CN113460518B

CN113460518B - Hinge device for folding container and folding container

Info

Publication number: CN113460518B
Application number: CN202110909062.4A
Authority: CN
Inventors: 李升奇; 赵建刚
Original assignee: Guangdong Xinhui CIMC Special Transportation Equipment Co Ltd
Current assignee: Guangdong Xinhui CIMC Special Transportation Equipment Co Ltd
Priority date: 2021-08-09
Filing date: 2021-08-09
Publication date: 2022-12-30
Anticipated expiration: 2041-08-09
Also published as: CN113460518A

Abstract

The invention provides a hinge device for a folding container and the folding container. The outer end face of the movable hinge is provided with a twistlock hole for connecting a twistlock for installation, the connecting twistlock in the twistlock hole and a bottom hole of a corner fitting of the folding container are in the same vertical direction, and the force arm for limiting rotation of the locking pin can be increased by combining the arrangement that the movable locking hole is close to the edge of the movable hinge and the twistlock hole is close to the movable locking hole, so that the capacity of limiting rotation torque of the locking pin is improved, the folding container is ensured to be stably in a cargo loading state, and the integral structural strength of the folding container is ensured. In addition, the movable locking hole has the observation function concurrently, and operating personnel can observe the locking state of even hanging the twistlock by the movable locking hole, avoids leaking the operation or operates not in place, guarantees the security that the twistlock is connected, can also save the setting of observing the hole on the activity hinge simultaneously, improves the holistic structural strength of hinge means.

Description

Hinge device for folding container and folding container

Technical Field

The invention relates to the technical field of containers, in particular to a hinge device for a folding container and the folding container.

Background

A rack type container, which is one type of container, includes a base frame for carrying cargo and end walls provided at both ends of the base frame. The end wall foldable platform type container is called as a folding container for short, and can be used for lifting, stacking and transporting as a conventional container.

When the folding container is in an empty state, the end wall can be folded onto the bottom frame, and then a plurality of folding containers are linked together to form an integral module. The plurality of foldable containers which are linked into the module occupy small space, are convenient to hoist and only need one-time hoisting operation, and the cost of empty container transportation, storage and wharf hoisting is low, so that the foldable containers are deeply loved by customers.

In a collapsible container, the folding of the end walls relative to the base frame is accomplished by relative rotation of the fixed hinges and the living hinges. The fixed hinge and the movable hinge are relatively fixed through the locking pin, the locking pin is arranged at any position on the fixed hinge and the movable hinge at present, the locking pin cannot meet the strength requirement of the folding container when locked, and the container body is easy to damage.

In addition, when the folding container is in a folding state, the twist lock on the movable hinge can connect a plurality of box bodies into a whole. The twist lock needs to be in a locking state when in use, and due to the arrangement of the fixed hinge, an operator cannot confirm the state of the twist lock from the outer side, so that operation leakage or operation failure is easy to occur during the coupling operation to cause safety accidents.

Disclosure of Invention

The invention aims to solve the technical problems that in the folding container in the prior art, the locking pins are arranged on the fixed hinge and the movable hinge at random, the locking pins cannot meet the strength requirement of the folding container when locked, the container body is easy to damage, and meanwhile, an operator cannot confirm the state of the twist lock on the movable hinge from the outer side, so that misoperation is easy to occur.

In order to solve the technical problem, the invention provides a hinge device for a folding container, which comprises a fixed hinge, a movable hinge and a locking pin, wherein the fixed hinge is arranged on the underframe of the folding container; the fixed hinge is provided with a fixed locking hole, and the fixed locking hole is arranged close to the edge of the fixed hinge; the movable hinge is used for being arranged on the end wall of the folding container; the movable hinge is rotatably connected to the fixed hinge so as to enable the movable hinge to rotate between a first position and a second position; the movable hinge is provided with a movable locking hole, and the movable locking hole is arranged close to the edge of the movable hinge; when the movable hinge rotates to the second position, the movable locking hole corresponds to the fixed locking hole; the locking pin penetrates through the corresponding fixed locking hole and the movable locking hole so as to enable the movable hinge to be relatively fixed with the fixed hinge when in the second position; the outer end face of the movable hinge is provided with a twist lock hole, the twist lock hole is close to the movable locking hole, the twist lock hole is used for installing a chain-hung twist lock, the movable hinge is located at the first position, the twist lock hole and a bottom hole of a corner fitting of the folding container are in the same vertical direction, and the movable locking hole is used for observing whether the chain-hung twist lock in the twist lock hole is in a locking state or not.

Optionally, the cross section of the fixed locking hole is rectangular, the cross section of the locking pin is rectangular, and the locking pin is fittingly inserted into the fixed locking hole.

Optionally, the cross-sectional area of the movable locking hole is larger than the cross-sectional area of the locking pin.

Optionally, the cross section of the movable locking hole is rectangular.

Optionally, the length and width of the rectangular section of the locking pin are 60mm and 30mm, respectively, and the length and width of the rectangular section of the movable locking hole are 110mm and 55mm, respectively.

Optionally, the cross-section of the fixed locking hole, the cross-section of the movable locking hole and the cross-section of the locking pin are all circular.

Optionally, the movable hinge includes a pair of oppositely disposed movable portions and a connecting portion connected to the tops of the two movable portions; the movable parts are rotatably connected to the fixed hinges, and the movable locking holes are formed in the corresponding positions of the two movable parts; the connecting part is provided with the twist locking hole at a position close to the movable locking hole.

Optionally, the connecting portion is further provided with a storage hole, the storage hole is disposed on one side of the twistlock hole, and the storage hole is used for placing the linked twistlock.

Optionally, the living hinge rotates from the first position to the second position by an angle of 90 °.

The invention also provides a folding container, which comprises a bottom frame and end walls, and further comprises the hinge device for the folding container, wherein the fixed hinge is arranged on the bottom frame, and the movable hinge is arranged on the end walls, so that the end walls can rotate between a folding position folded on the bottom frame and an opening position vertical to the bottom frame.

According to the technical scheme, the beneficial effects of the invention are as follows: according to the hinge device for the folding container and the folding container, the twist lock hole for installing the connecting twist lock is arranged on the outer end face of the movable hinge, the connecting twist lock in the twist lock hole and the bottom hole of the corner fitting of the folding container are in the same vertical direction, and the force arm for limiting the rotation of the locking pin is increased by combining the arrangement that the movable locking hole is close to the edge of the movable hinge and the arrangement that the twist lock hole is close to the movable locking hole, so that the capacity of limiting the rotation torque of the locking pin is improved, the folding container is ensured to be stably in a cargo loading state, and the integral structural strength of the folding container is ensured. In addition, the movable locking hole has the observation function concurrently, and operating personnel can observe the locking state who links string twistlock by the movable locking hole, avoids leaking the operation or operates not in place, guarantees the security that the twistlock is connected, can also save the setting of observing the hole on the activity hinge simultaneously, improves the holistic structural strength of hinge means.

Drawings

Fig. 1 is a schematic structural view of a living hinge in a second position according to an embodiment of the hinge device for a collapsible container of the present application.

Fig. 2 is a schematic view of the living hinge of the hinge device shown in fig. 1 in a first position.

Fig. 3 is a side view of fig. 2.

Fig. 4 is another view of fig. 2.

Fig. 5 is a schematic structural view of a living hinge in a second position according to another embodiment of the hinge device for a collapsible container of the present application.

Fig. 6 is a schematic view of the living hinge of the hinge device shown in fig. 5 in a first position.

Fig. 7 is a schematic structural diagram of an embodiment of the collapsible container of the present application.

The reference numerals are explained below: 100. a collapsible container; 10. a hinge device; 11. fixing the hinge; 111. Fixing the locking hole; 112. a fixed part; 113. an installation space; 114. a fixed rotation hole; 12. a living hinge; 121. a movable locking hole; 122. a movable portion; 123. a connecting portion; 1231. twisting the lock hole; 1232. A storage hole; 124. a movable rotating hole; 13. a locking pin; 15. a rotation pin; 16. a support plate; 161. A support hole; 20. an end wall; 30. a chassis; 31. a corner fitting; 311. a bottom hole; 40. and a twist lock is hung.

Detailed Description

Exemplary embodiments that embody features and advantages of the invention are described in detail below in the specification. It is to be understood that the invention is capable of other embodiments and that various changes in form and details may be made therein without departing from the scope of the invention and the description and drawings are to be regarded as illustrative in nature and not as restrictive.

For further explanation of the principles and construction of the present invention, reference will now be made in detail to the preferred embodiments of the present invention, which are illustrated in the accompanying drawings.

Referring to fig. 1 to 4, an embodiment of the present invention provides a hinge device 10 (hereinafter referred to as "hinge device 10") for a foldable container, which is used to realize the rotation of the end wall of the foldable container relative to the bottom frame, so that the end wall can be folded on the bottom frame, or the end wall can be unfolded to be erected on the bottom frame, so as to facilitate the stacking of the foldable container in an unloaded condition and the loading of goods in a loaded condition.

In the present embodiment, the hinge device 10 includes a fixed hinge 11, a movable hinge 12, and a locking pin 13.

Wherein the fixed hinge 11 is used for being arranged on the bottom frame of the folding container. The fixed hinge 11 is provided with a fixed locking hole 111, and the fixed locking hole 111 is provided near an edge of the fixed hinge 11. The living hinge 12 is adapted to be arranged on an end wall of a collapsible container, the living hinge 12 being pivotally connected to said fixed hinge 11 for pivoting the living hinge 12 between a first position and a second position.

The movable hinge 12 is provided with a movable locking hole 121, and the movable locking hole 121 is arranged near the edge of the movable hinge 12. When the movable hinge 12 rotates to the second position, the movable locking hole 121 corresponds to the fixed locking hole 111. The locking pin 13 is inserted into the corresponding fixed locking hole 111 and the movable locking hole 121, so that the movable hinge 12 is fixed relative to the fixed hinge 11 when in the second position.

In this embodiment, a twist lock hole 1231 is opened on the outer end surface of the movable hinge 12, and the twist lock hole 1231 is disposed near the movable lock hole 121. The twist lock hole 1231 is used to mount the attached twist lock 40. When the living hinge 12 is in the first position, the twist-lock aperture 1231 is in the same vertical orientation as the bottom aperture 311 of the corner fitting 31 of the collapsible container and the movable locking aperture 121 can be used to observe whether the hitch twist-lock 40 is in a locked position.

With the living hinge 12 in the first position, the hitch twistlock 40 mounted in the twistlock aperture 1231 is in the same vertical orientation as the bottom aperture 311 of the corner fitting 31 of the folding container. The hitch twistlock 40 can be matched with the corner fitting 31, so that the bottom hole of the corner fitting 31 of the upper layer of the foldable container falls on the hitch twistlock 40, and the stacking of a plurality of foldable containers is realized. Through the setting of even string twist lock 40, a plurality of foldable containers after folding can a plurality of box antithetical couplets hang and form a transportation module, and whole shared space is little, and the hoist and mount number of times is few when the pier hoist and mount, can reduce handling and operating cost. The hitch twistlock 40 may be integrated with the collapsible container to form a unitary product, or may be configured independently according to the hitch requirements of the collapsible container.

In the present embodiment, the angle of rotation of the living hinge 12 from the first position to the second position is 90 °.

With the living hinge 12 in the first position, the end wall is folded over the base frame in the folded position, with the living hinge 12 oriented in a generally horizontal orientation. With the living hinge 12 in the second position, the headwall 20 is open standing on the underframe and in the open position with the living hinge 12 generally in a vertical orientation.

The hinge device 10 is arranged at the joint of the four corners of the bottom frame and the bottom of the end wall, the corner fittings 31 are arranged at the four corners of the bottom frame, and the fixed hinges 11 are arranged on the corner fittings 31. When the folding container carries goods, the end wall is erected, the goods are placed on the underframe, and the folding container transports the goods like a conventional container and can meet the lifting requirement at the same time.

When the collapsible container is empty, the end walls are folded onto the base frame 30 by means of the hinge means. The folded foldable container can be formed into a transportation module by connecting a plurality of containers, so that the occupied space is small, the hoisting times of a wharf are few, and the hoisting and operating costs are reduced.

Further, the fixed hinge 11 of the present embodiment includes a pair of fixing portions 112 disposed oppositely, and the two fixing portions 112 are disposed on the corner member 31 oppositely and at intervals. The fixing portions 112 are vertically connected to the corner member 31, and the space between the two fixing portions 112 constitutes an installation space 113.

The two fixing portions 112 are provided with fixing and locking holes 111 at corresponding positions, and the fixing and locking holes 111 are used for the insertion of the locking pin 13, so that the fixed hinge 11 and the movable hinge 12 rotate relatively. In the present embodiment, the fixing and locking hole 111 is disposed near the outer edge of the fixing portion 112. The fixing-locking hole 111 is in the same vertical direction as the bottom hole 311 of the corner piece 31 with respect to the bottom hole 311.

In addition, the fixing portion 112 is further provided with fixing and rotating holes 114, and the fixing and rotating holes 114 on the two fixing portions 112 correspond to each other. The fixed rotation hole 114 is provided spaced apart from the fixed locking hole 111, and the fixed rotation hole 114 is used for coupling the movable hinge 12 with the fixed hinge 11 so that the movable hinge 12 can rotate with respect to the fixed hinge 11.

The living hinge 12 is disposed in the installation space 113 between the two fixed portions 112, and the living hinge 12 includes a pair of movable portions 122 disposed opposite to each other and spaced apart from each other and a connecting portion 123 connected to the tops of the two movable portions 122. In the present embodiment, the two movable portions 122 are connected to the two fixed portions 112 of the fixed hinge 11, respectively. The movable portion 122 is provided with a movable rotating hole 124, and the movable rotating holes 124 of the two movable portions 122 are opposite.

The hinge device 10 of the present embodiment further includes a rotation pin 15, the rotation pin 15 having a circular cross section, and the diameter of the circular cross section of the rotation pin 15 is 50mm.

The rotation pin 15 is inserted into the movable rotation holes 124 of the two movable portions 122, and the rotation pin 15 is fixedly connected to the movable portions 122. Both ends of the rotating pin 15 extend out of the two movable portions 122, and both ends of the rotating pin 15 are rotatably inserted into the fixed rotating holes 114 of the two fixed portions 112, respectively, so that the movable hinge 12 can rotate relative to the fixed hinge 11.

In this embodiment, the connecting portion 123 has a twist lock hole 1231, and the twist lock hole 1231 is used to install the hitching twist lock 40, so that the hitching twist lock 40 is disposed on the living hinge 12. When the living hinge 12 is in the first position, the end wall is folded over the chassis, the hitch twistlock 40 is installed in the twistlock hole 1231 and the hitch twistlock 40 is in a locked state. At this time, the hitch twistlock 40 and the corner fitting 31 are in the same vertical direction, and the hitch twistlock 40 can be matched with the corner fitting 31 to stack a plurality of folding containers 100.

Through the setting of even string twist lock 40, a plurality of foldable container 100 after folding can a plurality of box antithetical couplets hang and form a transportation module, and whole shared space is little, and the hoist and mount number of times is few when the pier hoist and mount, can reduce handling and operating cost.

The connecting portion 123 of this embodiment is provided with a storage hole 1232, the storage hole 1232 is disposed on one side of the twistlock hole 1231, and the storage hole 1232 is used for placing the hitching twistlock 40.

When the hitch twistlock 40 is in a non-operational state, i.e., the folding container 100 is in a loaded state, the hitch twistlock 40 can be placed in the storage hole 1232 to prevent the hitch twistlock 40 from being lost. When the collapsible container 100 is to be stacked, the hitch twistlock 40 is removed from the storage hole 1232 and placed in the twistlock hole 1231.

In this embodiment, the movable hinge 12 further has a movable locking hole 121. The two oppositely arranged movable parts 122 are respectively provided with a movable locking hole 121, and the two movable locking holes 121 are oppositely arranged. The movable locking hole 121 is disposed at an edge of the movable portion 122 and is disposed adjacent to the twist-lock hole 1231.

When the movable hinge 12 is rotated to the second position, the movable locking hole 121 corresponds to the fixed locking hole 111 of the fixed hinge 11. The locking pin 13 is inserted through the movable locking hole 121 and the fixed locking hole 111 such that the movable hinge 12 is fixed relative to the fixed hinge 11. At this time, the end wall 20 is opened by the living hinge 12 to stand on the base frame 30 so that the collapsible container 100 is in the cargo loading state.

In this embodiment, the hinge device 10 further includes a support plate 16. The support plate 16 is vertically coupled to the base frame 30, and the support plate 16 is positioned at one side of the fixed hinge 11. The supporting plate 16 is provided with a supporting hole 161, and the supporting hole 161 and the fixing and locking hole 111 are located in the same horizontal direction.

The locking pin 13 is inserted into the supporting hole 161, the supporting plate 16 can support the locking pin 13, the locking pin 13 is prevented from being separated from the movable locking hole 121 and the fixed locking hole 111, the locking pin 13 is ensured to stably lock the movable hinge 12 and the fixed hinge 11, and the headwall 20 is ensured to be stably kept in the open state.

When the end wall 20 is in the open state, that is, the movable hinge 12 is in the second position, the movable locking hole 121 and the bottom hole 311 of the corner fitting 31 of the folding container are in the same vertical direction, and the movable locking hole 121 is disposed near the edge of the movable hinge 12, so that the distance between the locking pin 13 and the rotating pin 15 is increased, the force arm for limiting the rotation of the locking pin 13 is increased, the capability of limiting the rotation torque of the locking pin 13 is improved, the folding container is ensured to be stably in the cargo loading state, and the overall structural strength of the folding container 100 is ensured.

When the living hinge 12 is rotated from the second position to the first position, the collapsible shipping containers need to be stacked with the hitch twistlocks 40 in the twistlock holes 1231. At this time, through the movable locking hole 121 that is close to the twistlock hole 1231, the operator can observe whether the hitching twistlock 40 is in the locking state or not, so as to avoid the subsequent misoperation and ensure the safety of the operation.

The setting of activity locking hole 121 can guarantee the increase of the 13 restriction pivoted arm of force of fitting pin on the one hand, improves the ability of 13 restriction rotation moments of torsion of fitting pin, and on the other hand can have the observation function concurrently, makes activity hinge 12 be which setting of omitting the observation hole, avoids many trompils to cause weakening of structural strength.

In the present embodiment, the cross-section of the fixed locking hole 111, the cross-section of the movable locking hole 121, and the cross-section of the locking pin 13 are all rectangular. This kind of setting can avoid the fitting pin 13 to rotate in fixed locking hole 111 and activity locking hole 121, and deviates from fixed locking hole 111 and activity locking hole 121, guarantees that fixed hinge 11 and activity hinge 12 lock firmly fixedly steadily.

The cross-sectional size of the fixed locking hole 111 is matched with the cross-sectional size of the locking pin 13. The sectional area of the movable locking hole 121 is larger than that of the fixed locking hole 111, and the sectional area of the movable locking hole 121 is larger than that of the locking pin 13, so that an operator can observe the locking state of the hitch twistlock 40 through the movable locking hole 121 conveniently.

The locking pin 13 of the present embodiment has a rectangular cross-section having a length and width of 60mm and 30mm, respectively, and the movable locking hole 121 has a rectangular cross-section having a length and width of 110mm and 55mm, respectively.

Further, as shown in fig. 5 and 6, in one example of the present embodiment, the cross-section of the fixed locking hole 111, the cross-section of the movable locking hole 121, and the cross-section of the locking pin 13 are all circular.

The arrangement can simplify the processing of the fixed hinge 11, the movable hinge 12 and the locking pin 13 on the basis of ensuring the stable locking of the fixed hinge 11 and the movable hinge 12, and reduce the manufacturing and processing cost of the whole hinge device 10.

As shown in fig. 7, an embodiment of the present application also provides a collapsible container 100 that includes a base frame 30 and end walls 20. The collapsible container 100 of this embodiment also includes the hinge assembly 10 described above.

Wherein the fixed hinge 11 is provided on the base frame 30 and the movable hinge 12 is provided on the end wall 20. The living hinge 12 pivots relative to the fixed hinge 11 to allow the headwall 20 to pivot relative to the underframe 30. When the living hinge 12 is in the first position, the end wall 20 is folded over the base frame 30, with the end wall 20 in the folded position. When living hinge 12 is in the second position, endwall 20 is perpendicular to undercarriage 30 and endwall 20 is in the open position.

When the end walls 20 are in the folded position, the collapsible container 100 is in the folded state, and a plurality of collapsible containers 100 can be stacked in a hanging manner. When the end walls 20 are in the open position, the base frame 30 can be used to carry cargo, and the collapsed container is in a cargo loading position.

For the hinge device for the folding container and the folding container of the embodiment, the outer end face of the movable hinge is provided with the torsional lock hole for the connecting and hanging twist lock to be installed, the connecting and hanging twist lock in the torsional lock hole and the bottom hole of the corner fitting of the folding container are in the same vertical direction, and the arrangement that the movable locking hole is close to the edge of the movable hinge and the arrangement that the torsional lock hole is close to the movable locking hole are combined, so that the force arm of the locking pin for limiting rotation is increased, the capacity of the locking pin for limiting rotation torque is improved, the folding container is ensured to be stably in a cargo loading state, and the integral structural strength of the folding container is ensured. In addition, the movable locking hole has the observation function concurrently, and operating personnel can observe the locking state who links string twistlock by the movable locking hole, avoids leaking the operation or operates not in place, guarantees the security that the twistlock is connected, can also save the setting of observing the hole on the activity hinge simultaneously, improves the holistic structural strength of hinge means.

While the present invention has been described with reference to several exemplary embodiments, it is understood that the terminology used is intended to be in the nature of words of description and illustration, rather than of limitation. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims

1. A hinge device for a collapsible container, comprising:

the fixed hinge is arranged on the underframe of the folding container; the fixed hinge is provided with a fixed locking hole, and the fixed locking hole is arranged close to the edge of the fixed hinge;

the movable hinge is arranged on the end wall of the folding container; the movable hinge is rotatably connected to the fixed hinge so as to enable the movable hinge to rotate between a first position and a second position; the movable hinge is provided with a movable locking hole, and the movable locking hole is arranged close to the edge of the movable hinge; when the movable hinge rotates to the second position, the movable locking hole corresponds to the fixed locking hole;

the locking pin penetrates through the corresponding fixed locking hole and the movable locking hole so as to enable the movable hinge to be relatively fixed with the fixed hinge when the movable hinge is at the second position;

the outer end face of the movable hinge is provided with a twist lock hole, the twist lock hole is close to the movable locking hole, the twist lock hole is used for installing a linked twist lock, the movable hinge is located at the first position, the twist lock hole and a bottom hole of a corner fitting of the folding container are in the same vertical direction, and the movable locking hole is used for observing whether the linked twist lock in the twist lock hole is in a locking state or not.

2. The hinge device for a collapsible container as claimed in claim 1, wherein said fixing locking hole has a rectangular cross section, and said locking pin has a rectangular cross section and is fitted through said fixing locking hole.

3. The hinge device for a folding container as claimed in claim 2, wherein a sectional area of said movable locking hole is larger than a sectional area of said locking pin.

4. The hinge device for a collapsible container as claimed in claim 2, wherein said movable locking hole has a rectangular cross section.

5. The hinge device for a collapsible container as claimed in claim 4, wherein said locking pin has a rectangular section with a length and a width of 60mm and 30mm, respectively, and said movable locking hole has a rectangular section with a length and a width of 110mm and 55mm, respectively.

6. The hinge device for a collapsible container as claimed in claim 1, wherein said fixed locking hole, said movable locking hole and said locking pin are circular in cross section.

7. The hinge assembly for a collapsible container as claimed in claim 1 wherein said living hinge includes a pair of oppositely disposed movable portions and a connecting portion connected to the tops of said movable portions; the movable parts are rotatably connected to the fixed hinges, and the movable locking holes are formed in the corresponding positions of the two movable parts; the connecting part is provided with the twist locking hole at a position close to the movable locking hole.

8. The hinge device of claim 7, wherein the connecting portion further has a receiving hole formed therein, the receiving hole being disposed at one side of the twistlock hole, the receiving hole being used for receiving the twistlock.

9. A hinge device for a collapsible container as claimed in claim 1 wherein the angle of rotation of said living hinge from said first position to said second position is 90 °.

10. A collapsible container comprising a base frame and end walls, wherein the collapsible container further comprises a hinge arrangement for a collapsible container as claimed in any one of claims 1 to 9, said fixed hinge being provided on said base frame and said moveable hinge being provided on said end walls to enable said end walls to be pivoted between a collapsed position folded onto said base frame and an open position perpendicular to said base frame.