U.S. patent number 3,908,562 [Application Number 05/509,272] was granted by the patent office on 1975-09-30 for material handling apparatus with shelf extension panel.
This patent grant is currently assigned to Bonus Bilt, Inc.. Invention is credited to Royal C. Wittschen.
United States Patent |
3,908,562 |
Wittschen |
September 30, 1975 |
Material handling apparatus with shelf extension panel
Abstract
A material handling cart of the foldable type having a rear wall
supported on a pair of casters, a pair of foldable side walls each
supported on one individual caster, and middle and lower shelves
each hinged to the rear wall so that each can be folded up against
the rear wall before the side walls are folded around them. The
particular improvement disclosed herein is a shelf extension panel
associated with each of the shelves. Each extension panel is
slidable underneath its associated shelf into a fully stored
position, or it may be pulled partially forward to act as a shelf
extension, or when pulled to a fully forward position it may be
pivoted upward to provide a front wall enclosing the space above
the shelf.
Inventors: |
Wittschen; Royal C. (Burbank,
CA) |
Assignee: |
Bonus Bilt, Inc. (Glendale,
CA)
|
Family
ID: |
24025948 |
Appl.
No.: |
05/509,272 |
Filed: |
September 25, 1974 |
Current U.S.
Class: |
280/79.11;
108/93; D34/21; 108/163; 108/177 |
Current CPC
Class: |
B62B
3/02 (20130101); A47F 5/135 (20130101); B62B
3/006 (20130101); B62B 3/005 (20130101); B62B
2205/33 (20130101) |
Current International
Class: |
A47F
5/13 (20060101); A47F 5/10 (20060101); B62B
3/00 (20060101); A47F 005/00 () |
Field of
Search: |
;211/162,149,167,14
;108/27,111,143,93 ;5/100 ;297/7,10,12 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Frazier; Roy D.
Assistant Examiner: Hafer; Robert A.
Claims
What is claimed is:
1. In material handling apparatus including a rear wall, a pair of
generally parallel side walls, and a shelf extending horizontally
between said side walls, the improvement comprising:
horizontal guideway means carried beneath respective ends of said
shelf and extending parallel to the respective side walls;
a pair of horizontal guide members supported from respective ones
of said side walls at the front edges thereof and being disposed
inwardly from and beneath the respective guideway means;
a panel adapted to be horizontally stored beneath said shelf, said
panel having a plurality of parallel ribs disposed parallel to said
side walls, the two outermost ones of said ribs slidingly engaging
respective ones of said guide members, said panel also having on
its rearward edge a cross-member secured to the upper surfaces of
said ribs, said cross-member having laterally projecting ends which
engage respective ones of said guideway means;
said panel being adapted to be moved to a partially forward
position wherein said laterally projecting ends are retained within
said guideway means while said two outermost ribs provide a
cantilever support for said panel on said guide members, said panel
thereby serving as a horizontal extension of said shelf,
said guideway means extending forwardly at least to the forward
edge of said shelf and having forward stops thereon, whereby said
panel may also be moved to a fully forward position and then
pivoted upward into a vertical position with said laterally
projecting ends of said cross-member being still retained within
said guideway means by said forward stops; and
latch means cooperatively associated with said side walls and with
the forward edge of said panel for latching said panel in its
vertical position.
2. Material handling apparatus as in claim 1 which is a foldable
cart including a rear wall supported on a pair of wheels; said side
walls being pivotally attached to corresponding edges of said rear
wall, and each of said side walls having a wheel supporting its
outer edge.
3. Material handling apparatus as in claim 2 which includes a pair
of vertically spaced shelves having their rearward sides pivotally
secured to said rear wall, said panel being stored beneath the
upper one of said shelves.
4. A shelf structure comprising:
a normally horizontally disposed rectangular shelf having beneath
its respective ends horizontal guideway means extending parallel to
the shelf ends, and also having a pair of horizontal guide members
disposed beneath said shelf at the forward edge thereof and
disposed inwardly from and beneath the respective guideway
means;
a movable panel adapted to be supported from said guideway means
and said guide members in a stored position beneath said shelf,
said panel being of rectangular configuration with laterally
projecting posts on its rearward edge;
the ends of said panel being slidingly supported upon respective
ones of said guide members, and said projecting posts on the
rearward edge of said panel being slidingly engaged within
corresponding ones of said guideway means;
said guideway means extending forwardly at least to the forward
edge of said shelf and having front stop means thereon adapted to
retain said posts in a forward position of said panel;
whereby said panel may be entirely stored beneath said shelf, or
may be moved to a partially forward position to provide a shelf
extension with said panel ends receiving cantilever support from
said guide members, but the removal of said panel from said shelf
is prevented by said front stop means.
5. The shelf structure of claim 4 wherein said posts are pivotal in
said front stop means so that said panel may be rotated to a
vertical position enclosing the space above said shelf.
6. The shelf structure of claim 4 wherein said panel and guideway
means have interengaging stop means which prevent said panel from
being moved out to an extended position unless the front edge
thereof is first raised upward to disengage said stop means.
7. A foldable material handling cart comprising:
a rear wall supported on a pair of wheels;
a pair of side walls pivotally attached to corresponding edges of
said rear wall, each of said side walls having a wheel supporting
its outer edge, said side walls being pivotable between one
position in which they are parallel to each other and perpendicular
to said rear wall, and another position in which they are folded
back towards the rear wall;
a pair of vertically spaced shelves having their rearward sides
pivotally secured to said rear wall, said shelves being adapted to
be supported by said side walls in said first position of said side
walls and being pivotable upward against said rear wall prior to
the folding of said side walls towards said rear wall; and
a movable panel associated with one of said shelves, said movable
panel being slidably supported on means carried beneath said shelf
said means comprising horizontal guideway means carried beneath
respective ends of said shelf and extending parallel to the
respective side walls, a pair of horizontal guide members supported
from respective ones of said side walls at the front edges thereof
and being disposed inwardly from and beneath the respective
guideway means, the ends of said panel being slidingly supported on
said guide members and the rearward edge of said panel having
laterally projecting posts slidably supported within said guideway
means, said movable panel being normally stored beneath said shelf,
and being movable to a partially forward position in which said
panel provides a shelf extension, said panel when moved to its
fully forward position being also upwardly pivotable relative to
the associated shelf and having means associated with the ends of
said panel for securing same to respective ones of said side walls
to thereby enclose the space above said shelf.
Description
BACKGROUND OF THE INVENTION
Material handling apparatus must meet many and diverse requirements
which vary in numerous details depending upon the particular
application. Some of the important factors involved are
manufacturing cost, the ease and convenience of transporting and
storing the apparatus when it is not in use, and the effectiveness
of the apparatus when it is being used for its intended
purpose.
The prior art is replete with numerous examples of storage shelf
structures, and is also replete with numerous examples of wheeled
vehicles such as carts and the like which are used for material
handling purposes. The preferred embodiment of the present
invention relates to a wheeled cart which incorporates a shelf
structure.
One principal object of the invention is to provide an improvement
in the collapsible or foldable type of material handling cart.
Another separate and distinct object of the invention is to provide
an improvement in a shelf structure, which improvement will be of
value irrespective of whether or not the shelf structure is
associated with a wheeled vehicled.
SUMMARY OF THE INVENTION
According to the present invention an improved shelf structure is
provided by incorporating guideway means beneath the respective
ends of a normally horizontally disposed rectangular shelf. A
movable panel is also provided which is adapted to be supported
from the guideway means, beneath the shelf. In one position the
panel may be entirely stored underneath the shelf; in another
position it may be moved partially forward so as to provide a
horizontal shelf extension; in yet another position the panel is
moved to an extreme forward position and is pivoted upward so as to
enclose the space about the shelf.
According to the present invention a collapsible or foldable
material handling cart is provided which has two vertically spaced
shelves, and a movable panel associated with each of the shelves.
The movable panel may be stored beneath its respective shelf, may
be moved to a partially forward position in which it acts as a
shelf extension, or may be moved to an entirely forward position
and pivoted upward so as to enclose the space above the shelf.
DRAWING SUMMARY
FIG. 1 is a perspective view of a material handling cart in
accordance with the present invention;
FIG. 2 is a cross-sectional view of the lower shelf, with movable
panel in stored position, taken on the line 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view of the center shelf with movable
panel in partially extended position, taken on the line 3--3 of
FIG. 1;
FIG. 4 is a cross-sectional view taken on the line 4--4 of FIG.
2;
FIG. 5 is an exploded perspective view of one of the shelf and
panel assemblies;
FIG. 6 is a perspective view of the material handling cart showing
different positions of the shelves and movable panels;
FIG. 7 is a cross-sectional view taken on the line 7--7 of FIG.
6;
FIG. 8 is an elevational view taken on the line 8--8 of FIG. 6;
FIG. 9 is a fragmentary elevational view taken on the line 9--9 of
FIG. 8;
FIG. 10 is a fragmentary cross-sectional view taken on the line
10--10 of FIG. 8;
FIG. 11 is a fragmentary cross-sectional view taken on the line
11--11 of FIG. 6;
FIG. 12 is an elevational view taken on the line 12--12 of FIG.
11;
FIG. 13 is a perspective view of the material handling cart showing
still a third position of the shelves and movable panels; and
FIG. 14 is a cross-sectional view taken on the line 14--14 of FIG.
13.
PREFERRED EMBODIMENT
Reference is now made to the drawings, FIGS. 1 to 14, inclusive,
illustrating the presently preferred form of the invention.
The novelty of the present invention resides in a movable panel
associated with a shelf, which could be used in other material
storage or material handling applications but is presently
illustrated in conjunction with a collapsible material handling
cart. The general arrangement of the collapsible cart is well-known
in the art and will be described briefly and in rather general
terms, since a more specific description would serve no useful
purpose.
Thus the collapsible cart 10 includes a rear wall 12 and a pair of
foldable side walls 20, 30. The rear wall 12 has bent-over edges
13, 14 which give the rear wall a shallow U-shaped configuration.
Side wall 20 is attached to the edge 13 by means of a vertically
spaced set of hinges 15, and in similar fashion the side wall 30 is
attached to the rear wall edge 14 by means of a vertically spaced
set of hinges 16.
A pair of casters 17, 18 are mounted by means of respective swivels
from corresponding lower corners of the rear wall 12. Casters 21,
31 are attached to the lowermost outer edges of the side walls 20
and 30, respectively. When the side walls are expanded to their
operative position, as shown in FIGS. 1, 6, and 13, the side walls
together with the rear wall form a frame structure comprised of a
plurality of vertical tubes and which has a U-shaped
cross-sectional configuration in the horizontal plane. As is
well-known in the art, the side walls 20, 30 may be folded in
toward the rear wall 12, and when this folding or collapsed
position is achieved the casters 21, 31 will then occupy positions
relatively close to the rear wall.
The folding cart 10 also includes a bottom shelf or deck 40, and a
center shelf 60. Bottom shelf 40 is attached to the lowermost frame
member of rear wall 12 by means of a pair of hinges 19, and may
therefore occupy either an operative horizontal position as shown
in the drawings or else may be folded vertically upward to a
folding position in which it is latched against the rear wall 12.
In similar fashion the center shelf 60 is attached to rear wall 12
by means of hinges 19a, thus permitting the shelf to be either
horizontally disposed in operative position or folded to a vertical
position for transportation or storage purposes. FIG. 1 shows the
horizontal position of center shelf 60 while FIGS. 6 and 13 show
its raised position.
The collapsible cart as thus far described is well-known in the
art, and the subject matter of the present invention resides in
specific improvements which are yet to be described.
The material handling cart 10 includes a pair of movable panels MP1
and MP2. Movable panel MP1 is associated with the deck or bottom
shelf 40, while movable panel MP2 is associated with the center
shelf 60. The movable panels are identical to each other in their
construction, and hence the same reference numerals will be used
throughout for identifying the corresponding parts of these
panels.
In general, each of the movable panels includes a rectangular frame
70 having a pair of laterally projecting posts 71a, 71b on its
rearward edge, and a pair of laterally projecting pins 72a, 72b on
its forward edge. The structure and function of both the posts and
the pins will now be described in some detail.
The frame 70 includes a plurality of laterally spaced tubular
members or ribs 75 which extend in a direction perpendicular to the
rear wall 12 of the cart 10. Tubular members 75 are of
approximately square cross-sectional configuration. Another square
tubular member 71 forms a cross-member which extends across the
rearward ends of the members 75, being welded to the upper surfaces
thereof, as best seen in FIG. 5. The length of tubular member 71 is
greater than the lateral extent of the frame members 75, and hence
the projecting ends of tubular member 71 provide the posts 71a, 71b
as previously described.
The posts 71a and 71b have several different functions or purposes.
One function or purpose is to provide vertical support for the
rearward edge of the moving panel when it is in a fully stored
position underneath its associated shelf (see FIG. 2). A second
function is to provide a cantilever support for the movable frame
when in its partially extended position (see FIG. 3). In this
position the upward movement of tubular member 71 is precluded by
frame members 41, 42 of the corresponding shelf (see FIG. 4). A
third function of the posts 41a, 41b is to provide a pivotal
support for the rearward edge of the moving panel, when in its
fully forward position, so that the moving panel can be raised to a
vertical position in which it encloses the space above its
associated shelf. FIG. 6 illustrates the vertical position of
moving panel MP1.
Across the front end of the tubular members 75 there is another
tubular member 72, located in the same plane as the members 75 and
which is welded to their respective ends. Pins 72a, 72b are
attached to the respective outer ends of the tubular member 72 (See
detail views as shown in FIGS. 9 and 12). The tubular member 72 is
used as a convenient handle for sliding the movable frame back and
forth between its fully stored position, its partially forward
position in which it acts as a shelf extension, and its fully
forward position in which it acts as a vertical forward wall. The
function of the pins 72a, 72b is to cooperate with latches 22, 32
attached to the respective side walls 20, 30, for holding the
movable panel in its vertical position. (See FIGS. 7, 11, and
12).
Each of the shelves 40, 60 is provided with appropriate guideway
means for supporting the corresponding movable panel. Since these
guideway structures are identical for both of the shelves, the same
reference numerals will be used throughout for the parts.
Referring particularly to FIG. 4, a pair of outer guide members 43,
44 are of L-shaped cross-sectional configuration and have their
upper edges secured to respective tubular members 41, 42 which form
a part of the corresponding shelf structure and extend in a
direction perpendicular to the rear wall 12 of the cart. The lower
portions of the guide members 43, 44 are horizontally disposed and
occupy the same horizontal plane being turned inwardly toward each
other. The outermost ones of the tubular members or ribs 75 of the
associated movable panel are slidingly rested upon the inner and
upper surfaces of the lower portions of the guide members 43,
44.
Still with reference to FIG. 4, there are a pair of guideways 45,
46 which are also of L-shaped configuration. The upper longitudinal
edges of these members are welded to the under surfaces of the
shelf frame members 41, 42, respectively. The lower portions of the
guideways 45, 46 occupy a common horizontal plane, and are turned
inwardly towards each other so as to provide sliding support for
the posts 71a, 71b of the movable panel.
The forward ends of the guideways 45, 46 are closed by end pieces
45a, 46a respectively. (See FIG. 5). These end pieces capture the
posts 71a, 71b, respectively, so that the moving panel cannot be
removed or detached from its associated shelf.
The guide members 43, 44 do not extend the full width of the
associated shelf, but are attached beneath the forward edge portion
thereof. (See FIGS. 3 and 5). The guideways 45, 46, on the other
hand, do extend the full front to rear distance of the shelf. (See
FIG. 3 where it is clearly shown that the closed end 45a of
guideway 45 is located somewhat forwardly of the most forward edge
of the shelf 60).
Each movable panel is also provided with stops for preventing it
from being accidentally dislodged from its stored position. As best
shown in FIGS. 3 and 4, a pair of stops 77 are welded to the
undersurfaces of the outermost ones of the members 75, near the
forward edge of the movable panel but yet some distance back from
the front edge bar 72. The position of the stops 77 is also clearly
shown in FIG. 7. When the moving panel is in its stored position
the stops 77 are located rearwardly of the guide members 43, 44.
The rearward end edges of the guides 43, 44, therefore act as
coacting stops. (See FIG. 2).
Pulling the movable panel out to an extended position is, however,
very simple. The leading edge bar 72 is simply raised a sufficient
distance so that the stops 77 will clear the upper surfaces of the
guides 43, 44, respectively. This can easily be done since the
outer dimension of the tubular members 75 of the movable frame is
somewhat less than the horizontal space between the inner edges of
the guideways 45, 46 (See FIG. 4).
FIG. 13 illustrates a very unique way in which the apparatus of the
present invention may be used. As shown in FIG. 13 the center shelf
60 is raised to a vertical position where it is folded back against
the rear wall 12. Movable panel MP2, rather than simply being
extended out or being rotated up relative to the shelf, is instead
rotated downward relative to the shelf. Thus movable panel MP2 is
able to occupy a horizontal position, with pins 72a, 72b being
latched by the latches 22, 32, respectively. Movable panel MP2
therefore acts as a top shelf or lid for the cart 10, with the
whole interior of the cart being open and accessible from the
front. This configuration of the cart is particularly useful when
transporting packages of exceptional vertical height.
Each shelf when occupying its horizontal position is supported by
studs 25, 35, attached to the inner surfaces of the side walls 20,
30, respectively.
A unique latch mechanism is provided for latching each of the
shelves in its vertical position. This is a self-operating, gravity
operated latch. There are only two of these latches, one for each
of the shelves, and both of these latches are attached to the end
portion 14 of rear wall 12. Each of the gravity latches L includes
an inclined plane 81, an L-shaped bolt 82, and a collar 83 for
holding the bolt. Latch L is also shown in FIG. 8. The collar 83 is
a square tubular member of relatively short length and is
vertically disposed. It is attached as by welding to one vertical
surface of the square tubular post 14a. Post 14a is a vertically
extending post which constitutes the forward-most portion of the
rear wall edge 14 (See FIG. 1).
The collar 83 is attached to the rearward side of post 14a, away
from the side wall 30. The L-shaped bolt 82 has a vertical shank
which extends upward through the collar 83, and also has a
horizontal shank which extends horizontally from the lowermost
extremity of the vertical shank. The exterior corner surface of the
L-shaped bolt 82 is rounded. Sloping cam member 81 is welded to the
same surface of post 14a, some distance below the collar 83. The
cam 81 slopes so that its lowermost end is directed toward the
interior of the cart, i.e., toward the opposite side edge 13 of
rear wall 12.
The operation of the gravity latch is illustrated in FIG. 10. When
shelf 60 is swung vertically upward to its folded position it
engages the horizontal arm of the bolt 82, swinging it back to the
dotted line position 82'. Shelf 60 is moved further back toward
rear wall 12, to the dotted line position 60'. This permits the
horizontal leg of bolt 82 to return to its solid line position as
shown in FIG. 10. Shelf 60, when released by the hand of the
operator, may then pivot outward where it is retained by the leg of
bolt 82, as shown in solid lines in FIG. 10. In order to release
the shelf it is necessary to push both the bolt 82 and the shelf 60
toward the rear wall 12, holding the bolt in the dotted line
position as shown by 82' until the shelf is able to clear it upon
returning towards its unfolded or horizontal position. The
advantage of this gravity latch is that the mere act of raising the
shelf to its vertical position causes the latch to operate, thus
preventing an inadvertent dropping of the shelf back to its
horizontal position.
The invention has been described in considerable detail in order to
comply with the patent laws by providing a full public disclosure
of at least one of its forms. However, such detailed description is
not intended in any way to limit the broad features or principles
of the invention, or the scope of patent monopoly to be
granted.
* * * * *