19 is positively caused to enter the socket assembly 13 appropriately. On the top of the socket auxiliary assembly 21 is provided a pair of screwdriver slots 23.By means of these slots 23 the user can rotate the socket auxiliary assembly 21 to adjust to the required gripforthe particular panels 12Aand 14or 1 2B and 4, and it is possible to adjust the socket auxiliary assembly 21 to a suitable position within the grommet 22 of the socket assembly. The lower end of the socket auxiliary assembly 21 extends lower than the lower end of the grommet 22. An end cap 36 is provided on this lower end of the socket auxiliary assembly. In order that the friction can be reduced, when the cross pin 19 moves within the socket auxiliary assembly 21, turning the lower end of the indexing cam on the end cap 36, the lower end of the indexing cam 32 is formed with a conical shape.

The cross pin 19 is attached to one end of a stud 18, and projects in a T-shape from the stud 18. The other end of the stud 18, that is the upper end, is attached rotatably within a button 15. The plug assembly 11 has further a stud end cap 41 used as a support for a grommet 16 and the button 15, a press button return spring 39, and a retaining ring 17. The opening in the panel 1 2A receiving the grommet 16 of the plug assembly extends as shown by 24 such as to engage in the same plane as the upper part of the grommet 16. The retaining ring 17 is disposed on the reverse side of the opening, and fixes the grommet l6withinthe panel 12A.In order that when the panel 12A and the panel 14 are fastened by the fastener, the panel 1 2R and the panel 14 can be clamped closely together, a depression 27 is provided to house the retaining ring 17.

The grommet 16 extends below the panel 12A, and as shown in Figure 4 and Figure 6, is constructed so as to be compietely housed within the grommet 22 of the socket assembly 13. An aperture is provided in the lower centre of the grommet 16, and the shaft of the stud 18 passes movably th rough this aperture. This aperture, however, is of such a size as to prevent the cross pin 19 passing through. At the end of the stud 18 opposite to the cross pin 19 is sprovided an end cap 41. This end cap 41 retains the stud 18 and a return spring 39. The return spring 39 surrounds the shaft of the stud 18 between the end cap 41 and the lower aperture of the grommet. The cross pin 19 acts as a stopper against the force of the spring 39 urging the stud 18 upwards form the socket auxiliary assembly.

The button 15 is attached freely immediately above the end cap 41 of the stud 18. The button 15 is of such a size as to engage within the grommet 16 when depressed.

Next the operation will be described. Before engaging the plug assembly 11 with the socket assembly 13, the socket auxiliary assembly 21 is adjusted to a position within the grommet 22 of the socket assembly such as to satisfy the particular grip conditions to allow the movable panel 12Ato be fastened to the fixed panel 14. Next the movable panel 12A is positioned above the fixed panel 14.

The plug assembly 11 and the socket assembly 13 are aligned in order that the stud 18 and the cross pin 19 will enter the socket assembly 13. By just pressing the button 15 in the direction of the fixed panel, the cross pin 19 is guided by the guide protuberances 28 and 29, and enters the slots 30 of the detent cam 26. As the button 15 is pressed further, the force first compresses the spring 39, and then the stud 18 and the cross pin 19 press on the acting surfaces of the two cams 26 and 32. With the downward motion of the press button 15, the cross pin 19 acts on the cam surface 34 of the cam 32, as a result of which the cams 26 and 32 rotate through 90 degrees, and are indexed.When, having reached this position, the press button 15 is released, the spring 39 returns the press button 15 to the position in the same plane as the movable panel 1 2A, 1 2B, and at the same time the cross pin 19 is positioned within a pair of detents 31 of the detent cam 26.

Thus the ends of the cross pin 19 are retained within the detents 31. In this way the fastener reaches the locked position shown in Figure 2, Figure 4, and Figure 6. In order to release the lock of the fastener, and remove the movable panel 12A, 12B from the fixed panel 14, the button 15 is again depressed, and the stud 18 and the cross pin 19 perform a motion the reverse of that in the above stage. On returning to the initial release position, the cross pin 19 rotates the cams 26 and 32 through 90 degrees, that is indexes them, and therefore the slots 30 are aligned with the cross pin 19. When the press button 15 is released, the force of the spring 39 forces the cross pin 19 up through the slots 30, and out of the socket assembly. In this way the movable panel 12A, 12B can be removed from the fixed panel 14.

The operating positional relationship of the cross pin 19 thus removed and the two cams 26 and 32 will be easily understood from Figure 7. In this figure, it is drawn as though the cams were fixed and the cross pin rotating, but it will be clear that the same effect is obtained when constructed such that on the contrary the cams rotate and the cross pin does not rotate.

The embodiment shown in Figure 6 is the same as the embodiment of Figures 1 to 5 except in that the movable panel 1 2B has changed. The panel 1 2B is shown to illustrate the fastener in the case when the maximum grip is required. In Figure 6 the letter B indicates the distance that the cam housing extends from the bottom of the grommet in the case of the maximum grip. In Figure 4 the letter A indicates the distance that the cam housing extends from the bottom of the grommet in the case that only the minimum grip is required for the panel thickness.

The position of the socket auxiliary assembly 21 can be moved between these two extreme cases, to meet the various grip conditions to fasten the movable panel to the fixed panel, in order to utilise the present invention appropriately.

The method of attaching the grommet to the panel shown in the figures is only by way of example, and it will be clear that various variations are possible, such as by knurling the cylindrical outer wall of the grommet and pressing it into a circular hole.

The press button type fastener of the present invention is of the latest appearance, since it is fitted in the same plane it cannot be pressed in error, it is vastly superiorto the conventional article, and it is easyto keep clean. Furthermore,the press button fastener of the present invention can, without damaging the panel to which it is fitted, be removed and replaced. The fastener of the present invention has high reliability because ofthe effect ofthe guide protruberances in preventing the stud from jamming when the stud is inserted into the socket auxiliary assembly. Finally, the most important characteristic of the present invention is that a single fastener assembly can be adjusted to meet a number of conditions required for different grips. This is extremely advantageous for the user, and allows a reduction in the expensive stocks which were required in the case ofthe conventional devices which cannot be-adjusted.

Claims (2)

1. A press button type fastener having a plug assembly such that when the fastener is in the locked state the upper surface of said plug assembly attached to a movable panel is in the same plane as the surface of said movable panel, and a socket assembly constructed so as to be adjustable according to the necessary grip length of said movable panel and a fixed panel to be mutually fastened by said fastener.

2. The press button type fastener according to claim 1 characterised in that said socket assembly has a grommet having an internal thread cut therein, and a cam housing on the outside of which is cut a thread and threadingly engaged with said grommet, and in that said cam housing is adjustable to any position in the longitudinal direction of said grommet.