Note: Descriptions are shown in the official language in which they were submitted.
2!)1$6;~23
FIELD OF THE INVENTION
The present invention relates to a locking device for
interlocking at least two nestable carts in nested position.
BACKGROUND OF THE INVENTION r ~
Canadian Patent No 1,241,211 dated August 30th, 1988
entitled: "LOCKING DEVICE FOR INTERLOCKING NESTED SHOPPING
CARTS", inventor Antoine Truliano, describes a housing attachable
to the handle bar of a shopping cart and provided with a locking
mechanism to retain a key inserted in a key slot of the housing.
To unlock the key, a coin must be inserted in a coin-receiving
actuator, which is pushed inside the housing, thereby retaining
the coin therein. The key is attached by a flexible link, such
as a chain, to the housing of an adjacent cart, so that several
carts can be retained interlocked in nested position. A
disadvantage of this interlocking system resides in the fact that
the effective length of the chain attaching the key to a housing
must be shorter than that required to permit insertion in the key
slot of the same housing of the key attached to latter. If the
chain was long enough to permit this key insertion, then it would
be possible for the shopper to retrieve the coin inserted in the
housing by simply inserting the key carried by the housing of his
cart into the key slot of this housing, thus avoiding having to
return the cart to the row of nested carts for the insertion of
the key of the next cart for coin retrieval and locking of the
just-returned cart to the next cart. Therefore, the distance
Z!)15623
between the handle bars of nested carts must be somewhat less
than the above defined maximum length of the key chain. This is
not always possible to obtain because due to the large tolerances
allowed in their construction, carts even of the same make do not
always nest to the ~ame extent. Also it has been found that the
distance between the handle bars of nested carts of various makes
can vary between 9" and 18". It follows that the same model of
locking device in accordance with the patent cannot be used for
different makes of nestable carts.
Another problem resides in the fact that the key freely
hangs from the housing attached to the cart being used, and this
key can be a source of accidents especially for children. A
holder is provided for retaining the free key, but this is not
always used.
Another disadvantage of the patented device resides in
the complexity of its mechanism.
OBJECTS OF THE IVNENTION
The main object of the invention is to provide a device
for interlocking nestable carts which obviates the above-noted
disadvantages and, more specifically, in that it can accommodate
any lengh of flexible link for attaching the key to the housing
or to the cart associated with the key.
Another object of the invention is to provide a locking
device of the character described, in which the number of
component parts has been considerably reduced with respect to the
above-noted patented locking device.
ZOlS623
Another object of the present invention is to provide a
locking device of the character described, in which both a coin
and the key carried by the cart to be used have to be inserted
and locked into the housing to release the cart from the other
carts of the row and, thus, no key can dangle from the housing of
the cart being used and also this locked key cannot be used to
effect release of a coin from the housing of a stranded cart.
Another object of the invention is to provide a locking
device in which the locked key of the cart being used also serves
to trap the coin.
SUMMARY OF THE INVENTION
The locking device of the invention is designed for
interlocking a first and a second cart and comprises a first and
a second key attachable to said first and second carts,
respectively; a housing attachable to said first cart and hzaving
a first and a second key slot for receiving said first and second
keys, respectively; a two-state locking mechanism, mounted in
said housing, including a first and a second locking member
associated with said first and second key slots and each movable
from a key-releasing position to a key-locking position upon key
insertion in the associated slot and locking members
interconnecting and position-inverting means; the first and
second locking members being in key-locking and key-releasing
position, respectively in the first state of said locking
mechanism, and in key-releasing position and key-locking
position, respectively, in the second state of said locking
~!~1S6Z3
mechanism, whereby, with said second key locked within said
second key slot by said second locking member, insertion of said
first key within said first key slot causes locking of said first
key to said housing and release of said second key from said
housing.
The locking device further includes a coin-receiving
cavity in the housing; a coin feeler detecting the presence or
absence of a coin in the cavity and a retainer movably mounted in
the housing and controlled by the feeler for retaining the first
locking member in key-releasing position upon said feeler
detecting the absence of a coin in said cavity and for freeing
said first locking member for movement to said key-locking
position upon said feeler detecting the presence of a coin in the
cavity. The key shafts of the keys are substantially identical,
so that they can actuate either one of the locking members when
inserted in the respective key slots. Each key is preferably
attached to the housing by a flexible link. The link is long
enough to permit the key of one housing to be inserted into the
second slot of the housing of the adjacent nested cart.
Each key includes a head laterally protruding from its
key shaft and the coin-receiving cavity is located close to the
first key slot, so as to be concealed by the key head of the key
inserted into the first key slot. Thus, a coin partially
inserted into the cavity is fully pushed thereinto by the key
head upon key insertion into the key slot and is concealed by
said key head. Preferably, each key has a key shaft with a free
,
znl5623
end and an opening spaced from the free end, and each locking
member is C-shaped and pivoted within the housing to a position
in which the outer leg of the C is in the path of the key shaft
when inserted in said slot, while the inner leg clears said path,
and upon pivoting of said C-shaped locking member to a second
position by the key shaft pushing on the outer leg, the inner leg
enters said opening and locks the key to the housing.
Preferably, the inverting means includes spring-biased toggle
levers respectively fixed to the two C-shaped locking members and
cause pivoting of one locking member in one direction and
retention of the latter in.the new position upon pivoting of the
other locking member in the opposite direction. Preferably,
shock absorbing means are provided in the flexible link attaching
the key to its housing to prevent breakage of said link or of its
connection to the housing when subjected to a sudden and
important pull. Preferably, the housing is made in three parts,
two parts adapted to surround and be permanently fixed to the
handle bar of a cart, while the third part, which contains the
complete locking mechanism, is detachably secured to the other
two parts, whereby it can be detached for servicing of the
locking mechanism without having to detach the entire housing
from the handle bar.
BRIE ESCRIPTION OF THE DRAWINGS
In the annexed drawings:
Figure 1 is a partial side elevation o~ several inter-
nested carts interlocked by the system of the invention, except
2r)1~6~3
the last or frontmost cart of the row which has just been
released for use;
Figure 2 is a top plan view of a portion of the handle
bars and interlocking mechanisms corresponding to Figure 1;
Figure ~ is a perspective view showing the housing
attached to a portion of the handle bar of a cart being used, the
key attached to the housing being inserted into its key slot;
Figure 4 is an exploded view of the housing of the
locking device looking at the front face thereof;
Figure 5 is a plan view partly in section looking
through the bottom of the top part of the housing and taken along
line 5-5 of Figure 3, this view showing the locking mechanism in
its first state;
Figure 6 is a view similar to that of Figure 5 but
showing the mechanism in its second state;
Figures 7, 8 and 9 are cross-sections taken along lines
7-7, 8-8, and 9-9 of Figure 5, respectively;
Figure 10 is a vertical cross-section taken along line
10-10 of Figure 3;
Figure 11 is a partial section taken along 11-11 of
Figure 5; and
Figure 12 is an exploded perspective view of the coin-
receiving and retaining mechanism.
In the various figures, like reference characters
indicate like elements throughout.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
2~31~62~
Referring to Figures 1 and 2, there are shown shopping
carts A of a nestable type, each having a handle bar B to which
is fixed a housing 10 of the locking device in accordance with
the invention. The housing 10 has a front face 12 and a back
face 14, each provided with a key slot for receiving a key 16.
Key 16 is attached to the housing 10 at the front face thereof by
means of a flexible link, such as a chain 18.
As will be explained hereinafter, the housing 10
contains a locking mechanism which retains the key inserted in
the housing key slot at the back face 14, this locking mechanism
requiring the insertion of a coin and also of the free key 16a of
the last or frontmost cart of the row of nested carts into the
key slot at the front face 12 of the housing for release of the
key inserted at the back face, so that the frontmost cart can be
used. The front face key 16a cannot released and the coin
retrieved until the cart is returned and the key from the new
frontmost nested cart inserted within the key slot at the back
face 14 of the returned cart.
The chain 18 of the backmost key 16 is normally
attached to a fixed structure.
Housing 10 is made in three parts, as shown in Figure
3, 4 and 7 to 11, namely: a top part 20, an intermediate part 22,
and a bottom part 24. The three parts are preferably made of
cast or molded material and form a housing, of generally
rectangular shape when assembled. The intermediate part 22 and
bottom part 24 are provided with partly cylindrical channels 26,
zr)ls62~
28 respectively, which register one with the other when the two
parts are assembled by a pair of shorter bolts 30 located at
diagonally-opposed corners of the housing. The registering
partly cylindrical channels 26, 28 tightly fit around the
conventional cylindrical plastic sheath C surrounding the
metallic part sa of handle bar B of the shopping cart A. The
intermediate part 22 opens within the bottom opening 32 of the
top part 20. The top part carries all of the locking mechanism
and the latter partly extends within the intermediate housing
part 22. The top part 20 is secured to the intermediate part 22
by means of a pair of longer bolts 34 disposed at the remaining
two diagonally-arranged corners of the housing. The longer bolts
34, together with the shorter bolts 30, have their heads
accessible through bores 36 opening at the bottom face of the
bottom part 24. The longer bolts 34 freely extends through a
cylindrical sheath 38 integrally cast within the intermediate
part 22 and are threaded within a sheath 40 of upper part 20.
Similarly, the intermediate part 22 is provided with diagonally-
disposed threaded sheaths 42 in which shorter bolts 30 are
screwed. With this arrangement, it is clear that for servicing
the locking mechanism contained in the top part 20, only the long
bolts 34 have to be removed to detach the top housing part 20.
Therefore, the intermediate and bottom parts of the housing can
remain in adjusted position fixed to the handle bar.
Figure lO shows how the key chain 18 is attached to the
housing by a shock absorbing means. The last link 44 of the
2!)1S6~3
key chain 1~ partially freely enters a pair of registering slots
46 formed at the junction of the intermediate part 22 and bottom
part 24, as shown also in Figure 4. The last link 44 is free to
move in or out of the slots 46. This last link freely extends
through registering holes 48 made through the arms 50 of a split
elongated ring 52, which surrounds the plastic sheath C of the
handle bar and also a rubber shim 54 located opposite link 44.
Shim 54 acts as a shock-absorber to prevent chain or split ring
breakage should a sudden pull be exerted thereon for instance
when someone tries to yank the cart retained by the chain through
its key.
Channels 26, 28 are transversely elongated as shown at
26a, 28a to accomodate lateral shifting of split ring 52.
Figure 4 shows the key slot 56 formed at the front face
12 of the housing 10. Adjacent said key slot is coin-receiving
cavity 58 (see also Figure 7). Figures 5, 6, and 10 show the key
slot 60 opening at the back face 14 of the housing 10.
Each key 16 comprises a flat key shaft 62 having a free
end 64 and a through opening 66 at a predetermined distance ~rom
the free end 64. Each key has a key head 68 fixed to the other
end of the key shaft and of generally cylindrical shape,
làterally protruding from all sides of the key shaft. Each key
16 can be received into either one of the key slots 56, 60. The
key head has a U-shape element 70 fixed thereto and which is
connected to the last link of the chain 18. Each key slot 56, 60
has a rectangular flat cross-sectional shape to receive, with a
201S623
sliding fit, the key shaft 62.
Referring to Figures 5 and 6, the back key slot 60 is
provided at the inner end thereof with a C-shape locking member
72 pivoted on a shaft 74 for pivotal movement across the key slot
60 between a key-locking or retaining position in which the inner
leg 76 of locking member 72 engages hole 66 of the key shaft 62,
and a release position, as shown in Figure 6, in which this inner
leg clears the key shaft hole 66 and the key slot 60, so that the
key 16 may be released.
C-shaped locking member 72 has an outer leg 78, which
is in the path of the key slot 60 and which, when pushed by the
free end 64 of the key shaft 62, causes pivotal movement of the
C-shaped locking member 72 from a key-releasing position to a
key-locking position in which the inner leg 76 again engages the
hole 66 of the key shaft 62.
A similar arrangement is provided for the front key
slot 56. More particularly, a C-shaped locking member 80 is
pivoted on a transverse pivotal pin 82 for movement between a
key-retaining position in which the inner leg of locking member
80 extends through the hole 66 of the key shaft 62 of key 16a, as
shown in Figure 6, and a key-releasing position in which the
inner leg releases the key to allow withdrawal of the key 16a
from the front key slot 56. An interconnecting movement
reversing mechanism is provided between the two locking members
72 and 80. A cap 86 i5 integral with and formed on each locking
member 72, 80 around its pivot pin 74, 82 and each cap has an
Z015~23
extension 90, of reduced cross-sectional dimensions inserted
within the opposite ends of a compression coil spring 94, which
abuts against the oppositely~facing steps defined between the
ends of the caps 86 and their extensions 90. The spring 94 is in
compressed state. The system forms a toggle lever mechanism and
has two states, namely : a state as shown in Figure 5, wherein
the front C-shaped locking member 80 is in key-releasing
position, while the back locking member 72 is in key-retaining
position, the other state being shown in Figure 6, wherein the
positions are inverted, namely: the locking member 72 is in key-
releasing position, which the front locking member 80 is in key-
locking and retaining position. In both states, the limit
positions of both C-Shaped locking members take place when the
inner leg of one member fully engages the hole of the inserted
key. The front locking member 80 has its outer leg in the path
of the key shaft 62, when in key-releasing position, so that
insertion of the key 16A within its front key slot will abut
against the outer leg and cause pivoting movement of the locking
member 80 to its key-retaining position and inverse pivotal
movement of the back locking member 72 to its key-releasing
position.
A holder meachanism is provided, which is associated
with the front key slot 56 to hold the two C-shaped locking
members 72, 80 in their state shown in Figure 5, that is in the
position in which the back key 16 is retained by the back locking
member 72, while the front locking member 80 is in key-releasing
,
2!`)15~2~3
position. This holding mechanism consists of the flat open frame
98, which has inturned ears 100 pivoted on a pivot pin 102
carried by the housing top part 20, the frame 98 pivotable
between a holding position, as shown in Figure 5, in which it
surrounds the outer leg of the front locking member 80 to retain
the same in key-releasing position, and a clearing position, as
shown in Figure 6 in which the frame 98 is pivoted away from the
locking member 80 to permit free pivoting movement of the same.
A coil spring 104 is coiled around the pivot pin 102 and has one
end engaging the opening formed by the frame 98, which its other
end engages a step 106 of the housing top part 20, as shown in
Figure 6. This coil spring 104 is biased to always pivot frame
98 into its holding position, as shown in Figure 5.
The frame 98 is pivoted to its clearing position by
means of a coin D which has to be inserted into coin-receiving
cavity or slot 58 formed adjacent the front key slot 56 and in
register with the inner face 110 of the key head 68 of the key
16A when the key shaft 62 of said key is inserted in the front
key slot 56.
Referring to Figures 5, 7, and 12, there is shown a
coin holder 112 mounted in coin slot 58 and which is in the form
of a slide arranged for reciprocating movement along a guide
strip 114. The coin holder 112 has lateral guideways 116
engaging the sides of the yuide strip 114 and is provided at its
top with resilient leaf 118 to receive the edge of a coin D and
retain the same.
t;2;~
The coin holder 112 has a blind bore 120 opening at its
back and receiving one end of a compression coil spring 122,
which in inserted around a finger 124, so that the other end of
the coil spring abuts against a step 126 formed by a head portion
128 of the finger 124. This head portion has a rectangular
flange 130 of a size to enter the cross~portion of a T-shaped
hole 132 made in the guide strip 114. The restricted end of head
128 is pushed by the coiled spring 122 against the end of the T-
shaped hole 132, and the coin holder 112 is pushed by the coil
spring to its limit outer position, wherein it abuts against
steps 134 of guide strip 114.
In this position, the coil holder 112 is near the front
face 12 of the housing ready to receive a coin D which, when
inserted, partially protrudes from the housing front face 12, as
clearly shown in Figure S. The coin is fully inserted within the
housing by head 68 of the key 16A when the same is fully inserted
within its key slot. Upon coin insertion, a feeler arm 136,
integral with holding frame 98 and projecting away from said
frame towards the front face 12, comes in engagement with the
coin to cause pivoting of the frame to its locking member
clearing position. The COiII is prevented from lateral
displacement under the action of the feeler arm 136 by a guide
member 138, which is disposed diametrically opposite the feeler
arm 136 with respect to the coin D; the coin slides on the
yuiding surface 140 of member 13~. The inller end of guide 138 is
provided with a right-angle leg 142, which serves as a stop for
13
;~! )1~6~
the coin holder 112 being in the path of the same, thereby
limiting inward movement of said coin holder. The guide 138 is
secured to the top housing part 20 in such a manner that it can
be laterally adjusted towards or away from the coin feeler arm
136 for proper operation of the holding frame 98. More
particularly, guide 138 has a lateral arm 144 provided with an
elongated hole 146 through which extends a bolt 148 which is
screwed within the housing top part 20 (see Figures 5 and 11).
Figure 11 also shows that the front key slot 56 is formed as a
channel at the end of an extension 150 integral with housing top
part 20. This ~ey slot is closed by the guide strip 114 and the
latter is maintained in position by being provided with a
lateral arm 115 located under arm 144 and having a hole 115a for
bolt 148. Strip 114 also has at its outer end an inturned right
angular flange 152, which surrounds the opening of the front key
slot 56 at the front face 12 of the housing 10, flange 152 having
a hole 154 for uncovering the key slot 56, the flange 152 having
a rounded edge 156 which fits within a partly-circular groove 158
formed at the junction of the housing front face 12 with an
annular ledge 160 protruding from the housing top face 12 and
adapted to receive the key head 68.
Figure 4 shows clearly the flange 152 in position
within the ledge 160 with its hole 154 surrounding key slot 56.
The coin slot 58 is formed by the spacing between the guide strip
114 and the corresponding edge 170 of the intermediate housing
part 22, this edge being spaced frorn the guide strip 114 a
.
distance equivalent to the thickness of a coin D when the two
housing parts 20 and 22 are secured one to the other.
Referring to Figure 10, it is seen that the pivot pin
74 of the back locking member 72 extends on both sides of said
5 locking member 72 and is slidably fitted in corresponding blind
bores made in cylndrical post 172, 174 extending within and
secured to the housing top part 20 and intermediate part 22,
respectively, the blind bores made in the post 172, 174 opening
at the junction between the two housing parts. The same
10 arrangement is provided for the pivot pin 82 of the front locking
member 80. This enables the mechanism to be easily taken apart
for servicing.
The loclcing device of the invention is used as follows.
Referring to Figures 1 and 2, there is shown a series of nested
15 carts A which are interlocked by means of the lcey 16 attached to
the housing 10 of a back or left-hand cart engaging the back key
slot 60 of the housing 10 of the next front or right-hand cart A.
The carts are retained in the intended storage area by having the
backmost chain attached to a wall or the lilce fixed structure.
20 Therefore, for all the carts, the key 16 is retained in the back
key slot because the baclc C-shaped locking lever 72 is in the
Icey-rètaining position shown in Figure 5. When a user wants to
release the frontmost cart of the row of carts, he simply inserts
a coin D within the coil holder 112 and then inserts the key
25 which is suspended from the chain 18 of the cart into the front
key slot 56, thereby pushing the coin within the housing and
~!lS~
causing the feeler arm 136 to pivot outwardly, thereby to cause
the holding frame 98 to clear the locking member 80. Further
coin insertion and key shaft insertion will result in the
pivoting of the front locking member 80 to thereby retain the
front key 16A to the housing and simultaneously release the back
key 16 from the housing, whereby the cart can be released and
used. During the time the cart is used, the coin D remains
trapped within the housing 10 and the user has to return the cart
to the storage area and insert the key freely suspended from the
last cart into the back key slot 60 to cause release of the key
16A and locking of the key 16. UPon release of key 16A, the coin
holder 112 is pushed outwardly by means of the coil spring 122,
whereby the coin becomes accessible to the user for retrieval.
It follows that proper operation of the system is not dependent
on the length of the chain 18. It is sufficient to adjust this
length so as to keep the chain sufficiently taut for the
interconnected carts. Also, during the entire use of the cart,
the key 16A is retained in the housing 10, whereby accidents are
prevented and the key cannot be used in the parking lot to unlock
another stranded cart to get the coin off the locking means of
this stranded cart.
16
