US20080296243A1

US20080296243A1 - Seismic shelf restraint

Info

Publication number: US20080296243A1
Application number: US11/809,830
Authority: US
Inventors: William Michael Greenbaum
Original assignee: University of California
Current assignee: Lawrence Livermore National Security LLC
Priority date: 2007-05-31
Filing date: 2007-05-31
Publication date: 2008-12-04

Abstract

A seismic shelf restraint for use with a shelf structure of a type having a shelf and two front columns on opposite sides of the front ledge of the shelf with each front column having a mounting slot positioned higher than the shelf surface and facing the same direction as the other mounting slot. The seismic shelf restraint preferably is an elongated thin flat bar with two tabs, one at each end, which are seatable in the mounting slots of the two front columns so that the rigid body is wholly positioned alongside the front ledge, for restraining objects from falling from the front ledge.

Description

I. FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.

II. BACKGROUND OF THE INVENTION

A. Technical Field
The present invention relates to shelf restraints, and more particularly to an elongated, rigid-body shelf restraint capable of being mounted alongside a shelf ledge using two connector arms (e.g. tabs) at opposite ends of the restraint which are insertably seatable in mounting slots found on two columns located on opposite sides of the shelf ledge, for restraining objects placed on the shelf from falling off the ledge, especially during a seismic event.
B. Description of the Related Art
Seismic events, i.e. earthquakes, can be hazardous to occupants of home or office buildings due to moving or falling objects. In particular, unsecured books and other objects placed on open shelves have been known to fall out and cause damage and/or injury during seismic events.
In an effort to enhance seismic safety, various types of shelf restraints and ledge barriers are known in the art. Many are commercially available, such as for example, elastic stretch cords (either used alone or passed through a rigid-body tube), nets, plastic panels, etc. which span the width of the shelf adjacent the shelf ledge when attached. Even makeshift ledge barriers, such as simple wire straps, or cut-to-length strips of wood, metal or plastic, are sometimes used. In any case, installation and attachment is typically accomplished by fastening (e.g. with screws) the barrier to the shelf structure (e.g. bookcase). Unfortunately, this requires the drilling of holes for attachment which damages the shelf structure, leaves unsightly holes when the barrier is removed, and also has an associated installation cost. Furthermore, cord or wire type ledge barriers in particular may not be sufficiently strong and rigid to withstand the inertia of book volumes moving together during an earthquake.
One type of shelf restraint which does not require drilling for attachment is disclosed in U.S. Pat. No. 5,860,535 to Brown. This shelf restraint includes a pair of book ends 14, 16 and a rod 26 pivotally supported by the book ends at pivot points 28 to span the width of the bookshelf. Double coated adhesive tape 23 is used to attach the book ends to the surface of the bookshelf. The use of such tape, however, is meant for permanent installation of the shelf restraint, and may cause damage to the shelf surface if removed.
Another type of book restraint assembly which does not require drilling for attachment is disclosed in U.S. Pat. No. 5,038,689 to Duffy. This shelf restraint assembly includes a pair of inverted trapezoidal end plates 14 and an elongated tubular restraint member 12 connected at opposite ends to the end plates near the front edges 15 of the end plates. End tabs 22 extend from the rear edges 16 of the end plates, and are capable of being received in end tab slots 22 of post members 28 located at the back of the shelf structure. This arrangement allows the restraint assembly to pivot at the end tabs 22 to raise and lower the elongated tubular restraint member 12 spanning the width of the shelf. However, the attachment location at the rear/back side of the shelf structure may pose some installation difficulty especially when books are already present.
There is a need to effectively restrain the contents of open shelves from falling out during a seismic event. It would be advantageous to provide a seismic shelf restraint with a simplified rigid-body construction enabling simplified fabrication and use (attachment/removal) without the need for professional installation and without damaging the shelf structures.

III. SUMMARY OF THE INVENTION

One aspect of the present invention includes an apparatus for restraining objects on a shelf of a shelf structure of a type having two front columns on opposite sides of a front ledge of the shelf with each front column having a mounting slot positioned higher than the shelf surface, the apparatus comprising: an elongated substantially linear rigid body having two connector arms one at each end of the rigid body which are seatable in the mounting slots of the two front columns to mount the rigid body thereon whereby the rigid body spans the width of the shelf alongside the front ledge for restraining objects from falling therefrom.
Another aspect of the present invention includes an apparatus for restraining objects on a shelf of a shelf structure of a type having two front columns on opposite sides of a front ledge of the shelf with each front column having a mounting slot positioned higher than the shelf surface and facing the same direction as the other mounting slot, the apparatus comprising: an elongated thin flat bar having front and back faces, and two tabs one at each end of the elongated thin flat bar which are bent to protrude out of plane from the front face in the same direction as each other, said tabs being seatable in the mounting slots of the two front columns to mount the thin flat bar thereon and so that end portions of the front face confront the front columns to be substantially flush therewith and the thin flat bar is positioned alongside the front ledge for restraining objects from falling therefrom.
And another aspect of the present invention includes a shelf restraint comprising: an elongated rigid body having two catches one at each end of the rigid body, with each catch capable of catching a lower edge of a mounting slot on one of two columns on opposite sides of a ledge of a shelf to mount the rigid body on the two columns so that the rigid body spans the width of the shelf alongside the ledge for restraining objects from falling therefrom.

IV. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a part of the disclosure, are as follows:

FIG. 1 is a perspective view of a first exemplary embodiment of the seismic shelf restraint of the present invention.

FIG. 2 is an end view of the seismic shelf restraint of FIG. 1.

FIG. 3 is a top view of the seismic shelf restraint of FIG. 1 mounted on two front columns of a shelf structure.

FIG. 4 is an elevational view of the mounted seismic shelf restraint of FIG. 3 taken along the line 4-4 and showing the back face of the restraint.

FIG. 5 is a perspective view of one end of the mounted seismic shelf restraint mounted of FIG. 4.

FIG. 6 is an end view of the mounted seismic shelf restraint of FIG. 3 taken along line 6-6.

FIG. 7 is a perspective view of one end of a second exemplary embodiment of the seismic shelf restraint of the present invention, showing a tab formed at a lower corner of the seismic shelf restraint.

FIG. 8 is a perspective view of one end of a third exemplary embodiment of the seismic shelf restraint of the present invention, showing a tab formed along a lower edge of the seismic shelf restraint and removed from the corner.

FIG. 9A is a plan view of one end of a fourth exemplary embodiment of the present invention having a rod-like elongated rigid body with rod-like connector arms.

FIG. 9B is an end view of the seismic shelf restraint of FIG. 9B shown mounted on a front column.

FIG. 10 is a perspective view of a fifth exemplary embodiment of the present invention showing an elongated rigid body having two body modules which are slidably connected to adjust the length of the elongated rigid body.

V. DETAILED DESCRIPTION

The present invention is a rigid body shelf restraint for seismically restraining objects, e.g. books, notebooks, binders, and other objects, and capable of being quickly and easily attached and removed to a shelf structure or system without damaging or otherwise altering the structure for installation. Generally, the shelf restraint has an elongated, substantially linear, rigid-body structure with two ends, each with an arm, catch, hook, tab, flange, or other type of structural appendage (hereinafter “connector arm”) which extends/projects out from the elongated main rigid body preferably in the same direction as the other structural appendage on the other end. The shelf restraint is preferably made/constructed of a suitably rigid material, such as metals, alloys polymers, composites, etc. using conventional fabrication methods known in the art, so that the elongated rigid body is capable of sufficiently resisting (structurally) a force directed transverse to its longitudinal axis. It is appreciated that the elongated rigid body structure of the present invention can have either a monolithic construction, or a multi-component assembled construction, so long as rigidity in the transverse direction is sufficiently maintained. It is also appreciated that while shown in the drawings as a linear rigid body, other elongated substantially linear rigid body shapes and geometries are possible.
Turning now to the drawings, FIGS. 1 and 2 show the structure of a first exemplary embodiment of the shelf restraint of the present invention, generally indicated at reference character 10. The restraint 10 is shown as an elongated monolithic thin flat bar with opposing ends 11 and 12, a front face 13, a back face 35, an upper edge 14, a lower edge 15, and end edges 16 and 17 at the opposing ends 11 and 12, respectively. Also on the opposing ends 11 and 12 are connector arms 18 and 19, respectively, used for releasably mounting the restraint to a shelf structure of a type having mounting slots on front columns, discussed in detail below. The connector arms 18 and 19 are shown as tabs, i.e. thin flat sections, which are shown as partial cutouts of the thin flat bar. In particular, the tabs 18, 19 are each shown cut or otherwise separated from the main body of the thin flat bar along two edges, and bent along a bend axis 18′ and 19′, respectively, which is parallel to the longitudinal axis of the thin flat bar. In particular, the tabs are each bent to protrude out of plane from the front face 13 at an angle α, shown in FIG. 2. The angle α is preferably an acute angle so as to catch a lower edge of a mounting slot and seat the shelf restraint, as will be described next.
The shelf restraint of the present invention is preferably configured for use on and with a shelf structure or system (e.g. a bookcase) of a type having, at a minimum, a shelf with a front ledge, two support columns (i.e. front columns) on opposite sides of the front ledge, and one or more mounting slots (not limited to narrow thin openings) in vertically spaced arrangement along each of the two front support columns for enabling shelf height adjustments. Preferably, the mounting slots on the two front support columns are rear facing, so that they are not viewable from the front of the shelf. An exemplary shelf structure having such rear-facing mounting is the Steelcase® line of bookcases available from Steelcase, Inc. of Grand Rapids, Mich.
FIGS. 3-6 show the first exemplary embodiment of FIGS. 1 and 2 mounted on a representative shelf structure having a rectangular shelf 20, with a front ledge 21, a back edge 22, and side edges 23, 24. The shelf 20 is shown supported by four columns 25, 27, 29, and 31 at each of its four corners. The columns are hollow, with column 25 surrounding volume 26, column 27 surrounding volume 28, column 29 surrounding volume 30, column 31 surrounding volume 32. As shown in FIGS. 4 and 5, the front column 25 has a vertically-spaced arrangement of mounting slots 33 leading into the volume 28, and the front column 27 has a vertically-spaced arrangement of mounting slots 34 leading into the volume 26. While the shelf restraint 10 is shown mounted on the second tier (above shelf) mounting slots, other tier levels may be selected for a desired elevation above the shelf, since the spacing of each pair of same-tier mounting slots on the two front columns is the same for all tiers. And any level/tier of mounting slots will position the restraint above the top surface of the shelf 20 so that it functions as an effective barrier.
As can be best seen in FIGS. 3 and 6, the mounting of the shelf restraint to the shelf structure is accomplished by inserting tabs 18 and 19 into a pair of same-tier mounting slots on the two front columns, so that the tabs catch a lower edge of the mounting slot. In this manner, it is appreciated that the tabs are seated in the mounting slots by the weight of the restraint alone, and as such the restraint is at rest and the stable and will not fall out unless lifted out. And as best seen in FIGS. 3, 5, and 6, when the restraint is mounted in this manner, the front face 13 is made to confront, if not contact the front columns, and is substantially flush with the front columns. Furthermore, when mounted in this manner, the elongated rigid body is positioned alongside the front ledge, and the entire shelf restraint is positioned at the front of the shelf structure. In this manner, the shelf restraint can be installed and removed quickly for facilitating operation.
FIG. 7 is a perspective view of one end of a second exemplary embodiment of the seismic shelf restraint of the present invention, generally indicated at reference character 36, and showing a tab 37 formed at a lower corner of end 12. As such, tab 37 has one edge that is a formed from of end edge 17, and another edge that is a part of lower edge 15.
FIG. 8 is a perspective view of one end of a third exemplary embodiment of the seismic shelf restraint of the present invention, generally indicated at reference character 38, and showing a tab 39 formed along a lower edge 15 and removed from the corner and the end edge 17. As such, tab 39 has only one edge that is formed from one of the four edges of the thin flat bar.
FIG. 9A is a plan view of one end of a fourth exemplary embodiment of the present invention, generally indicated at reference character 40, and having a rod-like elongated rigid body 41 with rod-like connector arms, e.g. 42. As shown, the connector arm 42 is integrally formed (i.e. bent) from the elongated main rigid body 41.
FIG. 9B is an end view of the seismic shelf restraint 40 of FIG. 9A shown mounted on a front column 27. Similar to the first embodiment shown in FIG. 6, the connector arm 42 is insertably seated in the mounting slot 33, with the elongated rigid body 41 confronting, if not contacting, substantially flush with the front column,
FIG. 10 is a perspective view of a fifth exemplary embodiment of the present invention, generally indicated at reference character 50, and showing an elongated rigid body having two body modules 51 and 52, which are slidably connected to adjust the length of the elongated rigid body. The first body module 51 extends to a first end having a tab 56, shown here in a corner position, and the second body module 52 extends to a second end having a tab 55. Various methods may be used for adjustably connecting the two body modules 51, 52 together. One preferred method is shown in FIG. 10, having one (e.g. 51) of the two body modules having a longitudinally slotted track 53, and the other (e.g. 52) of the two body modules carrying at least one fastener 54 which is positioned in the slotted track. In FIG. 10, the fastener 54 is shown as a screw with a head on the opposite side of the body module 51, for fastening or releasing the two body modules against each other.
While particular operational sequences, materials, temperatures, parameters, and particular embodiments have been described and or illustrated, such are not intended to be limiting. Modifications and changes may become apparent to those skilled in the art, and it is intended that the invention be limited only by the scope of the appended claims.

Claims

1. An apparatus for restraining objects on a shelf of a shelf structure of a type having two front columns on opposite sides of a front ledge of the shelf with each front column having a mounting slot positioned higher than the shelf surface, the apparatus comprising:

an elongated substantially linear rigid body having two connector arms one at each end of the rigid body which are seatable in the mounting slots of the two front columns to mount the rigid body thereon whereby the rigid body spans the width of the shelf alongside the front ledge for restraining objects from falling therefrom.

2. The apparatus of claim 1,

wherein the mounting slots of the front columns are rear-facing mounting slots, and the connector arms protrude from the rigid body in the same direction as each other transverse to a longitudinal axis of the rigid body.

3. The apparatus of claim 2,

wherein the rigid body is a thin flat bar having front and back faces, and the connector arms protrude out of plane from the front face so that, upon seating the connector arms in the rear-facing mounting slots, end portions of the front face confront the front columns to be substantially flush therewith.

4. The apparatus of claim 3,

wherein the connector arms are tabs bent to protrude out of plane from the front face.

5. The apparatus of claim 4,

wherein each of the tabs is bent along a respective bend axis that is parallel to the longitudinal axis of the thin flat bar.

6. The apparatus of claim 5,

wherein each of the tabs form an acute angle with the front face of the thin flat bar to catch a lower edge of one of the mounting slots.

7. The apparatus of claim 1,

wherein the elongated substantially linear rigid body has at least two body sections operably connected to adjust the length of the rigid body.

8. An apparatus for restraining objects on a shelf of a shelf structure of a type having two front columns on opposite sides of a front ledge of the shelf with each front column having a mounting slot positioned higher than the shelf surface and facing the same direction as the other mounting slot, the apparatus comprising:

an elongated thin flat bar having front and back faces, and two tabs one at each end of the elongated thin flat bar which are bent to protrude out of plane from the front face in the same direction as each other, said tabs being seatable in the mounting slots of the two front columns to mount the thin flat bar thereon and so that end portions of the front face confront the front columns to be substantially flush therewith and the thin flat bar is positioned alongside the front ledge for restraining objects from falling therefrom.

9. The apparatus of claim 8,

10. The apparatus of claim 9,

11. The apparatus of claim 8,

wherein the elongated thin flat bar comprises at least two bar sections operably connected to adjust the length of the elongated thin flat bar.

12. A shelf restraint comprising:

an elongated rigid body having two catches one at each end of the rigid body, with each catch capable of catching a lower edge of a mounting slot on one of two columns on opposite sides of a ledge of a shelf to mount the rigid body on the two columns so that the rigid body spans the width of the shelf alongside the ledge for restraining objects from falling therefrom.

13. The shelf restraint of claim 12,

wherein the mounting slots face the same direction as each other and the catches protrude from the rigid body in the same direction as each other transverse to a longitudinal axis of the rigid body.

14. The shelf restraint of claim 13,

wherein the rigid body is a thin flat bar having front and back faces, and the catches protrude out of plane from the front face so that, upon catching the lower edges of the mounting slots with the catches, end portions of the front face confront the columns to be substantially flush therewith.

15. The shelf restraint of claim 14,

wherein the catches are tabs bent to protrude out of plane from the front face.

16. The shelf restraint of claim 15,

17. The shelf restraint of claim 16,

wherein each of the tabs form an acute angle with the front face of the thin flat bar to catch the lower edge of one of the mounting slots.

18. The shelf restraint of claim 12,

wherein the elongated rigid body has at least two body sections operably connected to adjust the length of the rigid body.