EP1387814A1

EP1387814A1 - Method and device for transporting nested springs to a spring-core assembly device

Info

Publication number: EP1387814A1
Application number: EP02717928A
Authority: EP
Inventors: Marco Frangi
Original assignee: Spuehl AG St Gallen; Spuehl AG
Current assignee: Spuehl AG St Gallen; Spuehl AG
Priority date: 2001-05-16
Filing date: 2002-04-25
Publication date: 2004-02-11
Also published as: WO2002092495A1

Abstract

The inventive device comprises four transport zones (A to D), through which a spring serpentine (3), which is initially delivered in a continuous manner, is guided and which is separated into spring serpentine sections (3') of length (L). The intervals between the springs (9) lying in the spring serpentine sections (3') can be adjusted. The intervals between individual springs (9), or the length (L) of the spring serpentine (3) can be adjusted by compression or stretching.

Description

Method and device for transporting pocketed springs to a spring core assembly device

The invention relates to a method for transporting pocketed springs according to the preamble of patent claim 1. The subject matter is also a device for transporting pocketed springs according to the preamble of patent claim 8.

Spring core inserts usually comprise a certain number of spring rows arranged next to one another and connected to one another from a plurality of springs arranged in line and connected to one another. For high quality spring cores, the rows of springs are welded into a tube made of thermoplastic material in separate pockets. The endlessly produced pockets filled with springs are divided into predetermined length sections of, for example, thirty springs in order to be able to produce the corresponding spring core therefrom. In a known device (WO 96/27553) on Three spring coiling machines arranged side by side, each with a downstream device for pocketing the springs produced on the spring coiling machine, introduced the endlessly produced pocket spring coils in three tracks into a magazine arranged in front of an automatic spring assembly machine. Between the spring coiling machines and the magazine there is a stowage section in which the endlessly and continuously produced spring coils can be stowed in front of the magazine during the separation process. The cut-off spring snake sections produced by cutting pass individually from the magazine into the spring assembly machine. The introduction of the spring snake sections into the automatic assembly machine and the mutual bonding to a spring core are not explained in detail, since these processes are sufficiently known from the prior art. There is also no explanation of the technology of cutting the endless spring snake into spring snake sections.

This known device has the advantage that the delivery of pocket spring coils from three spring coiling machines enables continuous work on the assembly machine, even if a temporary interruption occurs in one of the three spring coiling machines. It has turned out to be a disadvantage, however, that spring snake sections of unequal length due to differences in tolerance do not exist in this known device can be compensated. Such length deviations, if they are additive, can also lead to length deviations in the spring cores produced therefrom, which can significantly exceed the specified target values.

It is also known to always transport spring snakes in a form-fitting manner. The distances between the springs are determined by appropriate devices, e.g. Index wheels, conveyor belts with webs etc. specified. This means that with each change in the spring dimensions, the spacing of the springs or the diameter of the springs, the corresponding devices, i.e. the index wheels or conveyor belts with bars etc. must be replaced.

The present invention is based on the object of providing a method and a device for transporting spring coils, which enables spring coils to be fed to a spring mounting device in a precise manner and with a certain amount of variable length with little effort.

Another object of the invention is to create the possibility of changing the hardness of the spring core as a whole or in certain zones by changing the distances between the springs and / or spring lines with springs of different diameters. This object is achieved by a method with the features of claim 1 and a device with the features of claim 8.

With the method according to the invention and the device according to the invention, endlessly produced spring serpents, even those that have been temporarily stored, can be transported in the correct position and presented to the assembly device in an exactly predetermined length. The changeover of the device for spring snakes with a different spring dimension or different length of the spring snake sections can be carried out partly via the control of the machine and / or with a few simple steps. By temporarily pulling apart or compressing the spring snake sections, zones of the spring core can be made softer or harder than adjacent zones of the spring core.

The invention is explained in more detail using an illustrated exemplary embodiment. The figures show the individual process steps from feeding the endless spring coil to inserting the individual spring coil sections into the assembly device:

Figure 1 beginning of the process, in which the front end (trailing edge) of the endless spring coil in the insertion area A and Feed conveyor belt is fed

FIG. 2, the front end of the spring snake is gripped by the feed conveyor belt,

FIG. 3 the spring snake is drawn in in the feed conveyor belt up to the subsequent transport or transfer area C,

Figure 4 shows the required number of springs, i.e. a desired spring snake section length is counted and is separated from the endless spring snake by the cutting device,

FIG. 5 the separated spring snake section has left the feed area B and is led via transfer / transport area C to the insertion area D,

FIG. 6 the spring snake section has reached the insertion area D,

FIG. 7, the insertion area D is pivoted through 90 °, the pocket spring axes are now ready to be inserted into the assembly device; the following spring snake section has already arrived in the transfer / transport area C,

Figure 8 is a plan view of the device

FIG. 9 shows a pull-in device which can be adapted to the diameter of the springs.

In the figures, the device according to the invention is shown in Divided sections. These are sections A to D, section A representing the insertion area, section B the feed area, section C the transfer or transport area and section D the insertion area. The insertion area A comprises a slide guide 1, on which the front end of an endless spring coil 3, which is introduced into the device, is guided. A hold-down device 5 is mounted at a distance from the front end 2 of the slide guide 1, which is preferably horizontal and runs in a straight line, for example an elongated rail with an insertion section 7 which is expediently bent upward on the inlet side. The hold-down device 5 serves to hold the spring coil 3 to guide with the springs 9 inserted into it on the sliding guide 1. The hold-down device 5 can be adjusted and adjusted in the vertical direction by suitable means, not shown, so that its position can be adapted to the diameter of the springs 9 that are being processed. A first sensor 11 is arranged above the hold-down device 5 or at another point, by means of which the number of springs 9 pocketed in the spring coil 3, which are guided past the sensor 11, can be counted. Viewed in the direction of transport T, there can be a retainer 13 after the front end of the hold-down device 5, the function of which will be described later. The recooler 13 is pivotable about a pivot axis S and resiliently mounted, so that its front end 13 'is partially insertable between two adjacent springs 9 in the spring coil 3 and can be removed therefrom. After the retainer 13, above and below the transport path of the spring coil 3, a device 15 for separating and welding the separation points of the endless coil spring 3 into individual spring coil sections 3 'of a predetermined length L or a predetermined number of springs 9 is arranged so as to be vertically displaceable. In a preferred embodiment, the first sensor 11 is inserted between the retainer 13 and the device 15 for welding and separating the spring coil 3. This arrangement of the first sensor 11 means that differences in length of the spring snake sections 3 'cannot influence the counting device. Also between regions A and B, pliers 19 are mounted as a retractable element which is displaceable in the transport direction T. The drive means 17 for moving the pliers 19 are only shown schematically for the sake of clarity. The drive means 17 can be operated pneumatically or electrically.

The feed area B comprises two conveyor belts 21 ′ and 21 ″, which together form the feed device 21. The overhead conveyor belt 21 ″ can be pivoted about the axis X of the deflection roller 23 located at the front in the direction of the arrow P by an invisible drive. The swiveling movement enables a temporary enlargement the inlet-side distance of the two bands 21 'and 21 "when inserting the front end of the spring coil 3 with the pliers 19th

In the embodiment of the invention according to FIG. 9, the distance between the axis X of the front deflection roller 23 with respect to the axis of rotation Z of the front deflection roller 24 of the conveyor belt 21 can also be set. The adjustment of the distance between the strands of the conveyor belts 21 ′, 21 ″ is preferably carried out with the aid of a servo drive 26 and enables spring coils 3 with springs 9 of different diameters to be processed without long conversion work. The device can only be adapted to different spring diameters in sections A. and B. The springs 9 are held axially on their end rings in the remaining sections C and D. The introduction of spring coils 3 with springs 9 with a smaller diameter and consequently also a larger number of springs 3 per unit length of the spring coil 3 results in a spring core Increased hardness If springs 9 with a larger diameter are used, the number of springs 9 per unit length and thus also the hardness is reduced accordingly.

Between the areas B and C, spaced apart from one another, there can be a pair of cam-shaped transport rollers, or camshafts 25 for short, which are arranged about axes of rotation perpendicular to the image plane is drivable. The distance between the axes of rotation of the two camshafts 25 is adjustable and always larger than the diameter of the springs 9 and the distance between the two vertices of the cams on the camshafts 25 is normally smaller than the diameter of the processed springs 9. This enables the vertices of the cams to engage between two successive springs 9 in the spring coil 3. Positioning and auxiliary transport rollers or belts 27 arranged in pairs can lie essentially in the same plane as the camshafts 25. Rubber beads, for example in O-rings inserted into grooves, are preferably attached parallel to one another on their peripheries, which effect an essentially slip-free advance of the spring coil sections 3 'guided between the two positioning and auxiliary transport rollers or belts 27. The positioning and transport rollers 27 are driven by contact wheels or rollers 31 (indicated by broken lines) between the positioning and auxiliary transport rollers 27 and the two conveyor belts 29 'and 29 "of a conveying device 29. In the transport area or transfer area C, the axes of the Deflection rollers 33 of the conveyor belts 29 'and 29 "vertically, so that the spring coil 3, in contrast to the feed area B, is not detected tangentially on the spring windings, but there are the end rings of the springs 9 on the opposite strands of the Conveyor belts 29 'and 29 ".

The insertion area D comprises two circumferential insertion tapes 35 'and 35 ", which are arranged analogously to those in the transport area C. The two insertion tapes So and 35" are pivotally mounted on a swivel support 41. The axis Y on the swivel support 41 is at right angles to the direction of conveyance of the insertion belts 35 ', 35 ". After a spring snake section 3' has been transported between the insertion belts 35 ', 35", these are swiveled by 90 ° together with the spring snake section 3 located therein and in this way the spring snake section 2 'is presented in front of an insertion table 43 in the assembly device 45 for the production of a spring core 47. With a slide-in element (not shown), each spring snake section 3 'is moved individually from the two slide-in bands 35', 35 "into the

• Installation device 45 inserted and connected to the spring snake sections 2 'already present there. The connection can be made by laterally gluing the spring snake sections 3 'or with the aid of nonwovens resting on the end rings on the end rings

, respectively.

The following is the method of transporting the initially endless spring coil into the spring core assembly 45 and adjusting the length L of the Spring snake sections 3 'explained. At the beginning of the work process or each time the front end of a spring coil 3 is inserted, it is inserted between the sliding guide 1 and the hold-down device 5 until the retainer 13 engages between the front and second front springs 9 (FIG. 1). This step is usually done manually; if desired, it can also be automated. It is only necessary if a new spring coil is fed into the system.

In the second step (FIG. 2), the pliers 19 are moved in the direction of the hold-down device 5. The pliers 19 previously grips at least the two springs 9 lying in the front in the spring coil 3 at their end rings and pushes or pulls them in the direction of the arrow Z between the two bands 21 ″ and 21 ′ of the pull-in device 21. As soon as the first springs 9 between the strands of the two feed belts 21 'and 21 "lie, the end 22, which was previously slightly lifted to facilitate pulling in in the direction of arrow P, pivots downward, so that the two runs essentially parallel. The pliers 19 open as soon as the spring coil 3 has been gripped by the feed belts 21 and 21 ". With the feed belts 21 'and 21", the spring coil 3 is now transported through the entire feed area B into the transport area C. When the front end of the spring coil 3 enters the transport area C can be pushed by the cams of the camshaft 25 with each rotation of the shaft, the respectively arriving spring 9 between the two conveyor belts 29 'and 29 "of the transport device 29. The spring coil 3 is widened by the two positioning and auxiliary transport rollers 27 lying in the same vertical plane The desired number n of springs 9, which is to be contained in a spring snake section 3 ', is counted with the first sensor 11. As soon as the predetermined number n springs 9 has been reached, the conveyor belts 21 are stopped and the measured spring snake section 3 'with the sectioning and separating device 15 separated from the spring snake 3. In order to be able to make this separation exactly between two springs 9, the foremost spring 9' of the spring snake 3 which now follows is held lightly by the retainer 13, then one The spring snake material is welded to the cut on both sides Place a clean seal on the spring pocket containing the last spring 9 '(FIG. 4). Immediately after the spring snake section 2 'has been separated from the length L or with a predetermined, counted number n of springs 9, it is guided into the transport area C, detected there and released when the insertion area B is again in the transfer position. The spring snake section 3 then arrives from there into the Insertion area D. After passing through the camshaft pair 25 and the positioning and auxiliary transport rollers or belts 27, if there are any, the mutual spacings of the springs 9 in the spring coil sections 2 'are balanced, that is to say they are all at an equal distance from one another on. During the further transport of the spring snake section 3 'separated from the spring snake 3, the front end of the endless spring snake 3, as described with reference to FIGS. 1 and 2, is inserted into the feed area B by the pliers 19. At the same time, the insertion area D or the insertion straps 35 ', 35 "rotating around it takes place about the axis Y. The springs 9, which are now clamped with vertical axes between the two insertion straps 35' and 35", can be moved by a translational movement an insertion device can now be transferred to the assembly device 45.

With the insertion device, not shown, which can have positioning elements engaging between the springs in the spring coil sections 3 'for the springs 9 lying in the spring coil sections 3', the spring coil sections 2 'can be inserted into the spring mounting device 45 in an exactly aligned manner. If the spring snake sections 2 'are laterally displaced by a spring radius, the density of the Springs 9 per unit area of a spring core can be enlarged (no illustration).

The influencing of the distances between the individual springs 9 within the spring coil sections 3 'and consequently the total length of the individual spring coil sections 3' can be influenced by different speeds of the subsequent conveyor belts 29 ', 29 ";35',35" in the areas C and D of the plant can be reached. When the spring snake 3 is drawn from the insertion area A into the feed area B by the conveyor belts 21 'and 21 ", the spring snake 3 is initially stretched moderately. The stretching is supported by the retainer 13, which from above onto the springs 9 pocketed in the spring snake 3 The spring coil 3, with the springs 9 now arranged at regular intervals, is guided by the conveyor belts 21 and 21 "through the feed area B into the transfer area C. After entering the transfer area C, the front and rear ends of the spring coil 3 are detected by a second sensor 51 arranged there, and the actual length of the spring coil section 2 ′ is determined together with the measurement data obtained. At the beginning of the working process, when the front end of a new spring coil 3 is inserted into the system, the spring coil 3 is guided or drawn in up to the second sensor 51, the length of the first spring coil section 2 ′ is checked manually and as the reference length R saved. The reference length R is used to continuously record extraordinary deviations during the working process of the system and to stop the machine. Extraordinary deviations occur, for example, if no spring 9 is inserted in a pocket or if the seam between two springs 9 is missing. A control, not shown and also not described in more detail, makes a comparison of the measured actual length with the desired length for each spring-snake section 3, which must be present in the insertion area D before being inserted into the assembly device 45. If the ACTUAL length is too large, a reduction in the speed v _{D of} the conveyor belts 35 ', 35 "in the transfer area D results in a corresponding compression of the spring coil section 3' entering this area D. This spring coil section 3 then points the desired SHOULD length in the insertion area D. Similarly, by increasing the speed v _D, the length of the spring coil section 3 'can be increased if this should initially be too short.

Claims

claims

1. Method for transporting pocketed springs (9) to a spring core assembly device (45), in which an endlessly produced pocket spring coil (3) is divided into spring coil sections (3 ') with a predeterminable number of pocketed springs (9) and the spring coil Sections (3 ') are then connected to one another to form a spring core (47), characterized by the following method steps: a) Inserting the front end of the spring coil (3) between a guide (1) and a hold-down device (5) into an insertion area (A ), b) grasping the front end of the spring coil (3) with a feed element (19), c) advancing or pulling the spring coil (3) with the feed element (19) until at least two springs (9) between the strands of feed bands ( 21 ', 21 ") of a draw-in device (21) lie in the draw-in area (B), d) the spring coil (3) is gripped by the draw-in device (21), the draw-in element (19) is loosened and the spring coil (3 ) with the counted number of springs (9), e) separating the spring coil section (3 ') containing the predeterminable number of springs (9) from the spring coil (3) in front of the Feed device (21), f) further transport of the spring snake section (3 ') from the feed area (B) into a subsequent transport or transfer area (C), g) guiding the new front end of the spring snake (3) into the feed area (B ) according to method step c), h) transfer the first spring snake section

(3 ') from the transport or transfer area (C) into an insertion area (D) and swiveling the insertion area (D) by 90 ", so that the axes of the springs (9) are perpendicular, i) translational displacement of the first spring coil Section (3 ⁷ ) from the insertion tapes (35 ', 35 ") of the insertion device (35) into the mounting device (45).

2. The method according to claim 1, characterized in that the counting of the springs (9) in the insertion area (A) takes place during the retraction of the spring coil (3).

3. The method according to any one of claims 1 or 2, characterized in that in the insertion area (A) presses a spring-loaded retainer (13) on the spring coil (3) and this when inserting into the feed area (B) and when separating the preceding spring lines Section (3 ') temporarily positioned holds.

4. The method according to any one of claims 1 to 3, characterized in that between the end of the feed area (B) and before the entrance of the transport area (C) a spaced camshaft pair (25) is used, with whose cams irregularities or position errors of the springs ( 9) within the spring coil (3) and / or that in addition to the camshaft pair (25) and essentially in the same plane, a driven positioning and auxiliary transport roller or belt pair (27) is used with which the end rings of the Springs (9) are aligned.

5. The method according to any one of claims 1 to, characterized in that the desired length of the spring coil section (3 ') desired in the insertion area (D) by compressing or stretching the spring coil section (3') between the transfer area (C) and the insertion area (D).

6. The method according to claim 5, characterized in that the compression or stretching of the spring coil section (3 ') by different conveyor speeds (v _c , v _D ) of the conveyor belts (29 ', 29 ") and (35', 35").

7. The method according to any one of claims 5 and 6, characterized in that a measurement of the actual length of the spring coil section (3 ') with a second sensor (51) in the transfer area (C), which measures the distance between the front and the rear end of the spring coil section (3 ').

8. Device for transporting pocketed springs (9) to a spring core assembly device (45) with an insertion area (A), a feed area (B) and an insertion area (D), characterized in that a) the insertion area (A) Guide (1) and a hold-down device (5) and a pull-in element (19), which can be advanced from a waiting position into a gripping position and from this - holding the spring coil (3) - in the transport direction (7), b) the pull-in area (B ) comprises two drivable feed belts (21 ', 21 "), the effective range of which partially overlaps with the displacement range of the feed element (19), c) a transport or transfer area (C) between the feed area (B) and the insertion area (D) a pair of conveyor belts (29 ', 29 ") is inserted and that d) two conveyor belts in the insertion area (D)

(35 ', 35 ") are drivable and are pivoted together about an axis (y) through 90 °.

9. The device according to claim 8, characterized in that at least one of the feed belts (21 ', 21 ") is pivotally mounted about the axis (X), such that the distance between the two strands of the feed belts

(21 ', 21 ") can be changed at least on the feed side.

10. Device according to one of claims 8 or 9, characterized in that the strands of the conveyor belts (29 ', 29 ") run offset by 90 ° with respect to the strands of the feed belts (21', 21").

11. The device according to one of claims 8 to 10, characterized in that a first sensor (11) for counting the pocketed springs (9) guided past is arranged in the insertion area (A) and in that a second sensor (51) in the transfer area (C) arranged for detecting the passage of the front and rear ends of the spring coil section (3 ').

12. Device according to one of claims 8 to 10, characterized in that between the feed region (B) and a drivable pair of camshafts (25) is inserted into the transport area (C), the cams of which partially engage the following pocketed springs (9) and irregularities and position errors of the adjacent springs (9) are intended to be adjusted.

13. Device according to one of claims 8 to 11, characterized in that between the insertion area (A) and the feed area (B) a cutting device (15) for severing a spring coil section (3 ') with a predeterminable number of springs (9 ) is inserted from the spring snake (3).

14. The device according to claim 13, characterized in that the cutting device (15) additionally comprises a welding device for attaching at least one weld located to the side of the separation point.

15. Device according to one of claims 8 to 14, characterized in that the conveyor belts (29 ', 29 ") and (35', 35") between the transfer area (C) and the insertion area (D) at different speeds (v _c , v _D ) can be driven.

6. Device according to one of claims 8 to 15, characterized in that the distance between the two opposite strands of the conveyor belts (21 ', 21 ") is adjustable by adjusting means (26).