US20050172449A1 - Furniture glide with polyurethane base - Google Patents

Abstract

A furniture glide base having a substantially circular sliding surface that is of elastomeric material, preferably a thermoplastic urethane such as polyurethane. In one embodiment, the glide base has an annular rim portion extending obliquely upward from the periphery of the circular sliding surface to a first elevation, and a central post extending vertically upward from the center of the base, to a higher elevation. The post can have an upper end that forms a spherical surface to form part of a swivel joint. In another embodiment, the base has an annular rim portion of the same or different material, extending upward from the periphery of the circular sliding surface, for receiving a furniture leg.

Description

BACKGROUND OF THE INVENTION
• The present invention relates to furniture glides, and more particularly to an improved furniture glide base.
• Furniture glides are available in a variety of styles and constructions, but an essential purpose is to provide an upper portion for receiving a furniture leg and a lower portion defining a sliding surface. U.S. Pat. No. 5,991,974, “Swivelling Furniture Glide”, and U.S. Pat. No. 6,154,923, “High Hold Furniture Glide”, and U.S. Publication US2002/0088082A1 describe glides of the type having a three main components: (1) a ferrule including a bottom wall, an upstanding cylindrical side wall extending from the bottom wall and defining a socket for receiving a furniture leg, and clip means within the socket, for engaging a received furniture leg, (2) a swivelable glide support shell affixed to the bottom wall of the ferrule, and (3) a glide base affixed to the support shell and defining a substantially flat sliding surface for contacting the floor.
• U.S. Pat. No. 6,405,982, “Self-Attaching Sliding Support for Articles of Furniture”, describes another type of glide that does not have a ferrule or swivel capability, but rather consists of a generally cup-shaped, unitary body of a resilient element for gripping the legs and an integrated slidable base element for contact with the floor.
• In these and other known furniture glides, the sliding surface for contacting the floor is of a material specifically chosen for its relatively high hardness. Typical base element materials include steel (usually selected for carpeted floors) or hard plastics such as nylon or polyethylene (typically selected for tile floors). These materials should ideally provide durability and easy cleaning of the sliding surface, and easy and quiet sliding of the furniture along the floor, without abrasion or smudging. Although these materials may perform satisfactorily under new or clean conditions, the presence of dirt and debris on the floor in real operating environments, considerably degrades the performance of furniture glides that utilize these base materials.
SUMMARY OF THE INVENTION
• It is an object of the present invention to provide a furniture glide having a sliding surface that can be used on both carpet and tile floors, and which maintains for extended periods of use, satisfactory durability and easy cleaning, and easy and quiet sliding along the floor, without abrasion or smudging.
• In a general aspect, the invention can be summarized as a furniture glide base having a substantially circular sliding surface that is of elastomeric material, preferably a thermoplastic urethane such as polyurethane. In one embodiment, the glide base has an annular rim portion extending obliquely upward from the periphery of the circular sliding surface to a first elevation, and a central post extending vertically upward from the center of the base, to a higher elevation. The post can have an upper end that forms a spherical surface to form part of a swivel joint. In another embodiment, the base has an annular rim portion of the same or different material, extending upward from the periphery of the circular sliding surface, for receiving a furniture leg.
• In another aspect, the invention is a furniture glide comprising an upper portion for receiving a furniture leg and a lower portion defining a smooth sliding surface, wherein the lower portion consists of an elastomeric material.
• In yet another aspect, the invention is directed to a glide for a furniture leg, comprising (1) a ferrule including a bottom wall, an upstanding cylindrical side wall extending from the bottom wall and defining a socket for receiving a furniture leg, and clip means within the socket, for engaging a received furniture leg, (2) a glide support shell affixed to the bottom wall of the ferrule, and (3) and a glide base affixed to the support shell and defining a substantially flat sliding surface, wherein the sliding surface is an elastomer.
• Regardless of the embodiment, the relatively soft sliding surface of elastomeric material according to the invention performs surprisingly well on all floor surfaces. It is believed that as a result of the weight load transferred through the furniture leg causing localized high-pressure contact of dirt and debris, such as sand, glass shards, metal chips and slivers and other hard particles, the softer surface yields to temporarily “absorb” the particles. As an example, when a student sits on a chair having glides according to the invention, the particles under the sliding surface are temporarily absorbed by (i.e., recede into) the base such that when the seated student shifts the chair under a desk or table or the like, the particles trapped in the sliding surface do not interfere with the inherently low-friction interface between the sliding surface and the floor.
• This absorption effect not only reduces the deleterious effect on sliding due to the presence of particles between the floor and sliding surface, but by the same mechanism reduces the abrasion and smudging of the floor that can arise as particles are “scraped” across a floor by the movement of furniture such as the shifting of a chair. Similarly, the scraping of the sliding surface by such particles is also reduced, thereby extending the life of what conventional thinking would consider unsuitably soft and vulnerable material for this end use.
• Another advantage of the invention, is that when the weight on the base is relieved, the deformations in the base material caused by absorption of the particles are restored, thereby pushing the absorbed particles to the sliding surface where they can be easily cleaned.
• Accordingly, it should be evident that the present invention readily achieves the objective of providing a furniture glide having a sliding surface that can be used on both carpet and tile floors, and which maintains for extended periods of use, satisfactory durability and easy cleaning, and easy and quiet sliding along the floor, without abrasion or smudging.
BRIEF DESCRIPTION OF THE DRAWING
• The preferred embodiments of the invention will be described below with reference to the accompanying drawings, in which:
• FIG. 1 is a vertical sectional view through a swivel furniture glide having an elastomeric base according to a first embodiment of the present invention;
• FIG. 2 is a perspective view of the elastomeric base of the embodiment ofFIG. 1;
• FIG. 3 is a vertical section view through a furniture glide having an elastomeric sliding surface according to a second embodiment of the present invention; and
• FIG. 4 is a perspective view of the furniture glide of the embodiment ofFIG. 3.
• FIGS. 5 and 6 are plan and sectional elevational views, respectively, alternative to the embodiment shown inFIGS. 1 and 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
• FIGS. 1 and 2 illustrate a first embodiment of a glide base according to the invention, in the context of swivel furniture glides such as described in U.S. Pat. No. 5,991,974, “Swivelling Furniture Glide” and U.S. Pat. No. 6,154,923, “High Hold Furniture Glide”, and U.S. Publication US2002/0088082A1, the disclosures of which are hereby incorporated by reference.
• A clip and ferrule for receiving a furniture leg, are generally designated by thenumerals10 and12, respectively. Theferrule12 has acircular bottom wall14 and an upstandingcylindrical side wall16. The upper portion of the side wall preferably angles radially inward to define a circular ferrule opening18. Theferrule opening18 is preferably chosen to closely match the outer diameter of the furniture leg (not shown). Thebottom wall14 defines a circular rivet opening20 coaxial with the ferrule opening18. Thebottom wall14 of theferrule12 is further preferably contoured having a dropped portion adjacent the rivet opening20.
• Clip10 within theferrule12 may take a variety of forms; that depicted inFIG. 1 is formed from a longitudinal resilient metal strip. Theclip10 has aclip base22 which has a footprint smaller than the ferrule opening18, and a single pair of oppositely positionedclip arms24,26. Theclip arms24,26 extend generally perpendicularly upward from theclip base22. Theunstressed clip arms24,26 define a neutral diameter greater than the diameter28 of the ferrule opening18. Thearms24,26 andbase22 of theclip10 are resiliently deformable whereby as theclip10 is inserted base first into the ferrule opening18, theclip arms24,26 deform inwardly to the smaller diameter28 of the ferrule opening18. Theclip arms24,26 return to generally the neutral shape after passage through the ferrule opening18.
• Theclip base22 defines a central clip rivet opening30. The clip rivet opening30 is aligned with the ferrule rivet opening20 when theclip10 is mounted in theferrule12. Theclip base22 further projects downward to form a cylindrical portion having a length equivalent to the depth of the contour of the drop portion of theferrule12. Therivet openings20,30 are of the same diameter.
• Arivet32 is secured through the clip andferrule rivet openings30,20. Therivet32 has anexpandable head portion34 and an oppositeswivel portion36. Thehead portion34 of therivet32 is inserted through the alignedrivet openings20,30 and rounded or peened over to pull theswivel portion36 against thebottom wall14 of theferrule12. Therivet32 securely fastens theferrule12 and clip10 together. Theclip10 andferrule12, when riveted together, are capable of fully supporting a furniture leg, and therefore preferably do not require any additional structural elements. Theswivel portion36 of therivet32 extends downward from thebottom wall14 and radially outward to define a convex spherical outer swivel surface and a concentric inner spherical swivel surface.
• Ashell assembly38, having aninner shell40 and anouter shell42, slidably engages the outer swivel surface of therivet32. Theinner shell40 is generally spherical and defines a circularinner shell opening44 having a diameter less than theswivel portion36 of therivet32. Theinner shell40 is nested within theouter shell42. Theouter shell42 has a generally frustoconical shape forming an expandedportion46 defining an outer edge and a reducedportion48. Theouter shell42 defines a circularouter shell opening50 at the reducedportion48 having a diameter less than the outer diameter of theinner shell40. The spherical shape of theinner shell40 allows for improved swiveling sliding engagement of theinner shell40 with theouter shell42.
• Aglide base52 is mounted to the expandedportion46 of theouter shell42. Theglide base52 is preferably molded as a unitary or singular component of elastomeric material that is softer than material conventionally used for this purpose. Thebase52 is circular, having anannular rim portion54 for engagement to theouter shell42 and an axial elevatedcentral post portion56. Theglide base52 is mounted in position by the crimped outer edge of theouter shell42. Thepost portion56 of theglide base52 defines a generally convex base swivel surface in congruent surface-to-surface contact with the inner swivel surface of therivet32. Thepost portion56 is dimensioned of a sufficient height to maintain theshell assembly38 in tight engagement with theswivel portion36 of therivet32. Theswivel portion36,inner shell40,outer shell42 and glidebase52 are preferably dimensioned to allow swiveling motion of theferrule12 relative to thebase52 of up to 32 degrees from the vertical. Only theouter shell42 would be required for furniture glides58 that require a smaller degree of swiveling. Theglide base52 is preferably constructed of thermoplastic polyurethane elastomer. Theglide base52 acts a cushion and has a smooth, circular slidingsurface60 for contacting a floor surface.
• FIGS. 3 and 4 illustrate a second embodiment according to the invention, in the context of a glide such as described in U.S. Pat. No. 6,405,982, “Self-Attaching Sliding Support for Articles of Furniture”, the disclosure of which is hereby incorporated by reference.
• A self-attachingslidable support110 for an article of furniture includes a first resilient, especially elastomeric, support element112 and a second, slidingelement114. Support element112 includes a relativelythick base portion116, which serves to cushion the weight of the article to be supported. Molded integrally withbase portion116 of support element112 is an upstanding concave inwardly extendingcircumferential rim118.Rim118 is generally “C” shaped and serves to engage a leg120 of the article of furniture to be supported. Asrim118 is also preferably formed from elastomeric material, it is free to elastically engage the perimeter of leg120. Furthermore,rim118 is also capable of accommodating legs of a range of sizes and shapes.
• Theedge122 ofrim118 extends inwardly and overhangs theinterior space124 of support element112. The diameter of the circular opening126 ofrim118 is shown as dimension A. However, the diameter ofinterior space124 of element112 is shown as dimension B which is larger than that of dimension A. Asrim118 will elastically deform when leg120 is inserted therein,support110 can thus accommodate furniture legs in the diameter range of A to B. Furthermore,rim118 will also accommodate square or rectangular legs whose diagonal is within the range A to B. This reduces the number of sizes ofsupports110 that needs to be carries in stock. In addition, the generallycircular support110 shown herein could also be oval or rectangular in plan view.
• Slidingportion114 is generally cup shaped and is joined to the underside of support element112 so that it will rest on the surface on which the article of furniture is to be supported. Slidingportion114 is preferably fabricated from a thermoplastic polyurethane elastomer
• It should be appreciated that theslidable support110 according to the second embodiment could alternatively be made of a homogeneous elastomeric material, rather than diverse materials. In either variation, thelower portion114 defining the sliding surface consists of an elastomeric material, including blends of elastomers, whereas the upper support element or portion112 is not required to be elastomeric. Similarly, the glide base of the first embodiment could be a composite, so long as the sliding surface is elastomeric.
• FIGS. 5 and 6 show an alternative embodiment to that described above with respect toFIGS. 1 and 2. Theoverall glide210 of this embodiment has a clip structure including aferrule212 within which is supported a generallycircular clip member214 formed with a plurality of recesses or cut-outs, thereby defining individual, downwardly projectingclip arms216 for firmly securing the substantially tubular lower end of a furniture leg (not shown). Asteel rivet218 passes centrally through theferrule212 and has an upper end that is expanded during assembly to trap theclip214 against the top of thedome220 formed in the bottom of the ferrule. The ferrule itself rests on asupport platform222 that is in turn supported at the lower end of the rivet, where the rivet has aconcave seat224. This provides a swivel engagement with thepost portion226 ofbase228. As with the previously described embodiment, preferably,polyurethane base228 is mounted in position by the crimped outer edges of thecover shell230, which in turn is mounted over theinner shell232.
• The elastomeric material defining the sliding surface of any embodiment of the invention, is preferably a urethane, especially thermoplastic and particularly a polyester polycaprolactone resin. In general, the elastomer should have hardness in the range of 50-60, preferably about 55, on the Shore D scale. The preferred polyurethane material is available as Dow Series 2102 Pellethane TPE.
• It should also be appreciated that the exclusive rights in the invention are defined by the claims, and are not limited to the preferred embodiments. The elastomeric base or sliding surface according to the invention can be incorporated into other types of swivel glides e.g., such as various combinations of the ferrules, clips, and support shells described in the patents incorporated herein by reference; glides that do not swivel; temporary glides for moving furniture or the like; and glides that are adapted to fit over original equipment glides, such as described in U.S. Pat. No. 6,324,725, “Furniture Glide”.

Claims (21)

1. A furniture glide comprising an upper portion for receiving a furniture leg and a lower portion defining a smooth sliding surface, wherein the lower portion consists of an elastomeric material.

2. The furniture glide ofclaim 1, wherein the elastomeric material is polyurethane.

3. The furniture glide ofclaim 1, wherein the elastomeric material is thermoplastic.

4. The furniture glide ofclaim 1, wherein the elastomer has a Shore D hardness in the range of 50-60.

5. The furniture glide ofclaim 2, wherein the polyurethane is a pellethane thermoplastic polyurethane elastomer.

6. The furniture glide ofclaim 2, wherein the polyurethaine is a polyester polycaprolactone resin.

7. The furniture glide ofclaim 2, wherein the elastomer has a Shore D hardness of about 55.

8. A glide for a, furniture leg, comprising: a ferrule including a bottom wall, an upstanding cylindrical side wall extending from the bottom wall and defining a socket for receiving a furniture leg, and clip means within the socket, for engaging a received furniture leg; a glide support shell connected to the ferrule; and a glide base affixed to the support shell and defining a substantially flat sliding surface, wherein said sliding surface is an elastomer.

9. The glide ofclaim 8, wherein the sliding surface is polyurethane.

10. The glide ofclaim 8, wherein the glide shell is substantially frustoconical and includes a lower circular rim, and the glide base is of uniform composition and substantially circular with an upstanding annular rim that is captured within said lower circular rim.

11. The glide ofclaim 8, wherein the glide base has a body of one material affixed to the glide shell and said sliding surface is an elastomer material integral with the body.

12. The glide ofclaim 8, wherein the elastomer has a hardness in the range of 50-60 Shore D.

13. The glide ofclaim 9, wherein the polyurethane is a thermoplastic polyurethane having a Shore D hardness of about 55.

14. The glide ofclaim 10, wherein the support shell is pivotally connected to the ferrule at a central pivot connection and the glide base has a central post at the pivot connection that provides a vertical bearing surface for vertical force transmitted from the received leg through said ferrule, to said pivot connection.

15. A furniture glide base having a substantially circular sliding surface that is of elastomeric material.

16. The glide base ofclaim 15, wherein the sliding surface is polyurethane.

17. The glide base ofclaim 15, wherein the elastomeric material has a Shore D hardness in the range of 50-60.

18. The glide base ofclaim 16, wherein the polyurethane is a thermoplastic polyurethane having a hardness of about 55 Shore D.

19. The glide base ofclaim 15, wherein the base has an annular rim portion extending obliquely upward from the periphery of the circular sliding surface to a first elevation, and central post extending vertically upward from the center of the base, to a higher elevation.

20. The glide base ofclaim 15, wherein the post has an upper end that forms a spherical surface.

21. The glide base ofclaim 15, wherein the base has an annular rim portion extending upward from the periphery of the circular sliding surface.

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