Abstract: In order to delay the drying of an aqueous writing fluid at an exposed point of a writing utensil, an ether is added to the aqueous writing fluid, the ether having a polyglycol radical and a single alcohol radical whose gel point is above 30.degree. Celsius and which is dispersed in the writing fluid. An example of such an ether is cetyl alcohol-n-polyglycol ether with n=5 or 6.

Abstract: In a writing implement cap, especially for ball point pens, having at least one air channel penetrating the front face, an air channel is shaped so as to extend axially and radially and is located in the region of the otherwise closed front side. Apart from that the axially extending segments of the air channel are bounded by at least one baffle wall extending transversely or by at least one step or disk and are connected through at least one radial aperture with additional axial segments arranged to be offset or with the inside space of the cap so as to form continuous through air channels.Over and above that the cap wall, the end wall and the baffle wall or the step or the steps or the disk or the disks are to be designed so as to form one piece with each other.

Abstract: In writing instruments having an ink or India ink reservoir, the reservoir should remain sealed prior to first use of the instrument. For this reason, the writing tip and the shaft containing the reservoir are delivered to the user separately. When the instrument is to be used for the first time, the writing tip is screwed into the shaft until the reservoir is pierced by the writing tip. The writing instrument of the invention enables delivery to the user in which the writing tip is already screwed into the shaft without piercing the reservoir. The writing tip has a removable separator piece which comes to rest at the front edge of the instrument shaft when the writing tip has been screwed in and thus limits the screw-in depth of the writing tip, the back end of the writing tip being maintained at a distance from the plug of the reservoir.

Abstract: Apparatus for screwing a writing instrument tip into a writing fluid reservoir in a writing instrument in which the connection from the reservoir to the tip, in order to supply the writing fluid to the tip, is made by the screwing action just prior to using the writing instrument, in which the writing instrument tip has at least a first working surface upon which at least a second working surface of a wrench acts, the working surfaces being formed as a ratchet and pawl which only engage in a screwing direction and permitting a relative rotation of the working surfaces in an unscrewing direction. As a result the tip cannot be unscrewed from the writing fluid reservoir, avoiding contamination, air entry or blockages.

Abstract: To screw the writing tip in and out of the instrument shaft of a writing or drawing instrument, the cap has been used as a screwing tool. The cap is usually fabricated with a many-sided receiving bore for this purpose as an extension of its bore, which can be placed onto the writing tip after the cap has been turned around. As a result, the cap is relatively long. The writing or drawing instrument of the present invention in contrast, has a cap of standard length. A many-sided receiving bore which is to be placed on the writing tip, in order to be able to screw it in or out, is formed, in part, by the clip of the cap, and in part by the wall of cap in the region where the clip is connected to the cap.

Abstract: The housing (1') of a writing point (1) or tracing element for manual ink writing or drawing instruments or for plotter or similar automatic or mechanical tracing machines is or can be linked with a shaft (40) that contains the ink and/works as a holder and/or storage. The housing has also a compensating system and a writing body (1") and if necessary other parts. It is provided with a supply system having in the area of the housing (1') several annular spaces (52 and 57) arranged axially one after the other and having different capillarities, their capillarity increasing one or more times in the direction of the writing body (1"). At least one annular space is conically shaped (53) and has a capillarity different from that of the writing body (1"), increasing in the direction of the latter.

Abstract: A sealing cap for a writing, drawing or painting instrument includes an axially extending tubular member open at one end to receive the instrument. An interior space extends axially within the tubular member from the open end and is closed at the opposite end. An axially extending air channel, open at both ends, is located within tubular member. One open end of the air channel opens to an at least partially laterally closed space which is open outwardly from the closed end of the interior space. The other open end of the air channel is open to the interior space. The air channel does not interfere with the sealing effect of the interior space when an instrument is inserted into the space. Accordingly, whether the cap is fitted on the instrument or is removed from it, there is a continuous open path for the flow of air through the air channel.

Abstract: An axially removable cylindrical holding shaft or cap for placement over and for unscrewing or removing the tip of a writing or drawing instrument, the holding shaft or a cap having a receiving bore for the instrument tip, and being comprised of at least one approximately axially extending lever which can be tilted about an axis extending approximately tangentially to the cylinder wall. The lever has an arm on each side of the axis. One of the arms forms part off the wall and has a detent at its end, the detent projecting into the receiving bore for engaging a groove or an undercut of the tip when the tip is inserted into the receiving bore, fixing the tip in the axial direction. The structure makes it possible to clean the adjustment system of the tip, avoiding the danger of getting it dirty, and without touching the tip while reinserting it into the housing.

Abstract: An automatic lead pencil device has a casing which is releasably mountable in a bracket of a drafting machine. Within the casing, there is a clamp sleeve in which a clamping member is axially movable for clamping and releasing a lead during use of the pencil device. An axial movable lead guide tube projects outwardly of the casing in the rest position, and there is a pencil brake within the lead guide tube. The contact zone between the clamping member and the clamp sleeve is constructed so as to be of the non-self-locking type. There is an operative connection between the clamping member and the lead guide tube such that the clamping member is closed when the lead guide tube moves axially inwardly to assume the working position and opens when the lead guide tube moves axially outwardly toward a rest position.

Abstract: A writing point for a writing or recording instrument is completely or partially formed of a metallic glass or amorphous metal or the writing tip may be provided with a coating or surface layer of metallic glass or amorphous metal.

Abstract: An eraser composition composed of conventional fillers and additives wherein the binder is a styrene-butadiene-styrene block polymer having a butadiene portion of 10 to 40%. The eraser composition can be easily extruded using simple commercial machines presently available and thus is inexpensive to manufacture. Furthermore, the use of this particular material as a binder produces a superior eraser composition.

Abstract: An automatic lead advancing mechanism for a mechanical pencil has at its writing point a lead guide tube which is movable axially against a clamping member to cause radially movable components of the clamping member to clamp the lead therein during the writing position of the pencil. The lead guide tube moves axially inwardly against a force exerted by a compression spring interposed between the clamping member and a thrust member, a portion of which is engaged by the lead guide tube and another portion of which has a beveled surface engaging a correspondingly beveled surface on the clamping member. The co-acting beveled surfaces exert both axial and radial forces to the clamping member.

Abstract: Uniformly porous foamed erasers and process for the production thereof, the process comprising continuously mixing air or other gas into a flowable plasticized mixture and gelling the mixture by introducing the same continuously to a heating mean.

Abstract: A writing medium unit for a writing or drawing machine comprises at least one writing unit head, a filling unit and a control unit. The filling unit is interconnected to the writing unit head and to the control unit by flexible writing medium supply tubes which are detachably connected to at least the filling unit.

Abstract: An eraser based on polyvinyl chloride having particles of a crosslinked polymeric natural or synthetic rubber embedded in the polyvinyl chloride structure. Such erasers have high strength and good aging resistance. Additionally, conventional softeners in the eraser do not undergo significant migration and consequently, the eraser does not smudge. A process for manufacturing the eraser is also disclosed.

Abstract: An apparatus for supplying a liquid writing medium to the writing unit of a writing or drawing device has a writing unit connected by a flow line to a dip tube in a container for a liquid writing medium. The bottom of the container is located in substantially the same horizontal plane as the writing tip of the writing unit. From a suitable source, air is supplied under pressure to the surface of the writing medium within the container. The surface area of the writing medium within the container is greater than the surface area of the writing medium within the writing unit. A regulating valve connected between the container and source of air under pressure regulates the flow of liquid writing medium by supplying writing medium when the writing unit is operative and interrupting the writing medium when the writing unit is nonoperative.