Fastener for securing a gas bag module to a steering wheel

ABSTRACT

A fastener for securing a gas bag module to a steering wheel includes two fastening arms and a fastener part. The fastening arms enter into a snap-action connection with the fastener part and clasp the fastener part in a connected condition.

INFORMATION

DETAILED DESCRIPTION OF THE INVENTION

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, there is illustrated a fastener in accordance with the invention which connects a component, e.g., the inflator mount of a gas bag module to a fastener part secured, e.g., to a steering wheel by a snap-action connection. The fastener comprises two fastening arms preferably made of a plastics material which end in hooks . In the connected condition which is shown, the hooks clasp the fastener part in such a manner that the flat or slightly convex upper sides contact a corresponding undercut, preferably concave surface area on the fastener part . In this condition, the inflator mount is locked in place against tension in the direction of the arrow A away from the steering wheel.

In addition the hooks of the fastening arms comprise ramps at their side facing the fastener part . The fastener part comprises corresponding ramps . Both the ramps of the fastener part and the ramps of the hooks include angles whose legs run towards each other, as seen in the direction of the arrow A. The ramps of the fastener part are preferably configured with two steps ′, ″. The first step of the ramps ′ includes a smaller angle than the second step ″.

In making the connection the gas bag module is inserted contrary to the direction of the arrow A into its mount in the steering wheel and the fastening arms , pretensioned inwardly towards the fastener part t, slide by their ramps along the ramps and are pressed apart so gently that the edges of the hooks cannot be damaged. The less inclined ramps ′ first permit soft seating and shifting with little effort, whereas in the region of the more inclined ramps ″ a sharp increase in the counterforce materializes. Once the hooks have arrived at the end of the ramps ″ the hooks snap back by the distance spread apart and clasp the fastener part .

When the insertion movement of the gas bag module stops before the hooks snap in place in the surface area , the fastening arms and thus the gas bag module are urged back, due to the spring force of the fastening arms , contrary to the direction of the arrow A and away from the steering wheel due to the shape of the ramps of the fastener part—but especially due to that of the ramps ″—and the ramps of the hooks. This movement is assisted by a spring disposed between the steering wheel and the gas bag module, this spring being pretensioned by the insertion movement. It is thus easy to recognize any failure of the snap-action connection to occur.

To release the connection the hooks are pressed apart at their ramps by a suitable tool, e.g. a screwdriver until the contact surface area of the fastener part releases the contact surface areas of the hooks , the contact surface area serving here as a guide for the contact surface areas of the hooks. As soon as the ramps of the hooks are in contact with the ramps of the fastener part, the gas bag module is moved due to the shape of the ramps , and the spring force of the fastening arms so far in the direction of the arrow A that the hooks can no longer clasp the fastener part . The spring pretensioned on insertion of the gas bag module into the steering wheel assists this movement and urges the gas bag module from the steering wheel.

BRIEF DESCRIPTION OF THE DRAWING

The sole Figure shows a section through a fastener in accordance with the invention.

CLAIMS

1. Apparatus comprising: a gas bag module including an inflator mount and two fastening arms configured integrally with said inflator mount; and a fastener part configured integrally with a steering wheel, said fastening arms entering into a snap-action connection with said fastener part and clasping said fastener part in a connected condition to connect said gas bag module and said inflator mount with the steering wheel, said fastening arms comprising hooks having contact surface areas and said fastener part comprising a contact surface area into which said contact surface areas of said hooks engage in said connected condition, said fastener part and said fastening arms comprising ramps corresponding to each other, said ramps of said fastener part including an angle and said hocks sliding back towards the apex of said angle should the connection fail to be made.

2. The apparatus according to claim 1 wherein said contact surface of the fastener part is concave.

COPYRIGHT

User acknowledges that Fairview Research and its third party providers retain all right, title and interest in and to this xml under applicable copyright laws. User acquires no ownership rights to this xml including but not limited to its format. User hereby accepts the terms and conditions of the License Agreement.