US2823644A - Drawing pencil holders - Google Patents

Description

United States Patent DRAWING PENCIL HOLDERS Hendrik Karel Dominicus van den Bussche, Bergen, and Henri Bernard Wieringa, Amsterdam, Netherlands; said van den Bussche assignor to said Wieringa Application November 17, 1953, Serial No. 392,668 6 Claims. 01. 120-22 This invention relates to drawing pencil holders.

It is, an object of the invention to provide drawing pencil holders which are simpler to manufacture and to assemble than the known drawing pencil holders, thereby reducing the costs considerably.

- A further object of the invention is to provide drawing pencil holders which have less parts to be assembled.

Another object of the invention is to provide drawing pencil holders in which the reserve drawing pencils cannot get jammed in the pencil reservoir and cannot block the outlet of this reservoir.

Further objects and advantages of the invention will appear hereinafter.

In order that the invention may be fully understood, it will now be described by reference to the accompanying drawings.

Fig. 1 shows an embodiment of the invention, partly in sectional view, partly in elevational view.

Fig. 2 is a detail of Fig. 1 on a larger scale with one additional part.

Fig. 3 is a front view of the embodiment of Fig. 1.

Fig. 4 is another detail of Fig. 1 showing another additional part.

Fig. 5 is a sectional view of part of another embodiment of the invention.

Fig. 6 is a sectional view of the embodiment of Fig. 1, having an additional spring substantially running the length of the pencil reservoir.

The drawing pencil holder shown in Fig. 1 comprises a casing 11a having a point piece 12 connected to the casing by means of screw thread 12'. The point piece 12 is provided with a conical inner surface 13. A split tightening clasp 15 has a conical outer surface 14 cooperating with the conical inner surface 13 of the point piece 12. The end of the tightening clasp 15 which is in the casing, is provided at its rear part with screw thread 16. A spring 18a is screwed onto the screw thread 16. The lowest coil 17 of the spring 18a forms a shoulder for a compression spring 19 which abuts against the flat part 20 of the point piece 12 on the one side and against the said shoulder on the other side. The pressure of the compression spring 19 tends to pull the tightening clasp 15 into the point piece continuously.

If desired, a small ring 21 (see Fig. 2) may be placed between the spring 18a and the compression spring 19 in order to prevent a possible shoving of the latter over the former.

The end 22 of the spring 18a extends near to the upper end of the casing 11a. A push button 23a provided with a smooth or threaded shank 24 is pressed or screwed into the spring 18 and can slide in the casing 11a.

Both the screw thread 16 of the tightening clasp 15 and the screw thread of the push button 23a, if present, need not be finished accurately because the spring 18a fits to all kinds of screw thread.

The drawing pencil holder operates as follows. When the push button is pushed in, the spring 18a the coils "ice of which lie closely upon each other will push the tightening clasp 15 outwardly. Thereby the jaws of the tightening clasp 15 (see Fig. 3) will spread out so that a pencil 26 may be inserted. By releasing the push button 23a the tightening clasp 15 is pulled inwards by the compression spring 19 thereby holding the pencil 26 in a manner known per se.

Preferably the coils of the spring 18a are caused to have an initial pre-load so that the windings are pressed tightly together, and in operating the push button no clearance is to be overcome before the tightening clasp is pushed outwardly. In this way the push button is further better fixed in its normal position because the slightest stretching of the spring already requires a comparatively great force.

Of course a push button 23 with a shoulder 27 may instead be provided (see Fig. 4) abutting against an inwardly projecting rim of the casing or a special ring piece 28 screwed or otherwise attached to the upper end of the casing 11a to prevent the push button from getting too far out of the casing.

In the embodiment of Fig. 5 the spring 18 is provided with wider, loosely wound coils 18 beyond the point at which it is screwed to the tightening clasp 15. These coils abut against the flat part 20 of the point piece 12 thereby operating as a compression spring for pulling inwardly the tightening clasp and replacing the special compression spring 19 of the embodiment of Fig. 1.

In general the inner section of the spring 18 will be larger than two times the section of the pencils used. Therefore in case a holder contains several short pencils, one held by the tightening clasp 15 and the other ones lying freely within the spring 18 as reserve pencils, the upper entrance of the tightening clasp may become blocked by two pencils both abutting against the upper side of the tightening clasp. This drawback is avoided by the embodiment shown in Fig. 6 wherein an additional spring 29 extending substantially from the tightening clasp to the push button and having an inner section less than two times the section of the pencils used is inserted within the spring 18 thereby preventing the pencils from lying side by side.

What we claim is:

1. A drawing pencil holder comprising, in combination, a tubular casing, an axially-bored mouthpiece having an end providing an axially-inner surface secured in a first end of said casing, a lead-gripping clasp member received in the bore of said mouthpiece, one end of said clasp member projecting from said mouthpiece axially into said casing and having an upper end portion, and the other end of said clasp being'formed with lead gripping jaws and extending outwardly from said mouthpiece, an axially-slidable push button member received in the second end of said casing, a lead-holding tube secured to the end portion of said clasp member and to said push button, and a compression spring abutting against the inner surface of said mouthpiece and against the end of said lead-holding tube adjacent said end portion of said clasp member, said lead-holding tube consisting of a spring which is so closely-wound that it is rigid, the end coil of said last-named spring adjacent said compression spring providing a shoulder for engagement by said compression spring.

2. A drawing pencil holder as defined in claim 1, further comprising a second tightly-wound spring disposed interiorly of said first-named tightly wound spring and extending substantially from said clasp member to said push button.

3. A drawing pencil holder as defined in claim 1, wherein said tightly-wound spring is preloaded, with the 3 windings of the spring being pressed against one another by the initial tension in the spring in said casing.

4. A drawing pencil holder comprising, in combination, a tubular casing, an axially-bored mouthpiece having "an end providing an axially-inner surface secured in a first end of said casing, a Ieadgripping clasp member received in the bore of said mouthpiece, one end of said clasp member projecting from said mouthpiece axially into said casing and having an upper end portion, and the other end of said clasp being formed with lead gripping jaws and extending outwardly from said mouthpiece, an axially-slidable push button member received in the second end of said casing, a lead-holding tube secured to the-end portiorrof said clasp member and to said push button, and a compression spring abutting against the inner surface of said mouthpiece and against the end of said lead-holding tube adjacent said end portion of said clasp member, said lead-holding tube and said compression spring being formed from a single uni tary spring having a first closely-wound portion extending between said push button and said clasp member and a second loosely wound portion abutting against the inner surface of said mouthpiece and serving as a compression ,4 spring for urging said mouthpiece inwardly toward said casing.

5. A drawing pencil holder as defined in claim 4, further comprising a second tightly-wound spring disposed interiorly of said first tightly-wound spring portion and extending substantially from said clasp member to said push button.

6. A drawing pencil holder as defined in claim 5, wherein said first closely wound portion of said spring is preloaded.

References Cited in the file of this patent UNITED STATES PATENTS 325,959 Moses Sept. 8, 1885 347,439 Moses Aug. 17, 1886 1,262,859 Smith Apr. 16, 1918 1,848,224 "Schmid Mar. 8, '1932 1,950,960 Wisser Mar. '13, 1934 2,134,570 Meilner Oct. 25, 1938 FOREIGN PATENTS 964,731 France Feb. 1, 1950

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