MXPA98004748A - Marc instruments - Google Patents

Abstract

The present invention relates to a marking instrument characterized in that it comprises a reservoir chamber for a marking fluid, a channel for carrying the marking fluid from the reservoir chamber, for supplying a marking tip, and a valve for controlling the supply of fluid through the channel, the valve consists of a seat member or support with a hole, and a diaphragm having an edge for operation or joint operation with the support member to close the hole, and a free surface extending from that edge to a position in which the diaphragm is prevented from moving, the support member is movable to deflect the diaphragm to open the valve, and that free surface of the diaphragm extends away from that edge at an angle that goes from 45º to 85ºwhen the valve is closed

Description

MARKING INSTRUMENTS FIELD OF THE INVENTION This invention relates to marking instruments, and especially, although not necessarily, exclusively, to writing instruments, whose term is intended to include slate markers and text highlighters as well as different types of pens with deposit .

BACKGROUND OF THE INVENTION In WO 93/05966 there is described a marking instrument having a reservoir chamber for storing marking fluid, a feeding channel for driving fluid towards a marking tip from the reservoir chamber, and a valve for controlling the flow of the fluid. fluid through the channel. The channel is defined through a feeding device that carries the marking tip and that is capable of moving axially. The feeding device includes, in REF .: 27744 position adjacent to its inner end, a radially directed hole, and an annular diaphragm surrounding the feed device with its internal edge arranged to close the hole to interrupt the communication between the tank chamber and the feed channel. When the marking tip is pressed against a surface, the feeding device retracts causing the diaphragm to be tilted so that the marking fluid in the reservoir chamber is pressurized and the inner edge of the diaphragm is lifted away from the feeding device. to open the hole and allow the fluid to enter the feed channel and pass to the marking tip. It has been found that this marking instrument is effective in the control and dosage of the marking fluid. However, for some applications the distance through which the feed device must be displaced has been undesirably large and the deflection of the resulting diaphragm may cause an excess of fluid to be pumped to the marking tip by the pressure generated. in the deposit chamber.

DESCRIPTION OF THE INVENTION The present invention helps to eliminate, or at least mitigate this disadvantage and in accordance with the invention a marking instrument is provided consisting of a reservoir chamber for marking fluid, a channel for conducting marking fluid from the reservoir chamber to supply a marking tip, and a valve for controlling the supply of fluid through the channel, the valve comprises a support member with a hole, and a diaphragm having an edge for joint operation with the support member for closing the hole, and a free surface extending from that edge to a position in which the diaphragm is held against movement, the support member is movable to tilt to the diaphragm to open the valve, and the free surface of the diaphragm that diaphragm extends away from that edge at an angle ranging from 45 ° to 85 ° when the valve closes. The diaphragm could be a flap with a linear edge that operates or functions in conjunction with the valve seat or support, but in the preferred construction the diaphragm is annular and the support member is a core extending through the central opening of the diaphragm and is guided to move axially to open and close the valve. The core extending through the diaphragm could be a toconical fuse, but in the preferred construction it is currently cylindrical with one or more radial holes. The free surface of the diaphragm preferably extends away from the edge at an angle that varies within a range of 55 ° to 75 °, and ideally at an angle of between 60 and 70 °. With the inclined diaphragm according to the invention, the displacement of the valve support member, necessary to open the valve, can be substantially reduced. In addition, the operation of the valve is less sensitive to dimensional variations due to manufacturing tolerances than in a radial diaphragm. A clear understanding of the invention will be obtained from the following detailed description of an exemplary embodiment, with reference to the accompanying drawings, in which: Figure 1 is an axial section through a front end portion of a writing instrument embodying the invention and showing the valve in its normal closed condition; Fig. 2 is an axial section showing the writing instrument of Fig. 1 with the valve fully open; Y Figure 3 is a graph showing the radial opening created between the diaphragm and the valve support, plotted against the axial displacement of the valve support member for a valve embodying the invention and a valve of a prior art with a flat diaphragm.

The marking instrument illustrated in Figures 1 and 2 has a body with the front and the rear parts 1, 2 which are connected securely. Guided axially and slidably on an inner surface extending through the front part 1 of the body, there is a feeding device 3 to the front end of which a marking tip 4 is attached which extends in a sliding manner to through the front end of body part 1 to a marking point 5. As shown the marking point is a ball point, but any form of marking tip that is commonly used in reservoir pens, including tips of fiber, felt tips, tubular tips, etc., can be used. The feeding device 3 includes an ink feed channel 6 for conveying the ink to the marking tip from the storage chamber 7, the front end portion of which is defined by the rear body part 2. It will be understood that a reservoir housing will be fitted to the rear body part 2 to completely enclose the reservoir chamber, and this housing may be provided with a pusher of a grease plug, as described in WO 93/05966, of so that the volume of the deposit chamber decreases as the ink is used. The forward end of the reservoir chamber is delimited by a diaphragm 10 having an outer edge portion clamped between the two body parts, 1, 2 so that the diaphragm provides a seal against leakage of ink between those parts. The rear end of the feed device includes a cylindrical portion that forms a valve support in which four radial holes 11 evenly distributed around the cylindrical bearing surface and connected to the feed channel 6 open. Conveniently the feed device 3 is assembled or assembled from a sleeve member 12 with an axial passage hole, and a plug 13 which is fitted within the rear end of the hole and which defines the holes 11 with the sleeve member. The sleeve member has an outer radial flange at a short distance in front of the holes 11, and the inner peripheral edge of the diaphragm 10 engages the bearing or valve seat surface behind this flange so that the diaphragm covers and closes the holes 11 to interrupt communication between the reservoir chamber 7 and the feeding channel in a normal condition of the writing instrument, as shown in Figure 1. The diaphragm includes an integral sleeve portion projecting forward and surrounding the feed device forward of the holes 11 to provide an additional seal to prevent leakage of tint i between the diaphragm and the feeding device. The feature is also described in our copending UK Patent Application No. 9513391.4, and as also described in that application the feeder device could include a recess between the flange and the holes 11 to cause the ink to back out from the marking tip after closing the valve. When using the marking instrument, the marking point is applied to a surface on which it is to be written and under the force exerted on the marking point., the marking tip 4 and the feeding device 3 move backwards with respect to the body. As a result, the diaphragm 10 deviates backwards, causing pressure in the chamber 7 to be pressurized, and the inner edge of the diaphragm is deflected so that the holes are discovered and the communication between the reservoir chamber and the supply channel of the ink is set, which allows the ink to pass to the marking tip through the open valve. The rearward movement of the feeding device is limited by a stop which is formed by a perforated wall 14 forming part of the rear portion 2 of the body. When the marking point is lifted from the paper surface, the feeding device and the marking tip return to their initial positions in which the valve is closed. According to the invention, the free surface 15 of the diaphragm confronting the reservoir chamber 7 extends at an angle of less than 90 °, and in particular of about 60 °, to the surface of the inner edge which functions in conjunction with the cylindrical surface of the support or valve seat. Due to this frustoconical configuration of the diaphragm, the displacement of the feeding device that is needed to open the valve is reduced in comparison with that of the flat valve. This effect is illustrated in Figure 3 in which the upper line I is applied to a valve with an inclination angle of 30 ° with respect to the radial direction and an adjustment of 0.1 mm with the valve seat, and line II Applies to a corresponding flat valve. It can be seen that with a diagram according to the invention the valve opens much more quickly with the backward movement of the marking tip, and therefore the alternative stroke of the marking tip required to obtain the correct operation of the valve is reduced and the movement of the marking point will be noticed less by the user of the instrument. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, the content of the following is claimed as property:

Claims (6)

1. A marking instrument characterized in that it comprises a reservoir chamber for a marking fluid, a channel for carrying the marking fluid from the reservoir chamber, for supplying a marking tip, and a valve for controlling the supply of fluid through of the channel, the valve consists of a seat member or support with a hole, and a diaphragm having an edge for operation or joint operation with the support member to close the hole, and a free surface extending from that edge to a position in which the diaphragm is prevented from moving, the support member is movable to deflect the diaphragm to open the valve, and that free surface of the diaphragm extends away from that edge at an angle ranging from 45 ° to 85 °. ° when the valve is closed.

2. A marking instrument according to claim 1, characterized in that the free surface of the diaphragm extends by withdrawing from the edge at an angle of 55 ° to 75 ° when the valve is closed.

3. A marking instrument according to claim 2, characterized in that the free surface of the diaphragm extends by withdrawing from the edge at an angle ranging from 60 ° to 70 ° when the valve is closed.

4. A marking instrument according to claim 1, 2 or 3, characterized in that the diaphragm is annular with respect to a central opening, and the seat or support member extends through that central opening and is guided to move axially to open and close the valve.

5. A marking instrument according to claim 4, characterized in that the portion of the seat or support member extending through the diaphragm has a cylindrical surface and the hole is directed radially with respect to a cylindrical surface.

6. A marking instrument according to claim 4 or 5, characterized in that the valve seat or support member has a radial flange, a surface of the diaphragm opposite the free surface abutting the flange, and the diaphragm includes a portion of integral sleeve sealing in operation or joint operation with a feeding device through which the feed channel extends forward of the flange.