CAPSULE FOR A COMPASS AND USE THEREOF

Abstract

The invention relates to a capsule for a compass and use thereof. The capsule has a housing designed in multiple parts for receiving at least one scale device (10) for reading at least one geographical indication, wherein the scale device (10) is arranged mounted on a mounting device (8), and the housing has a cover part (2) for upper closure of the housing and a base part (4) for lower closure of the housing, wherein the cover part (2) and base part (4) are permanently connected to each other via a perforated shell surface (6). Furthermore, the capsule has a pressure equalization element (18) arranged around the housing and spanning the shell surface (6) at least in part for equalizing pressure fluctuations of a liquid medium arranged in the compass capsule (1), wherein the pressure equalization element (18) is designed in an elastic manner.

Claims

1. A capsule (1) for a compass, comprising at least a. a housing that is formed in multiple parts and is intended for receiving at least one scale device (10) for reading off at least one geographical specification, wherein the scale device (10) is arranged in a manner mounted on a bearing device (8), and the housing comprises a cover part (2) for closing the housing at the top, and a base part (4) for closing the housing at the bottom, wherein the cover part (2) and base part (4) are rigidly interconnected around the periphery by means of a perforated lateral surface (6), and b. furthermore a pressure compensation element (18) that is arranged peripherally around the housing and spans the lateral surface (6) at least in part, which element is intended for compensating pressure fluctuations of a fluid medium arranged in the compass capsule (1), wherein the pressure compensation element (18) is designed so as to be resilient.

2. The capsule for a compass according to claim 1, characterized in that the pressure compensation element (18) is formed of at least one plastics material, at least one metal foil, or at least one composite material, or a combination thereof.

3. The capsule for a compass according to claim 2, characterized in that the pressure compensation element (18) comprises at least one elastomer as a component.

4. The capsule for a compass according to claim 1, characterized in that the pressure compensation element (18) has a C-profile in cross section.

5. The capsule for a compass according to claim 1, characterized in that the lateral surface of the housing comprises at least one passage opening (16) in the form of a perforation, which allows for medium exchange between the housing volume (G) spanned by the cover part (2), base part (4) and lateral surface (6), and the additional pressure compensation element volume (D) spanned by the pressure compensation element (18), wherein the pressure compensation element volume (D) and the housing volume (G) form the capsule volume (K), which is completely filled with fluid medium upon the first filling therewith.

6. The capsule according to claim 1, characterized in that the lateral surface (6) is designed so as to be straight and/or curved.

7. The capsule according to claim 1, characterized in that the lateral surface (6) comprises two projections (20) that are arranged in a peripheral manner.

8. The capsule for a compass according to claim 7, characterized in that the two projections (20) are designed so as to extend away from one another, obliquely to the outside.

9. The capsule for a compass according to claim 7, characterized in that on the mutually facing projection surfaces 24 thereof, the projections 20 have an S-shaped course towards the outside.

10. Use of the capsule (1) according to claim 1, as a component of a compass and/or as a component of an optical device.

Description

IN THE DRAWINGS

[0053] FIG. 1 is a cross section of a compass capsule according to the invention;

[0054] FIG. 2 is a schematic view of a pressure compensation element; and

[0055] FIG. 3 is a schematic view of a further pressure compensation element.

[0056] FIG. 1 is a schematic cross section of a compass capsule 1 according to the invention. Said capsule comprises a cover part 2 and a base part 4 which are rigidly interconnected via a common lateral surface 6. Furthermore, the base part 4 comprises a bearing device 8. Said bearing device is advantageously designed as a pin, on which the scale device 10 is arranged, by means of a bearing 11, so as to be rotatably mounted. The scale device 10 is designed as a rose and comprises at least one magnet 12 on the lower face thereof. For the purpose of fastening and/or balancing the scale device 10, at least one washer 14 may furthermore be provided. Said arrangement is expedient for the use of the compass capsule 1 for determining the cardinal direction.

[0057] The cover part 2, the base part 4 and the lateral surface 6 span the housing volume G. Together with the pressure compensation element 18, which is designed as a C-profile, the part of the lateral surface 6 that is arranged outside the housing, spans the pressure compensation element volume D. The housing volume G and pressure compensation element volume D together form the capsule volume K.

[0058] The lateral surface 6 is designed so as to be peripheral and surrounding. Said surface creates a parallel mutual spacing between the cover part 2 and the base part 4. The compass capsule 1 shown herein is cylindrical.

[0059] The lateral surface 6 comprises a plurality of perforations which are formed as passage openings 16. The passage openings 16 allow for a flow of medium between the housing volume G and the pressure compensation element volume D that is formed by the pressure compensation element 16 that spans the lateral surface.

[0060] Furthermore, the passage openings 16 are also to be understood as perforations, through which air bubbles which may have formed can be removed from the housing volume G and trapped in the pressure compensation element volume D. For this purpose, the pressure compensation element 18 has a C-profile, wherein the two limbs 22 of the pressure compensation element 18 engage behind the two projections 20 of the lateral surface 6 that are arranged peripherally around the cover part 2 and base part 4.

[0061] Particularly advantageously, the two projections 20 are designed so as to be complementary to the two limbs 22, such that a form- and/or force-fitting operative connection is formed by means of plugging, snapping or clicking the two limbs 22 onto the projections 20. Both the projections 20 and the two limbs 22 are designed and arranged, overall, so as to completely surround the cover part 2 and base part 4.

[0062] The mutually facing projection surfaces 24 are S-shaped. Said surfaces have an S-shaped course towards the outside. This provides for expansion and a surface increase towards the outside. In the case of a fixedly arranged pressure compensation element 18, a gap 26 is formed between said element and the S-shaped projection surfaces 24. Air bubbles that are undesired in the housing can be transferred into and quasi trapped in said gap 26. This is possible for the first time due to the particular S-shaped design of the projection surfaces 24. Permanently arranging undesired air bubbles in said gap 26 does not influence the pressure compensation behavior of the resilient pressure compensation element 18, and the full functionality of said element is ensured.

[0063] If the compass capsule 1 is exposed to an increased temperature for example, as a result of the coefficients of thermal expansion thereof the materials of the cover part 2, base part 4 and lateral surface 6 react differently from the coefficient of thermal expansion of the fluid medium. Paraffin oil and/or petroleum is advantageously used as the fluid medium. The fluid medium expands more significantly than the cover part 2, base part 4 or lateral surface 6. As a result, the force resulting from the expansion behavior is guided through the passage openings 16, counter to the pressure compensation element 18. Said element is designed so as to be resilient. The acting compressive force results in elastic deformation of the pressure compensation element 18 and thus to corresponding force dissipation. The resulting pressure inside the compass capsule 1 is compensated by the pressure compensation element 18. Said element yields. In the simplest and best embodiment, this does not result in any air bubbles in the compass capsule itself.

[0064] FIG. 2 is a schematic detail of a pressure compensation element 18. The same components as hitherto are provided with the same reference signs and have the same functionality, and are not explained again. The pressure compensation element 18 has a different wall thickness. In the example shown herein, the inner face 28 that faces the housing is formed having three material tapers 30. This additionally improves the resilient behavior of the pressure compensation element 18, in particular if the material tapers are formed having a depth of from 0.1 to 0.5 mm.

[0065] The same also applies for the embodiment of a further pressure compensation element 18, shown schematically in FIG. 3. Said element comprises wedge-shaped recesses 32 on either side. This design, too, improves the resilient behavior of the pressure compensation element 18, in particular if the wedge-shaped recesses 32 have a depth of from 0.1 mm to 0.5 mm, more advantageously 0.3 mm, and an angle in the range of from 20 to 80, more advantageously 50.

[0066] All the features disclosed in the application documents are claimed as being essential to the invention, insofar as they are novel, individually or in combination, over the prior art.

LIST OF REFERENCE SIGNS

[0067] 1 compass capsule [0068] 2 cover part [0069] 4 base part [0070] 6 lateral surface [0071] 8 bearing device [0072] 10 scale device [0073] 11 bearing [0074] 12 magnet [0075] 14 washer [0076] 16 passage opening [0077] 18 pressure compensation element [0078] 29 projections [0079] 22 limb [0080] 24 S-shaped projection surface [0081] 26 gap [0082] 28 inner face [0083] 30 material taper [0084] 32 wedge-shaped recess [0085] K capsule volume [0086] D pressure compensation element volume [0087] G housing volume [0088] angle