Abstract
A cover layer of a fleece material for an innerspring unit comprising a plurality of pocketed springs is manufactured by supplying at least two longitudinal fleece webs, which extend substantially parallel in a longitudinal direction and are spaced from one another, and repeatedly attaching a transverse fleece web, which extends between the longitudinal fleece webs in a direction substantially perpendicular to the longitudinal direction, to the longitudinal fleece webs. The transverse fleece web segments are attached to the longitudinal fleece webs such that they form together with the longitudinal fleece webs a frame-like structure serving as the cover layer.
Claims
1. A method of manufacturing a cover layer of a fleece material for an innerspring unit, comprising the steps of: supplying at least two longitudinal fleece webs, which extend substantially parallel in a longitudinal direction and are spaced from one another; repeatedly attaching a transverse fleece web, which extends between the longitudinal fleece webs in a direction substantially perpendicular to the longitudinal direction, to the longitudinal fleece webs, the transverse fleece web attached to the longitudinal fleece webs forming together with the longitudinal fleece webs a frame-like structure serving as the cover layer; wherein the step of repeatedly attaching the transverse fleece web is carried out while the longitudinal fleece webs are conveyed in the longitudinal direction by a respective conveyor; wherein the step of repeatedly attaching the transverse fleece web comprises the following steps repeatedly performed for each transverse fleece web of the frame-like structure: holding the transverse fleece web with a holding device and positioning the transverse fleece web with the holding device at the longitudinal fleece webs; attaching the transverse fleece web adjacent to a first transverse edge of the transverse fleece web to the longitudinal fleece webs; releasing the holding device so that the transverse fleece web attached to the longitudinal fleece webs is conveyed together with the longitudinal fleece webs; cutting the transverse fleece web to a desired width in the longitudinal direction to obtain a second transverse edge of the transverse fleece web; and attaching the transverse fleece web adjacent to the second transverse edge to the longitudinal fleece webs.
2. The method of claim 1, further comprising: supplying the longitudinal fleece webs as endless longitudinal fleece webs, and repeatedly cutting the longitudinal fleece webs to repeatedly obtain the frame-like structure formed by two segments of the two longitudinal fleece webs and two successive transverse fleece webs attached to the two segments of the longitudinal fleece webs.
3. The method of claim 1, wherein the step of attaching the transverse fleece web comprises welding the transverse fleece web to each of the longitudinal fleece webs.
4. The method of claim 1, wherein the method is carried out as a fully automated process in an innerspring unit assembly machine.
5. The method of claim 1, wherein the cover layer of the fleece material is manufactured as the frame-like structure comprising a closed edge area where fleece material of the longitudinal fleece webs or fleece material of the transverse fleece web is present and a middle area surrounded by the edge area, where no fleece material is present.
6. The method of claim 1, further comprising activating the holding device to hold the transverse fleece web before the step of cutting.
7. The method of claim 6, further comprising supplying a fleece material and repeatedly cutting the fleece material to obtain the transverse fleece web.
8. A method of manufacturing an innerspring unit comprising a plurality of pocketed springs, comprising the steps of: manufacturing a cover layer of a fleece material according to the method of claim 1; and attaching the cover layer to a surface of a body comprising the plurality of pocketed springs to form the innerspring unit.
9. The method of claim 8, further comprising: manufacturing a first cover layer and a second cover layer; and attaching the first cover layer to a top surface of the body comprising the plurality of pocketed springs and the second cover layer to a bottom surface of the body comprising the plurality of pocketed springs.
10. The method of claim 8, wherein the step of manufacturing the cover layer is carried out at a first automated station of an innerspring unit assembly machine; and wherein the step of attaching the cover layer to the body comprising the plurality of pocketed springs is carried out at a second automated station of the innerspring unit assembly machine.
11. The method of claim 10, wherein the first automated station and the second automated station are located apart from one another; and wherein the method further comprises conveying the cover layer by means of a conveying device conveying the longitudinal fleece webs from the first station to the second station.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIGS. 1A and 1B shows a plan view of an innerspring unit and of a cover layer of the innerspring unit according to an embodiment of the invention;
(2) FIG. 2 is a schematic view of an innerspring unit assembly machine according to an embodiment of the invention;
(3) FIG. 3 shows an apparatus for manufacturing a cover layer for an innerspring unit according to an embodiment of the invention;
(4) FIGS. 4A and 4B illustrate the functionality of the manufacturing apparatus of FIG. 3; and
(5) FIGS. 5A-5F show a method of manufacturing a cover layer for an innerspring unit according to an embodiment of the invention.
(6) FIGS. 6A and 6B show a method of manufacturing a cover layer for an innerspring unit according to a further embodiment of the invention.
DETAILED DESCRIPTION OF THE DRAWINGS
(7) FIGS. 1A and 1B shows a plan view of an innerspring unit and of a cover layer of the innerspring unit according to an embodiment of the invention.
(8) The innerspring unit 20 shown in FIG. 1A comprises a body or a core of a plurality of pocketed springs 29. In more detail, the body of the innerspring unit 20 is manufactured from an endless row of pocketed springs 29 from which individual strings of pocketed springs 29 are cut and attached or glued to one another so as to form the body shown in FIG. 1A in which the individual springs 29 are arranged in an array of rows and columns. In the embodiment shown in FIG. 1A, the body comprising the plurality of springs 29 is covered by a cover layer 23 which is made from a fleece or nonwoven material. In the embodiment shown in FIG. 1A, the cover layer 23 is attached or glued to the upper surface of the body having the plurality of springs 29, and in particular the cover layer 23 has a frame-like structure with an edge area 21 where fleece material is present and a middle area 22 when no fleece material is present. In other words, in the middle area 22, the corresponding springs of the body of the innerspring unit 20 are not covered by the material of the cover layer 23, so that at least in this area the response of the individual springs is independent of the adjacent or surrounding springs as the pockets of the springs are not connected by the cover layer 23.
(9) FIG. 1B shows a plan view of the cover layer 23 of FIG. 1A. As indicated in FIG. 1B, the frame-like structure 21 of the cover layer 23 is formed by two longitudinal fleece web segments 24, 25 and two transverse fleece web segments 26, 27. In particular, in the embodiment of FIG. 1B, the transverse fleece web segments 26, 27 are attached, preferably welded, to the longitudinal fleece webs or segments 24, 25 to form the frame-like structure of the cover layer 23.
(10) Although not shown in FIGS. 1A and 1B, according to a preferred embodiment, a cover layer 23 of the type shown in FIGS. 1A and 1B may be attached to each of the top and bottom surfaces of the innerspring unit 20, so that the strings of the pocketed springs 29 are sandwiched between the pair of cover layers 23.
(11) FIG. 2 shows a schematic view of an innerspring unit assembly machine 30 which may be configured to assemble and manufacture the innerspring unit of FIG. 1.
(12) The innerspring unit assembly machine 30 shown in FIG. 2 comprises a device 31 for the storage and supply of fleece material. As will be discussed below in more detail, the storage and supply device 31 may comprise a separate device for the supply of longitudinal fleece webs and a separate device for the supply of transverse fleece webs.
(13) The fleece webs provided by the storage and supply device 31 are supplied to an apparatus 32 for the manufacturing of a fleece cover layer, for example the fleece cover layer 23 shown in FIGS. 1A and 1B. The apparatus 32 is configured such that it attaches the transverse fleece webs to the longitudinal fleece webs to obtain the cover layer 23 made from the fleece material and having the frame-like structure shown in FIGS. 1A and 1B.
(14) The cover layer thus manufactured by the manufacturing apparatus 32 is supplied to a station 34 which in addition receives pocketed springs from a pocketed spring storage and supply device 33. In particular, the pocketed spring storage and supply device 33 may provide an endless row of pocketed springs to the station 34 where the endless row of pocketed springs is cut into individual strings of pocketed springs which are then assembled to an innerspring unit, e.g., an innerspring unit 20 of the type shown in FIG. 1A. Furthermore, the station 34 is configured and designed to attach to the top and/or bottom surfaces of the innerspring unit cover layers which have been manufactured by the manufacturing apparatus 32.
(15) The innerspring unit thus assembled and manufactured by the station 34 is output at 35 as the final product of the innerspring unit assembly machine 30.
(16) The innerspring unit assembly machine 30 manufactures the innerspring unit in a fully automated process. The operation of each of the stations 31 to 35 of the innerspring unit assembly machine 30 is computer-controlled and coordinated by one or more control units.
(17) FIG. 3 shows an embodiment of the fleece cover layer manufacturing apparatus 32 of FIG. 2.
(18) The fleece cover layer manufacturing apparatus 32 has a section for the manufacturing of a top fleece cover layer and a separate section for the manufacturing of a bottom fleece cover layer. The structure and the functionality of both manufacturing sections are substantially similar, so that in the following only the configuration of the lower section for the manufacturing of the lower fleece cover layer will be described, which however likewise applies to the configuration of the upper section for the manufacturing of the upper fleece cover layer.
(19) As indicated in FIG. 3, a supply device 31a is provided for supplying a transverse fleece web, and separate supply devices 31b are provided for supplying at least two longitudinal fleece webs (for example, the longitudinal fleece webs 24 and 25 shown in FIGS. 1B and 1n FIGS. 5A-5F). The two longitudinal fleece webs are provided to extend substantially parallel and spaced apart from each other to form the two longitudinal sides of the cover layer of the innerspring unit. The transverse fleece web is provided to form the transverse fleece segments of the cover layer of the innerspring unit. The two longitudinal fleece webs are each supplied and provided as an endless fleece web which is conveyed by a conveying device 8 in a direction indicated by an arrow in FIG. 3. Both the two longitudinal fleece webs and the transverse fleece web are guided along a series of rollers 7a, 7b which correspondingly change the direction of the respective fleece web such that the transverse fleece web can be positioned at the two longitudinal fleece webs and attached thereto by means of an attachment device.
(20) As also indicated in FIG. 3, the attachment device may comprise a holding device 1-3 for clamping and holding the transverse fleece web, a welding device 4 acting as an attachment unit for attaching or welding the transverse fleece web to the two longitudinal fleece webs, and a cutting device 5 to cut the transverse fleece web into corresponding transverse fleece web segments.
(21) As will be discussed in the following in more detail, the attachment device shown in FIG. 3 is configured such that segments of the transverse fleece web are repeatedly attached to the two longitudinal fleece webs, so that an endless semifinished fleece product is created which is then conveyed by means of the conveying device 8 to the assembly station 34 shown in FIG. 2 where the individual frame-like cover layers 33 are cut from this semi-finished fleece product by means of cutting devices 9 which cut the longitudinal fleece webs at appropriate positions to obtain the frame-like cover layer 23 (in FIG. 3, separate cutting devices 9 are depicted for the cutting of the semi-finished fleece product of the top cover layer and for the cutting of the semi-finished fleece product of the bottom cover layer, respectively). In other words, the longitudinal fleece webs are used to transport the transverse fleece web segments, which have been attached thereto by means of the attachment device described above, to the assembly station 34 shown in FIG. 2.
(22) The operation of the attachment device shown in FIG. 3 will now be described in more detail with reference to FIGS. 4A and 4B.
(23) In FIGS. 4A and 4B, it is assumed that the transverse web segment 27 of the frame-like cover layer 23 shown in FIG. 1B is manufactured and attached to the longitudinal fleece webs 24, 25. Furthermore, in FIGS. 4A and 4B, it is assumed that the transverse web segment 26 of FIG. 1B has already been attached to the longitudinal fleece webs 24, 25 and is conveyed together with the longitudinal fleece webs 24, 25 by means of the conveying device 8 in the direction indicated by an arrow. As FIGS. 4A and 4B are side views, only the longitudinal fleece web 24 is depicted.
(24) In the embodiment shown in FIGS. 4A and 4B, the holding device comprises a moveable clamping unit 1, an L-shaped profile 2 and a clamping cylinder 3. The clamping cylinder 3 activates the clamping unit 1 to selectively press it against the L-shaped profile 2 to clamp the transverse fleece web therebetween or to move it away from the L-shaped profile 2 to release the transverse fleece web. The holding device 1-3 is provided to hold and clamp the transverse fleece web and to arrange it at a desired position with respect to the longitudinal fleece webs 24, 25. As indicated in FIG. 4A, the L-shaped profile 2 is arranged between the transverse fleece web 27 and the longitudinal fleece webs 24, 25. Preferably, the holding device 1-3 is configured to clamp the transverse fleece web 27 over its entire width, the width direction being perpendicular to the drawing plane of FIGS. 4A and 4B.
(25) FIG. 4A shows a state in which a front edge of the transverse fleece web 27 has already been positioned by means of the holding device 1-3 at an appropriate position with respect to the longitudinal fleece web 24 (and the parallel longitudinal fleece web 25) and welded to the longitudinal fleece webs by means of the welding device 4. Since the front edge of the transverse fleece web 27 has been attached to the longitudinal fleece webs 24, 25, the clamping cylinder 3 is operated to release the clamping unit 1 from the L-shaped profile 2, as indicated in FIG. 4 A, and the holding device 1-3 can return to its starting position by moving the clamping cylinder 3 downwards. In this state, the transverse fleece web 27 is no longer held or clamped by the holding device 1-3, so that the transverse fleece web 27 will be drawn by the longitudinal fleece webs 24, 25 due to the attachment of its front edge to the longitudinal fleece webs in the conveying direction of the longitudinal fleece webs.
(26) When the transverse fleece web 27 has reached a desired position with respect to the longitudinal fleece webs 24, 25, which corresponds to a desired width of the transverse fleece web 27 in the conveying direction of the transverse webs 24, 25, the cutting device 5 is operated to cut the transverse fleece web 27 to the desired width.
(27) FIG. 4B shows the state in which the cutting device 5 cuts the transverse fleece web to obtain the desired segment 27 of the transverse fleece web segment. Furthermore, FIG. 4B also shows that in this state the holding device 1-3 is again operated to clamp the front edge of the remaining transverse fleece web so as to avoid that the transverse fleece web gets lost. As the holding device 1-3 clamps the front edge of the remaining transverse fleece web, in a subsequent operating step this front edge can then be positioned again at the longitudinal fleece webs 24, 25 by moving the clamping cylinder 3 upwards and attached thereto as shown in FIG. 4A.
(28) In the state shown in FIG. 4B, the rear edge of the transverse fleece web segment 27 has not yet been fixed to the longitudinal fleece webs 24, 25. As explained above, the transverse fleece web segment 27 is conveyed together with the longitudinal fleece webs 24, 25 in the arrow direction indicated in FIG. 4B. When the free rear edge of the transverse fleece web segment 27 reaches the position where the welding unit 4 is located, the rear edge of the transverse fleece web segment 27 is welded by means of the wedding unit 4 to the longitudinal fleece webs 24, 25, so that ultimately the transverse fleece web segment 27 is attached to the longitudinal fleece webs 24, 25 both at its front edge and at its rear edge.
(29) The transverse fleece web segments 26, 27 shown in FIG. 4B form together with the longitudinal fleece webs 24, 25 the semi-finished fleece product which is then cut by the cutting device 9 shown in FIG. 3 into the frame-like structure of the cover layer 23 of FIGS. 1A and 1B. The cutting device 9 cuts the longitudinal fleece webs 24, 25 at appropriate positions so as to obtain the structure of the cover layer 23 shown in FIGS. 1A and 1B.
(30) The manufacturing method performed by the manufacturing apparatus 32 shown in FIGS. 3 and 4 is completely automated and to this end controlled by one or more control units, for example the control unit 10 shown in FIG. 3, which coordinate the operation of the individual components of the manufacturing apparatus 32. In particular, the operation of the individual components of the manufacturing apparatus 32 preferably is also coordinated with the operation of the other components of the innerspring unit assembly machine 30 depicted in FIG. 2, so that the entire innerspring unit can be manufactured in a fully automated process.
(31) The operation and functionality of the attachment device of the manufacturing apparatus 32 will now also be illustrated with respect to FIGS. 5A-5F. FIGS. 5A-5F show plan views of the longitudinal fleece webs 24, 25 during different states or steps of the attachment of the transverse fleece web 27 to the longitudinal fleece webs 24, 25. The conveying direction/running direction of the longitudinal fleece webs 24, 25 is indicated by arrows in FIGS. 5A-5F, so that the longitudinal fleece webs 24, 25 are conveyed in FIGS. 5A-5F from right to left. Furthermore, in FIGS. 5A-5F, the position of the welding unit 4 or its welding head with respect to the transverse fleece web 27 is indicated by WH, while the position of the cutting unit 5 is indicated by C.
(32) FIG. 5A shows a state in which the front edge of the transverse fleece web 27 is clamped by the holding device 1-3 and is positioned at the longitudinal fleece webs 24, 25, similar to the state shown in FIG. 4A.
(33) When the front edge of the transverse fleece web 27 reaches the position WH of the welding unit 4, the welding unit 4 is operated to weld the front edge of the transverse fleece web 27 to both longitudinal fleece webs 24, 25, as shown in FIG. 5B.
(34) Thereafter, as explained above, the holding device 1-3 is opened to release the transverse fleece web 27, so that the transverse fleece web 27 can be conveyed along with the longitudinal fleece webs 24, 25 due to the attachment of its front edge to the longitudinal fleece webs 24, 25. In other words, the transverse fleece web 27 is drawn at its front edge by the longitudinal fleece webs 24, 25 in the conveying direction.
(35) FIG. 5C shows a state in which the transverse fleece web 27 has already been conveyed to some extent by the longitudinal fleece webs 24, 25 in the conveying direction.
(36) When the transverse fleece web 27 has reached a predetermined position with respect to the cutting device 5, which corresponds to a desired width of the transverse fleece web 27 in the longitudinal direction of the longitudinal fleece webs 24, 25 (which corresponds to the longitudinal direction of the corresponding cover layer 23, see FIG. 1B) the cutting device 5 is activated to cut the transverse fleece web 27 over its entire width to form a corresponding transverse fleece web segment, as shown in FIG. 5D.
(37) Before cutting the transverse fleece web, the holding device 1-3 is activated again to clamp the transverse fleece web at a position which—in the running direction of the longitudinal fleece webs 24, 25—is after the position C of the cutting unit 5 and to avoid that the front edge of the remaining transverse fleece web material gets lost.
(38) At this stage of the process, the free rear end of the transverse fleece web segment 27 is not yet attached to the longitudinal fleece webs 24, 25.
(39) However, as shown in FIG. 5E, when the rear and of the transverse fleece web segment 27 reaches the position WH of the welding unit 4, the welding unit 4 is operated to weld the rear edge of the transverse fleece web segments 27 to both longitudinal fleece webs 24, 25.
(40) The entire process may then be repeated with the next transverse fleece web segment 28, as shown in FIG. 5F, the front edge of this next transverse fleece web segment 28 being positioned at the longitudinal fleece webs 24, 25 similar to the transverse fleece web segment 27 shown in FIG. 5A.
(41) The position WH of the welding device 4 may be variable, so that the width of the welding unit 4 may be adjustable to process different fleece widths. Furthermore, the position C of the cutting device 5 may be variable so as to be able to cut transverse web segments having a variable width in the longitudinal direction of the longitudinal fleece webs 24, 25.
(42) The transverse fleece web segments 26, 27 shown in FIG. 4B form together with the longitudinal fleece webs 24, 25 the semi-finished fleece product which is then cut by the cutting device 9 shown in FIG. 3 into the frame-like structure of the cover layer 23 of FIGS. 1A and 1B. The cutting device 9 cuts the longitudinal fleece webs 24, 25 at appropriate positions so as to obtain the structure of the cover layer 23 shown in FIGS. 1A and 1B.
(43) FIG. 6A and FIG. 6B show the attachment of the transverse fleece web 27 to the longitudinal fleece webs 24, 25 and the cutting according to a further embodiment.
(44) As shown in FIG. 6A, the transverse fleece web 27 may be attachment to the longitudinal fleece webs 24, 25 at a plurality of positions, which in particular may be equally spaced.
(45) As shown in FIG. 6B, the position C and the function of the cutting device may be such that the transverse fleece 27 is cut together with the longitudinal fleece webs 24, 25, as it is indicated by a dashed line in FIG. 6B.
