DK2669050T3

DK2669050T3 - Tool, system and method for screwing compression springs to a screw spring

Info

Publication number: DK2669050T3
Application number: DK13169751.8T
Authority: DK
Inventors: Philipp Koepff
Original assignee: Dr Werner Roehrs Gmbh & Co Kg
Priority date: 2012-05-30
Filing date: 2013-05-29
Publication date: 2018-06-06
Also published as: ES2670829T3; DK2669050T5; EP2669050A3; RS57276B1; PL2669050T3; SI2669050T1; AT14133U1; HRP20180857T1; PT2669050T; DE102012104673B3; HUE038435T2; EP2669050B1; TR201807521T4; EP2669050A2

Abstract

The arrangement has two tools (1) comprising respective cylindrical tool bodies (2). The tool bodies comprise a transit (3) for receiving a cylindrical arbor (5). The transit is arranged concentric to a rotational axis (7) around which one tool rotates opposite to another tool. A claw (12) is formed adjacent to the transit at an end surface (9), for clamping an end of a helical compression spring. The claw comprises a projection in a rotational direction. The arbor partially exhibits a constant cross-section. The spring is fitted on an outer surface of the arbor with small clearance. Independent claims are also included for the following: (1) a system for fastening a helical compression spring to a helical plate spring (2) a method for fastening a helical compression spring to a helical plate spring.

Description

Description [0001] The present invention relates to a tool, a system and a method for screwing helical compression springs to a helical plate spring.

[0002] DE 476 852 A discloses a nose-loaded clamp for retaining a spring end on a mandrel of coil spring winding machines. The nose is fixed to a rotatable ring, which is arranged eccentrically to the mandrel. By means of this arrangement, the nose is moved closer to the mandrel at the beginning of the rotational movement of the mandrel and a constantly increasing pressure on the clamped spring end are exerted by the nose, so that only a short piece of spring, which is not protruding over the nose, needs to be clamped.

[0003] In DE 898 143 an apparatus for winding springs on a rotating mandrel is indicated. According to this device, it is Intended that a disc is adjustably mounted on the front part of a handgrip of a tool, and is designed so that it's periphery is at a changes in thickness from minimum to a maximum. In this way the device can be applied to the rotating mandrel so that the thickness of the disc at the point of contact with the mandrel corresponds to the desired spacing of the turns of the spring to be produced. The disc is then applied to the last turn of the wire on the mandrel, so that the wire runs exactly at the desired distance from this to the mandrel.

[0004] In DE 29 16 446 C2 a coil spring set is disclosed. This coil spring set comprises two coil springs which are wound from a spring band edgewise to the spring axis, with a longer cross-sectional side of the spring band having an angle smaller than 90° to the spring axis. These two coil springs are screwed together with oppositely directed inclination of the cross sections.

[0005] A helical spring is indicated in DE 41 00 842 C1. The coil spring includes at least one support element attached to one end of the spring body. The support element and the spring body are integrally formed, wherein the spring body is made by dissolving material between the turns.

[0006] From US 26 49 130 A, a device for winding coil springs is indicated. This device has a drive spindle, in which a mandrel is arranged. Through a guide assembly, a wire is applied to the mandrel, said wire is wound by the rotational movement of the drive spindle to form a coil spring on the mandrel.

[0007] In EP 2 223 752 A1 a tool kit for forming bending tools that can be used on a bending machine for bending or winding strand-shaped workpieces is described. A single bending tool of the tool kit comprises a cylindrical tool holder. On its front side of a mandrel element is arranged. At the front side of the mandrel element, a bending mandrel is formed. Furthermore, a bending element with a forming jaw is provided on the bending tool, which has a shaping groove for pressing a strandshaped workpiece when bending against the bending mandrel. The forming grooves of different mold jaws are designed for different workpiece cross sections.

[0008] From US 4 253 350 A, a device for biasing garage door springs is indicated. For this device, it is provided to arrange a spring on a cylindrical, mandrel-like body, and fix one end of the spring locally with a corresponding reception, which is associated with the mandrel. The other free end of the spring is connected to a ratchet mechanism of the device. By operating the ratchet mechanism, the spring can be prestressed accordingly, and used in a corresponding mechanism of a garage door.

[0009] The industrial production and the use of Belleville springs has numerous disadvantages. In the production, the high material and labor costs are mentioned. The application of disc springs has the disadvantage that assembly and maintenance are time-consuming due to the numerous individual plates. In addition, the unfavorable fiber shape of the material promotes the occurrence of fractures.

[0010] In order to avoid these disadvantages, wound helical plate springs have been developed. In many cases, these can replace oppositely stacked disc spring columns.

[0011] The helical plate spring is a one-piece spring element which consists of two identical helical compression springs which are screwed into each other, each of which is wound from strip steel having a plate spring-like cross-section upright and are wrapped diagonally to the central axis.

[0012] Since screw-spring springs do not disintegrate into single plates, they have the advantage that they can be delivered with a recorded fixed spring diagram.

The edges of the outer and inner diameter of the helical spring can be rounded when rolling or pulling the desired rectangular or trapezoidal cross section of the spring steel strip. The fiber course of the band is advantageous, which ensures a high resistance to breakage under the same load. The force is applied via the flat-ground spring, similar to helical compression springs.

[0013] The objective of the present invention is to provide a tool which simplifies the screwing together of helical plate springs.

[0014] The invention has the features set forth in the independent claims to solve this problem. Advantageous configurations thereof are specified in the respective subclaims.

[0015] Inventively, a tool for screwing disc springs according to claim 1 is provided. A helical plate spring is a one-piece spring element, which consists of two identical, screwed together helical compression springs, each of which is wound from strip steel with plate, spring-like cross-section upright and wrapped diagionally to the central axis.

[0016] One end of a helical compression spring can be inventively clamped onto the tool. One end of a helical compression spring is fixed in the claw, for fixing the helical compression spring.

[0017] By inventively providing a tool assembly comprising two tools, it is possible to screw two helical compression springs to form a helical spring. In this case, specifically a helical compression spring, or the corresponding tool is set in the direction of rotation wherein the second tool or the helical compression spring arranged therein, undergoes no rotation. In this way, the two helical compression springs are screwed together.

[0018] Furthermore, in terms of the rotation period, the claw may be disposed approximately diametrically opposite a stop for limiting the rotational movement of a second helical compression spring.

[0019] When screwing two helical compression springs after reaching the stop both helical compression springs are completely screwed together.

[0020] According to a second embodiment of the tool, a diameter of the passage can be adjusted by means of a fixative, which is preferably designed as a clamping device, that mandrels with different diameters can be accommodated.

[0021] In this way, it is possible to screw together helical compression springs of different diameters with a single tool.

[0022] The mandrel has a circumferential surface which has a cylindrical portion on which a corresponding helical compression spring with little clearance can be attached. The mandrel may be equipped with a conical tip.

[0023] Furthermore, according to the second exemplary embodiment, the distance between the claw and the stop to the axis of rotation can be adjusted by means of an adjusting device such that helical compression springs of various diameters can be received. As a result, helical compression springs with different diameters can be fixed.

[0024] The claw and the stop may be releasably connected to the front of the tool, so that an arrangement of the protrusion of the claw with respect to the rotational direction is changeable.

[0025] In this way, left- and right-handed helical compression springs can be screwed to a helical plate spring. Furthermore, a system for screwing a screw plate spring set is provided. This comprises a turning machine and two tools, referencedin claims 1 to 8, wherein a helical compression spring can be arranged on each tool and a tool in the turning machine is rotatably fixed about the axis of rotation and by means of the turning machine in a rotary motion can be set. A mandrel is in a fixed rotation of one of the two tools. The other tool has a passage into which the mandrel can be inserted with little play, so that the two tools are axially aligned. On each of the two tools is a helical compression spring in the respective claw that is is fixable, so that the two helical compression springs are screwed into one another to a helical spring, wherein the mandrel extends during screwing through a passage of the other tool. The shank of a tool may be fixed in placed in a chuck of a turning machine.

[0026] a lathe, as seen in the design, describes all rotating working machines such as: lathes, milling machines, drills, motors or drives or similar.

[0027] The invention will now be described in more detail with reference to the drawings. These can be found in:

Fig. 1 is a perspective view of the first embodiment of the invention with mandrel,

Fig. 2 is a perspective view of the first embodiment of the invention with handles,

Fig. 3 is a perspective view of the second embodiment of the invention with mandrel and clamping device.

Fig. 4 is a perspective view of the second embodiment of the invention with handles, and

Fig. 5 is a schematic representation of a system according to the invention, for screwing helical compression springs to a screw plate spring set.

[0028] According to the first embodiment of the tool 1, the latter has developed a somewhat cylindrical tool body 2 (Fig. 1, Fig 2).

[0029] The surface of the tool body 2 is arranged concentrically to a rotation axis 7. Tool 1 can be rotated about the axis of rotation 7 in use. In the tool body 2, a passage 3 extending in the axial direction is formed. The passage 3 is arranged concentrically with the axis of rotation 7 in the tool body 2.

[0030] Furthermore, four threaded bores 4 are provided on the tool body 2, longitudinally extending radially.

[0031] In the passage 3, a somewhat cylindrical mandrel 5 is arranged. The mandrel 5 is fixed by means of four screws which are arranged in the threaded holes 4, 6.

[0032] The mandrel 5 has a constant cross-section, which is dimensioned so that the helical compression spring can be screwed and arranged on a lateral surface of the mandrel 5 with little clearance.

[0033] The tool body 2 has a front face 9, which is arranged approximately perpendicular to the axis of rotation 7. On the front face 9, a claw/stop body 11 is formed. The claw/stop body 11 forms a wide bridge which extends transversely across the front face 9 and is arranged centrally on the tool body 2. The passage 3 extends through the bridge. The bridge has two parallel, narrow side surfaces 10. On a narrow side surface 10, a recess or a groove is introduced, so that the groove defining portion of the bridge forms a claw 12 for fixing a helical compression spring. The claw 12 extends approximately in the radial direction, and forms a projection in the direction of rotation 8. The region of the narrow side surface 10 of the bridge, which is arranged approximately diametrically opposite the claw 12 with respect to the passage 3, forms a stop 25 against which the helical compression spring strikes. The claw 12 and the stop 25 are thus arranged rotationally symmetrical to the axis of rotation 7 and to the mandrel 5.

[0034] At the end of the tool 1, the opposite of the front face 9 of the tool body 2, a shaft 13 is formed. The shaft 13 is designed so that I can be clamped In the chuck of a turning machine. The shaft (13) can, in principle, have any shape which is suitable for connecting the tool (1) to a turning machine or for clamping the tool (1) in its chuck. In a plan view, the axial direction of the shaft 13 can be circular, elliptical or polygonal with three, four, five or more, optionally rounded, corners formed. The shaft 13 and the mandrel 5 are preferably formed from a single pin which is fixed in the passage 3 of the tool body 2.

[0035] Another embodiment of the tool 1 (Fig. 2) has substantially the same tool body 2, whereas in the second embodiment neither a mandrel nor a shank are provided. The passage 3 of this embodiment of the tool body 2 is slightly larger than that of the first embodiment, so that the tool body 2 can be inserted with a little play on the mandrel 5 and the mandrel 5 is freely rotatable within the tool body 2. At the two opposite threaded holes 4, a handgrip 26 is attached to each.

[0036] A tool 1 according to the invention is designed according to a second exemplary embodiment such that the tool 1 can produce helical disk springs of different diameters. The structure of the tool 1, according to the second embodiment of the invention, substantially corresponds to the structure of the tool in regards to the first embodiment. Unless otherwise described, the tool regarding the second embodiment has the same features as the tool in regards to the first embodiment. Identical components are provided with the same reference numbers.

[0037] The tool 1 according to the second embodiment, comprises a tool body 2 which is formed in two parts (Figs. 3 to 5).

[0038] The tool body 2 according to the first embodiment (Fig. 3) is formed of two semicircular segments 14,15 which are screwed together (not shown).

[0039] In the assembled state, a rectangular recess 16 is provided centrally in the two semicircular segments 14, 15 or in the region of the axis of rotation 7. In the recess 16, two leading mounted jaws 17,18 are arranged. The two clamping jaws 17,18 are spaced apart from one another in the radial direction on a guide device, for example on a rail (not shown). The jaws 17,18 in conjunction with an adjuster form a clamping device. With the adjuster, the two jaws 17,18 move together towards or away from each other at the same time. In the embodiment of fig. 3, this adjustment is not shown.

[0040] Between the jaws 17,18 the mandrel 5 can be clamped.

[0041] Each of the jaws 17,18 has two bores 21,22.

[0042] According to the second embodiment, the claw 12 is formed as an L-shaped body wherein one leg forms a projection, projecting in the direction of rotation 8 and the other leg extends in the axial direction and is provided with a cylindrical pin. The claw 12 is inserted by means of the cylindrical pin, in one of the holes 21 of the jaw 17.

[0043] The stop 25 is an approximately couboid shaped body which is likewise provided with a cylindrical pin extending in the axial direction 10. The stop 25 is inserted by means of the cylindrical pin in the corresponding bore 22 of the jaw 18, which is arranged in relation to the passage 3 diametrically opposite to the claw 12.

[0044] In the following, a system 24 for screwing a helical plate spring set is described (Fig. 5).

[0045] Since the jaws 17,18 each have two holes, the claw 12 and the stopper 25 can be fixed in two different positions on the tool 1. The positions are set so that the claw is aligned in the two positions in each case in the opposite direction, wherein a tongue of the claw is arranged approximately tangential to the axis of the rotation 7, so that one end of a helical compression spring which is placed on the mandrel 5 in the recess of the claw comes to rest. The different positions of the holes 21,22 thus allowing the arrangement of the claws for a different rotational or winding direction of the springs. This tool can then be used for left- or right-wound springs.

[0046] Since the distance between the jaws 17,18 is adjustable, the tool can also be used for mandrels 5 with different thickness. The present tool is thus very flexible for different sized helical plate springs used.

[0047] Fig. 4 shows a second embodiment with two handgrips 26. The tool body is divided in this embodiment into two different sized circle segments 27, 28. Otherwise, this tool corresponds to the first embodiment of Fig 3.

[0048] The system 24 comprises a claw-and-stop tool which is fixed in a chuck of a turning machine.

[0049] In this tool, a helical compression spring can be arranged. The tool is rotatably fixed about the axis of rotation in the chuck of the turning machine and can be set in a rotary motion by means of the turning machine.

[0050] Another tool with claw and stop as well as handgrips is axially fixed in alignment with the first tool rotatably.

[0051] The mandrel 5 is fixed in the passage of the first tool 1/1.

[0052] A first helical compression spring 29 is arranged on the mandrel 5, wherein it comprises 1/1 with one end of the claw 12 of the first tool and is fixed in a rotational manner. A second helical compression spring 30 is also located on the mandrel, wherein the two springs 29, 30 are arranged interlocked with a first turn section. The free end of the second helical compression spring 30 is received in the recess of the claw 12 of the second tool 1/2 and thereby fixed against rotation.

[0053] When the turning machine 20 is operated, the first tool 1/1 and the first coil springs 29 are rotated. The second tool 1/2 is rotatably held by a user on the handgrips 26, whereby the second helical compression spring 30 is fixed against rotation. The two springs 29, 30 are screwed together. It is expedient to pull the second tool 1/2 with a counterforce away from the first tool 1/1, whereby the unit of the two helical compression springs 29, 30 is held slightly under tension. As a result, the frictional forces arising when screwing the two springs 29, 30 are minimized. The turning machine 20 is actuated until the two helical compression springs 29, 30 stop against the respective stops 25. Preferably, a foot key is provided, with which the user can adjust the rotational speed of the turning machine 20.

[0054] If the two helical compression springs 29, 30 are completely screwed to form a helical spring, the ends of the helical compression springs are released from the claws 12, the second tool 1/2 is lifted off the mandrel 5 and the screws are removed from the helical compression spring which screwed on the mandrel 5. Preferably, the two helical compression springs 29, 30, are already screwed together a bit, half a turn, before they are plugged onto the mandrel 5.

[0055] In this exemplary embodiment, the mandrel 5 is fixed to the first tool 1/1 fixed to the turning machine 20. In the context of the invention, it is of course also possible to fix the mandrel 5 on the second tool 1/2, which is held manually, and to provide a passage for the mandrel on the other tool 1/1.

List of References [0056] 1 Tool 2 Tool Body 3 Passage 4 Threaded Bore 5 Mandrel 6 Screw 7 Rotary Axis 8 Direction of Rotation 9 Front Face 10 Narrow Lateral Faces 11 Claw/Stop Body 12 Claw 13 Shank 14 Semicircular Segment 15 Semicircular Segment 16 Recess 17 Jaws 18 Jaws 19 20 Turning Machine 21 Through Bore 22 Through Bore 23 24 Screw Cap Spring System 25 Stop 26 Handgrip 27 Pie Segment 28 Pie Segment 29 Helical Compression Spring 30 Helical Compression Spring

Claims

A tool for screwing helical compression springs to a helical spring with a tool body (2) having a passage (3) for receiving a mandrel (5) on which a helical compression spring (29, 30) can be arranged, wherein the passage is arranged concentric with a axis of rotation 7, whereby the tool (1) is rotated in a predetermined direction of rotation by screwing on the helical compression springs (29, 30) and the tool body (2) has a front surface (9) disposed approximately perpendicular to the the axis of rotation 7 wherein, next to the passage (3) on the front surface (9), a claw (12) is formed for securing an end of a helical compression spring (29,30) characterized in that it has a projection in the direction of rotation. (8).

Tool according to claim 1, characterized in that approximately a diametrically opposite to the projection relative to the passage (3) is arranged a stop (25) for limiting the rotational movement of another helical compression spring.

Tool according to claim 1 or 2, characterized in that the internal width of the passage (3) can be adjusted so that mandrels (5) of different thickness can be used.

Tool according to one of Claims 1 to 3, characterized in that the mandrel (5) has at least partially a lateral surface of a constant cross-section to which a helical compression spring can be connected at a small distance.

Tool according to one of claims 1 to 4, characterized in that the claw (12) and the stop (25) are detachably connected to the front surface (1) of the tool, so that an arrangement of the claw protrusion (12) with respect to the direction of rotation (8) ) is variable so that left and right-sided helical springs can be used.

Tool according to one of claims 2 to 4, characterized in that the distance between the claw (12) and the stop (25) of the axis of rotation (7) can be adjusted by means of an adjusting device such that helical compression springs of different internal diameters can be fixed.

Tool according to one of claims 1 to 6, characterized in that at least one and preferably two handles (26) are provided on the tool (1/2) to hold the tool during rotation.

Tool according to one of claims 1 to 6, characterized in that the tool (1/2) has a shank (13) which can be connected to a lathe (20) and preferably can be fixed to a part of the lathe.

Tool according to claim 8, characterized in that the shaft (13) and the mandrel (5) are integrally formed.

A system for screwing in helical compression springs to a helical plate spring comprising - a lathe (20), - two tools performed according to one of claims 1 to 8, wherein a helical compression spring can be secured to each tool (1), and one of the the two tools (1) in the lathe (20) are pivotally hinged about the axis of rotation (7) and are rotatable by the lathe (20), and the other tool (1) is fixed in a rotary fixed axial device with the one tool, and a mandrel (5) secured in a passage by one of the two tools (1) so that by means of the system two helical compression springs (29, 30) can be screwed into each other as the mandrel (5) extends through a passage (3) of the second tool (1) during screwing.

System according to claim 10, characterized in that a shaft (13) of one of the tools (1) is fixed in the chuck (20) of the lathe.

The method of screwing helical compression springs together to form a helical plate spring, wherein a first helical compression spring (29) is attached to a first tool (1/1) constructed according to claims 1 to 8 and arranged on a mandrel (5), wherein the first tool (1/1) is fixed in the lathe (20) pivotally about the axis of rotation (7) and is adjusted by means of the lathe (20) in a rotary motion and a second tool (1/2) in which a helical compression spring (30) also fixed, axially directed to the first tool (1/1) held to the rotation, whereby with the rotary movement of the lathe (20) the two helical compression springs (29, 30) are screwed together so that the two helical compression springs (29, 30) forms a helical plate spring.

The method according to claim 12, characterized in that the compression of the two helical compression springs is limited by a stop (25).

The method according to claim 12 or 13, characterized in that the mandrel (5) is attached to one of the two tools and during the screwing extends freely pivotally through a passage (3) of the other tool (1/1, 1/2 ).

The method according to one of claims 12 to 14, characterized in that during the screwing, an axial pulling force is exerted on the two helical springs, preferably by means of handles (26).