Patent Application
20250027535
The present invention relates to a slide system having a first slide member and a second slide member. Such sliding systems may for example be used in sliding door arrangements, extendable tables, kits for hanging curtains, and sliding drawer arrangements. The invention further relates to a method for forming said slide system.
Linear plain furniture bearings in the form of slide systems are known in the art and have been used in several further constructions within the home, including extendable tables, chests of drawers, extendable sofa beds, and sliding doors etc. They are relatively simple, reliable constructions, and are easy to use. An exemplary slide system comprising a slide member is disclosed in e.g. the patent application WO2017/044032A1. The slide member in said document has a slide surface coated with a lacquer comprising a resin. The lacquer is in turn at least partly coated with a lipophilic composition coating to provide a slide layer with lowered friction. Such slide system has a very wide range of use, including heavy sliding doors, heavy drawers and the like.
However, in lighter furniture applications, such as lighter sliding drawers in bedside tables, smaller extendable tables, sliding doors in sideboards, or kits for hanging curtains, there is no need for such a robust slide system as disclosed in WO2017/044032A1. Therefore, it is of interest to provide a simpler, inexpensive, safe means form for providing a slide system with lowered friction for lighter sliding furniture applications. The lowered friction should preferably be in principle permanent and easy to manufacture. Further, the slide system should preferably be essentially maintenance-free.
Consequently, the present invention seeks to mitigate, alleviate, eliminate or circumvent one or more of the above identified deficiencies and disadvantages in the art singly or in any combination by providing in a first aspect a slide system comprising a first slide member having a slide surface at least partly coated with a lipophilic composition coating to provide a slide layer with lowered friction, and a second slide member arranged in sliding contact with the slide layer at an interface to provide a slide system. The interface between the slide layer and the second slide member forms a plain bearing to allow for sliding movement of the second slide member and the first slide member relative to each other. At least the slide surface of the first slide member is made of a first plastic, and at least a part of the second slide member being in sliding contact with the slide layer is made of a second plastic. The first and the second plastics are different plastics.
According to an embodiment, the first slide member is statically arranged whereas the second slide member is dynamically arranged, such as the second slide member being arranged to slide along the first slide member. However, also the first slide member may be dynamically arranged. According to an alternative embodiment, the second slide member is statically arranged, whereas the first slide member is dynamically arranged, such as the first slide member being arranged to slide along the second slide member.
This provides for a low friction slide system with efficient function in many applications, including furniture applications such as sliding doors, drawers, extendable bed frames and extendable tables, etc. The slide system disclosed herein is specifically suitable for furniture applications exposed to lighter loads, such as lighter sliding doors, extendable tables and drawers in e.g. a bedside table. Application of the lipophilic composition coating on the first slide member and the use of different plastics on the first and second slide members surprisingly reduced the long term dynamic friction after repeated use (up to about 80%) of the slide system. For instance, experiments have shown that the long term dynamic friction between a first and a second plastic slide member can be decreased from 14N to 3N upon addition of the lipophilic composition coating on the first slide member and the use of different plastics on the first and second slide members. Whereas the initial dynamic friction is quite high, the dynamic friction increases even further after a few cycles, without application of the lipophilic composition coating. On the contrary, if a lipophilic composition coating is applied, the dynamic friction remains low even after repeated use.
The slide system is further inexpensive and easy to manufacture, since plastic parts may be formed by e.g. extrusion or injection moulding. For instance, the first slide member can be formed by extrusion while the second slide member may be made using injection moulding. The extrusion process is fast and efficient when manufacturing continuous shapes with uniform cross-section along its longitudinal extension, such as the first slide member, in varying lengths. Hence, manufacturing with extrusion can easily be adapted depending on which length or shape one wish to obtain for the first slide member. Since extrusion can be performed as a continuous process, the first slide member can be produced in high volumes quickly, with a low amount of waste material. The second slide member can easily be formed using injection moulding, a manufacturing process which enables the formation of almost any type of shape, even complex structures, with very high precision and replicability. It is also a very efficient process, where a large number of second slide members may be formed quickly.
Having slide members made of plastics also provide parts of the slide system being somewhat flexible, which may be advantages in tight spaces during for instance mounting of the slide system. Furthermore, it has surprisingly been found that the decreased friction effect was not only temporary, but also seemingly permanent or at least long-lasting. There is thus no need to replenish the lubricant in the form of the lipophilic composition coating.
Moreover, plain bearings in slide systems used in furniture applications exposed to lighter loads do not normally comprise an interface comprising two plastic surfaces in contact with each other. Hence, it is surprising that the present invention providing a slide surface arranged on a first slide member made of a first plastic in sliding contact with a part of a second slide member made of a second plastic provides an advantageous slide system, where the need of a metal support or the like can be dispensed with. In addition, since both surfaces of the interface where the sliding contacts takes place are made of plastics rather than a metal surface, no additional lacquer coating of the surface is required.
The first and the second plastics are different plastics. Thus, the plastics not only are different grades of plastics (e.g. PET with different intrinsic viscosity), but also at least plastics of different sub-types of plastics (e.g. PA 6 and PA 66, or PET and PBT), or preferably different types of plastics (e.g. polyacetal and polyamide), i.e. plastics comprising different types of polymers. According to an embodiment, the first and the second plastics are different types of plastics. Thus, the first plastic may comprise a first type of polymer, e.g. a polyoxymethylene (POM), whereas the second plastic may comprise another type of polymer, e.g. a polyamide (PA), such as PA6. In different types of polymers, the linkage between the monomers typically differs (e.g. amide coupling and acetal coupling, respectively), and/or the functional groups attached to the polymer chain differ (e.g. amide group and methyl group, respectively).
The first plastic and/or the second plastic are typically a thermoplastic.
In one embodiment, the first and the second plastic are polymers selected from the group of polymers consisting of polyoxymethylenes (POM), polymethyl methacrylate (PMMA), polycarbonate (PC), polypropylene (PP), polypropylene copolymers (PPCO), polyesters (e.g. thermoplastic polyesters, such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), and polylactic acid (PLA), as well as bio-based thermoplastic polyesters, such as polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), and polyethylene furanoate (PEF)), polyamides (PA), such as polyamide 6 (PA6), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), polyaryletherketone (PAEK; e.g. Polyether ether ketone (PEEK)), and Polytetrafluoroethylene (PTFE). As already stated, the first and the second plastics are different plastics. Preferably, first and the second plastics are different types of plastics, such as POM and PA.
In another embodiment, the first slide member is made of PA, PC, PPCO, or PMMA, and the second slide member is made of POM or PA; or the second slide member is made of PA, PC, PPCO, or PMMA, and the first slide member is made of POM or PA. The first slide member and the second slide member are made of different plastics; preferably different types of plastics. In a preferred embodiment, one of the slide members is made of POM and the other slide member is made of PA, such as PA6, or PC, most preferred the second slide member is made of POM, and the first slide member is made of PA or PC.
According to an embodiment, the second slide member is made of POM and the first slide member is made of PA, such as PA6. Preferably, the first slide member is made of PA6. Such a combination provides a low dynamic friction.
According to another embodiment, the second slide member is made of POM and the first slide member is made of PET. Also this combination, was found to provide low dynamic friction.
The first slide member may be a slide bar forming a linear slide profile. Such a slide bar is typically statically arranged. Preferably, the slide bar is a plastic slide bar made of the first plastic, such as PA. In such case, the slide bar forming the linear slide profile may be provided with a plastic profile surface arranged on or in a support structure. When arranged in a support structure, the first slide member may be an insert, such as a U-profile, arranged in a recess of the support structure, such as in a rim for a table surface of an extendable table. Further, also the floor portion of e.g. a wardrobe or the bottom portion of e.g. a kitchen fixture may serve as the support structure to accept an insert. In one embodiment, the first slide member is arranged on a support structure with a snap-fit engagement.
According to an embodiment, the slide bar is a plastic slide bar made of the first plastic. The plastic slide bar may have the form of an insert to be arranged in a recess of a support structure.
However, a plastic profile may also form the linear slide profile on its own without any need for a support structure. According to an alternative embodiment, wherein the second slide member is statically arranged, it may be a slide bar forming a linear slide profile, such as a plastic slide bar made of the second plastic.
Further, the first slide member, such as in the form of a slide bar, may be monolithic. The slide bar may be extruded or injection moulded in one piece, i.e. a monolithic slide member. Injection moulding is a simple and commonly used method for forming plastic articles. Hence, the manufacturing of such a slide bar with injection moulding is quick, easy and cheap. Extruding the slide bar is also an efficient manner of forming a slide bar, in particular when forming a long, such as longer than 50 cm, slide bar having a constant profile along its entire length.
Similarly, the second slide member may be moulded, e.g. injection moulded, in one piece. Thus, the second slide member may be monolithic. As already mentioned, injection moulding is a simple and commonly used method for forming plastic articles. Hence, the manufacturing of such a slide member with injection moulding is quick, easy and cheap.
Contrary to the teaching of the prior art, e.g. WO 2017/044032A1, the lipophilic composition coating of the present slide system is coated directly on the slide surface of the first slide member, not on an intermediate lacquer. As the slide surface is made of a first plastic, thereby dispensing with the need to lacquer the first slide member in order to provide it with low friction, the slide surface of the first slide member is typically at least 150 μm thick to provide the first slide member with structural integrity. The slide surface may be at least 250 μm, at least 500 μm, at least 750 μm, or at least 1 mm thick. The smallest dimension of the cross section of the slide member perpendicular to the slide surface may thus be at least 150 μm, such as at least 250 μm, at least 500 μm, at least 750 μm, or at least 1 mm. Further, the thickness of the first slide member may vary over its cross-section. The thickness of the first slide member may be at least 150 μm, such as at least 250 μm, at least 500 μm, at least 750 μm, or at least 1 mm.
Hence, the first slide member and the second slide member are typically non-lacquered, or have at least a non-lacquered surface at the interface arranged to form the sliding contact between the slide layer of the first slide member and the second slide member.
In one embodiment, a lipophilic composition may be applied to the second slide member, and transferred, at least partly, to the first slide member from said second slide member when the first and second slide members are brought into contact with each other. Preferably, in such case, the lipophilic composition is applied onto the second slide member at the interface arranged to be in sliding contact with the first slide member.
In one embodiment, the part of the second slide member being in contact with the slide layer of the slide surface is configured as having at least one blade extending in a sliding direction. In such case, the slide layer may be present at a track, such as a groove or a ridge, extending along the sliding direction. The track may serve to guide the at least one blade in sliding along the slide bar. Further, the second slide member may be provided with more than one blade, such as 2, 3, 4 or 5 blades, being arranged in contact with the slide layer. According to one embodiment, each blade has a length, as seen along the sliding direction, of maximum 15 mm, such as maximum 10 mm or even maximum 5 mm. According to one embodiment, each blade has a length of at least 1 mm, such as at least 2 mm. Especially if the slide layer is present at a ridge, it may be preferred to provide the second slide member may be with more than one blade.
In another embodiment, the second slide member comprises at least one individual contact point in contact with the first slide member at the interface between the first slide member and the second slide member. The contact area of each individual contact point is preferably less than 3 mm2, more preferably less than 1.5 mm2, and most preferably less than 0.75 mm2. Preferably, the contact pressure in said at least one contact point is at least 4 N/mm2, preferably at least 8 N/mm2, and more preferably at least 12 N/mm2, and preferably the contact pressure is lower than the strain at yield of the material of the second slide member at the contact point. Normally, it is preferable to provide a larger surface area of the contact point, in order to distribute the load as much as possible, especially in the case of interfaces between two plastic surfaces being slightly soft (as compared to e.g. a metal). Hence, it is surprising that the contact area of each individual contact point in the slide system disclosed herein is preferably less than 3 mm2.
In a further embodiment, the first slide member and the second slide member of the slide system are provided in a sliding application of a furniture in which the slide system is carrying a load of less than 35 kg, such as less than 20 kg, such as less than 15 kg, or even less than 10 kg. The slide system may carry a load of 15 to 20 kg.
The first slide member and the second slide member of the slide system may be provided in an extendable table sliding system, a drawer sliding system, a sliding door system, a sofa bed, or a furniture rotary system, such as a roller bearing system. According to an embodiment, the first slide member and the second slide member of the slide system is provided in a drawer sliding system, an extendable table sliding system, or a sliding door system.
As already mention, the second slide member may be statically arranged, whereas the first slide member is dynamically arranged according to an alternative embodiment. In such an embodiment, the second slide member may be a linear slide profile provided with at least one blade. The first slide member with the slide layer may then be arranged to slide along the longitudinal extension of the second slide member.
In one embodiment, the lipophilic composition coating comprises compounds comprising C6 to C40, such as C8 to C30, or even C10 to C24, non-aromatic hydrocarbyl groups, such as alkenyl groups and/or alkyl groups, e.g. alkyl groups. The lipophilic composition coating may comprise at least 25 wt. %, such as at least 50 wt. %, at least 75 wt. %, or at least 90 wt. %, of compounds comprising C6 to C40, such as C8 to C30, alkyl groups. Typically, the lipophilic composition coating comprises non-aromatic hydrocarbons, such as alkenes and/or alkanes, e.g. alkanes, and/or triglycerides and/or fatty acids, e.g. triglycerides. According to an embodiment, the lipophilic composition coating comprises a mixture of alkanes and triglycerides. Whereas the triglycerides provide even lower dynamic friction, the alkanes improve the long term stability of the lipophilic composition.
The lipophilic composition coating may comprise at least 25 wt. %, such as at least 50 wt. %, C6 to C40, such as C8 to C30, non-aromatic hydrocarbons, such as alkenes and/or alkanes, e.g. alkanes.
As already mentioned, the lipophilic composition may further comprise triglycerides and/or fatty acids, such as triglycerides. Preferably said triglycerides, if present, are composed of saturated fatty acids residues. Similarly, said fatty acids, if present, are saturated fatty acids. Preferably the lipophilic composition coating comprises 1 to 40 wt. % triglycerides and/or fatty acids. In such case, preferably the triglycerides, if present, are to at least 90% composed of fatty acids with C6 to C40, such as C8 to C30, alkyl groups. Preferably said fatty acids, if present, having C6 to C40, such as C8 to C30, alkyl groups. Alternatively, the lipophilic composition coating preferably comprises at least 25 wt. %, such as at least 50 wt. %, of triglycerides and/or fatty acids, preferably said triglycerides, if present, to at least 90% being composed of fatty acids with C6 to C40, such as C8 to C30, alkyl groups, and preferably said fatty acids, if present, having C8 to C40, such as C8 to C30, alkyl groups. Preferably, the lipophilic composition is not only composed of fatty acids.
In another embodiment, the lipophilic composition coating comprises a C10 to C28 alkane and a tri-glyceride, and the viscosity, according to ISO 3104:1994/C or 1:1997, of the lipophilic composition coating at 40° C. is 20 to 80 mm2/s.
The lipophilic composition coating may further comprise an anti-oxidant. Preferably the lipophilic composition coating comprises up to 5 wt. % of the anti-oxidant, such as up to 2.5 wt. % of the anti-oxidant, such as 0.1 to 1 wt. % of the anti-oxidant. Preferably the anti-oxidant has an E-number (accepted as food-ingredient), and preferably the anti-oxidant has a log P (n-octanol/water) value of at least 1 at 25° C.
In one embodiment, the anti-oxidant is selected from the group consisting of tocopherols, e.g. (±)-α-tocopherol, and sterically hindered phenols, e.g. dibutylhydroxy-toluene or butylated hydroxyanisole.
The lipophilic composition coating may comprise a mixture of at least two different tri-glycerides, and/or a mixture of at least two different C10 to C28 alkanes. Preferably, the lipophilic composition coating comprises a mixture of at least two different tri-glycerides and at least two different C10 to C28 alkanes.
In another embodiment, the lipophilic composition coating comprises at least 50 wt. % of a C10 to C28 alkane, or a mixture of C10 to C28 alkanes, and 1 to 50 wt. % of a tri-glyceride, or a mixture of tri-glycerides. In such case, the lipophilic composition coating may comprise at least 60 wt. % of a C10 to C28 alkane, or a mixture of C10 to C28 alkanes, and 5 to 40 wt. % of a tri-glyceride, or a mixture of tri-glycerides. Further, in such case, the lipophilic composition coating may comprise at least 70 wt. % of a C10 to C28 alkane, or a mixture of C10 to C28 alkanes, and 10 to 30 wt. % of a tri-glyceride, or a mixture of tri-glycerides.
Typically, the lipophilic composition coating comprises less than 5 wt. % aromatics. Preferably, the lipophilic composition coating comprises less than 2.5 wt. % aromatics, even more preferably less than 1.0 wt. % aromatics.
In a further embodiment, the lipophilic composition coating has a Total Iodine Value according to ASTM D1541-97 of less than 10; preferably less than 5. As recognized by the skilled per, the Total Iodine Value is representative for the amount of unsaturation in a composition.
In a second aspect, there is provided a method for providing a slide system comprising the steps of providing a member having a slide surface, wherein at least the slide surface is made of a first plastic, and coating at least part of the slide surface with a lipophilic composition coating to provide a first slide member having a slide layer with lowered friction. The method further comprises providing a second slide member, wherein at least a part of said second slide member configured to be in sliding contact with the slide layer is made of a second plastic, which is different from the first plastic, and arranging the first slide member and second slide member such that an interface between the slide layer and the second slide member forms a plain bearing to allow for sliding movement of the second slide member and the first slide member relative to each other. Aspects and preferred features in relation to such a method have already been described herein above in relation to the slide system. As appreciated by the skilled person, they are equally applicable in relation to the method.
Further advantageous features of the invention are elaborated in embodiments disclosed herein. In addition, advantageous features of the invention are defined in the dependent claims.
The above and other aspects, features and advantages of which the invention is capable of will be apparent and elucidated from the following description of the present invention, reference being made to the accompanying drawings, in which
The present inventors have surprisingly found that a slide system 1 with very low slide friction can be obtained by using a first slide member 10 provided with a slide surface 14 at least partly coated with a lipophilic composition coating 18 to provide a slide layer 19, and a second slide member 20 arranged in sliding contact with the slide layer 19 at an interface. The interface between the slide layer 19 and the second slide member 20 forms a plain bearing allowing sliding movement of the second slide member 20 and the first slide member 10 in relation to each other. At least the slide surface 14 of the first slide member 10 is made of a first plastic, and at least a part of the second slide member 20 in sliding contact with the slide layer 19 is made of a second plastic, which is a different plastic from the first plastic.
Without being bound by any theory, it is believed that the use of first and seconds plastics being different from each other, lowers the attraction forces between the slide layer 19 and the second slide member 20, thus resulting in a lowered sliding friction there between. In addition, the lipophilic composition coating acts as a lubricating coating, and may comprise for example sebum (natural or artificial), coconut oil, or liquid paraffin, and provides a slide layer with extremely low dynamic friction (sliding resistance). The application of the lipophilic composition coating and the use of different plastics for the first and second slide members 10, 20 reduce the dynamic friction with as much as about 75-80% (see for instance Example 2 and 3 presented in the Experimental section below). Further, and even more surprisingly, the effect is not temporarily, but seemingly permanent or at least long-lasting. The need to replenish the lubricant may hence be dispensed with.
In experiments employing a slide system according to the present invention, where a slide surface of a first slide member has been coated with a lipophilic composition coating, the friction remained nearly the same after more than 50,000 test cycles. So many cycles by far exceed the expected number on lifetime cycles in most furniture applications. The experiments are described in more detail in the section Experiments below.
Further, very low amounts of the lipophilic composition coating are needed to provide lowered friction. Thus, contamination of the lubricating coating does not pose any pronounced problem, as the coating, due to the very low amount present, does not have substantial adhesive properties. This is in contrast to the normal use of lubricants in plain bearings. Further, exposure to contaminations, e.g. dust etc., has been shown not to affect the lowered friction. Neither is the lubricating coating sensitive to washing. Wiping the slide member, e.g. the first slide member 10, with a dry and/or wet cloth, does not affect the lowered friction. These properties make the slide member, e.g. the slide bar 10, very useful for use in systems for sliding wardrobe doors, extendable tables, drawers of chests of drawers, hanging curtains, and similar applications.
According to an embodiment, the slide system 1 comprises the first slide member 10 and the second slide member 20, as depicted in
As shown in an enlarged view of
Further, as shown to the left in
Alternatively, the second slide member 20 may comprise at least one blade 21 arranged in contact with a sliding layer 19 present on a flat slide surface 14 of the first slide member 10 (not shown). Hence, in such case, the at least one blade 21 slides along the flat surface of the first slide member 10.
The slide surface 14 of the first slide member 10 is made of a first plastic, while the blade 21 of the second slide member 20 is made of a second plastic, being different from the first plastic. Optionally, the entire first slide member 10 is made from the first plastic and/or the entire second slide member 20 is made from the second plastics.
The first slide member 10 may be a slide bar 10 forming a linear slide profile. Alternatively, the first slide member 10 forming the linear slide profile is provided with a plastic profile surface arranged on a support structure (not shown). Said support structure may be made from a non-plastic material, such as metal or wood, or another type of plastic material than the plastic profile. In one embodiment, the first slide member 10 is arranged on a support structure, preferably with a snap-fit engagement.
As shown in
The moveable part 120 comprises two parallel members 122, 124 being inter-connected at some position along their respective length, such as at one of their respective ends, by a traverse beam 126. The traverse beam 126 is preferably arranged perpendicularly to the two parallel members 122, 124. Optionally an additional cross beam 128 is provided at the opposite ends of the parallel members 122, 124. Each parallel member 122, 124 forms a second slide member 20 of the respective slide systems 1 as will be described in more detail with reference to
The upper and lower inner surfaces 153a, 154a are preferably extending in parallel with each other whereby the distal inner surface 155a extends perpendicularly to the upper and lower surfaces 153a, 154a. The upper and lower surfaces 153a, 154a thus extend in the horizontal plane, while the distal surface 155a extends in the vertical plane. All surfaces 153a, 154a, 155a are provided with superior low friction properties according to the principles described above, and these together form, in this embodiment, the first slide member 10 provided with a slide surface 14 of the slide system 1. The insert 15 is attached to the recess 115 e.g. by an adhesive, by friction or similar. In particular, the insert 15 may comprise ridges 153b on its horizontal outer faces, thereby providing for friction engagement to the recess 115. The insert 15 could be made by extruding a plastic material, such as PA (e.g. PA6). The parallel beams 122, 124 are each provided with a second slide member 20 configured to slide along the first slide member 10 of the parallel beams 112, 114. The insert 15 shown in
Now turning to
Further, the second slide members 20 each comprise a plurality of blades 221, each blade 221 corresponding to the blade 21 as described with reference to
The Intermediate slide bar 130 is thus configured to be received by the C-shaped first guiding rail 210. The sliding system 1 also comprises a second guiding rail 140 to be fixedly mounted to a moveable part, e.g. the drawer extractable from the drawer frame. The second guiding rail 140 is provided with means (not shown), such as screw holes or similar, for attaching the second guiding rail 140 to the moveable part, i.e. the drawer.
The second guiding rail 140 is provided with one or more third slide members 150 protruding outwards for engagement with the inner slide surfaces 134, 136 of the intermediate slide bar 130. A plurality of separate third slide members 150 may be attached to the vertical part 144 of each second guiding rail 140. The vertical height of the third slide members 150 thus corresponds to the distance between the two inner slide surfaces 134, 136 of the intermediate slide bar 130. The third slide members 150 may be made of a third plastic being different from the first plastic according to the principles described hereinbefore. For example, the third slide members 150 may be formed by injection moulding a third plastic, such as POM, that is different from that of the intermediate slide bar 130. The third plastic may be the same type of plastic as the second plastic, such as POM.
In the slide system 1 shown in
Thus,
While the embodiment of
Compared to metal slide members, which are hard and stiff and which may accept heavy loads while providing lowered friction, the plastic slide members 10, 20 of the present invention are easier and cheaper to manufacture. Plastic can be injection moulded or formed through extrusion in one piece, which are both simple and cheap processes. Elongated parts with uniform cross-section along its longitudinal extension, such as for instance the first slide member when being a slide bar, can advantageously be manufactured efficiently with extrusion. This process is fast, and can produce first slide members of varying lengths easily and cheaply. The second slide member, even if designed with details, can be manufactured by means of injection moulding in high volumes efficiently, with little waste material and with high precision. In addition, the need of surface treatment, washing and providing a lacquer on top of a metal slide member (as disclosed in e.g. WO 2017/044032) may be dispensed with. In the present invention, the first slide member 10 and the second slide member 20 are typically non-lacquered; or at least have a non-lacquered surface at the position where the first and second slide members 10, 20 are configured to come into contact with each other, forming the sliding contact between them.
To facilitate the application of the lipophilic composition onto the first slide member 10, the lipophilic composition can be applied to the second slide member 20, and subsequently be transferred, at least partly, to the first slide member 10 when the first and second slide members 10, 20 are brought into contact with each other.
The plastic slide members 10, 20 are also suitable for somewhat lighter applications than for instance metal slide members, which may be heavy and rigid. The present slide system 1 may thus preferably be used for sliding drawers, lighter sliding doors and the like.
Another benefit of using plastic slide members is that while metals are non-flexible, plastics are more flexible, thus enabling for instance the second slide member 20 to be snap-fitted into connection with the first slide member 10 in narrow, tight spaces.
Further, as shown in
Alternatively, as shown in
As shown in
The first slide member 10 is provided with fastening arrangements 18, e.g. holes, pins, etc., for connecting the first slide member 10 further to a furniture part, such as a sliding door 30. Further, the first slide member 10 may, in an alternative embodiment, be provided with grooves or tracks 11 along which each blade 21 slides along a slide direction.
As described above, the plastic slide members 10, 20 of the present slide system 1 are cheaper and easier to manufacture than for instance slide members made of metal. Further, as described above, the slide system 1 of the present invention is particularly suitable for lighter furniture applications. It has been found that the friction becomes lower when the contact pressure between the second slide member and the first slide member is relatively high. The contact pressure is calculated by dividing the load carried by each individual contact point by the contact area of the contact point. For example, if a sliding door has a total weight of 8.5 kg this represents a total load of 83.3 N. If this sliding door of 8.5 kg, meaning a load of 83.3 N, is carried by two second slide members, and each such second slide member has four individual contact points having a contact surface, between such contact point and the first slide member, of 0.675 mm2, the contact pressure is then calculated as: 83.3 N/(2 slide members×4 contact points×0.675 mm2)=15.4 N/mm2. Preferably, the contact pressure in said at least one contact point is at least 4 N/mm2, more preferably at least 8 N/mm2, such as at least 12 N/mm2. Preferably, the contact pressure is lower than the strain at yield (=yield strength) for the plastic material from which the second slide member 20 is made.
The following examples are mere examples and should by no means be interpreted to limit the scope of the invention, as the invention is limited only by the accompanying claims.
The test procedure used was based on a set up 80 schematically shown in
Said groove of the disc 81 is imagined to correspond to the groove 11 present in the slide system 1 of the present invention, while the tip 82 is imagined to correspond to the blade 21 present in the slide system 1 of the present invention. The groove is coated with the lipophilic composition coating 18 to provide a slide layer 19 having lowered friction. Thereby, the principle during testing with the set-up 80 will be the same as illustrated in the upper right enlargement of
A weight 83 is arranged on top of the tips 82 to exert a load thereon. During these experiments, the weight 83 mounted to 15 kg, divided equally onto the two tips 82. Once the load 83 of 15 kg is applied to the two tips 82, the plastic disc 81 is rotated/moved with a reciprocating circular movement in a clockwise or counterclockwise direction around a rotational axis A, indicated by the double ended rounded arrow in
The circular disc 81 is mounted on a support connected to a motor 84 turning the disc 81 clockwise and counterclockwise, while the tips 82 are static. The frictional force F is measured against the rotation. The energy input to the motor 84 needed for reciprocating the disc 81 is a measure of the frictional force F that the motor 84 has to overcome to rotate the disc 81, being in contact with the two tips 82.
Each test included 50 000 cycles to verify the satisfying results. Each such cycle including turning the disc almost a complete round and then turning it back to its starting position. If unsatisfying results were obtained already early in the test process, e.g. after 10 000 cycles, the experiment was terminated since the material selections were not considered to fulfil the resistance requirements. The test results are disclosed below in the Examples.
Before the tests using the test set up using plastic materials as described with reference to
The test results for the testing setup as described above using tips of POM and a disc also formed from POM, and covered by a lipophilic composition, are presented below in Table 2. Already after a low number of cycles, the resistance increased up to 10 N. After approximately 1000 cycles the resistance was kept constant at these high forces. Hence, the testing was terminated after about 13 000 cycles. It could thus be concluded that the use of two plastic slide members of the same plastic is less preferable.
The test results for the testing setup as described above using tips of POM and a disc formed from PA6 are presented below in Table 3. From the first cycle to the last, this combination of plastic materials depicted an even and low resistance. The initial dynamic resistance was lower than in Example 2. Since the same lipophilic composition coating was used as in Example 2, the selection of the plastic materials seemingly influences the resistance between the slide members, both initially and especially in the long run. The value of 3.5 N is also matching the measurements obtained for the positive control (Example 1).
The test using POM and PA6 was also conducted without the use of the lipophilic composition coating. The initial dynamic friction was significantly higher. Further, test results show that the friction without the lipophilic composition coating present rapidly, i.e. within only a few hundred cycles (compared to the 50000 rounds performed in Example 2), escalated to as high as about 14-15 N. The test results of Example 4 are shown below in Table 4. The test was terminated after only 250 cycles.
The test results for the testing setup as described above using tips of POM and a disc formed from PC are presented below in Table 5. Similarly to Example 3, from the first cycle to the last, this combination of plastic materials depicted a fairly even and low resistance, with a maximum value of 5 N. As for Example 3, we can conclude that since the same lipophilic composition coating was used as in Example 2, the selection of the plastic materials seemingly influencing the resistance between the slide members, both initially and in the long run. The maximum value of 5 N is considered acceptable and satisfying, as for instance compared to the values of e.g. 10 and 14 N exhibited in Examples 2 and 4, respectively.
The test results for the testing setup as described above using tips of POM and a disc formed from PMMA are presented below in Table 6. Similarly to Example 5, from the first cycle to the last, this combination of plastic materials depicted a fairly even and low resistance, with a maximum value of 6.5 N. As for Example 5, we can conclude that even though the initial frictional force (4.5 N) was slightly lower than the maximum force measured in the end of the experiment (6.5 N), the maximum value of 6.5 N is considered low enough to be a satisfying test result. This is in contrast to for instance the values of e.g. 10 and 14 N exhibited in Examples 2 and 4, respectively.
The combination of POM and PMMA hence provide a satisfying result both initially and in the long run.
The test results for the testing setup as described above using tips of POM and a disc formed from PPCO are presented below in Table 7. As opposed to for instance the test in Example 6, from the first cycle to the last, this combination of plastic materials depicted a decreasingly lowered resistance, with a maximum initial frictional value of 6 N.
We can conclude that even though the initial frictional force (6 N) was slightly higher than the maximum values measured in Examples 3 and 5, the frictional force stabilized relatively quickly and dropped to as low as 3.5 N, which is as low as the result depicted in Example 3, and almost as low as for the positive control (3 N) described in Example 1. The combination of POM and PPCO hence provide a satisfying result both initially and in the long run.
From the Examples 1-7, we can conclude that using a first slide member and a second slide member made from the same plastic material (Example 2), such as POM, does not result in a satisfying lowering of the friction between the two slide members.
However, it has surprisingly been found that by using slide members of two different plastics, such as POM and PA6, the friction can be decreased significantly. Without being bound by any theory, this effect is thought to derive from that two parts of the same plastic material exhibit larger attraction forces against each other than two different plastic materials, resulting in a higher friction there between. Example 3 also indicate that there is a synergistic effect between the use of the lipophilic composition coating and plastic slide members formed of different plastic materials, such as POM and PA6. Seemingly, the degree of synergism differs between different combinations of plastic materials. The combination of POM and PA6 represents a preferred combination. Another advantageous combination between two different plastics is using slide members formed from PET and POM, which also benefits from the effects described above (data not shown).
An experimental set-up in line with what is shown in
Without further elaboration, it is believed that one skilled in the art may, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative and not limitative of the disclosure in any way whatsoever.
Although the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims and other embodiments than those specifically described above are equally possible within the scope of these appended claims, e.g. different embodiments than those described above.
In the claims, the term “comprises/comprising” does not exclude the presence of other elements or steps. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion of two features in different claims does not imply that a combination of those features is not feasible and/or advantageous.
In addition, singular references do not exclude a plurality. The terms “a”, “an”, “first”, “second” etc. do not preclude a plurality.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2151376-7 | Nov 2021 | SE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/081238 | 11/9/2022 | WO |
