Pin

Abstract

A pen with a lead (18) and a rotary mechanism for adjusting the lead in the longitudinal direction of the pen, wherein the rotary mechanism has a spindle (16) and a threaded nut (22) and the internal thread of the threaded nut is divided at least partially into first thread segments (24, 26, 28) which each extend over less than 360° in the circumferential direction, characterized in that the external thread of the spindle (16) is divided at least partially into second thread segments (30, 32) which extend over less than 360° in the circumferential direction, the distance (A) in the circumferential direction between circumferentially adjacent second thread segments is smaller than the extent (B) in the circumferential direction of the first thread segments (24, 26, 28) and the distance (C) in the circumferential direction between circumferentially adjacent first thread segments is smaller than the extent (D) in the circumferential direction of the second thread segments.

Description

The invention relates to a pin having a lead and a rotation mechanism for adjusting the lead in the longitudinal direction of the pin, wherein the rotation mechanism has a spindle and a matching threaded nut and the internal thread of the threaded nut is divided at least in sections into first threaded segments which each extend over less than 360° in the circumferential direction.Pins of the above-mentioned type are known. In some cases, the threaded nut is configured like a tong.However, it has been found that the rotating mechanism sometimes tends to be difficult to catch or become hooked, particularly when made using PET (polyethylene terephthalate).The invention is based on the object of further developing pins of the type mentioned at the beginning in such a way that their rotary mechanism is reliably smooth and does not tend to jam.According to the invention, the object set is achieved in that the external thread of the spindle is divided at least in sections into second thread segments which each extend over less than 360° in the circumferential direction, the spacing in the circumferential direction between second thread segments adjacent in the circumferential direction is smaller than the extension in the circumferential direction of the first thread segments, and the spacing in the circumferential direction between first thread segments adjacent in the circumferential direction is smaller than the extension in the circumferential direction of the second thread segments.In other words, not only is the internal thread of the threaded nut of the rotary mechanism divided at least in sections into thread segments, but also the external thread of the spindle. As a result, the friction in the rotary mechanism is reduced, which increases the ease of movement and reduces the risk of jamming and tilting.The external thread of the spindle can have two or more second thread segments per 360° revolution.It has been found that even a division of the circulation into two involves considerable advantages in the sense of achieving the above object.It is further preferably provided according to the invention that the internal thread of the threaded nut has two, three or more first thread segments per 360° revolution.In the case of the internal thread, a higher number of division than in the case of the internal thread of the threaded nut has proven to be appropriate, wherein, however, even a division of two (as in the case of the external thread of the spindle) offers considerable advantages in the sense of the above task.According to a particularly preferred embodiment of the invention, it is provided that the threaded nut has slots at least between some first threaded segments adjacent in the circumferential direction.These slots make it possible for the threaded nut to expand when the rotary mechanism is over-rotated and thus to allow thread turns to be skipped. This prevents the rotary mechanism from being blocked or even destroyed by over-rotation.In this case, it can be provided according to the invention that at least some of the slots are open towards at least one end of the threaded nut.This simplifies the expansion of the threaded nut to protect the rotary mechanism from over-rotation, which increases the effectiveness.The above measures allow the most varied materials to be used for the production of the pin. This applies in particular to PET. Therefore, according to the invention, it is preferably provided that the pin is exclusively made of PET, apart from the lead material or lead filling.As a result, the pin is particularly easy to recycle.In this connection, it is pointed out that the stick according to the invention can be a stick in which the lead material is present in rod form.According to the invention, the PET is preferably recycled PET.Finally, the invention also provides a rotating mechanism for a pin of the type described above.The invention is explained in more detail below with reference to a preferred exemplary embodiment. Figure shows FIG. 1 is a schematic longitudinal sectional view of a pin according to an embodiment of the invention, FIG. 2 is a longitudinal sectional view of the pin according to FIG. 1 along the plane B-B, FIG. 3 shows a perspective view of a mine holder with spindle of the pin according to FIGS. 1 and 2, FIG. 4 is a schematic partial view, partly in section, of the lead holder with spindle according to FIG. 3, FIG. 5 shows partially cut schematic partial views of a threaded nut of the pin according to FIGS. 1 and 2, and FIG. 6 shows the same views as FIGS. 4 and 5, but with the threaded nut screwed onto the spindle.The pencil shown in the drawings includes a protector 10, a cartridge 12, a pencil holder 14 having a spindle 16, a pencil 18 held by the pencil holder 14, and a shank 20.The cartridge 12 and the shaft 20 are rotatable relative to each other but are coupled together in the longitudinal direction of the pin. Disposed in the shank 20 is a threaded nut 22 which is coupled to the shank 20 in both the rotational and longitudinal directions of the pin.The threaded nut 22 has an internal thread which is divided into a plurality of thread segments. Of these thread segments, three thread segments are designated in FIG. 5 by the reference numerals 24, 26 and 28.The external thread of the spindle 16 is also divided into thread segments. Two of these are designated in Fig. 4 by the reference numerals 30 and 32, respectively.By means of the threaded segments 24, 26 and 28, on the one hand, and the threaded segments 30, 32, on the other hand, the threaded nut 22 is screwed to the spindle 16 of the mine holder 14. Because of this screw connection, a rotation of the shaft 20 relative to the cartridge 12 about the longitudinal axis L of the pin leads to a longitudinal displacement of the spindle 16 of the lead holder 14 together with the lead 18 within the cartridge 12.The thread segments 30, 32 each extend over a distance D in the circumferential direction, which is 100° in the exemplary embodiment shown. Two thread segments are provided per revolution, resulting in a spacing A of 80° in the direction of revolution.The thread segments 24, 26 and 28 of the threaded nut 22 each have an extension B of 90°, wherein three thread segments are provided per 360°. The distance C between circumferentially adjacent thread segments 24, 26, 28 is 30°.Consequently, the distance A between the thread segments 30 and 32 is smaller than the extension B of the thread segments 24, 26 and 28, and the distance C of the thread segments 24, 26 and 28 is smaller than the extension D of the thread segments 30 and 32, which ensures that none of the thread segments 24, 26 and 28 and of the thread segments 30 and 32 falls into an intermediate space between the other thread segments in each case. This ensures reliable operation of the rotary mechanism for displacing the lead 18 in the longitudinal direction of the pin.Because of the division of the external thread of the spindle 16 into two thread segments 30, 32 per 360°, the ready running of the rotary mechanism is simultaneously ensured and jamming is prevented.To protect the rotary mechanism from damage due to over-rotation, the threaded nut 22 is provided with slots, one of which is designated by the reference numeral 34. They are located between circumferentially adjacent thread segments 24, 26, 28 and are open toward the end of the threaded nut 22. As a result, the threaded nut 22 can expand in the radial direction when the rotary mechanism is over-rotated, and the threaded segments 24, 26 and 28 can jump over the threaded segments 30, 32.Except for the lead 18, all parts of the stick are recycled PET (polyethylene terephthalate). Because of the division of the external thread of the spindle 16 into thread segments 30, 32 and the division of the internal thread of the threaded nut 22 into thread segments 24, 26, 28, the required ready-to-moveability of the rotary mechanism is provided despite the use of the above-mentioned material. It does not tend to jam.The features of the invention disclosed in the above description, the claims and the drawing can be essential for the realization of the invention in its various embodiments both individually and in any combinations.

Claims

A pin having a lead (18) and a rotary mechanism for adjusting the lead in the longitudinal direction of the pin, wherein the rotary mechanism has a spindle (16) and a threaded nut (22) and the internal thread of the threaded nut is divided at least in sections into first threaded segments (24, 26, 28) which each extend over less than 360° in the circumferential direction, characterized in that the external thread of the spindle (16) is divided at least in sections into second threaded segments (30, 32) which extend over less than 360° in the circumferential direction, the distance (A) in the circumferential direction between second threaded segments adjacent in the circumferential direction is smaller than the extension (B) in the circumferential direction of the first threaded segments (24, 26, 28) and the distance (C) in the circumferential direction between first threaded segments adjacent in the circumferential direction is smaller than the extension (D) in the circumferential direction of the second threaded segments.The pin according to claim 1, characterized in that the external thread of the spindle (16) has two or more second thread segments (30, 32) per 360° revolution.Pin according to claim 1 or 2, characterised in that the internal thread of the threaded nut (22) has two, three or more first thread segments (24, 26, 28) per 360° revolution.A pin according to any preceding claim, characterised in that the threaded nut (22) has slots (34) between circumferentially adjacent first threaded segments (24, 26, 28).The pin of claim 4, characterized in that at least some of the slots (34) are open to at least one end of the threaded nut (22).Pencil according to one of the preceding claims, characterized in that it is made exclusively of PET, apart from the lead material or lead filling.The pen according to claim 6, characterized in that the PET is recycled PET.A pin rotating mechanism according to any preceding claim.

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