GB2335183A

GB2335183A - Locking device for a foldable container

Info

Publication number: GB2335183A
Application number: GB9901339A
Authority: GB
Inventors: Wen Sheng He
Original assignee: Polyearn Development Corp
Current assignee: Polyearn Development Corp
Priority date: 1998-03-09
Filing date: 1999-01-21
Publication date: 1999-09-15
Anticipated expiration: 2019-01-21
Also published as: CN1109178C; GB2335183B; CN1228503A; GB9901339D0

Abstract

A locking device for a locking a corner post 4 of a foldable container substantially perpendicular to a platform base (1 Fig. 1) comprises a locking pin 15 having an outer surface which has a radial radius of curvature which changes constantly and evenly (Figs.5,6), a locking pin aperture 18 through side plates 12,13 for accepting said pin and having a corresponding inner surface such that the outer surface of the pin and the inner surface of the aperture have a similar spiral camber (Figs.5,6). The device is unlocked by rotation and slidable disengagement of the pin via handle 17 and axle 16 members of said pin. The comer post is connected to the platform via a hinge assembly, through which the device may extend, which may include an inner hinge 10 secured to the post and an outer hinge secured to the platform, wherein said inner and outer hinges are connected to each other via a rotation axle about which the post is rotatable.

Description

Locking Device for a Foldable Container 2335183

In the field of containers, there is a special container known as foldable containers. It is made up of a horizontal platform base and four vertical corner posts. The corner posts are located at the four corners of the platform base, and are connected to the platform base via hinges. The two corner posts at each end are generally connected by an end wall board. Each of the corner posts can be locked at the vertical position through a locking device. When the locking devices are unlocked, the corner posts can be folded onto the platform base. Once the corner posts are folded onto the platform base, this type of foldable container may also be used as a platform container, on top of which other foldable containers may be placed. Such an arrangement is more economical in terms of storage and transportation.

When goods are contained in the foldable container in the actual transportation process, the corner posts are locked in the vertical position, and on top of the foldable container may be placed other containers. At this time, very large force will be exerted on the top part of the corner posts, and such force will be transmitted through the corner posts to the hinges and the locking devices. Thus, not only are the corner posts, hinges and the locking devices required to be firm and strong enough, there should also be no clearance in the locking device after locking, in order to prevent the corner posts from swaying, and thus to ensure that it is relatively easy to pile up other containers on top of the corner posts of the container, and that such piling up of containers is steady and reliable.

Usually, the lock pin in the locking device is in the shape of a rectangular prism, cylinder, wedge, or circular cone. When a rectangular prism or cylinder is used as the -2lock pin, the space between the lock pin and the pin hole cannot be cleared. When a wedge or circular cone is used as the lock pin, although there is no space between the lock pin and the pin hole, when force is exerted on the corner posts, the lock pins will experience a force in their respective axial direction, which will urge the lock pins to move in their respective axial direction. A clearance between the lock pin and the pin hole will thus appear. A conical shaped lock pin is used, e.g. in United Kingdom Patent No. 2073149.

An object of the present invention is to eliminate the clearance between the lock pin and the pin hole when the locking device is locked, and thus to prevent swaying of the corner posts, thereby ensuring that it is relatively easy to pile up other containers on top of the corner posts of the container, and that such piling up of containers is steady and reliable.

According to the present invention, there is provided a locking device for a foldable container including a platform member and at least one post member, wherein said locking device includes locking means which, when locked, positions said post member substantially perpendicular to said platform member and prevents movement of said post member relative to said platform member, wherein when said locking means is unlocked, said post member is movable to lie on said platform member, wherein said locking member includes a pin member and at least one corresponding pin hole, wherein the radial radius of curvature of the outer surface of said pin member changes evenly and constantly, wherein the radial radius of curvature of the inner surface of the pin hole changes evenly and constantly, and wherein the 1 -3 outer surface of said pin member and the inner surface of the pin holes are of the same or similar spiral camber, whereby said locking means is locked or unlocked by rotation of said pin member in said pin hole.

Advantageously, said locking device may extend through a hinge which connects the platform member and the post member.

Conveniently, said hinge may include an inner hinge and an outer hinge, wherein said post member may be fixedly secured to said inner hinge, wherein said outer hinge may be fixedly secured to said platform member, and wherein said inner hinge and said outer hinge may be connected to each other via a rotation axle about which said post member is rotatably movable.

Suitably, when said locking means is unlocked, said pin member may be movable in the axial direction relative to said pin hole.

Said pin member may advantageously be engaged at one end with an axle member secured with a handle member, and wherein said handle member may be operable to cause said axle member and said pin member to rotate or move in the axial direction.

The lock pin in the locking means is a pin with a spiral surface, and the pin hole is also of a spiral surface. The outer surface of the lock pin and the surface of the pin hole are of the same or similar spiral camber. The locking means can be -4locked or unlocked through rotation of the lock pin in the pin hole. When the locking means is locked, most of the outer surface of the lock pin and most of the inner surface of the pin hole are in contact, thus giving rise to a very large locking force, which can bear a relatively heavy load. When the locking means is unlocked, there is space between the lock pin and the pin hole, thus allowing the lock pin to move in the axial direction.

The advantages of this invention are that when the locking means is locked, most of the outer surface of the lock pin and the inner surface of the pin hole are in contact, thus giving rise to a very large locking force, which can bear a relatively heavy load, and that, after locking, the locking means exhibits a self-locking feature. Even if there are wearing away of the lock pin and the pin hole during use, they can still be locked tightly together, i.e. the locking means has a compensatory function. As the lock pins are in prism form, when the force is exerted on the posts after locking of the lock means, the pins will not experience any axial force, and the pins will thus not exhibit any movement in the axial direction.

The invention will now be described by way of an example and with reference to the accompanying drawings in which:- Fig. 1 is a perspective view of a foldable container including a locking device according to the present invention.' Fig. 2 is a side view showing the piling up of a number of foldable containers shown in Fig. 1.1 Fig, 3 is a side view of a corner of the foldable container shown in Fig. 1.1 1 Fig. 4 is a front vie' of the corner of the foldable container shown in Fig. 3; Fig. 5 is a sectional view of the lock pin in the pin hole of the foldable container shown in Fig. 1, in the unlocked position; and Fig. 6 is a sectional view of the lock pin in the pin hole of the foldable container shown in Fig. 1, in the locked position.

Fig. 1 shows a container including a locking device according to the present invention, which container including a platform base 1, end walls 2 and hinges 3. Included in the end walls 2 are corner posts 4. The end walls 2 may be locked in the erect position as shown in Fig. 1 by means of the hinges 3. It is also possible to unlock the hinges 3 to allow the end walls 2 to be folded onto, and thus lie on, the platform base 1.

Fig. 2 shows a number of similar foldable containers 5, 6, 7, 8 and 9 piled up one on another after folding.

As shown in Fig. 3, the corner posts 4 are in the erect position, i.e. they are perpendicular to the platform base 1. The corner posts 4 are engaged with a respective inner hinge 10. The platform base 1 is engaged via its bottom side rail 11 with an inner-side hinge plate 12 of an outer hinge (which includes the inner-side hinge plate 12 and an outer-side hinge plate 13). A rotation pin 14 extends through the outer hinge (which includes the inner-side hinge plate 12 and the outer-side hinge plate 13) and the inner hinge 10, and thereby to connect the inner hinge 10 and the outer hinge. When a lock pin 15 is loosened, the comer post 4 together with the inner -6hinge 10 can rotate about the rotation pin 14 in the direction of the arrow "K' shown in Fig. 3, so as to allow the end wall 2 to fold onto the platform base 1. On the other hand, the end wall 2 may move from the folded position to the erect position, through the rotational movement of the corner post 4 and the inner hinge 10 about the rotation pin 14 in a direction opposite to the direction of the arrow 'W' shown in Fig. 3. The end wall 2 may be locked in the erect position upon locking of the lock pin 15.

In Fig. 4, the inner hinge 10, the inner-side hinge plate 12 and the outer-side hinge plate 13 are partially sectioned to show the lock pin 15 more clearly. In this figure, the corner post 4 is in the erect position and the locking device is in the locked position. The lock pin 15 may be loosened, and thus unlocked, upon rotation of a handle 17 around an axle 16. When the handle 17 is moved to position 17' as shown in dotted line, the lock pin 15 will be moved away from the inner hinge 10, and the corner post 4 may then be folded onto the platform base 1. Conversely, when the foldable container is in the folded position, the corner post 4 may be moved to the erect position by rotation about the rotation pin 14. The handle 17 may then be moved from the position 17' to 17 so as to extend the lock pin 15 through the innerside hinge plate 12 and the outer- side hinge plate 13 of the outer hinge and the inner hinge 10. The handle 17 may then be rotated about the axle 16, so as to lock the lock pin 15 to the inner hinge 10 and the outer hinge. The end wall 2 is thus locked in the erect position.

In Fig. 5, the lock pin 15 and the inner hinge 10 are both sectioned transversely. As the locking between the lock pin 15 and the outer hinge is achieved in the same -7manner, there will be no description on this latter feature. The outer surface of the lock pin 15 and the inner surface of a pin hole 18 of the inner hinge 10 are of the same or similar spiral camber. The radial radius of curvature of the outer surface of the lock pin 15 and the radial radius of curvature of the inner surface of the pin hole 18 change evenly and constantly. As shown in Fig. 5, the lock pin 15 is in an unlocked position relative to the pin hole 18 of the inner hinge 10. The clearance 19 between the lock pin 15 and the pin hole 18 is at a maximum, and the lock pin 15 may move in the axial direction in and relative to the pin hole 18. When the lock pin 15 is rotated in the pin hole 18 in the direction of the arrow "B", the clearance 19 is gradually reduced, until the clearance is reduced to zero when the lock pin 15 is locked against the pin hole 18 of the inner hinge 10.

In Fig. 6, the lock pin 15 and the inner hinge 10 are both sectioned transversely. Again, as the locking between the lock pin 15 and the outer hinge is achieved in the same manner, there will be no description on this latter feature. The lock pin 15 is in a locked position relative to the pin hole 18 of the inner hinge 10. The clearance 19 between the lock pin 15 and the pin hole 18 is zero. When the lock pin 15 is rotated in the pin hole 18 in the direction of the arrow "C", the clearance 19 will gradually increase, and thereby to unlock the locking device, whereupon the lock pin 15 can move in and relative to the pin hole 18 in the axial direction.

Claims

CLAIMS:-

1. A locking device for a foldable container including a platform member and at least one post member, wherein said locking device includes locking means which, when locked, positions said post member substantially perpendicular to said platform member and prevents movement of said post member relative to said platform member, wherein when said locking means is unlocked, said post member is movable to lie on said platform member, wherein said locking member includes a pin member and at least one corresponding pin hole, wherein the radial radius of curvature of the outer surface of said pin member changes evenly and constantly, wherein the radial radius of curvature of the inner surface of the pin hole changes evenly and constantly, and wherein the outer surface of said pin member and the inner surface of the pin holes are of the same or similar spiral camber, whereby said locking means is locked or unlocked by rotation of said pin member in said pin hole.

A locking device according to Claim 1 wherein said locking device extends through a hinge which connects the platform member and the post member.

3. A locking device according to Claim 2 wherein said hinge includes an inner hinge and an outer hinge, wherein said post member is fixedly secured to said inner hinge, wherein said outer hinge is fixedly secured to said platform member, and wherein said inner hinge and said outer hinge are connected to each other via a rotation axle about which said post member is rotatably movable.

A locking device according to Claims 1, 2 or 3 wherein when said locking means is unlocked, said pin member is movable in the axial direction relative to said pin hole.

2.

4.

1 -9A locking device according to any of the preceding claims wherein said pin member is engaged at one end with an axle member secured with a handle member, and wherein said handle member is operable to cause said axle member and said pin member to rotate or move in the axial direction.

6. A locking device substantially as herein described and with reference to the accompanying drawings.