Library shelf support system

A guide channel member for a shelving system permits a shelf with an electrical safety device mounted thereon to be vertically repositioned while minimizing potential damage to the wire leads and maintaining a neat appearance. The invention is particularly useful in mobile storage systems wherein movement of a movable unit is stocked, thereby preventing injury to a person standing next to the unit, when the safety device is actuated. The channel member defines a vertically oriented slot leading to a vertical passage. The wires pass from the safety device, through the slot, along the vertical passage, and to the system control unit. Storing excess wires in the channel member permits convenient repositioning of the shelf while protecting and hiding the wires.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention pertains to electrical safety devices, and more particularly 
to apparatus which facilitates positioning electrical safety devices at 
desired locations on mobile storage systems. 
2. Description of the Prior Art 
Horizontally movable systems for storing books and other materials are well 
known. The mobile storage units may be moved along a building floor under 
either manual or electrical power. It is conceivable that a person may 
operate a mobile unit without realizing another person is standing in the 
aisle next to the unit. That situation is especially dangerous with 
electrically powered mobile units. To reduce the danger to a person caught 
next to a moving unit, various safety devices are commonly employed. A 
particularly desirable safety device is an elongated pressure operated 
safety switch attached horizontally along the external edge of a shelf. 
Momentary contact of the safety switch breaks the circuit controlling the 
mobile unit motors to stop movement of the unit. 
A problem with present safety switch designs is the exposure of the 
electrical wires leading to the switches, thus creating the risk of damage 
to the wires. A related problem is that, in providing a neat appearance as 
well as minimizing the amount of exposed wire, the wire lengths are 
usually cut to accommodate only one shelf location within the unit frame. 
As a result, the shelf with the safety switch cannot be readily 
repositioned on the frame without altering the wires. Depending on the 
desired new location of the shelf relative to the original location, a way 
must be found to either pull additional wire from somewhere in the 
circuit, or to protect and hide newly created excess wire; both procedures 
are time consuming and inconvenient. 
Thus, a need exists for apparatus which facilitates vertical adjustment of 
mobile storage unit shelves having a safety switch attached thereto while 
maintaining wire protection and a neat appearance. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, a mobile storage unit is provided 
having safety devices mounted to storage shelves which may be quickly and 
conveniently repositioned on the unit frame while protecting the 
electrical wires and maintaining a neat appearance. This is accomplished 
by apparatus which includes an elongated guide channel member joined to an 
upright unit frame. The channel member defines a vertical passage for 
storing and protecting the wires and includes one or more slots through 
which the wires pass from the safety device to the vertical passage. 
The safety device, and thus the channel member, may be mounted to either or 
both mobile and stationary units. The channel member may extend the full 
height of the storage unit, thus permitting the wires to be fed to the 
safety device from either the top or bottom of the unit. 
The wires pass from the safety device through a channel member slot and 
into a wire passage wherein they are protected. In addition, the channel 
member hides and stores the access wires, thereby permitting convenient 
repositioning of the shelf. 
The closed wire protecting passage is preferably created through the 
cooperation of the channel member and the storage unit frame. The channel 
member vertical passage is formed with an open side, and the channel 
member is fastened to the storage unit frame such that the vertical 
passage opening is closed by the frame wall. Consequently, the storage 
unit frame and the channel member combine to both protect and hide the 
wires. 
Other objects and advantages of the invention will become apparent to those 
skilled in the art from the disclosure.

DETAILED DESCRIPTION OF THE INVENTION 
Although the disclosure hereof is detailed and exact to enable those 
skilled in the art to practice the invention, the physical embodiments 
herein disclosed merely exemplify the invention which may be embodied in 
other specific structure. The scope of the invention is defined in the 
claims appended hereto. 
Referring to FIG. 1, a storage unit 1 of a mobile storage system is 
illustrated which includes the present invention. Mobile storage systems 
find particular usefulness in libraries and offices, but it will be 
understood that the invention is not limited to material storage 
applications. 
The storage unit 1 may be either a movable or stationary unit; merely for 
illustrative purposes, the unit 1 is depicted as a stationary unit. Also 
merely by way of example, the storage unit 1 is shown in conjunction with 
similar stationary units 3 and 5 which may be separated by building 
columns 7. It will be understood that corresponding movable units of the 
mobile storage system, not shown, are adapted to move along the floor 2 in 
association with the stationary units 1, 3 and 5 to create conventional 
mobile storage systems as disclosed in U.S. Pat. No. 3,640,595 
incorporated herein by reference. 
The storage unit 1 may be manufactured with a pair of upright side frames 9 
joined at their upper ends by a top brace 11. The lower ends of the side 
frames are joined to a horizontal base member 13, which is anchored to the 
building floor 2 by suitable and conventional devices. In the case of a 
movable unit, the base is equipped with suitable wheels and other well 
known mechanisms for moving the storage unit along the floor. The unit 1 
may also include an upright center frame 15. 
Suspended between upright frames 9 and 15 are a plurality of conventional 
shelves 17 which typically are utilized for storing books and similar 
items. As best shown in FIGS. 2 and 3, the shelves may be suspended by 
rivets 19 secured to the shelves and engaged in key hole slots 21 in frame 
wall 22. For that purpose, each shelf is provided with vertically disposed 
ear-like shelf supports 23 extending from both ends. The rivets 19 are 
permanently joined to the shelf supports 23 at the rivet heads 25 and 
shanks 27. Each rivet includes an annular flange portion 29. To receive 
the rivets and for supporting the shelves, the key hole slots are formed 
with an upper opening 31 large enough for the rivet flange 29 to pass 
through and a lower opening 33 large enough to accommodate rivet shank 27 
but smaller than the diameter of the rivet flange, all in a well known 
manner. To permit flexibility in locating the shelf in the mobile storage 
system, the key hole slots are spaced at generally regular intervals along 
the frames 9 and 15. To hide the rivet flanges and thus provide an 
attractive appearance, the frames may be constructed with a flat front 
wall 35 generally parallel to the wall 22. 
To prevent injury to a person standing in the aisle between the stationary 
unit 1 and a movable unit, or between two movable units, in case of 
accidental start-up of an electrically powered movable unit, a safety 
device is commonly employed. Actuating the device de-energizes the movable 
unit drive motors in well known fashion. In the construction illustrated 
in FIGS. 1-4, the safety device is in the form of an elongated pressure 
actuated electrical switch 37 commonly known as a safety tape. Pressing 
the tape at any point along the length thereof actuates the switch through 
contacts 38 which are normally held apart by spring members 40. The safety 
tape 37 is mounted by well known means to the front face 39 of one or more 
shelves 17. Usually the safety tape is placed about waist height above the 
floor. The safety tape may be applied to shelves of either or both the 
stationary unit 1 and the adjacent movable unit. The safety tape includes 
one or more wire leads 41 which electrically connect the tapes to the 
mobile storage system control unit, not illustrated in FIG. 1. The wires 
41 may follow the side frames 9 and center frame 15 to the base 13, from 
which, in the case of stationary unit 1, they may pass to nearby 
stationary units 3 and 5 by any appropriate route. Alternatively, the 
wires may pass upwardly from the safety tape along the upright frames 9 
and 15. In either case, the wires may pass directly from either a 
stationary or a movable unit to the control without also passing through 
another unit. 
In accordance with the present invention, the wires 41 of safety tapes 37 
are both protected from damage and hidden from view in the vertical runs 
along the frames 9 and 15 by elongated guide channel members 43. The 
channel members 43 may extend from approximately the bottom of the unit 1 
to slightly above the highest expected location of a shelf 17 bearing a 
safety tape 37. Normally that would be slightly higher than waist height. 
To permit the wires to pass either upwardly or downwardly from the safety 
tape and thereby enhance the versatility and convenience of the invention, 
the channel members may extend the full height of the storage unit. 
In the construction of the channel member 43 illustrated in FIG. 2, the 
channel member is fabricated as a four-legged member. Legs 45 and 47 are 
adapted to conform to the contours of the walls 49 and 51, respectively, 
of frame 9, which may form an obtuse angle, and to which the legs 45 and 
47 are fastened. The legs 45 and 47 are secured to the respective frame 
walls 49 and 51 by any appropriate means, such as rivets or threaded 
fasteners, not shown in FIGS. 2 and 3. Legs 53 and 55 of the channel 
member lie intermediate the legs 45 and 47, and legs 47, 53, and 55 form a 
vertical wire passage 57. To efficiently utilize the available space 
defined by frame walls 22, 49, and 51, the vertical passage 57 is 
preferably generally triangular-shaped. In the preferred embodiment, the 
passage 57 is not completely enclosed but has an opening 59 located 
between the edge of leg 47 and the junctions of legs 45 and 53. When the 
channel member is fastened to the frame, the wall 51 cooperates with leg 
47 to create a completely enclosed passage. 
To provide access to the wire passage 57 for the wires 41, leg 53 of the 
channel member 43 includes one or more vertically disposed slots 61. As 
best illustrated in FIGS. 2 and 3, the wires pass from the safety tape 37, 
under and behind the shelf support 23, and into the slot 61. The width of 
the slot may be only sufficient for a wire to pass therethrough; a width 
of approximately 3/16 inch is considered satisfactory. The vertical 
mid-point of the slot is preferably located at the estimated location of 
the shelf to which the safety tape 37 is attached. The slots are long 
enough to accommodate several different positions of the shelves 17 on the 
frames 9 and 15 without excessive exposure of the wires. Accordingly, in 
the present embodiment, a six inch slot length is acceptable. Thus, the 
shelf with the safety tape attached thereto may be vertically adjusted 
through a range of about six inches before the wires become inordinately 
exposed between the safety tape and the channel member. During 
manufacture, the wires 41 may be cut long enough to suit the farthest 
possible location of the safety switch shelf from the control unit. If the 
shelf is located at any lesser distance from the control, the excess wire 
will be stored unobtrusively within the passage 57. Later repositioning of 
the shelf merely withdraws the stored wire. Repositioning the shelf is 
accomplished quickly and conveniently because the wires merely slide in 
and out of slot 61. 
The channel member 43 of the present invention may be constructed of any 
suitable material. The preferred material is a strong and light weight 
plastic of a color and texture to match the decor of the mobile storage 
system. 
Thus, it is apparent that there has been provided, in accordance with the 
invention, a library shelf support system which fully satisfies the 
objects, aims, and advantages set forth above. While the invention has 
been described in conjunction with specific embodiments thereof, it is 
evident that many alternatives, modifications, and variations will be 
apparent to those skilled in the art in light of the foregoing 
description. For example, more than one slot 61 may be utilized if more 
than one shelf 17 is equipped with a safety tape 37, and the slots may be 
located to suit the locations of the safety tapes. Accordingly, it is 
intended to embrace all such alternatives, modifications, and variations 
as fall within the spirit and broad scope of the apended claims.