AN IMPROVED COLLAPSIBLE PLASTIC BIN
FIELD OF INVENTION
The present invention relates to an interlocking mechanism for collapsible or foldable plastic
container or bin. More particularly, the collapsible container or bins are provided with
interlocking mechanism for the purpose of the stacking so as to prevent slipping or falling of
stacked collapsible plastic container or bins during storage, handling, and transportation.
BACKGROUND AND PRIOR ART OF THE INVENTION
It is known that plastic container or bins are an indispensable part of several industries such as
automotive, household appliances, retail, FMCG, food, dairy, health care, textile, and electronics.
These container or bins are being used for storage, handling, and transportation of numerous
items that are crucial part of our everyday lives and our growing economy. Management of these
container or bins is thus a vital part of logistics and supply chain management.
To achieve efficient storage and transportation many container or bins have designs that allow
them to be stacked on top of each other (India Patent# 117704). When the container or bins are
being transported on an uneven surface or road this can cause the container or bins to jump and
fall off, thus likely to damage the goods being transported. The loss and damage sustained during
handling and transportation adds time and economic costs to the cost of goods being transported
- which is a waste. To secure these stacking arrangements during transportation, ropes and tapes
have to be strategically used to tie down these stacks to prevent them from falling or slipping.
The securing of these stacks of container or bins takes time and the method may vary based on
the mode of transportation.
To achieve effective space utilization container or bins are being stacked higher in stores and
warehouses. However, this raises the issue of safety since these stacks are prone to falling if
accidentally hit by material handling equipment or personnel.
Therefore the inventors of the proposed invention felt a grave need of afore-said problems, and
proposed a solution of these issues by providing an interlocking mechanism between the stacked
container or bins thus securing the container or bins in place.
OBJECTIVES OF THE PROPOSED INVENTION
The primary objective of the present invention is to provide interlocking mechanism for
collapsible container or bins for the purpose of the stacking and to prevent slipping or falling of
stacked collapsible plastic container or bins during storage, handling, and transportation.
Another objective of the present invention is to provide collapsible container or bins to achieve
effective space utilization in a given storage space of warehouse or transport vehicle.
Yet another objective of the present invention is to provide easy and user friendly interlocking of
stacked container or bins by fastening the container or bin stacked on top to the container or bin
at the bottom.
When the container or bins are being transported on an uneven surface or road this can cause the
container or bins to jump and fall off, thus likely to damage the goods being transported.
SUMMARY OF THE INVENTION
The stacking interlocking mechanism fastens the contai.ner or bin stacked on top to the container
or bin below it, thus preventing it from jumping off and slipping during handling and
transportation. The locks are provided on the sides of the base of the container or bins and are
engaged by a sliding button. The locking and unlocking positions and directions are clearly
marked on the lock case in symbols and words. The right hand side lock is closed by sliding the
lock button forward while the left hand side lock is closed by sliding the lock button backwards.
The locks are opened by reversing the sliding motion of the button. The locks have a safety
feature which prevents them from being locked when the container or bins are not stacked, so the
person handling the container or bins does not have to check the position of the sliding button
before stacking and locking the container or bins.
When the locks are engaged for the container or bin on top, it cannot be lifted without lifting the
bottom container or bin as well since the locks are now fastened onto the top side of the bottom
container or bin. The same can now be repeated by stacking another container or bin on top of
this arrangement. Thus a stack of these container or bins, which have been interlocked, can be
stored, moved, or transported without the need to secure them with ropes or tapes since the
interlocking prevents the container or bins from slipping or jumping off.
BRIEF DESCRIPTION OF THE FIGURES
Figure 1 shows Lock Case: Has the markings in words and symbols showing the locking and
unlocking directions. The bottom of the case has six latch hooks that snap attach into the
openings on the lower sides of the container or bins. The case also acts as a guide for the sliding
Button. The surface on which the Button slides has four small dimples to prevent the Button
from inadvertently sliding out of lock or unlock positions.
Figure 2 indicate Button: Is the part that slides for locking and unlocking of the mechanism. The
top surface has a raised wave like crest in the middle with six ridges provided, three on each side
of the crest, for grip. The two sliding surfaces on the side of the button have indentations, which
match with the dimples on the sliding surface of the Lock Case, provided to prevent the
inadvertent sliding of the button from lock or unlock positions. The bottom side of the Button
has two projections in the shape of an inverted U and a key hole that match with the cut outs on
the top surface of the Lock.
Figure 3 shows Lock Strip: Has a short cylinder projection on top that slides into the spring and
it have side ridges that match the grooves in the side slot of the lock opening. The bottom part of
the strip touches the top surface of the side of the container or bin on the bottom.
Figure 4 shows Lock: Has its hollow side at the bottom and two hooks on one side. There is a
rectangular opening provided at the side of the Lock to prevent the Lock Strip and SS Spring
from falling out of the slot. The face of the Lock has cut outs in the shape of an inverted U and a
key hole that match with the protruding profile of the bottom of the Button.
Figure 5 shows SS Spring: Rests on top of the Lock Strip and pushes the Lock Strip down.
Figure 6 shows Side View of the Lock Opening and Housing on the Container or bin: The
opening in the middle houses the Lock and the Button. The six rectangular holes are for latch
hooks of the Lock Case that snap fit into them.
Figure 7 shows Bottom View of the Lock Opening and Housing on the Container or bin: The
small slot on the left with grooves on the sides houses the SS Spring and Lock Strip. The large
opening is for housing the Lock.
Figure 8 depict Two Stacked Container or bins: This figure shows a container or bin stacked on
top of another.
Figure 9 shows Lock Catch: The slots provided on the top sides of container or bins to allow the
movement of Lock Hooks into catch and release positions.
DETAIL DESCRIPTION OF THE INVENTION
While the invention is susceptible to various modifications and alternative forms, specific
embodiment thereof has been shown by way of example in the figures and will be
described in detail below. It should be understood, however that it is not intended to limit the
invention to the particular forms disclosed, but on the contrary, the invention is to cover all
modifications, equivalents, and alternative falling within the spirit and the scope of the
invention as defined by the appended claims.
Accordingly, the drawings are showing only those specific details that are pertinent to
understanding the aspects of the present invention so as not to obscure the disclosure with
details that will be readily apparent to those of ordinary skill in the art having benefit of the
description herein. The terms "comprises", "comprising", or any other variations thereof, are
intended to cover a non-exclusive inclusion, such that a setup, device, container or bins,
that comprises a list of components does not include only those components but may
include other components not expressly listed or inherent to such setup or collapsible
container or bins. In other words, one or more elements in a system proceeded by
"comprises.. . a" does not, without more constraints, preclude the existence of other elements
or additional elements in the collapsible container or bins. The following paragraphs explain
present invention wherein an improved collapsible container or bin (as shown in figure 8). The
invention in respect of the same may be deduced accordingly.
Accordingly, the present invention relates to an interlocking mechanism for collapsible
containers to prevent slipping or falling of stacked collapsible containers during storage,
handling and transportation, the said interlocking mechanism comprising a slot (7) being
provided in at least one bottom edge of the wall of the container and the said slot having two
sections namely a) lock section and b) Spring and Lock Strip section, at least one Lock catch slot
(9b, 9c) being provided on the top surface of each container, a lock (4) being adapted and placed
in the slot (7) and comprising at least two hooks (41a, 41b) on bottom surface /side and having
an opening (4a) to accommodate the extended portion (3dd) of lock strip (3) protruding out from
the Spring and Lock strip slot, a lock strip (3) being provided in the Spring & Lock Strip slot
section having one end of circular cross section and connected with a spring mean (5) and
another end (3dd) is protruding out from the opening (4a) of the Lock, a switch (2) being
operationally configured with Lock (4) from the outer face of the container, so that hooks (41a,
41 b) of lock (4) are being adjusted to engage or disengage with lock catch slots of the another
container, so as to achieve LOCK and UNLOCK condition between stacked containers.
In a first embodiment of the present invention wherein the Lock (4) is confined by the faces and
one face (43) of the Lock has two cut outs in the shape of an inverted U (43a) and a key hole
(43b) that accommodate and adapted with the protruding profile (2a, 2b) of the switch (2).
In a second embodiment of the present invention wherein the shape and size of the protruding
portion on button (2a) and (2b) is in accordance with shape and size of cut out (43a, 43b) on the
face (43) of the lock.
In a third embodiment of the present invention wherein the two different shapes of cut out on the
face of Lock (4) ensure correct assembly of the switch (2) with lock (4).
In a yet another embodiment of the present invention wherein the Lock (4) having hooks (41a
and 41b) that are being adjusted only when lock strip (3) remains in the pushed condition due to
placing of the bottom surface of top bin, on the top surface of the bottom bin, during stacking.
In a yet another embodiment of the present invention wherein the container having side walls of
sufficient thickness so that a slot or cavity being provided at the top and bottom edges of the
walls to incorporate the interlocking mechanism.
In a yet another embodiment of the present invention wherein the lock strip (3) being assembled
with circular spring (5) and inserted vertically in the spring and Lock strip slot section in such a
way that second end (5b) of spring (5) is pushed fit in the base of the lock slot and extended
portion (3dd) of lock strip remain outside.
In a yet another embodiment of the present invention wherein the container of stacking of same
shape and size and all sides are matched with each other.
In a yet another embodiment of the present invention wherein the interlocking mechanism is
fixed on top box (7) is in match with width sides of bottom plastic bin whereby the proper slots
(9b, 9c) are being provided on the top surface of bottom container.
In a yet another embodiment of the present invention wherein the interlocking of bins is achieved
by simply placing a container on top of another and in the top container sliding the button of the
right hand lock forward and button of the left hand lock backwards.
In a yet another embodiment of the present invention wherein the lock is covered by a Lock
Case that acts as a guide for the sliding Button and having markings to indicate locking and
unlocking directions.
A further embodiment of the present invention wherein an improved collapsible container
incorporated with interlocking mechanism is incorporated with features as above-said.
Accordingly, the present invention relates to an improved collapsible plastic container or bins.
More particularly, the collapsible container or bins are provided with interlocking mechanism for
the purpose of the stacking so as to prevent slipping or falling of stacked collapsible plastic
container or bins during storage, handling, and transportation. The interlocking mechanism is
composed of five parts that are assembled directly on the opening provided on the two sides of
the base of plastic collapsible container or bins. The parts are:
1. Lock Case (Figure 1)
2. Button (Figure 2)
3. Lock Strip (Figure 3)
4. Lock (Figure 4)
5. SS Spring (Figure 5)
All parts except the stainless steel spring are injection molded plastic components. The molds are
made from hard steel and have been manufactured in tool room.
Colla~siblep lastic container or bin:
It is a box or container having base, four side walls, and lid in two parts. The four side walls of
container are hinged and foldable in inside portion of the container. The container may construct
in a rectangular or square shape. The container having side walls of thickness, so that a slot of
cavity can be provided at the top and /or bottom edges of the walls. The said slots or cavities in
the side walls are used to incorporate the interlocking mechanism for the purpose of the locking
and stacking so as to prevent slipping or falling of stacked collapsible plastic container or bins
during storage, handling, and transportation. The interlocking mechanism in an un-stacked
plastic container or bin the Lock Strip is by default at lower position as shown in figure 6. In
figure 6, there are six small slots are indicated, whereby the lock case (1) is push fit by six latch
hooks. The lock case also indicates the LOCK and UNLOCKS signs for user to move button /
switch in desired direction.
According to the present invention, as shown in figure 7, a slot or cavities have been created in
the bottom edge of the wall. The said slot is divided into two parts namely a) lock slot section
and b) spring and Lock strip slot section. The lock slot is basically a rectangular slot to
accommodate a lock as shown in figure 4. The lock slot having two long sides 7a and 7c and two
short sides 7b and 7d. The lock slot consisting a vertical groove (7dd) in the side wall (7d) as
shown in figure 7.
The lock slot further consisting a rectangular opening (7cc) in the side wall of 7c, the said
opening being adapted to accommodate button/ switch as shown in figure 2. Second part of lock
slot having a square shape slot being made of walls 7d, 7e, 7f, and 7g. Wall 7g having vertical
guide ribs at inner side of the square slot as shown in figure 7.
Another part of the interlocking mechanism is lock strip (3) as shown in figure 3. The said lock
strip having visible sides 3 1, 32, 33, 34 and 35. The side 31 and 32 are perpendicular to each
other and side 32 having a small circular protrusion to accommodate first end 5a of circular
spring as shown in figure 5. The side 33 having two protrusions 33a and 33b to accommodate the
same in the vertical guide ribs 7gg of side wall 7g of lock slot. Similarly, a protrusion 35a is
provided to accommodate in the side wall 7d of lock slot.
The said lock strip (3) being assembled with circular spring (5) and inserted vertically in the
spring and Lock strip slot section being made of walls 7d, 7e, 7f, and 7g in such a way that
second end 5b of spring (5) is pushed fit in the base of the lock slot and extended portion (3dd)
of lock strip remain outside. The lock strip (3) protrusions 33a and 33b remain in the vertical
guide ribs (7gg) of side wall 7g of lock slot and similarly protrusion 35a remain in the side wall
7d of lock slot.
Further as shown in figure 4, a Lock (4), is confined by the faces which is having a rectangular
hollow side (41) and at the bottom there are two hooks (41a, 41b) on one side. In addition there
is a rectangular opening (4a) confined by edges (45,46,47 ,48) provided at the side of the Lock
to accommodate the extended portion of lock strip (3dd) and to prevent the Lock Strip (3) and SS
Spring from falling out of the slot. The face (43) of the Lock has two cut outs in the shape of an
inverted U (43a) and a key hole (43b) that accommodate and adapted with the protruding profile
(2a, 2b) of the Button (2). The shape and size of the protruding portion on button 2a and 2b is in
accordance with shape and size of cut out (43a, 43b) on the face 43 of the lock. The two different
shapes of cut out on the face ensure correct assembly of the button (2) with lock (4).
After assembly the button/ switch (2) with lock (4), the hooks (4 la and 4 1 b) can be displaced in
the slots (9b, 9c) of the bottom plastic coritainer or bin (9), which is being locked below and
stacked with Top plastic container or bin (7). The hooks (41a and 41b) can be displaced only
when lock strip remains in the pushed condition due to placing of the bottom surface (made of
7a, 7b, 7c, 7d, 7e, 7f, 7g) of top container or bin on the top surface (9a) of the bottom container
or bin.
Generally, during stacking, while the top plastic container or bin (7) is placed on bottom plastic
container or bin (9), of same shape and size, all sides are matched with each other. It is ensured
that at least two sides (width sides) whereby the interlocking mechanism is fixed on top box (7)
is in match with width sides of bottom plastic container or bin whereby the proper slots (9b, 9c)
are being provided on the top surface of bottom plastic container or bin. Upon placing the top
plastic container or bin (7) on the bottom plastic container or bin (9), the extended portion (3dd)
of lock strip undergo in pressed condition, and thereby, by button / switch (2) which is
operationally configured with the Lock (4) from the outer face of top plastic container or bin, the
lock can be displaced and the hooks (41a 41b) got engaged in the slots (9b, 9c) of bottom plastic
container or bin (9). Hence, top plastic container or bin and bottom plastic container or bin can
be stacked and locked together. To unlock, the locking mechanism, the button / switch is
displaced to UNLOCK direction (as indicated on the cover set 1) of the lock.
The interlocking of container or bins is achieved by simply placing a collapsible container or bin
on top of another and in the top container or bin, sliding the Button of the right hand lock
forward and Button of the left hand lock backwards. The mechanism of how this is achieved is
given below.
In an un-stacked container or bin the Lock Strip is by default in a lower position, because of the
downward push from the SS Spring, which prevents the Button and the Lock from sliding to a
lock position. However, when a container or bin is placed on top of another container or bin, the
Lock Strip of the top container or bin gets pushed up by the top surface of the container or bin on
bottom. This frees the Lock and the Button to be moved into the lock position. Sliding the Button
to lock position moves the Lock Hooks below the Lock Catch of the bottom container or bin,
thus locking the top container or bin in place.
This is repeated for the second Lock thus securing the container or bin from two sides. Any
movement that tries to push the top container or bin away from the stationary position atop
another container or bin will be arrested by the Lock Hooks which are now grab container or bin
the Lock Catch.
Before moving, the container or bins should be un-stacked by sliding the Buttons of the top
container or bin in the unlocked position and then simply lifting it apart.
The assembly of the lock begins by lifting the container or bin and placing it on its short side so
that the bottom portion of the opening (Figure 6 & 7), which houses the lock, is accessible.
The spring is inserted into the slot shown in Figure 7 and then the Lock Strip is inserted
into the slot so that the short cylindrical end goes inside the spring and the side protrusions on the
strip slide into the grooves on either side of the slot.
Next, the Lock is slid from the bottom into the opening next to the slot. The Lock has its
hollow side at the bottom and the hooks should be pointing to the right.
The bottom of the Lock Strip should pass between the rectangular openings provided at
the side of the Lock. The face of the Lock should now be visible from the opening on the side.
This face has cut outs in the shape of an inverted U and a key hole that match with the protruding
profile of the bottom of the Button.
The Button is now placed on top of the Lock face through the side opening so that the
bottom protrusions of the Button insert snugly into the cut outs. The Button is pressed down to
ensure a tight fit into the Lock. Next, the Lock Case is placed on top of the Button so that the six
small latches snap into the rectangular holes provided on the sides of the opening. This concludes
the assembly of the interlocking mechanism.
ADVANTAGES OF THE INVENTION
The primary advantage of the proposed invention is to provide interlocking mechanism for
collapsible container or bins for the purpose of the stacking and to prevent slipping or falling of
stacked collapsible plastic container or bins during storage, handling, and transportation.
Another advantage of the proposed invention is to provide collapsible container or bins to
achieve effective space utilization in a given storage space of warehouse or transport vehicle.
Yet another advantage of the proposed invention is to provide easy and user friendly interlocking
of stacked container or bins by fastening the container or bin stacked on top to the container or
bin at the bottom.
Yet another advantage of the proposed invention is to provide secure interlocking of stacked
container or bins by fastening the container or bin stacked on top to the container or bin at the
bottom.
Yet another advantage of the proposed invention is to provide a quick, secure and consistent way
of interlocking of stacked container or bins to prevent them from jumping off or slipping during
storage and transportation.
The inventors have been developed the invention, so that advantage can be achieved in an
economical, practical, and facile manner. While preferred aspects and example
configurations have been shown and described, it is to be understood that various further
modifications and additional configurations will be apparent to those skilled in the art. It is
intended that the specific aspects and configurations herein disclosed are illustrative of the
preferred nature of the invention, and should not be interpreted as limitations on the scope of
the invention.

WE CLAIM
1. An interlocking mechanism for collapsible containers to prevent slipping or falling of
stacked collapsible containers during storage, handling and transportation, the said
interlocking mechanism comprising
a slot (7) being provided in at least one bottom edge of the wall of the container
and the said slot having two sections namely a) lock section and b) Spring and Lock
Strip section,
at least one Lock catch slot (9b, 9c) being provided on the top surface of each
container,
a lock (4) being adapted and placed in the slot (7) and comprising at least two
hooks (4 1 a, 4 1 b) on bottom surface /side and having an opening (4a) to accommodate
the extended portion (3dd) of lock strip (3) protruding out from the Spring and Lock
strip slot,
a lock strip (3) being provided in the Spring & Lock Strip slot section having one
end of circular cross section and connected with a spring mean (5) and another end
(3dd) is protruding out from the opening (4a) of the Lock,
a switch (2) being operationally configured with Lock (4) from the outer face of
the container, so that hooks (41a, 41b) of lock (4) are being adjusted to engage or
disengage with lock catch slots of the another container, so as to achieve LOCK and
UNLOCK condition between stacked containers.
2. The interlocking mechanism as claimed in claim 1, wherein the Lock (4) is confined by
the faces and one face (43) of the Lock has two cut outs in the shape of an inverted U
(43a) and a key hole (43b) that accommodate and adapted with the protruding profile (2a,
2b) of the switch (2).
3. The interlocking mechanism as claimed in claim 1, wherein the shape and size of the
protruding portion on button (2a) and (2b) is in accordance with shape and size of cut out
(43a, 43b) on the face (43) of the lock.
4. The interlocking mechanism as claimed in claim 1 , wherein the two different shapes of
cut out on the face of Lock (4) ensure correct assembly of the switch (2) with lock (4).
5. The interlocking mechanism as claimed in claim I, wherein the Lock (4) having hooks
(41a and 41b) that are being adjusted only when lock strip (3) remains in the pushed
condition due to placing of the bottom surface of top bin, on the top surface of the bottom
bin, during stacking.
6. The interlocking mechanism as claimed in claim 1, wherein the container having side
walls of sufficient thickness so that a slot or cavity being provided at the top and bottom
edges of the walls to incorporate the interlocking mechanism.
7. The interlocking mechanism as claimed in claim 1, wherein the lock strip (3) being
assembled with circular spring (5) and inserted vertically in the spring and Lock strip slot
section in such a way that second end (5b) of spring (5) is pushed fit in the base of the
lock slot and extended portion (3dd) of lock strip remain outside.
8. The interlocking mechanism as claimed in claim 1, wherein the container of stacking of
same shape and size and all sides are matched with each other.
9. The interlocking mechanism as claimed in claim 1, wherein the interlocking mechanism
is fixed on top box (7) is in match with width sides of bottom plastic bin whereby the
proper slots (9b, 9c) are being provided on the top surface of bottom container.
10. The interlocking mechanism as claimed in claim 1, wherein the interlocking of bins is
achieved by simply placing a container on top of another and in the top container sliding
the button of the right hand lock forward and button of the left hand lock backwards.
11. The interlocking mechanism as claimed in claim 1, wherein the lock is covered by a
Lock Case that acts as a guide for the sliding Button and having markings to indicate
locking and unlocking directions.
12. An improved collapsible container incorporated with interlocking mechanism as claimed
in claims 1 to 11.
Dated this 15'~da y of April, 2014
ANUPAM TRIVEDI
OF K & S PARTNERS
ATTORNEY FOR THE APPLICANT(S)