FIELD OF THE INVENTION
The present invention relates to improvements in hardware, and more particularly to hardware that permits table legs, appliance legs, and other legs of an article to be quickly converted from being suited for stationary support, to being capable of easy movement of the article. The hardware of the present invention also permits a leg or a base to which the device is attached to be height adjusted to suit a variety of conditions.
BACKGROUND OF THE INVENTION
There are many appliances and articles of furniture that have legs. Other articles have wheels or casters attached to a bottom surface. These include tables, chairs, breakfronts, etc. Appliances having legs can be stoves, sinks, ovens, etc. Other articles include medical equipment, such as walkers for the elderly that are made of hollow tubing, machinery, barbecues, etc. These legs or bases provide support for the device. Many of these articles, however, are used in applications and in situations where they have to be moved from time to time. Also, in many instances the floor is neither level nor smooth. For example, in a kitchen or other location an article such as a stove, refrigerator, table, etc. may need to be relocated or moved for cleaning. Many types of tables, refrigerators, stoves, medical equipment, tools, etc. are bulky and heavy. It is not uncommon for these devices to have to be moved. Stoves and refrigerators and other mechanical devices may need to undergo repairs and access to the rear of the device may be necessary. In other instances, many devices may need to be moved to a new location or moved away from their original location for cleaning behind them or underneath them or moved for other reasons. Also, a stove or table in an older home may wobble because the home has not settled uniformly over the years. In commercial establishments, a similar situation can occur. For example, the floor may be rough or worn in areas that cause the floor to not be level. Besides the aesthetics and comfort of a table or other article that wobbles, there can also be a safety issue. An unstable table can spill hot food products over workers and diners. Even outside of the kitchen, there are many applications such as in offices, laboratories and elsewhere where there is a need for a stable work surface.
Besides worn surfaces, there are also many flooring materials that are popular today that are also not smooth. One example is ceramic floor tile. Many homeowners and restaurants desire the rustic look provided by some floor tiles such as a tumbled marble or ceramic. This flooring material can have surfaces that are not smooth and level. In addition, there are frequently wide gaps between these tiles that can cause tables and appliances to not be level when resting thereon.
The traditional solution for solving the problem of wobbly legs has been to place a thin flat material or wedge under the offending leg to prevent movement. Alternatively, there have been adjustable legs that have an orifice in the center bottom tip of the leg. The orifice is threaded and receives a threaded member with a base or pad attached thereto. As the base is turned, the threaded member extends or retracts to level the leg. While these approaches eliminate the wobbling of a table or other article, these approaches are not satisfactory when the table leg has a roller on the bottom surface. A shim or wedge under the roller is usually not satisfactory because the roller would have a tendency of rolling off the shim.
There are a number of different approaches to solving the problem of unsteady tables and other devices. For example, in U.S. Pat. No. 6,644,216 to Cole, there is an adjustable leg that is pivotally attached to a table top. The leg has an adjuster that can vary the angle of the leg to steady a table. In U.S. Pat. No. 6,598,841 to Erickson, there is a height adjustable table leg that is attachable to the underside of a table. There is a pair of tube members and one tube member telescopes into the other tube member. An adjustable leg assembly is also disclosed in U.S. Pat. No. 6,595,144 to Doyle. Doyle has a mounting system in which an outer support or base leg receives a pair of spaced multiple section slides, each having one end coupled within the base leg and the opposite end coupled to a motor activator secured to the underside of a work surface. The slides provide lateral strength and stability for the telescopic motion between raised, lowered and intermediate adjustable positions and provide a trim cover for concealing the drive mechanism employed for adjusting the work surface.
An adjustable leg is also disclosed in U.S. Pat. No. 6,032,914 to Bastida. In Bastida, there is an adjustable leg for benches, stilts and the like. The leg has a first elongate strut that has a first strut end wall defining an outer surface. The first strut wall has a first aperture therein. A second elongate strut having a second strut end wall is telescopically received in the first strut. The first strut end wall and the second strut wall have a plurality of apertures therein. A lever is journalled for rotational movement which causes the leg to adjust in height using the apertures. There is a need for an adjustable leg that can glide over a floor because of the presence of a roller or other suitable rotating member.
OBJECTS OF THE INVENTION
It is an object of the invention to provide an improved adjustable leg.
It is an object of the invention to provide an adjustable leg that has a roller base.
It is an object of the invention to provide an adjustable roller arrangement for a leg or base.
It is an object of the invention to provide an adjustable roller arrangement that can readily be activated to a movable condition and deactivated to a stationary condition.
It is also an object of the invention to provide a roller that can be extended to permit an article to be readily moved and retracted to prevent easy movement.
It is also an object of the invention to provide an improved mechanism for adjusting the height of a table, chair or other article.
It is another object of the invention to provide a device that can adjust the height of a leg to expose or conceal a roller ball or caster/wheel used on a chair, table or other leg or other means for support.
SUMMARY OF THE INVENTION
The present invention is directed to an improved adjustable leg that has a bearing assembly that may be in an extended position when an article is to be moved or be in a concealed position when the article is to be stationary. The bearing assembly may comprise of a spherical bearing and race, or a caster/wheel. A first embodiment of the invention has a mounting plate cylinder, a housing cylinder with a bearing engagement cylinder and a bearing assembly. The bearing assembly may include, but is not limited to, a spherical ball bearing and race, or a wheel that rotates, such as a caster. When the bearing engagement cylinder is in a retracted position, the spherical ball bearing or wheel is exposed and can rotate. When the bearing engagement cylinder is in an extended position, the spherical ball bearing does not contact a floor or other surface, and thus the article will not be capable of movement on the bearing. In one embodiment, the spherical ball bearing will be positioned in a recess in the bearing engagement cylinder. The bearing engagement cylinder provides an externally threaded surface that mates with the internally threaded surface of the housing cylinder and permits the bearing engagement cylinder to be moved from a retracted to an extended position, and vice versa. A second end of the housing cylinder may be externally threaded and provide additional, course adjustment by mating with the internal threading of the base mounting cylinder. The base mounting cylinder incorporates a plate that permits the article of the present invention to be secured to a table or other leg or surface.
A second embodiment has a bearing attached to a plunger tube which is spring biased into a retracted position within a hollow cylinder. Upon actuation by the user, the bearing and plunger tube travel so that the bearing protrudes from the bottom of the hollow cylinder, whereby that extended position is maintained by a mechanical catch that is pivotally mounted within the plunger tube, and has a lip that engages a slotted opening in the tube. Retraction of the bearing and plunger tube occurs by having the user depress a button that is connected to the mechanical catch, which forces the lip of the mechanical catch to disengage from the slotted opening, and allow the plunger tube to then be biased back to the retracted position, with the bearing once again stowed completely within the hollow cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a representative leg of a first embodiment of the present invention, shown supporting an article.
FIG. 2 is a perspective view of a first side of a representative leg of a first embodiment of the present invention.
FIG. 3 is a perspective view of a second side of a representative leg of a first embodiment of the present invention.
FIG. 4 is an end-wise perspective view of a representative leg of a first embodiment of the present invention.
FIG. 5 is a partially exploded view of the first embodiment of FIG. 1, showing the housing cylinder unscrewed from the mounting plate cylinder.
FIG. 6 is a partially exploded view of the first embodiment of FIG. 1, showing the housing cylinder unscrewed from the mounting plate cylinder, and the bearing engagement cylinder unscrewed from the housing cylinder.
FIG. 7 is a partially exploded view of the first embodiment of FIG. 1, showing the housing cylinder unscrewed from the mounting plate cylinder, the bearing engagement cylinder unscrewed from the housing cylinder, one of the “C”-shaped spring clips removed from the elongated stem of the bearing assembly, and the bearing assembly removed from the housing cylinder.
FIG. 8 is an end view of the flat end wall of the housing cylinder, with the elongated stem of the bearing assembly protruding beyond it, and secured to it using a “C”-shaped spring clip.
FIG. 9 is an end view of the flat end wall of the housing cylinder, with the elongated stem of the bearing assembly removed to expose the orifice in the flat end wall.
FIG. 10 is a perspective view of the mounting plate cylinder.
FIG. 11 is a reverse perspective view of the mounting plate cylinder.
FIG. 12 is an end-wise perspective view of the bearing assembly with one “C”-shaped spring clip attached to the elongated stem.
FIG. 13 is a perspective view of the side of the bearing assembly, with one “C”-shaped spring clip attached to the elongated stem, and the, other removed to show the spring retaining groove.
FIG. 14 is a side view of the race and spherical bearing of the bearing assembly.
FIG. 15 is a variation of the first embodiment wherein the housing cylinder is eliminated.
FIG. 16 is a perspective view of a representative leg of a second embodiment of the present invention, shown with the roller in the extended position, rolling along the ground.
FIG. 17 is a perspective view of a representative leg of the second embodiment of the present invention, shown with the roller in the retracted position, and with the hollow cylinder is resting on the ground.
FIG. 18 is a perspective view of a representative leg of the second embodiment of the present invention, shown with the roller in the extended position, looking directly at the mechanical catch button.
FIG. 19 is a perspective view of a representative leg of the second embodiment of the present invention, shown with the roller in the extended position, looking at the back side at the mechanical catch button.
FIG. 20 is a perspective view of a representative leg of the second embodiment of the present invention, shown with the roller in the extended position, looking at the opposite side of the hollow cylinder.
FIG. 21 is a perspective view of a representative leg of the second embodiment of the present invention, shown with the roller in the retracted position, looking directly at the mechanical catch button.
FIG. 22 is a perspective view of a representative leg of the second embodiment of the present invention, shown with the roller in the retracted position, looking at the back side at the mechanical catch button.
FIG. 23 is a top perspective view of a representative leg of the second embodiment of the present invention, showing the first end of the hollow cylinder with the plunger tube in the second position.
FIG. 24 is a reverse perspective view of the top of a representative leg of the second embodiment of the present invention, showing the first end of the hollow cylinder with the plunger tube in the first position.
FIG. 25 is a bottom view of the top of a representative leg of a second embodiment of the present invention, where the roller is a caster with a single wheel.
FIG. 26 is a perspective view of the caster with a single wheel.
FIG. 27 is a perspective view of the plunger assembly of the second embodiment of the present invention, looking directly at the protruding portion of the mechanical catch.
FIG. 28 is a perspective view of the plunger assembly of the second embodiment of the present invention, looking at the side of the protruding portion of the mechanical catch.
FIG. 29 is a perspective view of the plunger assembly of the second embodiment of the present invention, looking at the side opposite of the protruding portion of the mechanical catch.
FIG. 30 is a bottom view of the plunger assembly of the second embodiment of the present invention, looking at the side opposite of the protruding portion of the mechanical catch.
FIG. 31 is an exploded view of the parts comprising the plunger assembly of the second embodiment of the present invention.
FIG. 32 is a perspective view of the plunger assembly and roller of the second embodiment of the present invention, looking directly at the protruding portion of the mechanical catch, and where the roller is a race and spherical bearing.
FIG. 33 is a perspective view of the plunger assembly and roller of the second embodiment of the present invention, looking at the side of the protruding portion of the mechanical catch, and where the roller is a race and spherical bearing.
FIG. 34 is a perspective view of the plunger assembly and roller of the second embodiment of the present invention, looking at the side opposite of the protruding portion of the mechanical catch, and where the roller is a race and spherical bearing.
FIG. 35 is a perspective view of the plunger assembly and roller of the second embodiment of the present invention, looking at the side opposite of the protruding portion of the mechanical catch, and where the roller is a race and spherical bearing.
FIG. 36 is a side view of a third embodiment of the present invention having an extra-long hollow cylinder with a plunger tube lever to extend the roller, and having an adjustable mounting plate cover.
FIG. 37 is a perspective view of the third embodiment of the present invention, looking at the second end of the hollow cylinder, and where the roller is a race and spherical bearing in the extended position.
FIG. 38 is a perspective view of the third embodiment of the present invention, looking at the second end of the hollow cylinder, and where the roller is a race and spherical bearing in the retracted position.
FIG. 39 is a perspective view of the third embodiment of the present invention, looking at the side of the second end of the hollow cylinder, before installation of the rubber glide cap.
FIG. 40 is a perspective view of the third embodiment of the present invention, looking endwise at the second end of the hollow cylinder, as the rubber glide cap is being installed.
FIG. 41 is a perspective view of the third embodiment of the present invention, looking at the side of the second end of the hollow cylinder, as the rubber glide cap is being installed.
FIG. 42 is a perspective view of the rubber glide cap.
FIG. 43 is a reverse perspective view of the rubber glide cap.
FIG. 44 is a perspective view of the adjustable mounting plate cover of the third embodiment of the present invention, before being inserted into the second end of the hollow cylinder.
FIG. 45 is a reverse perspective view of the adjustable mounting plate cover of the third embodiment of the present invention, before being inserted into the second end of the hollow cylinder.
FIG. 46 is a perspective view of the fixed cylinder of the mounting plate cover of the third embodiment of the present invention.
FIG. 46A is a perspective view of the fixed cylinder of the mounting plate cover of the fourth embodiment of the present invention.
FIG. 47 is a perspective view of the two halves of the adjustment cylinder of the mounting plate cover of the third embodiment of the present invention, shown before being mated together.
FIG. 48 is a perspective view of the first half of the adjustment cylinder of the mounting plate cover of the third embodiment of the present invention, having male protrusions.
FIG. 49 is a perspective view of the second half of the adjustment cylinder of the mounting plate cover of the third embodiment of the present invention, having female indentations.
FIG. 50 is a perspective view of the first half and second half of the adjustment cylinder of the mounting plate cover of the third embodiment of the present invention, being assembled over the fixed cylinder.
FIG. 50A is a perspective view of the first half and second half of the cylinder insert of the fourth embodiment of the present invention, being assembled over the bearing engagement cylinder.
FIG. 50B is an exploded view showing the first half and second half of the cylinder insert, the bearing engagement cylinder, and the bearing assembly of the fourth embodiment of the present invention.
FIG. 50C is an exploded view showing the first half and second half of the cylinder insert already assembly, the bearing engagement cylinder, and the bearing assembly of the fourth embodiment of the present invention.
FIG. 50D is a perspective view of the fourth embodiment of the present invention shown fully assembled.
FIG. 50E is an end view of the fourth embodiment of the present invention shown fully assembled.
FIG. 51 is a perspective view of the first half and second half of the adjustment cylinder of the mounting plate cover of the third embodiment of the present invention, assembled with the fixed cylinder that is attached to the mounting plate.
FIG. 52 is a front view of the third embodiment of the present invention,
FIG. 53 is a section view of the third embodiment of the present invention.
FIG. 53A is a side view of the caster of the third embodiment of the present invention.
FIG. 54 is a section view of the third embodiment of the present invention.
FIG. 55 is a side view of the plunger assembly of the third embodiment of the present invention.
FIG. 56 is a section view of the plunger assembly of the third embodiment of the present invention, looking at the side of the mechanical catch.
FIG. 57 is a section view of the plunger assembly of the third embodiment of the present invention, looking at the front of the mechanical catch.
FIG. 58 is a section cut of the plunger assembly of a third embodiment of the present invention.
FIG. 59 is a section view of the plunger assembly of a third embodiment of the present invention, with the roller retracted.
FIG. 60 is a section view of the plunger assembly of a third embodiment of the present invention, with the roller extended.
FIG. 61 is a section cut of the third embodiment of the present invention, with the roller protruding beyond the hollow cylinder.
FIG. 62 is a section view of the third embodiment of the present invention, with the roller retracted within the hollow cylinder.
FIG. 63 is an exploded view of the parts of the plunger assembly of the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a representative adjustable roller leg assembly 1 of a first embodiment of the present invention. As seen in FIG. 4, the adjustable roller leg assembly 1 may be comprised, in a first embodiment, of a mounting plate cylinder 10, a housing cylinder 30, a bearing assembly 50, and a bearing engagement cylinder 60. Progressive disassembly of the adjustable leg 1 is shown in FIG. 5 with removal of the mounting plate cylinder 10, followed by removal of the bearing engagement cylinder 60 in FIG. 6, and finally, as seen in the exploded view of FIG. 7, by detachment of the bearing assembly 50 from the housing cylinder 30.
The mounting plate cylinder 10 may be comprised of a plate portion 13 and a cylinder portion 19. The plate portion may serve as a means for securing the adjustable roller leg assembly to an article. The plate portion 13, shown in detail in FIGS. 7, 10 and 11, may preferably have an upper mounting surface 16, a lower plate surface 17, and an outer edge surface 18. The plate portion 13 may be any shape suitable for attachment to the article, including, but not limited to, having forms a square shape, a circular shape, or a rectangular shape. The outer edge surface 18 of plate portion 13 of the first preferred embodiment has a square shape. The thickness of the plate shown- the outer edge surface 18 shown in FIG. 7—may be varied according to the strength requirements of the particular article being supported.
The cylinder portion 19 may have an outside cylinder surface 20 which may actually take any shape desired, but is usually configured so that it matches the style or shape of the article that has the adjustable leg. The length of the cylinder portion 19, shown by outside cylinder surface 20, may be longer or shorter to suit the style of a particular article. Where the style is not a significant factor, the outside cylinder surface 20 of cylinder portion 19 will, in fact, have a true cylindrical shape and be concentric with inside cylinder surface 21.
Cylinder portion 19 may have a first cylinder end 23 and a second cylinder end 24, where first cylinder end 23 will preferably be connected to lower plate surface 17 of plate portion 13. The connection may be achieved in a number of different ways. First cylinder end 23 may be integrally formed with plate surface 17 by machining a single piece, by casting a single piece, by creating a single forged part, or by any other appropriate means of manufacture. Alternatively, first cylinder portion 19 and plate portion 13 may be manufactured as separate parts, and thereafter be joined through any appropriate manufacturing process including, but not limited to, the means shown in FIG. 4 where first end 23 of cylinder portion 19 is connected to lower plate surface 17 of plate portion 13 by a weld 25. The weld may take the form of a butt-joint, lap-joint, corner joint, edge joint, or T-joint weld. To one trained in the art, it should be apparent that instead of the weld as shown, plate portion 13 could have an opening to receive outside cylinder surface 20 of cylindrical portion 19, whereby the two were then joined by a V-joint weld 25A on upper mounting surface 16 (see FIG. 11). Additionally, it should be noted that lower plate surface 17 need not be planar, as shown in the figures, and could alternatively by a curved surface so as to maintain an appropriate thickness at the outer edge surface 18 with spot-facing as needed at the mounting orifices 14 for fastener heads, but with increasing thickness and support for the outside cylinder surface 21 of cylinder portion 19. It should also be apparent to one trained in the art that cylinder portion 19 may be threadably attached to plate portion 13.
Inside cylinder surface 21 will preferably be smooth and begin at second cylinder end 24, and run a portion of the way to first cylinder end 23. Inside cylinder surface 21 transitions to second inside cylinder surface 22 which continues the remainder of the distance to first cylinder end 23, and preferably has internal threads formed thereon. Inside cylinder surface 21 and the threads formed on second inside cylinder surface 22, as will discussed hereinafter are designed to receive and provide adjustment relative to housing cylinder 30. The inside cylinder surface 21 and second inside cylinder surface 22 are necessarily concentric, with second inside cylinder surface 22 having a lesser diameter than inside cylinder surface 21.
Plate portion 13 may, in the first preferred embodiment, have a plurality of orifices 14 extending from upper mounting surface 16 to lower plate surface, in the region of the plate external to the cylinder portion 19. The periphery orifices 14 may be used in combination with mechanical fasteners, such screws, bolts and nuts, and the like, for mounting the adjustable roller leg assembly 1 to the article. However, other mounting arrangements for adjustable roller leg assembly 1 are also possible, such as, but not limited to, welding of the mounting plate portion 13 to the article, or brackets that slideably receive the mounting plate portion 13. Plate portion 13 may also have a central orifice 15, which has its axis located concentric to that of inside cylinder surface 21, where the central orifice 15 may serve to provide clearance for the bearing assembly 50 as hereinafter described.
Mounting plate cylinder 10, as well as housing cylinder 30 and bearing engagement cylinder 60, may be manufactured from any suitable material, including, but not limited to steel, titanium, aluminum, brass, composite, wood, or plastic. The material selection may be made based upon requirements that are dictated by the particular article that adjustable roller leg assembly 1 must support, and they may be produced using any appropriate manufacturing process, including, but not limited to machining, casting, forging, turning on a lathe, injection molding, etc.
Housing cylinder 30 may be described as having a first housing end 31 and a second housing end 36. Housing cylinder 30 may preferably be formed having a first outer cylinder wall 32 and a second outer cylinder wall 37. Second outer cylinder wall 37, which may be smooth, may begin at second housing end 36 and run a portion of the way to first housing end 31. Second outer cylinder wall 37 preferably transitions, at transition 38, into first outer cylinder wall 32. First outer cylinder wall 32 runs the remainder of the distance to first housing end 31, and preferably has external threads formed thereon which permit threadable attachment to the internal threads of inside cylinder surface 21 of mounting plate cylinder 10. Also, first outer cylinder wall 32 preferably has a lesser diameter than that of second outer cylinder wall 37. The diameter of second outer cylinder wall 37, between transition 38 and 39, may preferably be sized to provide a tight clearance fit with inside cylinder surface 21 of the cylinder portion 19 of mounting plate cylinder 10. The diameter of second outer cylinder wall 37, between second housing end 36 and transition 39 is not critical,' and in an alternate embodiment may actually be formed to a shape other than a true cylinder, and may be styled to match the shape of the outside cylinder surface 20 of the cylinder portion 19 of mounting plate cylinder 10, which may reflect the style of the article.
Housing cylinder 30 may have an inner cylinder wall 41, which may run from second housing end 36 to first housing end 31. Inner cylinder wall 41 preferably has internal threads 42 beginning at second housing end 36 but preferably only running a portion of the distance to first housing end 31. The extent of threading running toward first housing end 31 could be used to limit travel of bearing adjustment cylinder 60 within housing cylinder 30. Housing cylinder 30 may also have, as shown in FIG. 9, a wall that may partition inner cylinder wall 41, but is preferably a flat end wall 33 that is located at first housing end 31. Flat end wall 33 may have an orifice 34 having an axis that is located concentric to that of inner cylinder wall 41. Finally, Housing cylinder 30 may have one or more pairs of wrench flats 43 on the second outer cylinder wall 37 which may permit a user, as described later, to change the height of adjustable roller leg assembly 1, through use of a wrench or other tool to rotate the housing cylinder 30 relative to the mounting plate cylinder 10.
Bearing assembly 50 may be constructed in a number of different ways, including, but not limited to, incorporating a caster, or a series of ball bearings rotatably mounted within an inner and an outer race, or a single spherical ball bearing rotatably mounted in a race. In a preferred embodiment, bearing assembly 50 may be comprised of spherical bearing 51 that is rotatably mounted in race 52, as seen in FIG. 7 and FIGS. 12 through 14. Rotatable mounting of spherical bearing 51 may be achieved with a plurality of small ball bearings, which may also serve to disperse the bearing loads. The race 53 may have an axial load bearing surface 53, axial non-load bearing surface 54, and side bearing surface 55. Bearing assembly 50 may have an upper end 56 which serves as a transition between the race 53 and an elongated stem which extends therefrom. Elongated stem 57 may be comprised of any cross-section, including, but not limited to, a square cross-section, a rectangular cross-section, an oval cross-section, an irregularly-shaped cross-section, or simply a circular cross-section. In a preferred embodiment, elongated stem 57 may have a circular cross-section and thus form a cylinder.
Bearing assembly 50 may be attached to housing cylinder 30 using elongated stem 57 through a number of different attachment schemes. In a preferred embodiment, elongated stem 57 of bearing assembly 50 has a first retaining groove 58 (not visible) and second retaining grooves 59 (see FIG. 13). A spring clip 26 is affixed to bearing stem 57 by snapping it over the cylindrical shape of elongated stem 57 at first retaining groove 58. The bearing assembly is then installed in the housing cylinder 30 by feeding it into the inner cylinder wall 41 such that the elongated stem 57 is received through orifice 34 in flat end wall 33 of the housing cylinder 30.
The first and second retaining grooves, 58 and 59, may be located on elongated stem 57 such that when the bearing assembly 50 is so installed, the spring clip at recess 58 will inhibit motion of the bearing assembly within the housing cylinder upon contacting the flat end wall 33, resulting in a portion of the elongated stem 57, including retaining groove 59, protruding beyond flat end wall 33 (See FIG. 5). A second spring clip 26 may then be snapped into retaining groove 59 (see FIG. 8) to inhibit inward and outward motion of bearing assembly 50 relative to housing cylinder 30, and leave a portion of the bearing assembly 30 protruding from the end of housing cylinder 30, as seen in FIG. 6. Central orifice 15 of plate portion 13 of the mounting plate cylinder 10 may be so located to provide clearance for any overhang of the elongated stem 57 beyond end wail 33, when the housing cylinder is threaded all the way into mounting plate cylinder 10.
The amount of bearing assembly 50 protruding beyond housing 30, as well as the amount of elongated stem 57 protruding beyond end wall 33 are not critical, and may be adjusted as needed depending on the further design of the bearing engagement cylinder as hereinafter discussed. In fact, in an alternate embodiment, use of the retaining grooves 58 and 59 and spring clips 26 may be eliminated by having the elongated stem 57 formed with external threading, and by having orifice 34 in flat end wall 33 similarly formed with internal threads 35 that are capable of threadably receiving externally threaded elongated stem 57. Alternatively, the spring clips 26 may be replaced by use of retaining pins, including, but not limited to, a cotter pin; or may be replaced by a weld or be fastened by any other means to prevent movement.
Bearing engagement cylinder 60 may be described as having a first end 61 and a second end 62 (See FIG. 7). Bearing engagement cylinder 60 preferably has a cylindrical outer surface 63 between first end 61 and second end 62. Outer surface 63, beginning at first end 61, may have external threads 64 that run a portion of the way to second end 62. Outer surface 63, at second end 62, may also have one or more pairs of wrench flats 68. Bearing engagement cylinder 60 may also have a first inner surface 65 that may be sized to create a tight clearance fit with side bearing surface 55 of race 52 of bearing assembly 50. First inner surface 65 may run from first end 61 until reaching shoulder bearing area 67 which may be created in close proximity to second end 62, by second inner surface 66. Shoulder bearing area 67 may be so shaped and located to contact axial load bearing surface 53 of race 52 of bearing assembly 50.
With assembly of the first embodiment of the present invention—adjustable roller leg assembly 1—seen from viewing FIGS. 7, 6, and 5, and from the complete assembly in FIG. 4, its operation can be described as follows. With the adjustable roller leg assembly 1 mounted to an article (see FIG. 1), the bearing engagement cylinder 60 may be threadably inserted (rotated) into housing cylinder 30 until the point at which the shoulder bearing area 67 of bearing engagement cylinder 60 bears against the axial load bearing surface 53 of race 52 of bearing assembly 50, thereby causing the spring clip 26 located in first spring retaining groove 58 to simultaneously bear against flat end wall 33 of housing cylinder 30. The resulting arrangement, visible in FIG. 1, leaves the race 52 and elongated stem 57 of bearing assembly 50 fixed relative to housing cylinder 30 and the bearing engagement cylinder 60, but with a portion of the spherical ball bearing 51 rotatably exposed from and protruding beyond second end 62 of bearing engagement cylinder 60. With similar adjustment made to each of the adjustable roller leg assemblies 1 that may be attached to an article—presumably being four such assemblies for most articles—the article may then be moved as desired to another location, by the rolling motion of the spherical ball bearings 51 contacting the floor or other surface upon which the article rests.
Conversely, the reverse adjustment may be made by counter-rotating the bearing engagement cylinder 60 relative to the housing cylinder 30, and thus causing it to withdraw from the interior of the housing cylinder 30. Counter-rotating the bearing engagement cylinder 60 results in extending the length of the adjustable roller leg assembly 1, raising the height of the article, and allowing the spherical bearing 51 of the bearing assembly 50 to be in an unexposed position within the bearing engagement cylinder 60, which causes the article to be stationary.
Rotation and counter-rotation of the bearing engagement cylinder 60 relative to housing cylinder 30 may be achieved by hand turning of the bearing engagement cylinder 60. With a heavy apparatus it may be necessary to apply a wrench to the wrench flats 68 of the bearing engagement cylinder 60 to accomplish rotation or counter-rotation. It may also be necessary to prevent inadvertent rotation of the housing cylinder (relative motion between the housing cylinder 30 and mounting plate cylinder 10, instead of only relative motion between the housing cylinder 30 and bearing engagement cylinder 60) by also applying a wrench to the wrench flats 43 of housing cylinder 30 to keep it stationary while causing rotation of the bearing engagement cylinder 60. Course adjustment to the height of the adjustable roller leg apparatus, without affecting the bearing assembly, may be achieved by rotation or counter-rotation of the housing cylinder 30 relative to the mounting plate cylinder 10.
To one skilled in the art, it may be apparent that the invention could be still employed while having one fewer part, by eliminating the housing cylinder, and thus eliminating the course height adjustment just described. This alternate embodiment is illustrated in FIG. 15.
A second embodiment of the present invention is the adjustable roller leg assembly 100, shown having a caster assembly 193 in the extended position in FIG. 16, and with the caster in the retracted position in FIG. 17. This second embodiment may also use a spherical bearing 191 as shown in FIGS. 32 and 33. The second embodiment may preferably be comprised of a plunger assembly 110, which is shown in FIG. 27, and also shown in an exploded view in FIG. 31. Plunger assembly 110 may be comprised of a plunger tube 140 having an inner wall, an outer wall, a first tube end 142, a second tube end 143, and a plurality of openings forming pairs of in-line openings on opposite sides of the tube. The openings are preferably a pair of slotted openings 141 to allow the neck 125 and protruding portion 124 of mechanical catch 120 to extend therefrom; and also second slotted opening pair 144 to permit slideable movement of pin 135 therein without limiting travel of the plunger tube 140, as will be discussed later.
The leg 122 of the mechanical catch 120 extends from the neck 125 and is sized to be retained within plunger tube 140. Leg 122 has a lip 123 which, when properly positioned, as described hereinafter, will engage the slotted opening 141 to prevent backward movement of the plunger tube 140, locking the plunger tube in position. The mechanical catch 120 may be biased by a double conical coil spring 130 that is retained between the mechanical catch 120 and the first plunger tube end 142 by tube mounting cap 160. The double conical feature of the spring 130 yields a non linear spring constant, which provides for actuation of the plunger tube 140 with a varying force at different positions of the tube's stroke.
An end cap 150 covers the second tube end 143 of the plunger tube 140. End cap 150 may have an integral flange 151 extending radially outward as described hereinafter for use in a third embodiment—adjustable roller leg assembly 200—but flange 151 is not necessary for the adjustable roller leg assembly 100. The plunger assembly 110 may also comprise a plunger assembly bracket 111, which may have a first opening 112, a pair of orifices to accommodate a mounting pin 135, and a plurality of mounting orifices 114. The plunger assembly bracket 111 may generally be Ω-shaped whereby a large curved loop 115 transitions into two small inside bends 116, which connect to mounting flanges 117. The large curved loop 115 may be capable of slideably receiving the plunger tube 140, and also of having mechanical catch 120 pivotally mounted within the tube by passing pin 135 through the orifice 113 of plunger assembly bracket 111, through second slotted opening pair 144, and through the orifice 121 in the mechanical catch 120 and out the second orifice 113 in plunger assembly bracket 111 (see FIGS. 30 and 32). The pin 135 may then be crimped on both ends to secure the assembly as described, which facilitates pivotal movement of the mechanical catch 120. The neck 125 of mechanical catch 120, once protruding beyond slotted opening 141 of plunger tube 140, may be received by first opening 112 of plunger assembly bracket 111. Once the plunger tube 140 is assembled together with the mechanical catch 120, the double conical spring 130, the end cap 150, mounting cap 160, pin 135, and the plunger assembly bracket 111, plunger assembly 100 may then be installed into hollow cylinder 170, by attaching the plunger assembly bracket 111 within the hollow cylinder 170. For ease of installation, plunger assembly 110 may include a flat mounting plate 180, to which the plunger assembly bracket 111 may be either mechanically fastened or electrically welded. Thereafter, the flat plate 180 of the plunger assembly 110 may be attached to the interior cylinder wall 174 of hollow cylinder 170 by any suitable manufacturing means, including, but not limited to, electrical welding.
The hollow cylinder 170 may have exterior cylinder wall 173, and be described as having a first end 171 and a second end 172, and a slotted opening 175. Attachment of plunger assembly 110 to interior cylinder wall 174 should be such that the protruding portion 124 of mechanical catch 120 protrudes out of slotted opening 175 of hollow cylinder 170. A button 185 (FIG. 18) with a suitable shape may be attached to protruding portion 124 of mechanical catch 120. The button 185 may be mechanically fastened directly to protruding portion 124 of mechanical catch 120, or may be attached through an intermediate part 186, which may be formed from metal, phenolic resin, or any other appropriate material which may be formed to serve as an intermediary between button 185 and protruding portion 124 of mechanical catch 120.
Attached to the tube mounting cap 160 may be the caster assembly 193 (FIG. 26), or alternatively; race 190 and spherical bearing 191 (FIGS. 32 through 34). Where either roller type is utilized, a rubber glide cap 192, shown in FIG. 37 with spherical bearing 191, may be fitted into second end 172 of hollow cylinder 170, as seen in FIGS. 30 through 43. Caster assembly 193 may be comprised of a caster mounting plate 194, which attaches to the tube mounting cap 160, a plurality of ball bearings 195, a caster wheel 196, a caster bracket 197, a caster rolling pin 198, and a caster fastener 199.
Operation of the adjustable roller leg assembly 100 may occur, as seen in FIG. 17, by applying pressure to tube end cap 150 of the plunger assembly 110, moving the plunger assembly, from a first position, until the slotted opening 141 of plunger tube 140 reaches the lip 123 of mechanical catch 120, and is thereby engaged by the lip to retain the plunger assembly 110 and caster assembly 193 (or spherical bearing 191) in the second, extended position shown in FIG. 16. Retraction of the plunger assembly 110 and caster assembly 193 occurs by depressing button 185, which causes the mechanical catch 120 to pivot within plunger tube 140 and disengage from the plunger tube. Biasing by double conical spring 130 causes the plunger assembly 110 to return to the first (retracted) position of FIG. 17, where the caster assembly 193 (or spherical bearing 191) is entirely within hollow cylinder, with the second end 172 of hollow cylinder 170 resting of the floor or other surface.
A slight variation of the second embodiment—adjustable roller leg assembly 100—may create a third embodiment shown in FIG. 36, wherein adjustable roller leg assembly 200 is created the same as adjustable roller leg assembly 100, except that a second button may be created by flange 151 of end cap 150, which protrudes out of a second opening 176 of hollow cylinder 170. As with mechanical catch 120 of adjustable roller leg assembly 100, a button similar to button 188 may be attached to flange 151 for ease of use (not shown in FIG. 36 for the mechanical catch 120 or flange 151), and may include intermediate part 186.
Extension of the roller may then occur by applying downward pressure to the flange 151, or a button 188 attached thereto, which would move the plunger assembly 110 from the first position to the second position. Retraction of the plunger assembly 110 from the second position to the first position would still occur by depressing the mechanical catch 120 or a button 185 attached thereto, to cause mechanical catch 120 to pivot within plunger tube 140 and disengage from the plunger tube, with the double conical spring 130 biasing the plunger assembly 110 back to the first, retracted position.
Adjustable roller leg assembly 100 and adjustable roller leg assembly 200 (FIG. 36) may have a height adjustment capability that is provided by an adjustable mounting plate cover 210, shown installed in a representative roller leg assembly in FIG. 36, and shown by itself in FIG. 44. The adjustable mounting plate cover 210 may be comprised of a plate portion 211 with a plurality of orifices 212, a fixed cylinder 214, and an adjustment cylinder 220. The combination of fixed cylinder 214 and adjustment cylinder 220 are adapted from the Adjustable Foot Insert of U.S. Pat. No. 5,169,259 to Cornell, which may be described as follows. Fixed cylinder 214 may have a free end 216 (FIG. 46), and a fixed end 215 that is attached to plate portion 211, where plate portion 211 would be utilized to affix the adjustable roller leg assembly to an article.
Fixed cylinder 214 may have external threading which begins at free end 216, and which runs part of the way to fixed end 215. The adjustment cylinder 220 may have a polished end 226, a rough end 227, an internal cylinder wall 228, a first external cylinder wall 229, and a second external cylinder wall 230. First external cylinder wall 229 may be lip-shaped at the polished end 226, and may abruptly transition to second external cylinder wall 230 to produce lip shoulder 233. Second external cylinder wall 230 may have a plurality of ribs 231 protruding outward. Internal cylinder wall 228 may have internal threading 225 on at least a part of the wall, but preferably does not run all the way to either the polished end 226 or the rough end 227 of adjustment cylinder 220, the significance of which is described hereinafter. Internal cylinder wall 228 preferably runs all the way from rough end 227 to polished end 226, but may be interrupted at polished end 226 by a temporary wall 232, which may be necessary for manufacture of the part if formed as a casting. Wall 232, if simply a fallout of the manufacturing process, may be removed thereafter by a machining or a boring operation. In a fourth embodiment, wall 232 may be utilized, and is discussed hereinafter.
As seen in FIGS. 47 and 48, a casting process would lend to formation of adjustment cylinder 220 in two halves, a first half 221 having male protrusions 222, and a second half 223 having female indentations 224. The first half 221 and second half 223 could be mated together (FIG. 50) by alignment of the male protrusions 222 of the first half 221 with the female indentations 224 of second half 223, and then by pushing the halves together such that the internal threading 225 of the adjustment cylinder 220 engages the external threading 217 of the fixed cylinder 214. After assembly of the two halves in this manner, the temporary walls 232 could be removed by a manufacturing operation as discussed previously. This construction arrangement permits height adjustment by rotation of the adjustment cylinder 220 relative to the fixed cylinder 214, without concern of those parts disengaging from each other, as the relative travel will be inhibited at the extremes of travel in either direction, once the external threading 217 of the fixed cylinder 214 reaches the end of the internal threading 225 of the adjustment cylinder 220, which as already mentioned, preferably does not run all the way to either rough end 227 or polished end 226.
Adjustable mounting plate cover 210, as seen in FIG. 44, may then be mounted into the hollow cylinder 170 of either adjustable roller leg assembly 100 or adjustable roller leg assembly 200. Installation is accomplished by inserting the rough end 227 of adjustment cylinder 220 of the adjustable mounting plate cover 210, into the first end 171 of hollow cylinder 170, whereby the ribs 231 protruding from second external cylinder wall 230 contact interior cylinder wall 174 of the hollow cylinder 170, and are therein be retained by a press fit or interference fit, or by use of a mechanical feature or fasteners or locking clip. The adjustment cylinder 220 should be inserted until the lip shoulder 233 contacts the hollow cylinder first end 171. Once the adjustable roller leg assembly is attached to an article by fasteners through the orifices 212 of plate portion 211, of adjustable mounting plate cover 210, height adjustment may be achieved by causing rotation of the hollow cylinder relative to the article.
The exterior cylinder wall 173 of the hollow cylinder 170 may have a smooth metallic finish as shown in FIG. 36, as may the polished end 226 of adjustment cylinder 220, the fixed cylinder 214, and the plate portion 211.
A still further embodiment may be created by again using an adaptation of the Adjustable Foot Insert of U.S. Pat. No. 5,169,259 to Cornell. In a this fourth embodiment, shown in FIG. 50A, adjustable roller leg assembly 300 may be comprised of bearing cylinder 314, which is exactly like fixed cylinder 214 except for orifice 318 at fixed end 315, with first half 321 and second half 323 mated together as with adjustable roller leg assembly 200, but where temporary walls 332 are not removed, and are used to support stem mounting bracket 301. It may be seen by a comparison to the first embodiment that bearing cylinder 314 closely resembles bearing engagement cylinder 60. Stem mounting bracket 301 is capable of mounting bearing assembly 50 to wall 332 of cylinder first half 321 and cylinder second half 323 of cylinder insert 320. Adjustment of roller leg assembly 300 may be accomplished the same as previously described for adjustable roller leg assembly 200.
The examples and descriptions provided merely illustrate several preferred embodiment of the present invention. Those skilled in the art and having the benefit of the present disclosure will appreciate that further embodiments may be implemented with various changes within the scope of the present invention, particularly by combining various elements of the disclosed embodiments.
Patent Application
20120091299
