This application makes no priority claim.
Exemplary embodiments of the present invention relate generally to parts racks used with assembly lines, and more specifically to collapsible racks that are stackable whether in a collapsed or upright position.
Many forms of racks, stands, shelves and other such support structures, hereinafter referred to simply as “racks,” have been used for holding articles. Portable racks are used in manufacturing environments to deliver parts to an assembly line for inclusion in or preparation for inclusion in a manufacturing product. Racks are also used to provide uniform storage for articles, parts or components, and further in situations in which transportation and delivery of such items is needed.
Racks are numerous in design, and attempts to improve upon them have been made in the past to suit a variety of needs. One general improvement has been to provide for collapsible racks that may be collapsed, folded or dismantled when not in use, primarily to reduce to the space needed to transport empty racks back to their point of origin. Another general improvement has been to provide for stackable racks that are configured to be stacked vertically on top of other similar racks to utilize space in storage and transportation circumstances.
In both cases, rack designs have been used that provide various advantages and disadvantages to the user. For example, some designs have utilized foldable opposing end frames that, while providing strength and stability, interfere with the rack surface when in a collapsed position. This becomes a disadvantage in manufacturing situations wherein it is preferable for the rack surface of the topmost rack in a vertical stack to be freely accessible to assembly line workers or machines picking parts and components from the rack for utilization on the assembly line. Therefore, it is preferable for racks to be collapsible so that structural components do not interfere with the rack surfaces or the parts stored thereon.
Other racks designs provide collapsibility via dismantling. However, this is not desirable for situations in which quick and safe removal of the rack from an active area is needed, as is the case for assembly lines. Disaggregate rack components may pose a safety hazard if not secured properly in and around assembly line areas, and on board transportation vehicles. Furthermore, separable components generally result in much longer breakdown times for racks. For these reasons, racks with removable components are not favored.
Various hinge or bearing mechanisms have been used to enable folding of leg or frame structures relative to the rack surface or base. It has also been recognized that it is desirous for safety and convenience reasons to avoid bearing designs in which components protrude from the jointed areas which may in turn catch on clothing, machinery, or the articles or parts themselves. To avoid such issues, some designs have utilized a leg or post configuration wherein the leg or support posts slide into or around another structural component of the rack. These designs have often suffered from shaky stability due to loose-fitting parts. Various elaborate mating cuts and welded components have been introduced to increase strength and stability of such configurations, but at the cost of increased production difficulty, expense and complication, and often introduce disadvantages such as protruding components that are undesirable for the reasons mentioned above.
It is therefore an unmet need in the prior art for a collapsible rack that is stackable upon other similar racks when in both the upright and collapsed positions, that has foldable legs that do not interfere with or inhibit access to the rack surface when in the collapsed position, has movable components that remain within the footprint of the rack regardless of position, that has a hinging mechanism that contains no protruding parts and requires no welding or intricate mating surface finishing, that has no separable, removable parts, and that may be quickly collapsed and unfolded in a safe manner.
One object of the invention is to provide a collapsible and portable rack that is stackable upon other similar racks whether any one rack is in an upright (e.g., unfolded or active) or a collapsed (e.g., folded or inactive) position.
Another object of the invention is to provide a rack with a shelf having a top surface and a perimeter, and further at least three leg assemblies distributed symmetrically about the perimeter, wherein each leg assembly is provided with a leg footer affixed to the perimeter and having a proximal end, a distal end and a bearing bracket at the proximal end, a leg member having a proximal end and a distal end wherein the proximal end of the leg member is shaped to be received into the bearing bracket, and a slider pivot bearing joining the leg member to the bearing bracket at a pivot axis and having a journal in contact with a linear bearing surface and a circular bearing surface, wherein the slider pivot bearing constrains, via the journal, the pivot axis to linear motion along the linear bearing surface and axial rotation along the circular bearing surface.
It is another object of the invention to provide a rack with a retaining tab protruding from the leg member and a notch in the bearing bracket shaped to receive the retaining tab, thereby locking the slider pivot bearing against axial rotation when the leg member is in an upright position.
Further objects of the invention are provided in racks having an upright position wherein the leg member extends vertically from the leg footer wherein the retaining tab is retained within the notch, and a collapsed position wherein the leg member is slid upward so that the retaining tab is released from the notch and the leg member is pivoted into a horizontal position, thereby extending horizontally from an opening in the leg footer body.
Yet another object of the invention is to provide a leg footer with a stacking socket at the distal end of the leg footer sized to receive from a second rack for stacking thereon a distal end of a leg member or a proximal end of a leg footer.
Another object of the invention is provided in a rack with at least two leg assembly pairs spaced apart about the perimeter, wherein each leg assembly pair comprises a first leg assembly and a second leg assembly joined by a primary connecting frame element that forms a portion of the perimeter. Racks may also be provided with a secondary connecting frame element joining perimetrically adjacent leg assembly pairs in the at least two leg assembly pairs, wherein the secondary connecting frame element forms a portion of the perimeter.
It is another object of the invention to provide a rack wherein the journal is carried by a shaft pin coaxial with the pivot axis, the linear bearing surface being an interior surface of a slot through the leg member and the circular bearing surface being an interior surface of a hole through the bearing bracket of the leg footer. Alternatively, the linear bearing surface may be an interior surface of a slot through the bearing bracket of the leg footer and the circular bearing surface may be an interior surface of a hole through the leg member.
It is another object of the invention to provide a rack with spaced apart fork guides affixed to the rack in parallel beneath the shelf.
It is another object of the invention to provide a rack with a plurality of tie-downs affixed to the rack, a plurality of mounting brackets affixed to the shelf, and a plurality of mounting holes through the shelf.
It is another object of the invention to provide a rack with a shelf having a top surface, a perimeter and a geometric center, and further a plurality of leg assemblies distributed about the perimeter in rotational symmetry with respect to the geometric center. Each leg assembly has a leg member having an outer surface, a maximum leg member width, a proximal end and a distal end, and further includes a bearing surface being closed and extending through the proximal end of the leg member, and a retaining tab protruding from the outer surface longitudinally between the bearing surface and the distal end of the leg member body. Each leg assembly further has a leg footer having a proximal end and a distal end, is affixed to the perimeter, and further includes a tubular shell body having an interior shape sized to receive the proximal end of the leg member, a notch sized to receive the retaining tab formed in and open to the proximal end of the leg footer, a bearing surface being closed and extending through the proximal end of the leg footer, an opening in the leg footer extending longitudinally from the proximal end of the leg footer having a transverse width greater than the maximum leg member width, and a stacking socket extending from the distal end of the leg footer sized to receive from a second rack for stacking thereon a distal end of a leg member or a proximal end of a leg footer. Each leg assembly further includes a slider pivot bearing connecting the proximal end of the leg member to the proximal end of the leg footer and has a shaft pin secured within the bearing surface of the leg footer and the bearing surface of the leg member wherein the proximal end of the leg member is contained within the tubular shell of the leg footer, the leg member being thereby movable between the upright position and the collapsed position.
Another object of the invention is provided wherein the bearing surface of the leg footer is a circular bearing surface being an interior surface of a hole and the bearing surface of the leg member is a linear bearing surface being an interior surface of a slot, whereby the shaft pin constrains the leg member to linear motion with respect to the shaft pin, and the leg footer and leg member are constrained to axial rotation about the shaft pin with respect to one another.
Another object of the invention is provided wherein the bearing surface of the leg member is a circular bearing surface being an interior surface of a hole and the bearing surface of the leg footer is a linear bearing surface being an interior surface of a slot, whereby the shaft pin is constrained to linear motion with respect to the leg footer, and the leg footer and leg member are constrained to axial rotation about the shaft pin with respect to one another.
It is another object of the invention to provide a rack with a shelf having a top surface and a first and second pair of parallel sides together forming a perimeter, and further pair of primary support structures each having a pair of leg assemblies. Each leg assembly has a leg member having a proximal end and a distal end, and further includes a leg member body having a pair of opposing sides each having an outer surface and together defining a maximum leg member width there between, a pair of slots in the pair of opposing sides and extending longitudinally from the proximal end of the leg member, and a retaining tab protruding from the outer surface of each opposing side and located longitudinally between the slot and the distal end of the leg member. Each leg assembly is further provided with a leg footer having a proximal end and a distal end, and further includes a leg footer body having a U-channel shell with two parallel sides defining an interior diameter greater than the maximum leg member width, a perpendicular side joining the two parallel sides and an open side, further a notch sized to receive the retaining tab formed in and open to the proximal end of the leg footer on each parallel side of the leg footer body, a hole formed in the proximal end of the leg footer on each parallel side of the leg footer body, and a stacking socket at the distal end of the leg footer sized to receive from a second rack for stacking thereon a distal end of a leg member or a proximal end of a leg footer body. Each leg assembly further includes a slider pivot bearing securing the proximal end of the leg member within the proximal end of the leg footer and has a shaft pin secured through each hole in the leg footer and each slot in the leg member wherein the proximal end of the leg member is contained within the leg footer, the leg member being thereby movable between the upright position and the collapsed position. Each pair of leg assemblies further includes a primary connecting frame element affixed between and joining the pair of leg assemblies to form the primary support structure, and wherein the pair of primary support structures are each affixed to a side in the first pair of parallel sides of the shelf. The rack is further provided with a pair of secondary connecting frame elements each affixed between a joining a leg assembly from each of the primary support structures, and wherein the pair of secondary connecting frame elements are each affixed to a side in the second pair of parallel sides of the shelf.
It is an object of this invention to provide a collapsible and stackable rack of the type generally described herein and being adapted for the purposes set forth herein, and overcoming disadvantages found in the prior art. These and other advantages are provided by the invention described and shown in more detail below.
Novel features and advantages of the present invention, in addition to those mentioned above, will become apparent to those skilled in the art from a reading of the following detailed description in conjunction with the accompanying drawings wherein identical reference characters refer to identical parts and in which:
Exemplary embodiments of the present invention are directed to improved collapsible racks that are stackable whether in a collapsed or upright position, and being generally adapted for the purposes and advantages as set forth herein. One such exemplary embodiment of a rack 10 is shown in perspective view in an upright position in
At least three leg assemblies 16 are included and distributed about the perimeter 18 of the shelf 12. The leg assemblies 16 are preferably distributed symmetrically about the perimeter 18 to ensure stability and to assist in achieving proper orientation of the racks with respect to other racks during stacking. As explained in further detail below, the exemplary embodiment of the rack 10 shown in FIGS. 1 and 3-6 is rotationally symmetric at 180 degrees, in part aligning open ends (see the discussion of
The leg assemblies 16 each include a leg footer 20, a leg member 22 and a slider pivot bearing (see
It is preferred that the leg member 22 be formed as an elongate square- or rectangular-shaped body, but those skilled in the art will recognize that other shapes are readily employed. Regardless of the leg member shape, the leg member will have a maximum leg member width that must be accommodated by the leg footer as further defined below.
The proximal end of the leg footer 20 also includes a horizontal opening so that the leg member 22 may be rotated into the collapsed position without interference from the leg footer 20 structure, thereby extending horizontally away from the leg footer 20 (see
The leg footer 20 may optionally and preferably be provided as a three-sided U-channel shell having two parallel sides defining an interior diameter greater than the maximum leg member width, a perpendicular side joining the two parallel sides, and an open side, as shown in
The slider pivot bearing consists of the features that join the proximal ends of each leg footer 20 and leg member 22 in a leg assembly 16 thereby allowing rotational motion of the leg member 22 with respect to the leg footer 20, and linear motion of either the leg footer 20 or the leg member 22 with respect to the other. That is, the slider pivot bearing permits axial rotation of the leg member 22 about a pivot axis, and further permits linear motion of either the leg footer 20 or the leg member 22 with respect to the pivot axis, depending on the configuration. The location of a pivot axis for one of the leg assemblies in
Preferably, a shaft pin 30 coaxial with the pivot axis 24 carries the journal surface that contacts the linear and circular bearing surfaces and joins the proximal ends of the leg footers 20 and leg members 22. The shaft pin 30 is shown generally as a capped axle secured through the leg footers 20 and the leg members 22, and may comprise a locking pin, grooved clevis pin and retaining clamp configuration, axle and tension or cotter pin configuration, self-locking pin/axle, welded pin or the like. A preferred embodiment utilizes a welded pin for the shaft pin. Alternatively, as opposed to the preferred method of connecting the leg footer and member together with a separate pin secured through the components of the leg assembly, an axle may be fixed with respect to either the leg footer or the leg member in either a single or split axle configuration.
Further details and optional exemplary embodiments of the slider pivot bearing are depicted in connection with
In some embodiments of the invented rack, the leg members include at least one retaining tab 44 protruding from the side, and corresponding notches 46 in the proximal ends of the leg footer or its bearing bracket portion 20 shaped to receive the retaining tabs 44 to lock the slider pivot bearing against axial rotation when the leg member 22 is in the upright position. For added stability when in the upright position, it is preferred that two opposing retaining tabs 44 be employed on each leg member 22, for example one on each of the two opposing sides of a bearing bracket. Such opposing retaining tabs 44 are clearly depicted in the view shown in
Some embodiments also include a stacking socket 48 at the distal end of the leg footer 20. The stacking socket 48 is a cavity sized for receiving the distal end of a leg member 22 when the rack 10 is stacked upon another similarly configured rack that is in the upright position, and the proximal end of a leg footer 20 when stacked upon another rack that is in the collapsed position. The stacking socket 48 is preferably provided as a flared end cap defining a cavity 49 and affixed at the distal end of the leg footer 20. The stacking socket 48 should provide a sufficient barrier to lateral movement (e.g., the stacking socket walls) of the rack 10 when stacked upon other similar racks to prevent tipping or sliding from stacked positions.
The racks 70, 72 and 74 depicted in
The use of primary connecting frame elements such as 86 and 88, wherein those elements form a portion of the shelf perimeter 18, is the preferred method of securing the leg assemblies to the shelf 12. The use of connecting frame elements in general is preferred to provide increased load carrying capacity and even distribution of the load among the leg assemblies. Further secondary connecting frame elements, such as 90 and 92 in
Traversing the perimeter 18 of the shelf 12, the use of inwardly-facing leg assembly pairs allows for one or more open sides (“open ends” in the case of four-sided embodiments), where an “open side” is a portion of the perimeter that is free of leg members when the leg assemblies are in a collapsed position. The top rack 74 in
Some embodiments are provided with one or more optional spaced apart fork guides. For example, the top rack 74 in
It is preferred, as shown in the exemplary embodiments herein, to employ a four-sided rectangular shelf 12 with two primary connecting frame elements and two secondary connecting frame elements forming the shelf perimeter 18 so that, when several racks are stacked in the upright position, the leg assemblies of the top most rack may be collapsed, leaving two open ends as freely accessible to assembly line operations. Upon exhausting the parts held on the top most rack, the collapsed rack can be quickly removed and placed upon a second stack of collapsed racks out of the way of the assembly line operations. Such configurations are also useful in shipping and storage situations to permit unloaded racks to be stacked, stored or transported safely and with little floor space required.
It is further preferred to provide optional mounting brackets 106, interior tie-downs (similar to the tie-downs 98 in
Any embodiment of the present invention may include any of the optional or preferred features of the other embodiments of the present invention. The exemplary embodiments herein disclosed are not intended to be exhaustive or to unnecessarily limit the scope of the invention. The exemplary embodiments were chosen and described in order to explain some of the principles of the present invention so that others skilled in the art may practice the invention. Having shown and described exemplary embodiments of the present invention, those skilled in the art will realize that many variations and modifications may be made to the described invention. Many of those variations and modifications will provide the same result and fall within the spirit of the claimed invention. It is the intention, therefore, to limit the invention only as indicated by the scope of the claims.