DE20218768U1 - Spring assembly, comprising helical spring tensioned by device assembled of bolt and two conical holding elements - Google Patents

Abstract

The spring (2) rests with both ends on flanged collars (6) of two conical holding elements (4) which are joined with a bolt (8) guided through the center of the spiral (2). The bolt (8) is designed as a round shaft with a head (9) located at both of its ends which are inserted into slots (10) radial positioned at the bottom (7) of the holding elements (4) in order to put the spring (2) under tension. The maximal distance between the two holding elements (4) is determined by the length of the bolt (8). There could also be a version with a single cup-shaped holding element (4) joined with the bolt (8) to a disc.

Description

STC002

WESTPHAL, MUSSGNUG & PARTNER

Patent Attorneys · European Patent Attorneys

Stumpp + School GmbH Linsenhofer Str. 59 - 63

72 660 Beuren

- Utility model application -

Spring package

D-78048 Villingen-

D-80336 Munich

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Description
Spring package

The invention relates to a spring assembly according to the preamble of claim 1 and claim 5.

Such spring assemblies are used in a variety of ways in mechanical engineering wherever pre-loaded springs need to be installed easily and therefore cost-effectively.

A spring assembly of the generic type has a coil spring that can be compressed in the longitudinal direction and a tensioning device. The tensioning device causes the coil spring to be pre-tensioned in its longitudinal direction.

The spring assemblies known from the state of the art often have a spring travel limited by the tensioning device. In order to still achieve a spring travel that is only determined by the maximum deformation distance of the coil spring, complex adjustment measures are often necessary on the components surrounding the spring assembly.

The present invention is therefore based on the object of proposing a spring assembly in which the spring travel of the spring assembly is not limited by the tensioning device and in which no complex structural measures are necessary on the components surrounding the spring assembly in order to utilize the maximum deformation distance of the coil spring. 30

The object is achieved according to the invention by a spring assembly having the features of claim 1.

The spring assembly according to the type comprises a coil spring which can be compressed in the longitudinal direction and a tensioning device, wherein the coil spring is pretensioned in its longitudinal direction by the tensioning device.
5

In the spring assembly according to the invention, the maximum displacement path of the tensioning device, starting from a pre-tensioned state of the spring assembly, is also greater than the maximum deformation path of the coil spring. Furthermore, when the coil spring is in its maximally compressed state, the tensioning device does not extend any further in the longitudinal direction over the coil spring than it does in the pre-tensioned state.

The invention thus ensures that the maximum spring travel of the spring assembly is determined by the maximum deformation distance of the coil spring. The spring travel of the spring assembly is therefore not limited by elements of the tensioning device that collide with one another. Furthermore, the spring travel of the spring assembly is also not limited by elements of the tensioning device that protrude in the longitudinal direction, compared to the pre-tensioned state, and that collide with components arranged in the extension of the spring assembly.

According to a preferred embodiment, the spring assembly 5 has a tensioning device with two holding elements resting on the end faces of the coil spring, which are connected to one another via a spacer bolt so that they can move in the longitudinal direction, the maximum distance between the holding elements being determined by the spacer bolt. In this embodiment, it is possible for both holding elements to be movably connected to the spacer bolt, or for one holding element to be movably connected to the spacer bolt and one holding element to be firmly connected to the spacer bolt.

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If both holding elements are movably connected to the spacer bolt, a concrete embodiment of the features of patent claim 1 can consist in that the coil spring in the maximally compressed state is longer than the two holding elements extend in the longitudinal direction and than the spacer bolt extends in the longitudinal direction.

If a holding element is movable with the spacer bolt and a holding element is firmly connected to the spacer bolt, a concrete embodiment of the features of patent claim 1 can consist in that the coil spring in the maximally compressed state is longer than the two holding elements extend in the longitudinal direction and than the spacer bolt and the holding element firmly connected to it extend in the longitudinal direction.

In this context, it should be noted that the tensioning device disclosed in claim 2 is not limited to a single spacer bolt. For example, embodiments are conceivable in which several spacer bolts are arranged inside or outside the coil spring. Another embodiment provides that a single spacer bolt is arranged radially symmetrically inside the coil spring.

If the spring assembly has a tensioning device with two holding elements and a spacer bolt, the problem with the spring assemblies known from the prior art is to connect the holding elements to the spacer bolt r 0 while the spring is preloaded.

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A further object of the present invention is therefore to propose a spring assembly that is simple and cost-effective to assemble.

The problem is solved by a spring assembly having the features of the independent patent claim 5.

The spring package of this type has a tensioning device with two holding elements which are located on the front sides of the coil spring and which are connected to one another in a longitudinally movable manner via a spacer bolt which defines a maximum distance between the holding elements.

In the spring assembly according to the invention, the holding element has a slot that extends from the edge into the holding element. The spacer bolt has a head with a larger diameter than the area of the slot where the head is brought into contact with the holding element. Furthermore, the spacer bolt can be hooked into the holding element in the area of the slot 0.

The features of the independent patent claim 5 ensure that the spring assembly can be assembled in a simple manner. To do this, the spacer bolt is hooked into the holding element from the side using the slot. In the pre-tensioned state, the head of the spacer bolt is pressed against the holding element.

Preferred embodiments and advantageous further developments are listed in the subclaims.

In a preferred embodiment, the slot extends from the edge to the middle. In this embodiment,

Due to the symmetrical force effect of the spacer bolt on the holding element, it is possible to provide the clamping device with only one central spacer bolt.

A further preferred embodiment provides that the holding element has a circular cross-section. If the diameter of the circular holding element corresponds essentially to the diameter of the coil spring, a spring assembly is also created which essentially has the dimensions of the coil spring.

A particularly preferred embodiment provides that the head is formed in one piece with the spacer bolt. The one-piece design of the head on the spacer bolt reduces the number of components for the clamping device, which means that the spring assembly can be manufactured cost-effectively.

In order to make the spring package particularly compact, it is sensible to arrange the spacer bolt inside the coil spring.

A particularly preferred embodiment provides that a holding element is designed as a receiving pot with a base and a casing surface.

In order to construct the spring assembly simply and inexpensively, it is advisable for the clamping device to have as few components as possible. A preferred embodiment consists in constructing both holding elements identically. A further advantage of this embodiment is that the spring assembly can be installed in two orientations rotated by 180°, i.e. in an unoriented position.

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If the holding element is designed as a receiving pot, it is advisable for the slot to extend longitudinally along the entire length of the casing surface and then radially through the base to the middle.

In order to make the spring assembly as compact as possible, it is sensible if the tensioning device is arranged almost entirely within the coil spring. In addition to the arrangement of the spacer bolt within the coil spring described above, it is also sensible to arrange the receiving pot at least in sections within the coil spring. One possible embodiment of this embodiment is to arrange the outer surface of the receiving pot at least in sections and the base of the receiving pot completely within the coil spring.

Another particularly preferred embodiment of the invention is that the receiving pot has an outwardly facing collar which runs at least in sections in the circumferential direction of the receiving pot and whose surface facing the coil spring serves as a contact surface for the front side of the coil spring. In the pre-tensioned state, the force of the tensioning device is transferred to the coil spring through the contact surface.

In order to connect the receiving pot with a piston-shaped component, for example, which acts on the spring assembly in its functional purpose, it is useful if the outer surface of the receiving pot has a further slot that extends through the outer surface at least in sections in the longitudinal direction. If the receiving pot is made of a material that is at least partially spring-elastic, this can be done, for example, with a piston-shaped component.

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Ben-shaped component is frictionally connected to the receiving pot under pre-stressing by spring-elastic deformation of the receiving pot.

Another particularly preferred embodiment provides that the collar has a raised area on the surface facing the coil spring. This measure reduces the contact surface between the receiving pot and the component with which the spring assembly is in contact when used as intended. This makes it possible, for example, to reduce undesirable heat transfer. If the spring assembly is installed in a liquid medium, air inclusions, which are often observed with large contact surfaces, are largely prevented.

In order to manufacture the spring assembly simply and inexpensively, it is sensible if the retaining element can be manufactured as a pressed part from, for example, a flat section of material. It is also sensible to manufacture the spacer bolt as a cost-effective mass-produced component using a machining process.

The invention is further illustrated below with the aid of schematic drawings based on exemplary preferred embodiments. They show:

Fig. 1 shows a first embodiment of the spring assembly according to the invention in side view in cross section,

Fig. 2 shows a second embodiment of the spring assembly according to the invention in side view in cross section,

Fig. 3 shows a receiving pot of the spring assembly according to the invention of Fig. 1 in plan view and in side view.

Fig. 1 shows a spring assembly 1 according to the invention in side view in cross section.

Fig. 1a shows the spring assembly 1 in a pre-tensioned state. The spring assembly 1 has a coil spring 2 and a tensioning device 3. In the present embodiment, the tensioning device 3 consists of two holding elements arranged mirror-symmetrically to one another, which are designed as a receiving pot 4. Each receiving pot 4 has a jacket surface 5. The jacket surface 5 has a frustoconical section 20 and a cylinder section 19, the cylinder section 19 adjoining the axial end of the frustoconical section 20 with a larger diameter. An outward-facing collar is provided on the free axial end of the cylinder section 20. A base 7 is provided on the free axial end of the frustoconical section 20.

In the area of the collar 6, three elevations are provided on its surface facing away from the coil spring 2. Furthermore, the outer surface 5 has a slot 10 and two slots 16, which will be discussed below or in the description of Fig. 3.

In the present embodiment, both receiving pots 4 are constructed identically. Furthermore, both receiving pots 4 are movably connected to one another by a spacer bolt 8. This makes it possible to install the spring assembly 1 in an unoriented position, i.e. in two positions rotated by 180° to one another.

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The spacer bolt 8 has a rod-shaped section 17, at the axial ends of which a head 9 is formed in one piece. The maximum distance between the receiving pots 4 is determined by the spacer bolt 8. The spacer bolt 8 is suspended in the receiving pot 4 in the area of a slot 10, which extends through the outer surface 5 in the longitudinal direction over its entire length and then through the base radially up to the middle (shown in Fig. 3). When suspended, the rod-shaped section 17 extends through the slot

10. In the pre-tensioned state, the head 9 of the spacer bolt 8 comes to rest centrally on the inside of the base 7 in the area of the slot 10. Furthermore, the surface of the collar 6 facing the coil spring 2 serves as a contact surface for the front side of the coil spring 2. As can be seen from Fig. 1a, the pre-tensioned state of the coil spring 2 is essentially determined by the depth of the two receiving pots 4 and by the length of the spacer bolt 8.

From Fig. 1 it can be seen that the tensioning device 3 is arranged essentially within the coil spring 2.

In concrete terms, this means that the outer surfaces 5 and the bases 7 of the two receiving pots 4 as well as the spacer bolts 8 run completely inside the coil spring 2. Only the two collars 6 are arranged outside the coil spring 2, with one end face of the coil spring 2 being supported on a collar 6 in a pre-tensioned state. Furthermore, each receiving pot 4 has a circular cross-section (shown in Fig. 3).

0 Fig. Ib shows the spring assembly 1 with the coil spring 2 compressed to the maximum. As can be seen from Fig. Ib, the coils of the coil spring 2 lie against each other in a row. When the spring assembly 1 is compressed,

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the two receiving pots 4 are closer to one another in the longitudinal direction 11 than in the pre-tensioned state of Fig. 1a. Since both receiving pots 4 are movably connected to the spacer bolt 8, both receiving pots 4 are displaced relative to the spacer bolt 8 in the longitudinal direction 11. Furthermore, it can be seen that the spacer bolt 8 is immersed in the receiving pots 4 in sections on both sides without protruding beyond the receiving pots 4 in the area of the front side of the coil spring 2. Furthermore, it can be seen from Fig. 1b that the two receiving pots 4 do not touch when the coil spring 2 is compressed to its maximum. It follows that the maximum displacement path of the tensioning device 3 is greater than the maximum deformation path of the coil spring 2 and that the tensioning device 3 does not extend over the coil spring 2 in the longitudinal direction 11 any more when the coil spring 2 is compressed to its maximum than it does in the pre-tensioned state. Specifically related to this embodiment, this means that the coil spring 2 in the maximally compressed state is longer than the two receiving pots 4 and that the coil spring 2 in the maximally compressed state is longer than the spacer bolt 8.

Fig. 2 shows a further embodiment of the spring assembly 1 according to the invention.

The spring assembly 1 shown in Fig. 2a and b differs from that of Fig. 1 in that the spacer bolt 8 is firmly connected at one of its axial ends (top in Fig. 2) to a holding element designed as a circular plate 13. The other axial end of the spacer bolt 8 (bottom in Fig. 2) has a head 9 which, in the pre-tensioned state, is fixed to the bottom 14 of a receiving pot 15 (second embodiment).

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ing form). Analogous to Fig. 1, the spacer bolt 8 is movably connected to the receiving pot 15. In the present embodiment, the receiving pot 15 has a greater depth than the receiving pots 4 in Fig. 1. 5

Fig. 2a shows the spring assembly 1 in a pre-tensioned state. In this embodiment, the pre-tension of the spring 2 is essentially determined by the length of the spacer bolt 8 and by the depth of the receiving pot 15.

Figure 2b shows the spring assembly 1 of Figure 2a in the maximally compressed state, i.e. the turns of the coil spring 2 lie against one another, turn to turn. Since the spacer bolt 8 is firmly connected at its upper axial end to the holding element designed as a circular plate 13, the spacer bolt 8 in this state is only displaced in the longitudinal direction 11 relative to the receiving pot 15. Furthermore, it can be seen that the spacer bolt 8 is immersed in the receiving pot 15 without protruding beyond the lower axial end of the receiving pot 15. It follows from this that the tensioning device 3 in the maximally compressed state of the coil spring 2 does not extend any more in the longitudinal direction 11 over the coil spring 2 than in the pre-tensioned state of Figure 2a. Furthermore, it can be seen in Fig. 2b that the maximum displacement path of the clamping device 3 (starting from a pre-tensioned state) is greater than the maximum deformation path of the coil spring 2, since the maximum displacement path of the clamping device 3 of Fig. 2b is reached when the holding element designed as a circular plate 13 comes to rest on the bottom 14 of the receiving pot 15.

Fig. 3 shows the receiving pot 4 of Fig. 1 in top view and in side view. In this context, it should be noted that

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that the receiving pots 4 and 15 differ only in their depth, i.e. in the height of the shell surface 5.

Fig. 3a shows the receiving pot 4 in a top view. The slot 10 can be seen, which extends radially through the collar 6, the outer surface 5 in the longitudinal direction 11 over its entire length and the base 7 radially up to the middle. Due to the slot 10, it is possible to hang the spacer bolt 8 (shown in dashed lines) into the receiving pot 4 by feeding it in from the side. The rod-shaped section 17 of the spacer bolt 8 has a smaller diameter than the width of the slot 10, whereas the head 9 (dashed circle with a large diameter) has a larger diameter than the width of the slot 10 (at least in the area in which the head 9 comes to rest on the base 7 in the pre-tensioned state).

Due to the slot 10, it is possible to simply hang the one-piece spacer bolt 8 into the receiving pot 4, which significantly facilitates the assembly of the spring assembly 1 in the pre-tensioned state.

As can be seen in Fig. 3a, three elevations 12 are provided in the area of the collar 6, each offset by 120°. The elevations 12 extend, as can already be seen in Figs. 1 and 2, on the surface facing the coil spring. The elevations 12 have the effect of reducing the contact surface between the receiving pot 4 and a component 18, which is in contact with the receiving pot 4 when the spring package 1 is used as intended. This situation can be observed in Fig. 3b. Furthermore, Fig. 3a shows two slots 16, which connect the collar 6 and the outer surface 5 in the area of the cylinder head.

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The slots 16 ensure that the component 18, which is designed to be complementary in shape to the cylinder section 19 of the receiving pot 4, can be fastened to the receiving pot 4 in a form-fitting and friction-locking manner under spring-elastic prestress.

List of reference symbols

1 spring package

2 coil spring

3 Clamping device

4 receiving pot (first embodiment)

5 Shell surface (receiving pot first embodiment)

6 Collar (receiving pot first embodiment)

7 Base (receiving pot first version) 8 Distance bolt

9 Head (spacer bolt)

10 Slot

11 Longitudinal direction

12 Raised section (collar) 13 Circular plate

14 Base (receiving pot second embodiment)

15 Receptacle (second embodiment)

16 Slot

17 rod-shaped section (spacer bolt) 18 component

19 Cylinder section (lateral surface)

20 Truncated cone section (lateral surface)

Claims (20)

1. Spring assembly ( 1 ) with a coil spring ( 2 ) that can be compressed in the longitudinal direction ( 11 ) and with a tensioning device ( 3 ) by which the coil spring ( 2 ) is prestressed in its longitudinal direction ( 11 ), characterized in that the maximum displacement path of the tensioning device ( 3 ), starting from a prestressed state, is greater than the maximum deformation path of the coil spring ( 2 ), and that the tensioning device ( 3 ) does not extend any further over the coil spring ( 2 ) in the longitudinal direction ( 11 ) when the coil spring ( 2 ) is in its maximally compressed state than when it is in the prestressed state. 2. Spring assembly according to claim 1, characterized in that the tensioning device ( 3 ) has two holding elements ( 4 , 13 , 15 ) resting on the end faces of the helical spring ( 2 ), which are connected to one another in a movable manner in the longitudinal direction ( 11 ) via a spacer bolt ( 8 ) which defines a maximum distance between the holding elements ( 4 , 13 , 15 ). 3. Spring assembly according to claim 2, characterized in that both holding elements ( 4 ) are movably connected to the spacer bolt ( 8 ), and that the helical spring ( 2 ) in the maximally compressed state is longer than the two holding elements ( 4 ) extend in the longitudinal direction ( 11 ) and than the spacer bolt ( 8 ) extends in the longitudinal direction ( 11 ). 4. Spring assembly according to claim 2, characterized in that a holding element ( 15 ) is movable with the spacer bolt ( 8 ) and a holding element ( 13 ) is firmly connected to the spacer bolt ( 8 ), and that the coil spring ( 2 ) in the maximally compressed state is longer than the two holding elements ( 13 , 15 ) extend in the longitudinal direction ( 11 ) and than the spacer bolt ( 8 ) and the holding element ( 13 ) firmly connected to it extend in the longitudinal direction ( 11 ). 5. Spring assembly ( 1 ) with a coil spring ( 2 ) and a tensioning device ( 3 ) by which the coil spring ( 2 ) is pretensioned in its longitudinal direction ( 11 ), wherein the tensioning device ( 3 ) has two holding elements ( 4 , 13 , 15 ) which rest on the end faces of the coil spring ( 2 ) and which are connected to one another in a movable manner in the longitudinal direction ( 11 ) via a spacer bolt ( 8 ) which defines a maximum distance between the holding elements ( 4 , 13 , 15 ), characterized in that the holding element ( 4 , 15 ) has a slot ( 10 ) which extends from the edge into the holding element ( 4 , 15 ) and through which the spacer bolt ( 8 ) can be hooked into the holding element ( 4 , 15 ). 6. Spring assembly according to one of claims 2 to 5, characterized in that the spacer bolt ( 8 ) has a head ( 9 ) which functions as a contact surface of the suspended spacer bolt ( 8 ) on the holding element ( 4 , 15 ). 7. Spring assembly according to one of claims 5 to 6, characterized in that the slot ( 10 ) extends from the edge to the middle. 8. Spring assembly according to one of claims 2 to 7, characterized in that the holding element ( 4 , 13 , 15 ) has a circular cross-section. 9. Spring assembly according to one of claims 2 to 8, characterized in that the head ( 9 ) is formed integrally with the spacer bolt ( 8 ). 10. Spring assembly according to one of claims 2 to 9, characterized in that the spacer bolt ( 8 ) is arranged within the coil spring ( 2 ). 11. Spring assembly according to one of claims 2 to 10, characterized in that a holding element is designed as a receiving pot ( 4 , 15 ) which has a base ( 7 , 14 ) and a jacket surface ( 5 ). 12. Spring assembly according to one of claims 1 to 11, characterized in that both holding elements ( 4 ) are of identical construction. 13. Spring assembly according to one of claims 1 to 12, characterized in that the slot ( 10 ) extends through the casing surface ( 5 ) in the longitudinal direction ( 11 ) over the entire length and then through the base ( 7 , 14 ) radially up to the middle. 14. Spring assembly according to one of claims 2 to 13, characterized in that the receiving pot ( 4 , 15 ) is arranged at least in sections within the coil spring ( 2 ). 15. Spring assembly according to one of claims 2 to 14, characterized in that the receiving pot ( 4 , 15 ) has an outwardly facing collar ( 6 ) which runs at least in sections in the circumferential direction of the receiving pot ( 4 , 15 ), and whose surface facing the helical spring ( 2 ) serves as a contact surface for the front side of the helical spring ( 2 ). 16. Spring assembly according to one of claims 2 to 15, characterized in that the receiving pot ( 4 , 15 ) provides a further slot ( 16 ) which partially passes through the collar ( 6 ) and/or the casing surface ( 5 ). 17. Spring assembly according to one of claims 11 to 16, characterized in that the receiving pot ( 4 , 15 ) is essentially frustoconical, wherein the base ( 7 , 14 ) adjoins the region of the lateral surface ( 5 ) with a smaller diameter, and wherein the outwardly facing collar ( 6 ) adjoins the region of the lateral surface ( 5 ) with a larger diameter. 18. Spring assembly according to one of claims 16 to 17, characterized in that the collar has an elevation ( 12 ) on the surface facing away from the coil spring ( 2 ). 19. Spring assembly according to one of claims 2 to 18, characterized in that the holding element ( 4 , 15 , 13 ) can be produced as a pressed part from a flat material section. 20. Spring assembly according to one of claims 2 to 19, characterized in that the spacer bolt ( 8 ) can be produced by machining.