Utility bag

The present invention shows a multi-purpose, utility bag comprising: PA1 a bag member, said bag member having a base portion and a back portion and being constructed of flexible material; PA1 a support member integrated into said bag member and providing firm support for said bag member at least in the area of said base portion and said back portion of said bag member; and, PA1 a non-linear array of load-bearing, rotatable castors fixedly attached to the base portion of said support member permitting the utility bag to sit upright and roll across a flat surface upon said castors.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a multi-purpose utility bag. In 
particular, the present invention relates to a multi-purpose utility bag 
comprising: 
a bag member, said bag member having a base portion and a back portion and 
being constructed of flexible material; 
a support member integrated into said bag member and providing firm support 
for said bag member at least in the area of said base portion and said 
back portion of said bag member; and 
a non-linear array of load-bearing, rotatable castors fixedly attached to 
the base portion of said support member permitting the utility bag to sit 
upright and roll across a flat surface upon said castors. 
2. Description of Related Art 
Utility bags of various types are known to the prior art. One type of bag 
known for many years has been the "knapsack", typically a leather or 
canvas case for clothes and other supplies, carried on the back by 
soldiers, hikers and the like. Such bags have always been popular with 
students, as an inexpensive and convenient way of carrying books and other 
school supplies. 
In recent years, however, it has become common to replace the more 
traditional leather or canvas material with a lightweight and inexpensive 
nylon or other synthetic material. Such constructions have proved suitable 
for most uses such bags encounter, and are often heavily loaded with 
books, baseball gloves, footballs, frisbees, and other objects necessary 
and unnecessary to the student. 
Unfortunately, while such bags are designed to be worn on the back of the 
user, supported by shoulder straps, they are just as often carried by 
hand, using the same shoulder strap. Often, with such a bag in its 
typically overloaded condition, this results in the bag being dragged 
along the ground, pulled by the strap. 
This abuse quickly results in damage to the bag, the bottom of which is 
fabricated from a material chosen for lightweight construction, and not 
adapted to the abrasive treatment which results from contact with concrete 
and asphalt surfaces. 
Wheels have been fitted to other types of luggage. For example, it is 
common to see a traveller in an airport pulling a small cart with one or 
more suitcases strapped to it, or pulling along a suitcase provided with 
two small wheels by an attached handle. Larger suitcases and trunks may be 
provided with castors at each corner to assist in transporting them. 
All of these devices are intended for occasional use with large, 
hard-bodied luggage. None are adapted to the everyday, intermittent, 
multi-terrain use of a student carrying, or dragging, a book bag. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a simple adaptation of 
the multi-purpose utility bag which will avoid the damage caused by 
pulling the bag across abrasive surfaces. 
It is a further object of the present invention to provide a multi-purpose 
utility bag adapted to everyday, intermittent, multiterrain use. 
According to the preferred embodiment of the present invention, there is 
provided a multi-purpose utility bag comprising 
a bag member, said bag member having a base portion and a back portion and 
being constructed of flexible material; 
a support member integrated into said bag member and providing firm support 
for said bag member at least in the area of said base portion and said 
back portion of said bag member; and, 
a non-linear array of load-bearing, rotatable castors fixedly attached to 
the base portion of said support member permitting the utility bag to sit 
upright and roll across a flat surface upon said castors.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1a shows the support member of the present invention. The support 
member 10 is comprised of a back portion 12 and a base portion 14. The 
back portion 12 and base portion 14 may be formed from one integral piece 
of material bent at their juncture 16, and one-eighth inch or one-quarter 
inch Lexan has been used with success. Of course, the support member could 
be comprised of a separate back portion 12 and base portion 14 joined in 
some manner at the juncture 16 as shown in FIG. 1b, or by other similar 
construction. 
The base portion 14 is further provided with a non-linear array of 
load-bearing castors 20, 22 and 24 fixedly attached to the base portion 14 
of said support member 10. These castors 20, 22 and 24 are comprised of 
castor wheels 26, 28 and 30 mounted to the base member 14 by attachment 
means 32, 34 and 36. Commercially available one and five-eighths inch 
castor wheels have been used advantageously for this purpose. These castor 
wheels are suitably light in weight (the bag is still intended primarily 
to be carried) and rated to carry a loading weight of sixty pounds. 
In FIG. 2 the multi-purpose utility bag 50 of the present invention is 
shown. The utility bag 50 consists of a bag portion 52, typically provided 
with handles 54 and 56 and shoulder straps 58 and 60. These shoulder 
straps 58 and 60 are typically provided with a padded portion 62 and 64 to 
provide greater comfort when the bag is carried on the shoulders. The 
straps are also provided with an unpadded lower portion 66 which connects 
with the lower portion of the bag typically is some kind of arrangement 
wherein the length of the strap can be adjusted for the comfort of the 
wearer, as is well known to the art. 
The multi-purpose bag 50 is further provided with a closure mechanism for 
the body of the bag, illustrated in the present embodiment as zipper 68. 
The bag 50 may also be provided with any number of additional pockets, and 
side pocket 70 and front pocket 72 are illustrative. These pockets may be 
intended to be left open or may be secured by any of several means known 
to the art. Snap closure 74 is provided for fastening the side pocket 70, 
and zipper closure 76 is provided for fastening the front pocket 72. 
The multi-purpose bag 50 of the present invention has been provided with 
the support member shown in FIG. 1a. This support member is inserted into 
a typical multi-purpose bag of this kind, and holes are cut in the bag 
bottom to accommodate the addition of the castors. The support member may 
be comprised of a material such as plexiglass or lexan. Castor 78 is 
visible at the bottom of the illustrated multi-purpose bag 50. This castor 
is comprised of wheel 80 and attachment means 82. Two additional castors 
(not shown) are similarly attached to the base portion of the internal 
support member through the material of the bag 50. 
To facilitate movement of the bag 50, it may be useful to provide a 
detachable pull strap, such as that illustrated as 84 in FIG. 2. This pull 
strap may advantageously be fashioned of nylon or cotton webbing and 
stowed away when not in use in on of the convenient outer pockets, such as 
side pocket 70. The pull strap 84 may be conveniently provided with a 
handle 88 at the user's end, and a means for attaching the pull strap 84 
at the opposite end. In the illustrated embodiment, a snap closure 90 is 
illustrated as a means to attach the pull strap 84, although many other 
means are known to the art. 
Other features, advantages, and specific embodiments of this invention will 
become readily apparent to those exercising ordinary skill in the art 
after reading the foregoing disclosures. These specific embodiments are 
within the scope of the claimed subject matter unless otherwise expressly 
indicated to the contrary. 
Moreover, while specific embodiments of this invention have been described 
in considerable detail, variations and modifications of these embodiments 
can be effected without departing from the spirit and scope of this 
invention as disclosed and claimed.