Note: Descriptions are shown in the official language in which they were submitted.
CA 02344727 2001-04-20
BACKGROUND OF THE INVENTION
This invention relates to knock-down storage rack and more particularly to a
lock for
preventing the separation of the uprights from the shelves of a knock-down
storage rack after
they are interconnected.
Knock-down storage racks are well known and are in common use for storage in
such
places as warehouses, garages and basements. The racks are composed of columns
or
uprights and horizontal shelf supporting beams. Usually the uprights have a
number of
spaced apart slots and the beams have teeth or studs. The beams are connected
to the uprights
by insertion of the teeth or studs into the slots of the uprights. The beams
can be set at a
desired level by appropriate choice of slots in which the teeth or studs are
inserted.
Once the teeth or studs of the shelf supporting beams are in the slots, the
beams will
remain secure so long as there is a downward force on the beams. Thus if the
beams are
loaded, the storage rack will remain intact. If however an upward force is
applied to the
beams, the beams will separate from the uprights and the storage rack will
come apart. It may
also come apart when the beams are not loaded and a sideways force is applied
to the rack.
Fork lift trucks are commonly used to load and unload heavy items on storage
racks.
Such items are usually placed on pallets so that there is space beneath them
for the prongs
of the fork lift. In unloading an item from the shel f supporting beam, the
operator of the truck
may accidentally insert the prongs beneath the beam where the item is located
and not into
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the pallet. When the operator li:Fts the prongs, the beam will rise with the
load and the storage
rack may come apart. When this happens, heavy items on the beams may fall onto
the
operator of the truck or any bystanders in the vicinity of the rack with
resulting injury or, in
extreme instances, death. Items on the rack may be also damaged in the fall.
It is known to provide locks for preventing the shelves from separating from
the
uprights once the storage rack is assembled. Examples of such locks are
described in U.S.
patents no. 5,938,367 and no. 6,155,441. Such locks frequently have a pin
which when
activated, is within the same slat as a tooth or stud of a shelf where the pin
prevents the tooth
or stud from withdrawing from the slot in the upright. The pin is deactivated
by withdrawing
it from the slot at which time the shelf may be separated from the upright.
A shortcoming of many such locks is that they are susceptible to accidental
deactivation. Some, for example, become deactivated when they are rotated one
quarter or
one half turn. When such locks are accidentally struck, they may turn
incrementally. If they
are struck repeatedly, eventually they will rotate sufficiently to deactivate.
Other locks are
spring-loaded and activate and deactivate when they are pressed. They too can
deactivate
when accidentally struck.
The lock of the subject invention does not deactivate when accidentally
struck. The
lock can only be opened or deactivated by means of a relatively large force.
Preferably a tool
such as a screw driver is required to apply such a force and in that case, the
lock will not
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open unless an operator has such a tool and he uses it deliberately to open
the lock.
Accordingly a storage rack equipped with such a lock will not come apart
should it be
accidentally struck or should its shelf supporting beams be accidentally
raised when items
are being unloaded from them.
SUMMARY OF THE INVENTION
Briefly, the lock of my invention is attached to a connector for
interconnecting a
shelf supporting beam to an upright of a knock-down storage rack. The
connector is fixed
to the beam and is removably connected to the upright by means of the lock. A
pin is
connected to the connector and is slidable between locking and unlocking
positions. The pin
has a head and a shank connected to and extending from the head and
terminating at an outer
end. A recess is formed in the shank. The outer end of the pin, when in the
locking position,
is within one of a number of openings formed in the upright with resulting
locking of the
upright to the connector. The outer end o f the pin, when in the unlocking
position, is outside
the opening thus allowing the upright to be separated from the connector. The
lock includes
a retainer which is biased by rc;silient means into the recess when the pin is
in the locking
position and prevents the pin from moving from the locking pasition unless a
force, opposed
to the bias of the retainer, is applied to the pin to cause the retainer to
withdraw from the
recess.
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DESCRIPTION OF THE DRAWINGS
The lock of the invention is described with reference to the accompanying
drawings
in which:
Figure 1 is a perspective view of the lock in conjunction with a connector, a
shelf
supporting beam and an upright of a knock-down storage rack;
Figure 2 is a perspective view of the connector and an upright;
Figure 3 is a perspective view of the connector from the side opposite that
shown in
Figures 1 and 2;
Figure 4 is a perspective; view of the connector and upright from the side
opposite that
shown in Figure 2;
Figure 5 is a perspective view, partly in section and in enlarged scale, of
the lock in
a deactivated or unlocked position;
Figure 6 is another perspective view of the lock in a locked position;
Figures 7 and 8 are perspective views of portions of the lock. In Figure 7 the
lock is
in the locked position and in Figure 8 the lock is in the unlocked position.
Like reference characters refer to like parts throughout the description of
the
drawings.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVEN'CION
With reference to Figure 1 the lock of the invention, generally 10, is shown
in
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conjunction with an upright 12 of a conventional knock-down storage rack. A
cannector 14
serves to connect the upright to a shelf supporting beam 16. The connector is
affixed to the
beam by such means as welding .and bolting while the lock removably connects
the connector
to the upright in the manner described below.
With reference to Figures 2 and 3, the connector has inner and outer side
walls 16,
18 spaced apart by an intermediate wall 20. The outer side wall has an opening
22 for receipt
of a bolt for interconnecting the cannector to the upright. The bolt adds
rigidity to the storage
rack when assembled should that be desirable.
The inner side wall of the connector has a number of teeth or hooks 25 spaced
along
its inside edge. The inner wall is received in a channel 26 that divides the
upright into two
parts, one for connection to beam 16 and the ather to a like beam that extends
outwardly
from the opposite side of the upright.
The connector has a number of generally rectangular openings 28 on its outer
wall.
Above each opening is a smaller opening 29, the uppermost 29a of which
receives the lock.
On the inside face of the intermediate wall, tabs 32 extend outwardly at 32a
from the upper
edge of each opening 28 then downwardly.
With reference to Figures 2 and 4, vertically spaced openings 34 are formed in
the
front faces 36 of the upright and like openings 38 are formed in the channel.
The former
openings receive the lock of the invention as well as tabs 32 while the latter
openings receive
CA 02344727 2001-04-20
the teeth 25 of the connector.
With reference to Figures 5 and 6, the lock of the invention includes a pin,
generally
40, having a head 42 at the outer end of a shank 43. The shank is slidingly
mounted in a
bushing 44 which consists of inner and outer concentric cylinders 46, 48. The
outer cylinder
has an outer wall 48 which is stepped inward at 48a. The stepped-in area 48a
is received in
opening 29a of connector 14. Th.e outer wall is stepped cross-axially outward
at 48b and that
portion of the outer wall is connected to the outer wall of the connector.
The two cylinders which make up the bushing are pressed together and remain
together by friction between the walls of two cylinders that contact each
other.
With reference to Figures 7 and 8, the inner cylinder has an annular cavity 50
in
which a rod or retainer 52 is received. The rod is confined in the cavity by
means of a raised
portion 54 of the inner cylinder. 'The upper surface 56 of the raised portion
contacts the cross-
axially extending lower surface 58 of the outer cylinder 48 so that the rod is
confined within
the cavity. The rod is normally straight but resiliently deforms to a curved
shape when it is
within the groove.
With reference again to Figure 5, the outer wall of shank 43 has a pair of
spaced
annular outer and inner recesses or grooves 60, 62. The rod is received in
inner groove 62
when the pin is in the unlocking position as illustrated in Figure 6 and in
outer groove 60
when the pin is in the locking position as illustrated in Figure 7.
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The pin is in the locking position when the outer or distal end 64 of the
shank projects
through opening 34 of the upright and its head contacts the outer wall 44a of
the bushing.
Rod 52 is within outer groove fi0 and prevents the pin from being withdrawn
from the
bushing in the direction of arrow 65 unless an outward force is applied to the
head of the pin.
The inner side wall 60a of the groove is bevelled or chamfered so that outward
force applied
to the head will cause the rod to~ rise in the groove and withdraw from it.
When it does, the
pin can be drawn outwardly in the direction of the arrow.
When the pin reaches the point illustrated in Figure 5, the rod will enter
inner groove
62. That groove serves as a stop point and prevents further outward movement
of the pin.
That is because the groove has an inner side wall 62a which is flat and
unbevelled. That wall
prevents the rod from withdrawing from the groove when further outward force
is applied
to the pin.
The wall 62b of the inner groove opposite that of wall 62a is bevelled so that
if the
pin is pushed inward from the position illustrated in Figure 5, the rod will
withdraw from the
groove and allow the pin to slide to the locking position illustrated in
Figure 6.
The means by which the pin serves to lock the connector to the upright is best
seen
in Figure 4. In that Figure, tabs :32 and teeth 25 are in openings 34 and 38
respectively of the
upright and serve to prevent the connector from separating from the upright
unless the
connector is lifted. Lifting is resisted since there is little if any space
between the shank of
the pin and the upper edge of opening 34. Figures 4 and 6 illustrate this.
Only when the pin
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is removed from opening 34 can the connector be lifted and separated from the
upright.
The rod is composed c>f resilient material such as spring steel so that it
will yield to
allow the rod to withdraw from the grooves. However the material of the rod is
chosen such
that the rod does not yield in this manner unless a comparatively large
outward force is
applied to the pin.
Preferably, the force sufficient for this purpose can only be applied by means
of a
prying tool such as a screw driver. With reference to Figure 6, to apply such
force, the prying
edge of the tool must be inserted in the space 70 between the head and the
facing wall of the
outer cylinder of the bushing. The tool must be moved back and forth to pry
the head
outward. The rod should preferably be sufficiently stiff or inflexible that it
does not allow
the head to be removed by means of a force that is normally possible by a
human hand
unaided by a tool. As a result, the pin cannot be accidentally removed. It can
only be removed
by means of a screw driver or other prying tool intentionally inserted in
space 70 and
deliberately moved in a way that will cause the pin to move outward.
It will be understood of course that modifications can be made in the
preferred
embodiment of the lock illustrated and described herein without departing from
the scope
and purview of the invention as claimed.
a
