WO1986000574A1

WO1986000574A1 - "cricket" membranes for printer

Info

Publication number: WO1986000574A1
Application number: PCT/CH1984/000134
Authority: WO
Inventors: Jean-Pierre Schneebeli
Original assignee: Schneebeli Jean Pierre
Priority date: 1984-07-04
Filing date: 1984-08-23
Publication date: 1986-01-30
Also published as: EP0186661A1

Abstract

Membranes intended to be used as pulse generator on one hand and as printing element on the other hand, in a matrix printer. Said membranes are obtained by plastic deformation in the form of a dome made by stamping. In the application as a pulse generator A, the membrane is a simple dome. In the application as a printer element B a hole made by punching is made in the middle of the dome. The surroundings of the hole are superelevated by the punching operation; said circular superelevation will leave a point having the diameter of said superelevation when touching the paper to be printed. The point is the result of the "cricket" action of the membrane and of the ink passing in a minimum quantity through the hole.

Description

Crickets for printer

The present invention relates to a membrane made of a thin metal sheet curved in one direction by stamping. This membrane, after being attracted in the other direction by a magnetic field, can, when the magnetic field is cut, quickly resume its original domed shape and thus give impetus to a liquid contained by this membrane.

In membranes of known type comprising a flexible plastic membrane and a magnetic core, manufacturing requires several operations. The object of the invention is to remedy this complication and to make it possible to manufacture a whole series of membranes from a single sheet of metal and in a single stamping operation, thus forming a whole series of domes.

The invention applies not only to membranes of the pulse generator type A for liquid when driven by a magnetic field but also to membranes of the printing element B type which undergo a hydraulic thrust which causes them to tilt from their original convex position in the reverse.

The accompanying drawing shows, by way of example, an embodiment of the membrane of the pulse generator type A and of that used as a printing element B in a printer.

Figure 1. is a longitudinal section of the membrane you type pulse generator A and Figure 2. is a longitudinal section of the membrane of the printing element type B.

The two membranes were bent by stamping on a flat sheet of metal before being heat treated to become springs. The dome therefore deviates in its center by a fraction of its diameter relative to the center line of the flat metal sheet. The locust effect is obtained if the top of the dome is pushed back across the center line of the flat sheet until it reaches the same distance by relative to the center line of the flat sheet, but in the opposite direction to that in which the dome had been originally stamped.

This locust action is used in the application of pulse generator A by attracting the top of the dome, by a magnetic field, in the position opposite to that in which the dome had been originally stamped and then suddenly releases the dome when the magnetic field is cut off. This relaxation gives an impulse to the liquid contained by the member.

This locust action is also used in the application of the printing element B of a printer by punching the center of the dome with a punch before the heat treatment. Punching not only causes a hole in the middle of the dome, but also raises the immediate area around the hole relative to the curve of the membrane. This circular elevation will touch the paper to be printed when the membrane, under the effect of a hydraulic thrust, will deform from its original position in an inverted convex position (cricket effect).

Claims

1). "Cricket" membranes for printer, of the pulse generator type A and of the printing element type B, each consisting of a thin plate of hardened magnetic steel slightly deformed in the shape of a dome.

2). "Cricket" membranes according to claim 1, characterized by the spring action produced when the dome, deformed by a magnetic field applied in its center, is released by cutting this magnetic field.

3). "Cricket" membranes according to claim 1, characterized by the simplicity of their production individually or grouped on a thin plate of hardened magnetic steel intended for a multiple pulse generator or multiple printing element.

4). "Cricket" membrane according to claim 1, of type A, charac¬ terized by the violent hydraulic impulse resulting from the resumption of its initial domed shape, in the shape of a positive dome, after having been retained in a secondary shape, inversely convex, in shape negative dome, by a magnetic field.

5). "Locust" membrane according to claim 1, of type B, which, by the tiny hole caused in its center by the punch, lets escape a little ink during the hydraulic impulse and thus prints a point of the diameter of the part of the stamped mem¬ brane.

6). Membrane _. "cricket" according to claim 1, of type B, which by the configuration of its tiny hole created by the punch, will release its dried ink between two uses, under the effect of impact against the paper to be printed.

7). "Cricket" membrane according to claim 1, of type B, which, when the curved secondary shape is reached, leaves a small drop of ink from the tiny hole perforated in its center, thanks to the hydraulic pressure surge upstream of the membrane, and projects it onto the printing paper.