EP2197692B1 - Pair of compasses having a joint with a locking device - Google Patents

Description

The invention relates to a compass with a first compass section and a second compass section according to the preamble of claim 1.

Such a circle is from the document US-A-1466712 known. In circles that have a lockable joint, there is a long time the problem that the clamping action of the joint is often insufficient. Metal threaded bolted joints have been used in the past, but these have the disadvantage of loosening over use after some time and tightening the bolting. In addition, metallic joints are relatively expensive to manufacture. Likewise, already riveted joints have been proposed, but also represent an alternative also for cost reasons.

Conventionally, conventional circuits use plastic joints which are inserted into a U-shaped end section of a circular or compass leg section and held by a non-rotatable spindle. A screwed on the spindle knurled nut clamps the plastic joint with the compass or compass leg section. The problem, however, is the use of an extension rod, since then by the lever action comparatively large forces on the joint occur, which cause the joint displaced, whereby the radius of the compass is inadvertently changed.

The invention is therefore based on the object to provide a compass with an improved locking device, in which an unintentional adjustment of the joint is prevented.

To achieve this object, the invention provides that, according to claim 1 which is spaced from the axis of rotation of the joint piece and the clamping force acts perpendicular to the axis of rotation of the joint piece.

The invention is based on the finding that a significantly improved clamping effect can be achieved in comparison with the prior art if the surfaces generating the static friction are not located in or directly on the axis of rotation. When located away from the pivot axis of rotation, these surfaces can accommodate significantly greater torques compared to conventional locking devices to prevent inadvertent release and adjustment of the hinge.

According to a first variant of the compass according to the invention, the first compass portion and the second compass portion may be formed on an accessory of the compass, in particular on an extension rod.

According to a second, alternative variant of the compass according to the invention, the first compass section and the second circular section may be designed as compass leg sections which form a compass leg which is connected to a second compass leg via a compass head.

It is particularly preferred that the joint piece has the basic shape of a half-disk and that the contour of the end portion of the first or second compass leg portion cooperating with the joint piece is formed substantially opposite thereto. In an adjustment of the joint piece relative to the circular leg portion, the curved side surface of the half-disk performs a rotational movement relative to the opposite surface of the compass leg portion and can be fixed in any relative position by means of the locking device. When locking by means of the spindle, the opposite surfaces are pressed against each other, whereby the position of the joint is fixed.

For fixing a rotation axis, it may be provided in the compass according to the invention that the joint piece on opposite sides Has pin portions which engage in corresponding recesses of the circular leg portion. The imaginary connecting line of the two pin sections forms the axis of rotation of the joint piece. Alternatively, the pin sections could also be arranged on the circular leg section, which engage in corresponding recesses of the joint piece. It is also conceivable to use a separate shaft, which allows a rotational movement of the joint piece.

It is expedient that the end section of the first or second compass leg section is designed to be approximately U-shaped for receiving the hinge section. In this case, the hinge piece between the two U-shaped legs may be included so that it is partially hidden.

Preferably, the joint piece has a bore or recess for the threaded element formed as a spindle. The spindle may extend through the hinge piece and be locked on one side, preferably on the outside of the compass, by means of a nut.

According to one embodiment of the invention, it may be provided that the joint piece is releasably connectable or connected to the arranged away from the compass head circular leg section. In particular, in the compass according to the invention, the circular leg section arranged away from the compass head can be designed as a circular insert. In this way, conventional compass inserts can be connected via the joint piece with the compass.

Trained as a spindle threaded element of the compass according to the invention has a spindle head which is rotatably mounted relative to the joint piece. As a result, an undesired rotation of the spindle during actuation of the locking device is prevented.

In a particularly advantageous embodiment of the compass according to the invention, it may be provided that in the interior of the joint piece an opening having a clamping block is arranged, through which the spindle is guided and to which the head of the spindle rests. Since the clamping block is movable and the joint piece has an opening for a compass insert, compass inserts with different journal diameters can be clamped. The clamping automatically takes effect when the joint is locked. In particular, it may be provided in the compass according to the invention that the clamping block and the joint piece for compass inserts with a pin diameter of 3.5 mm and 4 mm are suitable.

In the compass according to the invention, the hinge piece on the curved side of the half-disc may have a projection which limits the rotational movement of the joint and prevents further rotation of the outer circular leg portion to the outside. Preferably, the projection may be movable along a U-shaped end portion of the compass leg portion. The projection may be cylindrical, particularly preferred is a variant in which the projection has a bore or recess for the spindle. In this variant, the spindle nut is in the locked state on the end face of the projection.

In a further embodiment of the invention, it may be provided that the joint piece has a projection pointing towards the compass head, which is movable along a groove of the compass leg section and limits the rotational movement of the joint when abutting against the end of the groove. This second projection, which is arranged on the joint piece as an alternative or in addition to the mentioned first projection, limits the rotational movement of the circular leg portion when a predetermined angle is reached.

The compass according to the invention can also have a known adjusting spindle.

A variant of the compass according to the invention provides that the joint piece forms an integral component with the threaded element. The joint piece and the threaded element are integrally formed by the threaded element is injection-molded, for example, by injection molding on the joint piece.

In the compass according to the invention, consisting of the threaded element and the joint piece integral component may have at least one projection or a recess, the one or with a corresponding counter-trained depression or a correspondingly opposite projection on a compass portion, in particular on a compass leg, generating a form fit interacts. With the aid of the at least one projection, the compass can be securely fixed in a desired relative position of the two compass sections. For this purpose, a plurality of juxtaposed projections or depressions may be arranged on the compass section.

It is particularly preferred that the at least one projection or the at least one depression is arranged in the region of the transition between the threaded element and the joint piece.

Fig. 1

einen erfindungsgemäßen Zirkel in einer perspektivischen Ansicht;

Fig. 2A - 2D

ein Gelenkstück des erfindungsgemäßen Zirkels in verschiedenen perspektivischen Ansichten;

Fig. 3A- 3C

perspektivische Ansichten des Endabschnitts des Zirkelschenkel-abschnitts des erfindungsgemäßen Zirkels;

Fig. 4A und 4B

einen Spannklotz des erfindungsgemäßen Zirkels in verschiedenen Ansichten;

Fig. 5

eine Teilansicht eines Zirkeleinsatzes im Bereich des Zapfens;

Fig. 6A und 6B

eine Seitenansicht eines Zirkelschenkels und eine geschnittene vergrößerte Ansicht des Gelenks entlang der Linie VI-VI;

Fig. 7A und 7B

eine Seitenansicht eines Zirkelschenkels mit abgewinkeltem Zirkeleinsatz und das Gelenk in einer geschnittenen vergrößerten Ansicht entlang der Linie VII-VII;

Fig. 8

ein Ausführungsbeispiel, bei dem das Gelenk an einer Verlängerungsstange ausgebildet ist;

Fig. 9A und 9B

eine perspektivische Ansicht und eine Seitenansicht eines Gelenkstücks mit einem Gewindeelement;

Fig. 10A und 10B

eine geschnittene Seitenansicht eines abgewinkelten Zirkelschenkels und das Gelenk in einer geschnittenen vergrößerten Ansicht;

Fig 11A bis 11 D

verschiedene Ansichten eines Gelenkstücks mit einem Gewindeelement;

Fig. 12A und 12B

eine geschnittene Seitenansicht eines Zirkelschenkels und das Gelenk in einer geschnittenen vergrößerten Ansicht; und

Fig. 13A bis 13C

eine Vorderansicht, eine entlang der Linie XIII-XIII geschnittene Ansicht eines Zirkelschenkels und eine vergrößerte Ansicht des Endabschnitts des Zirkelschenkels.

Further advantages and details of the invention will be explained in more detail by means of embodiments with reference to the figures. The figures are schematic representations and show:

Fig. 1

a compass according to the invention in a perspective view;

Fig. 2A - 2D

a hinge piece of the compass according to the invention in various perspective views;

Figs. 3A-3C

perspective views of the end portion of the compass leg portion of the compass according to the invention;

FIGS. 4A and 4B

a tension block of the compass according to the invention in different views;

Fig. 5

a partial view of a compass insert in the region of the pin;

FIGS. 6A and 6B

a side view of a compass leg and a sectional enlarged view of the joint along the line VI-VI;

Figs. 7A and 7B

a side view of a compass leg with angled compass insert and the joint in a sectioned enlarged view along the line VII-VII;

Fig. 8

an embodiment in which the hinge is formed on an extension rod;

Figs. 9A and 9B

a perspective view and a side view of a hinge piece with a threaded element;

Figs. 10A and 10B

a sectional side view of an angled compass leg and the joint in a sectioned enlarged view;

FIGS. 11A to 11D

different views of a joint piece with a threaded element;

Figs. 12A and 12B

a sectional side view of a compass leg and the joint in a sectional enlarged view; and

Figs. 13A to 13C

a front view, a cut along the line XIII-XIII view of a compass leg and an enlarged view of the end portion of the compass leg.

The in Fig. 1 Compass 1 shown in a perspective view comprises compass legs 2, 3, which are connected to one another via a compass head 4. Each circular leg 2, 3 consists of a first circular leg section 5, 6 and a second circular leg section 7, 8, wherein a first circular leg section 5, 6 and a second circular leg section 7, 8 are connected to each other via a hinge 9, 10. The joints 9, 10 each have a locking device, with which the second circular leg sections 7, 8 can be fixed in a certain position to set a desired radius of the compass.

The locking takes place by means of knurled nuts 11, 12, which are laterally attached to the joints 9, 10. In the in Fig. 1 illustrated embodiment, the second circular leg portions 7, 8 are formed as compass inserts, while the circular leg portion 7 at its end a needle, the circular leg portion 8 has at its end a pencil lead.

The joints 9, 10 of the circle 1 each have a joint piece 13, which in the Fig. 2A to 2D is shown in various perspective views. The hinge piece 13 has substantially the shape of a half-disc and has a bent peripheral surface 14 extending over approximately 180 ° and semicircular side surfaces 15, 16.

When installed, the joint piece 13 is in the region of the end portion of the circular leg portion 5, which in the Figs. 3A to 3C is shown in perspective views. On both semicircular surfaces 15, 16, the joint piece has cylindrical projections formed as pin sections 17, 18 which, when installed, are inserted into recesses 19, 20 of the limbs of the U-shaped end section 21 of the circular leg section 5. An imaginary line connecting the pin sections 17, 18 forms the axis of rotation of the joint piece 13. Approximately in the middle of the peripheral surface 14, the joint piece 13 has a cylindrical projection 22 with a bore through which a spindle can be inserted. The joint piece 13 has at one end of the peripheral surface 14 a further projection 23, which has a rectangular cross-section in the illustrated embodiment. This projection 23 is movable along a groove 24 in the center of the U-shaped end portion 21 of the circular leg portion 5. The groove 24 is bent according to the semicircular shape of the joint piece 13. At the end of the groove 24 of the projection 23 of the joint piece 13 runs against a stop, not shown, the the rotational movement of the joint piece 13 and thus limits the opening angle of the circle 1.

How best in Fig. 2A can be seen, the joint piece 13 on its flat side an opening 25, in which the in the FIGS. 4A and 4B shown clamping block 26 can be used. The clamping block 26 has a cuboidal basic shape, one side is concave and thus to the outer contour of the in Fig. 5 shown pin 27 of a compass insert 28 adapted. The clamping block 26 has an opening 29 through which a spindle can be inserted.

Fig. 6A shows a side view of a compass leg, Fig. 6B shows an enlarged view of a section along the line VI-VI. The knurled nut 11 is screwed onto the spindle 30, whose spindle head 31 is shaped so that it is non-rotatably inserted into the opening of the clamping block 26. The clamping block 26 abuts both the spindle head 31 and the U-shaped pin 27 of the compass insert 28 and clamps the compass insert 28 against the hinge piece 13, which in turn is pressed against the circular leg portion 5. The clamping force is generated by tightening the knurled nut 11. The laterally projecting from the joint piece 13 pin portions 17, 18, which form the axis of rotation of the joint piece 13, are supported in the recesses 19, 20 of the end portion 21 of the circular leg portion 5.

Fig. 7A shows a side view of the circle 1, Fig. 7B shows the area of the joint in an enlarged view cut along the line VII-VII. In Fig. 7B the joint 9 is shown in a bent position. The clamping effect is achieved by tightening the knurled nut 11, which is bolted to the spindle 30 and the spindle head 31 presses the clamping block 26 against the lower or outer circular leg portion 7. The hinge piece 13 rests with a part of its peripheral surface 14 on the corresponding counter surface of the first or upper circular leg portion 5. Likewise, it is due to mating surfaces of the second, lower circular leg portion 7, so that the circular leg sections 5, 7 set by the joint piece 13 in the Position held and clamped. In Fig. 7B is also the arranged on the hinge piece 13 projection 23 is shown, which abuts at a certain opening angle against a stop surface in the groove 24, whereby the opening angle is limited.

Fig. 8 shows an embodiment in which the joint is formed on an extension rod. In the Fig. 8 shown extension rod 32 has at its upper end a U-shaped pin 27 which can be inserted and locked in a corresponding opening of a circular portion. At the opposite end of the extension rod 32 is a hinge piece 13 with a clamping block 26 and a nut 11, wherein the hinge piece 13 and the components cooperating therewith identical to those in the FIGS. 2 to 4 shown compass components are constructed. The hinge piece 13 has at its free end an opening into which a compass insert can be inserted.

In the Figs. 9A, 9B, 10A and 10B an embodiment is shown in which the hinge piece forms an integral component with the threaded element. The semi-disc-shaped joint piece 33 has a molded thread element 34 which replaces the spindle provided in the previous embodiments. As in Fig. 10B a nut 11 can be screwed onto the threaded element in order to clamp circular leg sections 35, 36 together. The hinge piece 33 has a cavity 37 into which the compass leg 36 can be inserted. In Fig. 10B It is shown that the nut 11 generates a clamping force which acts perpendicular to the axis of rotation of the hinge piece 33. The hinge piece 33 is clamped in the clamped state on its inner side in the region of the cavity 37 against the circular portion 36 and on its outer side against the circular portion 35.

In the Figs. 11A to 11D . 12A, 12B, 13A, 13B and 13C another embodiment of a compass is shown, which is similar to that in the FIGS. 9 and 10 embodiment shown is constructed.

Fig. 11A shows a perspective view of a hinge piece 38 having a threaded member 34. In the region of the transition between the threaded member 34 and the hinge piece 38 are located on opposite sides of the threaded member 34, two projections 39th Fig. 11B shows the joint piece 38 in a side view, Fig. 11C shows the projection 39 in an enlarged view and Fig. 11D shows the hinge piece 38 in a side view.

Fig. 13A shows a front view, Fig. 13B a along the line XIII-XIII sectional view of a circular portion 40 and Fig. 13C shows the end portion 41 of the circular portion 40 in an enlarged view. In the rounded region of the end section 41 of the circular section 40, the latter has a plurality of recesses 42 arranged next to one another, the contour of which is in each case formed opposite to the contour of a projection 39. When dissolved nut 11 of the compass portion 40 can be rotated gradually relative to a compass portion 43 and then locked by tightening the nut 11 again.

In the Figs. 12A and 12B It is shown that the nut 11 via the hinge piece 38, the circular portion 40 jammed with the circular portion 43.

Since the clamping surfaces on which the static friction acts, are arranged away from the axis of rotation, the joint can withstand higher forces and torques than previously used joints, so that unintentional adjustment is prevented.

Claims (21)

1. Compasses (1), with a first compass portion (5,6) and a second compass portion (7,8), which are connected to one another via an articulated joint (9,10) providing a locking device, which comprises a joint element (13,33,38) mounted in a rotatable manner about an axis of rotation relative to the first or second compass portion (5,6,7,8), wherein the locking device provides a threaded element (34) generating a clamping force, cooperating with a nut (11,12), in order to clamp the joint element (13,33,38) in the locked condition against the first and the second compass portion,
   characterised in that
   the locking device is distanced from the axis of rotation of the joint element (13,33,38), and the clamping force acts perpendicular to the axis of rotation of the joint element (13,33,38).
2. The compasses according to claim 1,
   characterised in that
   the first compass portion and the second compass portion are embodied on an accessory part of the compass, especially on an extension bar.
3. The compasses according to claim 1,
   characterised in that
   the first compass portion and the second compass portion are embodied as compass-arm portions (5,7), which form a compass arm (2), which is connected via a compass head (4) to a second compass arm (3).
4. The compasses according to claim 3,
   characterised in that
   the joint element (13) provides the basic shape of a half disc, and the contour of the end portion (21) of the first or second compass-arm portion (5) cooperating with the joint element (13) is embodied substantially in diametric opposition to the latter.
5. The compasses according to any one of claims 3 or 4, characterised in that
   the joint element (13) provides pin portions (17,18) on opposite sides, which engage in corresponding recesses (19,20) of the compass-arm portion (5).
6. The compasses according to any one of claims 3 to 5, characterised in that
   the end portion (21) of the first or second compass-arm portion (5) is embodied approximately in a U-shape in order to receive the joint element (13).
7. The compasses according to any one of claims 3 to 6, characterised in that
   the joint element (13) provides a borehole or recess for the threaded element embodied as a spindle (30).
8. The compasses according to any one of claims 3 to 7, characterised in that
   the joint element (13) can be connected or is connected in a detachable manner to the compass-arm portion (7,8) disposed remote from the compass head (4).
9. The compasses according to claim 8,
   characterised in that
   the compass-arm portion (7,8) disposed remote from the compass head (4) is embodied as a compass insert (28).
10. The compasses according to any one of claims 7 to 9, characterised in that
    the spindle (30) is mounted in a rotationally rigid manner relative to the joint element (13) by means of its spindle head (31).
11. The compasses according to claim 10,
    characterised in that
    a movable clamping block (26) providing an opening (29), through which the spindle (30) is guided and against which the spindle head (31) is in contact, is arranged in the interior of the joint element (13).
12. The compasses according to claim 11,
    characterised in that
    the joint element (13) provides an opening (25) for a compass insert (28).
13. The compasses according to any one of claims 4 to 12, characterised in that
    the joint element (13) provides a projection (22) on its curved side, which limits the rotary movement of the articulated joint (9,10).
14. The compasses according to claim 13,
    characterised in that
    the projection (22) is displaceable along a recess of the U-shaped end portion (21) of the compass-arm portion (5).
15. The compasses according to claim 13 or 14, characterised in that
    the projection (22) is embodied in a cylindrical shape.
16. The compasses according to any one of claims 13 to 15, characterised in that
    the projection (22) provides a borehole or recess for the threaded element preferably embodied as a spindle (30).
17. The compasses according to any one of the preceding claims 3 to 16,
    characterised in that
    the joint element (13) provides a projection (23) facing towards the compass head, which is displaceable along a groove (24) of the compass-arm portion (5) and limits the rotary movement of the articulated joint (9) upon contact with the end of the groove (24).
18. The compasses according to any one of the preceding claims,
    characterised in that
    they provide an adjustment spindle.
19. The compasses according to any one of the preceding claims,
    characterised in that
    the joint element (33,38) forms an integral component with the threaded element (34).
20. The compasses according to claim 19,
    characterised in that
    the integral component comprising the threaded element (34) and the joint element (38) provides at least one projection (39) or indentation, which cooperates respectively with an indentation (42) embodied in corresponding diametrical opposition or a projection embodied in corresponding diametrical opposition on a compass portion (40), especially on a compass arm, generating a form fit connection.
21. The compasses according to claim 20,
    characterised in that
    the at least one projection (39) or the at least one indentation is arranged in the region of the transition between the threaded element (34) and the joint element (38).

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