MECHANICAL CONNECTION, A.O. FOR APPLICATION IN PLASTIC BUTTONS

Abstract: A mechanical connection between two plastic parts (a front plate and a locking plate) realised by swellings (2) around the brim of the locking plate and a roughened surface (5) inside the front plate. The locking plate has provisions (6) for easy assembly of a safety pin. Between front plate and locking plate there is room for an interjacent element (7).

Description: Mecanical connection, α.o. for application in plastic buttons. This invention concerns the connection of a shell-like front plate together with a locking plate. Both parts are made of hard plastic and are manufactured by means of a mass-production process like injection moulding and they can be used as an identification carrier or button|badge. A possible elemnt is known from the french publication FR|A11512473. In this french case two parts are being pressed into one another by force. It is also known to connect plastic parts by means of outstanding rims, behind which the part is kept in place. This production method has the disadvantage that socalled " Click-in-rims", when ejecting from the mould, cannot be applied when using hard plastic material. Also, hard plastics have little or no elasticity through which the flexible rim of the click-in connection either becomes extremely vulnerable or can hardly or not at all be realised. Normally a click-connection has the disadvantage that the part to be held in place, has some space to move. The mecanical connection can be described as follows: Figure 1 shows the composition, figure 2 the locking plate and figure 3 the front plate. The locking plate (1) has a number of swellings (2) around the circumference. The size measured over the swellings (2) is larger than the receiving opening (3) in the front plate (4). This opening (3) in the front plate (4) is provided with a roughened surface at the cylindrical part (5), preferably by means of sparkerosion. As soon as the locking plate (1) is being pressed into the front plate (4) the following occurs. By means of high surface pressure on the swellings (2) a deformation of the swellings (2) is brought about, whereby the size over the swellings (2) adapts itself. This adaptation of size causes a pressure fitting between the swellings (2) and the rough spark structure of the wall (5). Hereby a relatively strong connection is being achieved which depends in turn on the number of swellings (2). The connection avoids the locking plate (1) from turning in the front plate (4). The locking plate (1) can be equipped with slots (6) by means of which safety-pins f.e. can be attached. Between the front plate (4) and the locking plate (1) an interjacent element (7) can be locked in. The mecanical connection is not limited to round elements only.

Claims: C L A I M S 1. The mecanical connection of two plastic parts of little elasticity with the characteristic that a locking plate provided with swellings around the brim, which is fitted tightly into the cooperating part of which in turn the opening is provided with a roughened surface as will be obtained from sparking the mould. 2. The mecanical connection of two plastic parts of little elasticity with the characteristic that the roughness of the cooperating surface is at least 200 microns. 3. The mecanical connection of two plastic parts of little elasticity with the characteristic that the locking plate is provided with means for connecting a safety—pin and forms the basis for a number of shapes and sizes of buttons.

Inventors: BINK HILDE GERTRUD, BINK, HILDE, GERTRUD
Applicants: BINK HILDE GERTRUD, BINK, HILDE, GERTRUD
Application year: 1987
Main classification: A44C3
IPC codes: A44C3, B29C65