Note: Descriptions are shown in the official language in which they were submitted.
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VERTICALLY FOLDING HAND TRUCK AND METHODS
OF ITS OPERATION AND CONSTRUCTION
The present application relates to hand trucks of the type employing
a vertically extending skeletal frame and a forwardly extending nose plate
upon
which myriad and varied products may be supported for ready transport. Hand
trucks of this character are characterized by providing a pair of wheels on a
dead
axle at the lower end of the frame rearwardly of the nose plate.
Hand trucks of the type mentioned have been well described in a
number of prior patents such as the present assignee's U.S. Pat. Nos.
3,997,182,
4,563,014, 4,790,547, and 5,393,081, for example. Such hand trucks are
utilized for
moving a variety of products such as stacked cases of soft drinks or beer to
and
from a delivery truck for transporting them from warehouses to retail
establishments, for example. Typically, the hand trucks will be stored in the
delivery
vehicle during transport and then put into use when the various destinations
are
reached.
The present invention is concerned with a
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vertically folding hand truck comprising upper and lower
sections which are hingedly connected to permit the upper
section to be folded vertically down to a position of
vertical adjacency with the lower section. This is
accomplished in the present hand truck without the
sacrif ice of strength and rigidity when the hand truck is
in use by employing an internal locking mechanism
disposed within the frame side rails for securely locking
the sections in vertically co-extensive position.
Mechanism is also provided for pivotally mounting the
nose plate for movement to a vertical position and
securely and rigidly locking it in the horizontal
position of use automatically when the nose plate is
swung down from the stowed position.
One of the prime objects of the present
invention is to provide a hand truck of the character
described which has relatively few operating parts and
can be manufactured and marketed economically.
Another object of the invention is to provide a
lightweight foldable hand truck of very durable
construction which requires virtually no maintenance and
can be readily and easily locked in operative position.
A still further object of the invention is to
provide a foldable hand truck having parts which can be
readily unlocked to enable the truck to assume a
compacted position for ready storage.
Other objects and advantages of the invention
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will become apparent with reference to the accompanying
drawings and descriptive matter.
The presently preferred embodiment of the
invention is disclosed in the following description and
in the accompanying drawings, wherein:
Figure 1 is a front elevational view of the
hand truck shown in its operative position, certain parts
being omitted in the interest of clarity;
Figure 2 is a side elevational view thereof;
Figure 3 is a slightly enlarged side
elevational view showing the hand truck in folded
position ready for compact storage;
Figure 4 is a slightly enlarged front
elevational view of the two-part frame only in vertically
aligned position, the hinge uniting the two-frame
sections being shown in removed position at one side of
the frame;
Figure 4A is an enlarged fragmentary sectional
front elevational view of a portion of the frame
illustrated in Figure 4;
Figure 5 is an exterior side elevational view
thereof;
Figure 6 is an enlarged end elevational view of
the side rails in both the upper and lower frame
sections;
Figure 7 is an enlarged side elevational view
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of a typical hinge, illustrating its structure and
showing it in the position of extension;
Figure 8 is a similar view showing the folded
position of the hinge;
Figure 9 is an enlarged face elevational view
of one of the slide support extrusions fixed on each
interior side of the upper frame side rails;
Figure 10 is an edge elevational view thereof;
Figure il is an end elevational view of the
l0 extrusion depicted in Figure l0;
Figure 12 is an enlarged face elevational view
of one of the lock slides which are carried for vertical
movement within the support extrusions;
Figure 13 is an end elevational view thereof;
Figure 14 is an enlarged front elevational view
of one of the folding nose mounting brackets;
Figure 15 is a side elevational view thereof;
Figure 16 is an end elevational view thereof;
and
Figure 17 is a face elevational view of one of
the mount brackets fixed to the lower ends of the lower
frame section side rails to pivotally support the nose
plate.
Referring now more particularly to the drawings
mentioned, the hand truck is shown as comprising
preferably rubber-tired wheels, generally designated 10,
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which may comprise laterally spaced apart tires 11
mounted on rims 12 having flanged central hub portions
12a, supporting bearing sleeves 13, within which are
bearings rotatably supporting the wheels 10 for travel on
dead axle 15.
The axle 15 fixedly carries brackets 16 which
secure to the lower end of a generally rectangular, load
carrying, main frame, generally designated 17, which
comprises a two-piece generally rectangular skeletal
structure mounting a handle H at its upper end. As will
become apparent, the overall frame 17 comprises a
normally co-extensive upper frame portion 17a and a lower
frame portion 17b abutting at and interface "x", and it
is to the lower frame 17b that the brackets 16 are
mounted. It is also to the lower frame section 17b that
the foldable load supporting load support member or nose
1s is pivotally connected in a manner which will
presently be more specifically described.
The upper frame section 17a includes generally
channel-shaped side rail sections generally designated 19
with the open channels C of the sections facing laterally
inwardly to receive the ends of a brace member 20, which
is secured in position by suitable fasteners 20a. The
lower ends of handle H are also received within the
channel members 19 and may be secured by fasteners 21.
Also provided for the upper ends of the side rails 19 are
plastic guard fittings 22 which may be held in position
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by the fasteners 21. It will be noted that the front
faces of the channel members 19 are shallowly grooved as
at 23 and that the grooved or recessed portions 23 are
bordered by vertical lip portions 24. The upper frame
section 17a is hingedly connected to the lower frame
section 17b by hinge members, generally designated 25,
which will presently be described.
It will be seen that the lower frame section
17b comprises a like pair of channel-shaped side rails
generally designated 26 which similarly are disposed in
laterally opposed disposition with their channels C
facing inwardly to receive brace members 27 and 28, which
may be secured by fasteners 29 and 30, respectively. As
Figures 4, 7 and 8 illustrate, each of the hinges 25,
which may be referenced as left-hand hinges and right-
hand hinges, include a pair of hinge legs 31 and 32,
pivotally secured .together by a suitable pin 33. The
hinge legs 31, which are received in the side rail
recesses 23, may be secured in the recesses 23 by
fasteners 34 and the hinge legs 32, received within the
like exterior recesses 35 provided in the side rails 26
which are bordered by vertically extending lips 36, may
be secured by fasteners 37.
Fixed to the inner side of each of the side
rails 19 of the upper frame section 17a are support
extrusions (see Figures 9-11), generally designated 39,
which may be secured by fasteners 40 extending through
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openings 40a to side rails 19. As Figure 11 well
indicates, the members 39 comprise sidewisely disposed
webs 41 having elongate guide slots 42 with lower stop
surfaces 42a. Side ribs 43 engage the edges of the front
and rear walls of the side rails 19 to brace the
extrusion members 39 in position. Mounted sidewisely
behind the support extrusions 39 are U-shaped lock slide
members or parts 44 (see Figures 12 and 13) having slots
45 in walls 45a facing the slots 42 in the extrusion
members 39. The slots 45 receive the lower fastener pins
40 provided for securing the lower end of support
extrusions 39 in fixed position to each side rail 19 and
are guided thereby when the lock slides 44 are moved
upwardly and downwardly. Upward movement of the slides
44 may be limited by the slots 42 or 45.
Provided as a frame spanning handle to move the
lock slides 44 upwardly and downwardly in unison is a rod
member 46 which has end pins 47 with shank portions 47a
fixed in openings 46a in the slides 44 and riding in the
support extrusion guide slots 42. When the lock slides
44 are in their lowermost position as indicated in
Figures 4 and 4A, they are received within the upper ends
of the side rails 26 of the lower frame section 17b and
prevent the upper frame section 17a from being pivoted
downwardly relative to the lower section 17b to the
position shown in Figure 3.
It will be seen that the nose plate or member
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18 has an integral back plate 18a. Mounted to the front
face of back plate 18a are a pair of angle shaped lock
brackets, generally designated 18b in Figures 14-16. The
brackets 18b each include a base portion 18c which
rigidly secures to the back plate 18a, as with fasteners
48, in a position to leave each locking wall 49 extending
forwardly when the nose plate 18 extends forwardly. As
Figure 15 particularly shows, each wall 49 is provided
with a cut-out or recessed portion, generally designated
50, which includes an access portion formed by a top lip
50a and an inclined piloting or caroming wall 51, leading
to a downwardly extending vertical slot 52. A rod 53 has
its ends captured in the slot 52 in its lowered position,
but is freely vertically raisable to the position shown
in chain lines in Figure 15, which is free of the slots
52. When the rod 53 is in the lowermost position, shown
in solid lines in.Figure 15, the nose plate 18 is firmly
locked in the operative position. A pivot supporting
bracket plate, disclosed in Figure 17 and generally
indicated at 54, is fixed inside the lower end of each
side rail 26 on its laterally interior side to aid in
journaling the nose plate 15 for swinging movement.
Plates 54 include guide slots 53a within which the ends
of locking rod 53 are received. They may be fixed in
position on rails 26 by fasteners 55b. The plates 54 are
disposed within the recesses of channel members 56
secured to each of the side rails 26 and have bores 57 to
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receive the nose plate pivot pins 58 which fix to the brackets 18b fixed to
nose plate
18. Belleville washers (not shown) may be suitably provided on the pins 58 to
exert
a resilient frictional pressure between the members 46 and 54 to hold the nose
plate in the folded raised position.
When operative and in use, the nose plate 18 is in the down position
with rod 53 received in the locking slots 52 and maintained there by gravity.
The
very ends of the rod 53 can travel freely upwardly in the slots 53a shown in
FIG. 17
when rod 53 is raised. When it is desired to stow the hand truck in a
compacted
storage mode, the nose plate 18 can first be released to pivot upwardly to a
vertical
position flush with the side rails 26 by raising the rod 53 to the chain line
position
shown in FIG. 15 in which it is no longer captured in the slots 52. The nose
plate 18
is then grasped by its front horizontally disposed edge and pivoted upwardly
and
rearwardly. The back plate 18a and the locking members or locks 18b pivot
rearwardly with the rod 53 removed from the slots 50 so that full swinging
movement of the nose plate 18 to stowed position can be effected. The spring
washers provided on pins or pivot posts 58 hold the nose plate in this
vertical
position.
To fold the handle H and upper frame section rearwardly to the FIG.
3 position, the rod member 46 is
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raised until the lock slides 44 are raised to a position
within the upper frame section 17a clear of the lower
frame section. Because of the rearward position of hinge
pivots 33, handle H can then be swung rearwardly with
suitable clearance to the folded down position shown in
Figure 3. The weight of the upper section and handle will
be sufficient to maintain the upper frame section 17a in
the Figure 3 position.
To restore the upper frame section to the
Figures 1 and 2 position, it is merely necessary to grasp
the handle H and fold the upper frame section up into
vertical alignment with the lower frame section. The
locking rod handle 46 can then be moved downwardly with
the aid of gravity to slide the lower ends of the lock
slides 44 downwardly into the upper ends of the side rail
members 26. The slides 44 freely move downwardly toward
locked position until halted in locked position by member
47 reaching the lower stop ends of slots 42 because the
locks 45 can travel downwardly relative to the lower
fasteners 40. For rigidity purposes, the rod 46 is moved
to its lowermost position in which substantial lengths of
the lock plates 44 are received and closely confined in
the upper ends of side rails 26. The slots 42 function
as elongate vertical guides for the shanks of pins 47 and
the slots 45 do likewise for the lower fastener pin
shanks 40. Both mechanisms may function as guide
mechanism interacting between the upper frame rail
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section and the lock slides 44. The lower ends of slots
42 also provide and function as stop surfaces, as
indicated.
To restore the nose plate to operative
position, it is merely necessary to grasp the front edge
of 'the horizontal portion of nose plate 18 and pivot it
downwardly. As the back plate 18a of the nose plate
swings forwardly and upwardly, the inclined caroming walls
51 of the brackets 18b engage the ends of rod 53 (carried
in slots 53a) to automatically vertically raise the rod
53 to a position in which its ends are disposed above the
slots 52 and can descend under the influence of gravity
in the slots 52 to be captured in the locked position.
The brackets 18b and rod 53 function as interacting lock
mechanism to lock the nose plate 18 in operative
position.
In constructing the present vertically foldable
hand truck, standard hand truck side rail extrusions are
utilized and simply cut in half. The hinge members 25
are then mounted in position along with the fitting 39
and lock plate 44 sub-assemblies which include the lock
rod 46 fastener members 47 extending through the slots
42. The lower end of the lower frame section 17b is then
changed by adding the lock brackets 18b to nose 18 and
the lock rod 53 which is receivable in the slots 52
provided therein. The members 54 and 56 are, of course,
installed first of all.
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It is to be understood that the embodiment
described is exemplary of various forms of the invention
only and that the invention is defined in the appended
claims which contemplate various modifications and
embodiments within the spirit and scope of the invention.
