AN ARRANGEMENT IN A SPRING ELEMENT, AND A METHOD OF MANUFACTURING SAID ELEMENT

Abstract: An arrangement in a spring element consisting of at least two basic members (1), into which shock absorbing arcuate elements (2) are secured. Said basic elements (1) are formed as hollow profile lengths, preferably of a square shape, wherein a series of apertures is arranged, preferably on one side. Said apertures (3) have a diameter that is somewhat larger than that of said arcuate elements (2). Said arcuate elements (2) are inserted in said apertures (3) in a desired predetermined angle, and the profile void is filled with a moulding compound known per se. Two such spring elements may be combined to a unit and may be embedded in a moulding foam rendering said spring unit a block shape with a soft surface.

Description: AN ARRANGEMENT IN A SPRING ELEMENT, AND A METHOD OF MANUFACT¬ URING SAID ELEMENT. The invention relates to an arrangement in a spring element comprising at least two basic members with shock absorbing arcuate elements being integrally secured, e.g. by moulding, in said basic members. Spring elements are known comprising, e.g. two basic members with arcuate elements consisting of steel wire cables that are secured between said members, and the ends of said steel wire cables may then be inserted in retaining grooves or through holes in said basic members. Said steel wire cable is then in one piece for a number of said arcuate spring elements. Further¬ more, it is known to construct said basic members from a material capable of being moulded, e.g. from a plastic material, with said arcuate steel elements being inserted into the mould and being retained by moulding at the same time as said basic members are moulded. All these embodiments, however, either result in a static structure of the spring element or necessitate additional finishing of the basic members to permit a varied structure of the spring element per se. With steel wire elements provided with connectors at their ends for insertion in basic members, e.g. positioning of the hole for insertion of said connector will be critical, even though said spring elements may be varied by using a large or small number of shock absorbing arcuate elements. It is an object of the present invention to improve this kind of spring elements and to provide a device having the most simple and inexpensive structure possible at the same time as it permits highly varied designs. It is, furthermore, an object of the invention to be able to construct said spring element from the most simple standard material possible.. These objects are achieved in a device of the kind mentioned above that is characterized as stated in the claims. The invent¬ ion also relates to a method of manufacturing such a spring element, said method being characterized as stated in the method claims. According to the invention the original material is a standard hollow profile that is available in long lengths and may be cut into lengths according to demand. A series of apertures may then be provided along one side of said hollow profile, said apert¬ ures having a diameter that is larger than that of the intended shock absorbing elements, which are preferably steel wire cables, but which may consist of other kinds of shock absorbing elements and which may be manufactured from a material different from steel. If square profiles are used it is very simple, e.g. to combine two such elements by welding in order to achieve a symmetrical spring characteristic. The shock absorbing arcuate elements can also be cut to length from large lengths, frayed ends not creating any problem, since the ends are to be secured by moulding inside said hollow profile. For completion said hollow profile is filled with a suitable moulding compound that may be introduced in a simple manner from the end portions. In order to provide the spring element with a final spring characteristic as well as obtaining a soft surface it may be suitable to embed the entire shock absorbing structure in poly- urethane foam that will also settle between said basic members and said arcuate spring elements. Alternatively, a flexible material may be introduced to provide for additional shock absorption between said basic members. The invention is now to be disclosed in more detail with re¬ ference to an embodiment shown in the drawing, wherein Figure 1 is a side elevation showing a spring element according to the invention; and Figure 2 is a section taken along line A-A in Figure 1. In the Figures two spring elements according to the invention are shown assembled to a unit providing for symmetrical shock absorption in several directions. The unit shown in Figure 1 is, thus, composed of a top element and a lower element accord¬ ing to the invention, which are connected at their common plane of contact. In disclosing the invention we will, thus, only refer to one half of the figure. The spring element according to the invention is composed of two basic members 1 being, in the shown embodiment, made of a square profile which may be made from any suitable material, e.g. metal, like steel or aluminium, plastic,or the like. Said two basic members 1 are placed in parallel, and in their sides facing upwards holes 3 have been drilled for inserting shock absorbing, arcuate elements 2. Said arcuate elements 2 may be formed from cables cut to length, e.g. of steel fibre, glass fibre, carbon fibre, epoxy, urethane, or the like. Solid arcuate spring steel elements and leaf spring elements may be used as well. The essential feature of the elements as disclosed is that the basic members are, thus, formed by profile means that may be manufactured in lengths that are cut as to demand, and that the same goes for said arcuate spring means 2. The holes 3 in said basic members are made spacious in relat¬ ion to the diameter of the cable means 2. For manufacturing the spring elements according to the invent¬ ion, e.g. two square tubes are secured in parallel in a jig with the holes facing upwards. Said arcuate cable means 2 are then inserted into said spacious holes 3 and adjusted in the desired angular position and arc opening, and are firmly held in that position. In the Figures an embodiment is shown, where said cable arcs are provided at an angle of 45° outwards from a center portion in order to result in a spring element design that shows maximum stability against force loads in the longitudinal direction of the profile. When said arcuate cable means have been provided in the desir¬ ed position, which is easily obtained because of the spacious holes in relation to the cable diameter, moulding material may be introduced into the void of the tube profile, e.g. through its open ends. The moulding material may be, e.g. urethane/ polyurethane, epoxy, metal alloy, or a moulding material on the basis of cement. Said moulding material is designated 4 in the Figures. When the moulding compound has set, the spring element accord¬ ing to the invention is, in principle, completed. According to an advantageous feature of the invention, e.g. two elements of this kind may be glued or welded together, as illustrated in the figure. Thus, an element with shock absorbing arcs on both sides is achieved, which will result in better shock ab¬ sorption and a more stable spring characteristic. Such a de-. sign is very simple when square profiles are used. It should be mentioned that the shape of the elements may be varied as to demand, and it is possible to use profiles for the basic members showing completely different designs than the square tubes. Also, more than two basic members may be combined. Thus, the invention forms a basis for many different embodiments and for solving many different problems of shock absorption. According to an additional feature the spring characteristic may be further adjusted by moulding said elements into poly¬ urethane foam or polyethylene foam. Such foam will settle between said basic members 1 as well as around the shock absorbing arcuate elements 2, and it will, thus, influence their shock absorbing properties with a certain adjusting effect, without however, influencing their main properties. Also, a soft surface of said shock absorbing elements is achieved, and they may, e.g. receive a block shape. Between said basic members 1 it is also possible to provide a flexible material which can then act as an additional shock absorber . It will be obvious from the above mentioned that a large number of modifications is possible within the scope of the invention.

Claims: CLAIMS: 1. An arrangement in spring elements, comprising at least two basic members (1), in which shock absorbing arcuate elements (2) are secured, e.g. by being moulded into said basic members (1), c h a r a c t e r i z e d i n that said basis members (1) are designed as hollow profile lengths provided with a series of apertures (3), preferably on one side, that said arcuate elements (2) are provided at a desired predetermined angle in said apertures (3) and have a diameter smaller than that of said apertures, and that the profile void is filled with a moulding compound (4) known per se. 2. An arrangement as defined in claim 1, c h a r a c t e r i z e d i n that said spring element is moulded into a foam, preferably a polyurethane foam or a polyethylene foam. 3. An arrangement as defined in claim 1, c h a r a c t e r i z e d i n that a flexible material is provided between said basic members (1), e.g. by moulding. 4. An arrangement as defined in claim 1, c h a r a c t e r i z e d i n that said basic members are formed of square profiles. 5. An arrangement as defined in claim 1, c h a r a c t e r i z e d i n that said basic members (1) are positioned in parallel. 6. An arrangement as defined in claim 1, c h a r a c t e r i z e d i n that at least two spring elements are combined by welding og glueing together basic members (1) . 7. A method for the manufacture of a spring element as defined in one or several of the preceding claims, c h a r a c t e r i z e d i n that tube lengths, preferably showing a square profile, are drilled at one side to provide a series of apertures, that at least two tube lengths are secured in parallel with said apertures facing upwards, that the ends of cables having a smaller diameter than said tubes are insert¬ ed in the apertures of the at least two tube lengths, that the position of said cables in relation to said tube lengths is adjusted in accordance with predetermined angles, that said tubes are then filled with a moulding compound that is made to set, and that several elements of this kind are, if desired, ar combined to an assembled unit. 8. A method as defined in claim 7, c h a r a c t e r i z e d i n that said elements are mould¬ ed into a foam, e.g. polyurethane foam or polyethylene foam. 9. A method as defined in claim 7, c h a r a c t e r i z e d i n that a flexible material is provided between said parallel tube lengths and is secured by being welded or glued to said tube lengths.

Inventors: PEDERSEN REGNOR, PEDERSEN, REGNOR
Applicants: PEDERSEN REGNOR, PEDERSEN, REGNOR
Application year: 1986
Main classification: F16F7
IPC codes: F16F7