EP0722681A2

EP0722681A2 - Equipment leveling pad assembly and kit

Info

Publication number: EP0722681A2
Application number: EP95120390A
Authority: EP
Inventors: Ronald C. Lassy
Original assignee: Applied Power Inc
Current assignee: Enerpac Tool Group Corp
Priority date: 1995-01-17
Filing date: 1995-12-22
Publication date: 1996-07-24
Also published as: EP0722681A3

Abstract

An equipment leveling pad assembly (10) has a pad (12) and a stud (14). The pad (12) defines a recess (30) which has at its entry end an inwardly extending lip (40) past which a ball head (18) of the stud (14) may be snapped to establish a swivel connection between the stud (14) and pad (12). The recess (30) below the lip (40) is larger in diameter than the ball head (18), and the ball head (18) rests against solid material to transfer the load to the bottom of the pad (12). The pad (12) may be made in one piece of a relatively elastic material, or may include a foot (28) of an inelastic material such as metal with a relatively elastic cover (50) defining the lip (40') and secured to the metal foot (28).

Description

Field of the Invention

This invention relates to equipment leveling pad assemblies of the type that are used for furniture and light machinery.

Background of the Invention

Equipment leveling pad assemblies are commonly used on many different types of equipment including light machinery and furniture such as desks, tables, clocks, and almost any other floor standing structure which needs to be leveled. Typically, equipment leveling pad assemblies include a foot and a shank in an assembly such that the shank can be screwed into or out of a nut or other threaded hole which forms part of or is fixed to the furniture. By screwing the stud into or out of the furniture, the level of the furniture or furniture leg can be adjusted.
In the past, furniture pad assemblies were typically made so that the stud was not easily disassembled from the pad, and disassembly of the stud from the pad typically resulted in destruction of the assembly. For example, in one construction, a ball headed stud was inserted into a recess in a metal pad and the upper end of the pad around the recess rolled in a metal forming operation around the ball head so as to capture it in the recess. This required that many different complete assemblies had to be kept in inventory, since the threaded shanks of the studs can vary in diameter, and it is necessary to keep on hand a sufficient supply to meet the demand.

Summary of the Invention

The invention provides a equipment leveling pad assembly having a pad, a foot and an upwardly opening recess. The foot has a bottom floor engagement surface radiating perpendicularly from its axis and an opposite recess with a bottom support surface separated by solid material from the bottom floor engagement surface. A sidewall having a circular cross-section extends upwardly from the floor engagement surface and a circular lip extends inwardly from the sidewall, is spaced from the bottom support surface and defines an opening to the recess of a certain inner diameter. A stud of the assembly has an axis, a threaded shank at one end and a ball head at the other end. The ball head defines a spherically shaped surface which is larger in diameter than the inner diameter of the opening defined by the lip so that the ball head can be snapped past the lip into the recess. The lip closes over the spherically shaped surface to retain the ball head in the recess with the stud extending from the pad and alignable so as to be co-axial with the pad. Thereby, since different studs can be used with different pads and visa versa, supplies of the various pads and studs can be kept separately in inventory and different combinations made up as specific applications dictate. Assembly may occur just prior to delivery to the end user or may be done in the field or remotely by the end user. Thereby, the inventory of assembled products and the overall inventory which must be kept on hand can be reduced, with a greater variety of different assemblies available to the end user. This reduces the cost of distribution, which creates new markets and contributes to better customer service and value in existing markets.
Preferably, the bottom support surface of the recess is conical. Since the conical shape generally conforms to the spherical shape of the ball head, the ball head rests against a relatively larger surface area than if the bottom of the recess was flat, for better support and transmission of the supporting forces to the bottom of the pad. In addition, the spherical surface may be truncated with a flat surface at a free end of the ball head so as to increase the surface area of contact with the conical surface.
In one form, the pad is molded in one piece from plastic material and the recess sidewall is defined in part by a relatively thin-walled sleeve which is an upwardly extending portion of the pad. The sleeve is integral with the lip and flexes to allow expansion of the lip when the ball is pushed through it.
In another form, the lip is separate from a foot portion of the pad, and is defined by a cover which is made of a thermoplastic material. The cover engages the foot so as to be retained by the foot, and retain the ball in the recess of the foot.
In this form, the cover preferably includes an inwardly extending lower flange, a sleeve extending upwardly from the flange, and an inwardly extending upper flange at the top of the sleeve. The lip defines an inner diameter of the upper flange, and the foot has a conically shaped sleeve and a groove at the base of the sleeve. The sleeve of the foot cams against the lower flange to expand the lower flange as the cover is pushed over the sleeve, and the lower flange engages in the groove after the lower flange clears an upper edge of the groove.
In a kit of the invention, at least one pad and two studs, or at least two pads and one stud are provided to make at least two different leveling pad assemblies. If two pads are provided, they both fit with the same stud with a snap swivel connection, and if two studs are provided, they both fit with the same pad. Thereby, a variety of assemblies can be field assembled from a minimum of number of parts.

Brief Description of the Drawings

Fig. 1 is a partial cross-sectional view of a furniture leg into which is screwed a leveling pad assembly of the invention;
Fig. 2 is a view showing a pad portion of the assembly in cross-section and two different studs, either of which can be used with the pad;
Fig. 3 is an exploded cross-sectional view illustrating a recess in the pad of Figs. 1 and 2;
Fig. 4 is a detail view of a portion of the pad, illustrating a lip at the top of the recess;
Fig. 5 is a cross-sectional view illustrating how the ball head of a stud fits in the recess of a pad;
Fig. 6 is a cross-sectional view of an alternate pad for an assembly of the invention and illustrating the ball head of a stud in phantom; and
Fig. 7 is a detail view of the pad of Fig. 6.

Detailed Description of the Preferred Embodiments

Fig. 1 illustrates an equipment leveling pad assembly 10 including a pad 12 and a stud 14. As illustrated, the stud 14 has a threaded shank 16 at one end and a ball head 18 at the other end, with a nut 20 which defines an exterior polygonal surface for engagement by a wrench so as to turn the stud 14. As illustrated, the shank 16 is threaded into a nut 22 which is welded or otherwise affixed to a furniture leg 24, so that turning the stud 14 changes the elevation of the leg relative to the pad 12.
Referring to Fig. 2, the pad 10 has an axis 26, a generally pancake shaped foot 28 which is integral on its upper surface with a tapering sleeve 29, and an upwardly opening recess 30 aligned along axis 26 and formed in the sleeve 29 and extending into the foot 28. The foot 28 has a bottom floor engagement surface 32 which radiates perpendicularly from the axis 26, and the recess 30 is on the opposite side of the pad from the floor engagement surface 32. The recess 30 has a bottom support surface 34 which is conical in shape, a side wall 36 which is circular (which is defined by the generally cylindrical interior surface of sleeve 29) extending upwardly from the floor 34, and a circular lip 40 near the top of the recess 30 which extends inwardly toward the axis 26 from the sidewall 36 and is spaced above the bottom support surface 34.
Fig. 2 illustrates two different studs 14 or 14', either of which may be used with the pad 12. The studs 14 and 14' are identical except for the diameter of their respective shanks 16 and 16'. As illustrated in Fig. 2, the ball head 18 and 18' of each stud has a spherically shaped surface, although it may be truncated at its lower or free end as shown by the flat surface 42. Importantly, the ball heads 18 and 18' are the same diameter so that either stud 14 or 14' will fit in the same pad 12. If a different type of pad were also available, such as that shown in Figs. 6 and 7 and described below, from the two studs and two pads, a total of 4 different assemblies could easily be made. If there were 100 different shank diameters and/or thread configurations (e.g., metric, Anglo, right-hand, left-hand, etc.), then with two different pads, 200 different assemblies could be made, and more different pads and studs would multiply that number.
Referring particularly to Fig. 5, it can be seen that the lip 40 defines an opening to the recess 30 which is of a certain inner diameter which is less than the diameter of the spherically shaped surface of the head 18. As such, the ball head 18 can be snapped past the lip 40 into the recess 30 and the lip closes over this spherically shaped surface to retain the ball head 18 in the recess 30 with the stud 14 extending from the pad 12 and alignable so as to be co-axial with the pad. Preferably, the diameter of the wall 36 is slightly greater than the diameter of the spherical surface of the ball head 18 so as to allow the pad 12 to freely pivot relative to the stud 14 without binding.
The lip 40 is defined by the surfaces 40A, 40B and 40C. The surface 40A is an upwardly diverging conical surface so as to cam on a ball head 18 as it is being inserted into the recess 30 so as to expand the lip 40 outwardly. The surface 40B is generally cylindrical so as to provide a transition zone between the surfaces 40A and 40C. The surface 40C is downwardly diverging so as to cam on a ball head 18 when the ball head 18 is extracted from the recess 30 so as to facilitate expanding the lip 40 during removal of the stud 14 from the pad 12.
The ball head 18 rests against the floor engagement surface 34 so as to transfer the weight of the furniture to the floor engagement surface 34 and through solid material of the foot 28 to the floor engagement surface 32. The bottom support surface is preferably made conical so that it generally conforms to the shape of the ball head 18 so as to help radiate the downward thrust of the weight of the furniture on the ball head 18 to the floor engagement surface 32.
For practicing the invention, the pad 12 should be made of a thermoplastic material which can flex, so as to allow the ball head 18 to snap past the lip 40. Any suitable thermoplastic material may be used which is sufficiently hard to support the weight of the furniture to be supported without excessive creep. For example, Delrin™, which is an acetal resin commercially available from DuPont Engineering Polymers, has good hardness and lubricity properties for many applications.
However, in some applications, such as if the furniture is very heavy, the foot part 28 of the pad must be made of a harder and more inelastic material, such as steel or stainless steel so as to support the head 18 and the weight of the furniture. In those applications, the invention can be applied as shown in Figs. 6 and 7. In this embodiment, labelled 10', a cover 50 is provided on which the lip 40 is formed and which snaps over an inner sleeve 29' which is integral with the foot 28'. In addition, in this embodiment, it may be desireable in some applications to add a boot over the bottom of the foot 28, which may for example be made of rubber or neoprene, to provide a degree of skid resistance, anti-marring or vibration isolation to the pad assembly.
The cover 50 is made from a relatively elastic material, such as a thermoplastic, e.g., Delrin™, and has an inwardly extending lower flange 52 which engages in a groove 54 formed at the base of the inner sleeve 29'. Above groove 54, the outer surface of inner sleeve 29' is conical so as to expand flange 52 outwardly as the cover is pushed onto the sleeve 29', so that flange 52 snaps into the groove 54 when it clears the upper edge of the groove 54. The inner diameter of flange 52 is defined by conical surface 52A and cylindrical surface 52B, which are provided to engage and cam on the conical surface of sleeve 29' so as to expand flange 52 outwardly, and to positively engage in the groove 54.
A relatively thin walled outer sleeve 56 extends upwardly from the flange 52 to allow this expansion to take place without permanent deformation. At its upper end, sleeve 56 integrally joins with an inwardly extending upper flange 58, the inner diameter of which is partially defined by the lip 40'. The upper flange 58 has a somewhat thicker cross-section for rigidity, but to still allow the ball head of the stud to be snapped past the lip 40'. The assembly of Figs. 6 and 7 is made by first snapping the cover 50 over the sleeve 29', and thereafter snapping a ball head 18 of a stud past the lip 40' into the recess 30' defined by the cover 50 and foot 28'.
Many modifications and variations of the preferred embodiments described will be apparent to those skilled in the art. For example, the shank 16 of the stud need not be integral with the ball head 18, but the ball head could be internally threaded and the shank could be threaded into the ball head. Therefore, the invention should not be limited to the embodiments described, but should be defined by the claims which follow.

Claims

An equipment leveling pad assembly, comprising:
a pad having an axis and an upwardly opening recess, said pad having a bottom floor engagement surface radiating perpendicularly from said axis, said recess being on the opposite side of said pad from said floor engagement surface and having a bottom support surface separated by solid material from said bottom floor engagement surface, a sidewall having a circular cross-section extending upwardly from said floor engagement surface and a circular lip extending inwardly toward said axis from said sidewall and spaced from said bottom support surface, said lip defining an opening to said recess of a certain inner diameter; and
a stud having an axis, a threaded shank at one end and a ball head at the other end, said ball head defining at least at its periphery which is furthest from said stud axis a spherically shaped surface, said spherically shaped surface being larger in diameter than said inner diameter of said opening defined by said lip so that said ball head can be snapped past said lip into said recess and said lip closes over said spherically shaped surface to retain said ball head in said recess with said stud extending from said pad and alignable so as to be co-axial with said pad.
An equipment leveling pad assembly as claimed in claim 1, wherein said bottom support surface is conical.
An equipment leveling pad assembly as claimed in claim 1, wherein said spherical surface covers substantially the entire periphery of said ball head.
An equipment leveling pad assembly as claimed in claim 3, wherein said spherical surface is truncated with a flat surface at a free end of said ball head.
An equipment leveling pad assembly as claimed in claim 1, wherein said recess sidewall is defined at least in part by a relatively thin-walled sleeve which is an upwardly extending portion of said pad, said sleeve being integral with said lip and made of a plastic material.
An equipment leveling pad assembly as claimed in claim 5, wherein said pad is made of a plastic material and is integral with said sleeve and lip.
An equipment leveling pad assembly as claimed in claim 1, wherein said pad includes a foot and a separate cover, said lip is defined by said cover and said cover is made of a plastic material, and said cover engages said foot so as to be retained by said foot.
An equipment leveling pad assembly as claimed in claim 7, wherein said cover includes an inwardly extending lower flange, a sleeve extending upwardly from said flange, and an inwardly extending upper flange at the top of said sleeve, said lip defining an inner diameter of said upper flange, and said foot has a conically shaped sleeve and a groove at the base of said sleeve, said sleeve of said foot camming against said lower flange to expand said lower flange as said cover is pushed over said sleeve of said foot, and said lower flange engaging in said groove after said lower flange clears an upper edge of said groove.
An equipment leveling pad assembly as claimed in claim 8, wherein said ball head is received in said sleeve of said foot.
An equipment leveling pad assembly as claimed in claim 1, wherein said lip is defined at its inner diameter by an upwardly diverging conical surface and by a downwardly diverging conical surface.
An equipment leveling pad kit comprising:
at least two of one and at least one of the other of the following items:
a pad having an axis and an upwardly opening recess, said pad having a bottom floor engagement surface radiating perpendicularly from said axis, said recess being on the opposite side of said pad from said floor engagement surface and having a bottom support surface above said bottom floor engagement surface, a sidewall having a circular cross-section extending upwardly from said floor engagement surface and means for retaining a ball in said recess with a swivel connection; and
a stud having an axis, a threaded shank at one end and a ball head at the other end, said ball head defining at least at its periphery which is furthest from said stud axis a spherically shaped surface for retention in said recess of said pad;
wherein said ball head of any said stud can be snapped into said recess of any said pad to retain said ball head in said recess with said stud extending from said pad with a secure swivel connection created between each said stud and pad.