Expandable Shell of a Suitcase

Abstract

An expandable shell of a suitcase includes first and second surrounding shell bodies mated with and stackable on each other and cooperatively defining an expandable accommodation chamber for increasing the volume of the suitcase. A control unit includes a pulling cord secured to the first surrounding shell body and reeled on a reel member that is mounted to the second surrounding shell body, and a pawl and ratchet teeth disposed to control the rotation of the reel member so as to adjust a distance between the first and second surrounding shell bodies and the volume of the expandable accommodation chamber.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Chinese Utility Model Application No. 200920174026.2, filed on Aug. 26, 2009, the disclosure of which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a suitcase, more particularly to an expandable shell of a suitcase.

2. Description of the Related Art

A conventional suitcase generally includes a flexible expandable section which is displaceable between an expanded position for increasing the volume of the suitcase, and a retracted position where the flexible expandable section is folded and retained by a zipper. Thus, the volume of the suitcase can be varied by virtue of the flexible expandable section. However, no rigid structure is provided to support the flexible expandable section in the expanded position so that the structural strength of the suitcase is weak in use. Moreover, no adjusting means is provided for adjusting the volume of the flexible expandable section so as to meet the user's requirement.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an expandable shell of a suitcase which has sufficient structural strength and the volume of which is adjustable.

According to this invention, the expandable shell includes first and second surrounding shell bodies surrounding a longitudinal axis and configured to mate with and to be stackable on each other so as to cooperatively define an expandable accommodation chamber for increasing the volume of the suitcase. A pulling cord has an anchoring end secured to the first surrounding shell body, and a cord body which extends from the anchoring end to terminate at a connected end. A reel member is rotatably mounted to the second surrounding shell body, and is configured to permit the connected end to be secured thereon such that, by means of rotation of the reel member, the cord body is reeled in or out to shorten or lengthen a distance between the first and second surrounding shell bodies. The reel member has a flange which surrounds the reel axis and which is formed with a plurality of ratchet teeth that are angularly displaced from one another. A reel spring is disposed to bias the reel member to perform a reel-in movement. A pawl is movable relative to the reel member between a blocking position, where a retaining end of the pawl is engaged with one of the ratchet teeth so as to guard against a reeling-out movement of the reel member, and a free-rotating position, where the retaining end is disengaged from the reel member to permit the reel member to reel out the cord body. A pawl spring is disposed to bias the pawl to the blocking position. An extension spring is disposed to bias the second surrounding shell body away from the first surrounding shell body so as to enlarge the expandable accommodation chamber, and has a biasing force larger than that of the reel spring such that, once the pawl is moved to the free-rotating position, the second surrounding shell body is pushed away from the first surrounding shell body by the biasing force of the extension spring, while the cord body is permitted to be reeled out from the reel member against the biasing force of the reel spring.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of the preferred embodiment of an expandable shell according to this invention in an expanded position;

FIG. 2 is a fragmentary sectional view of a guiding unit of the preferred embodiment taken along line II-II of FIG. 1;

FIG. 3 is an exploded perspective view of a control unit of the preferred embodiment;

FIG. 4 is a fragmentary plan view of the control unit in a blocking state;

FIG. 5 is a fragmentary plan view of the control unit in an operated state; and

FIG. 6 is a perspective view of the preferred embodiment when folded.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the preferred embodiment of an expandable shell of a suitcase according to the present invention is shown to comprise a first surrounding shell body 10, a second surrounding shell body 20, a plurality of guiding units 30, and two control units 40.

The first surrounding shell body 10 is of a rectangular shape, and surrounds a longitudinal axis in a longitudinal direction. The first surrounding shell body 10 includes two first long walls 11 and two first short walls 12 interconnecting the first long walls 11.

The second surrounding shell body 20 is substantially the same as the first surrounding shell body 10 and includes two second long walls 21 and two second short walls 22 interconnecting the second long walls 21. The second surrounding shell body 20 surrounds the longitudinal axis and is disposed to mate with and to be stackable on the first surrounding shell body 10 so as to cooperate with the first surrounding shell body 10 to define an expandable accommodation chamber (A) for increasing the volume of the suitcase.

With reference to FIG. 2, each of the guiding units includes first and second mounting seats 31,32 respectively secured on the first and second long walls 11,21 and disposed opposite to each other in the longitudinal direction, first and second tubular members 33,34 which are respectively secured on the first and second mounting seats 31,32, which extend in the longitudinal direction toward each other, and which are telescopically fitted to each other to forma tubular unit that is movable between retracted and extended positions, and an extension spring 35 which is disposed in the tubular unit to bias the second surrounding shell body 20 away from the first surrounding shell body 10 in the longitudinal direction and to urge the tubular unit toward the extended position so as to enlarge the expandable accommodation chamber (A).

With reference to FIGS. 3 and 4, each of the control units 40 includes a mount 41 secured to the second surrounding shell body 20, a positioning mount 42 secured to the first surrounding shell body 10 and disposed opposite to the mount 41 in the longitudinal direction, a reel member 43 pivotably mounted on the mount 41, a reel spring 44 mounted on the mount 41 and biasing the reel member 43 to perform a reel-in movement (R), a pawl 44 pivotably mounted on the mount 41 to engage the reel member 43, a pawl spring 46, a push button 47, a button spring 48, and a pulling cord 49.

The mount 41 defines an accommodation space 411 and a slot 414, and has an axle 412 disposed in the space 411 and extending along a reel axis that is transverse to the longitudinal direction, and a guide rail 413 extending in the longitudinal direction.

The positioning mount 42 has a retaining cavity 421 and a guiding slot 422 in spatial communication with the retaining cavity 421.

The reel member 43 is received in the accommodation space 411, is rotatably mounted on the axle 412, and has a cord reeling portion 431, and a flange 432 which surrounds the reel axis and which is formed with a plurality of ratchet teeth 433 that are angularly displaced from one another.

The reel spring 44 is a coil spring having two ends respectively secured on the axle 412 and the reel member 43. The extension spring 35 has a biasing force larger than that of the reel spring 44.

The pawl 45 has a retaining end 451 and a force-transmitting end 452, and is pivotable between a blocking position, where the retaining end 451 is engaged with one of the ratchet teeth 433 so as to guard against a reeling-out movement (R′) of the reel member 43, and a free-rotating position, where the retaining end 451 is disengaged from the reel member 43 to permit the reeling-out movement (R′) of the reel member 43. The pawl spring 46 is a torsion spring disposed to bias the pawl 45 to the blocking position.

The push button 47 is mounted in the guide rail 413 and is manually operable to perform a stroke movement in the longitudinal direction so as to move the pawl 45 to the free-rotating position.

The button spring 48 is disposed between the mount 41 and the push button 47 to bias the push button 47 against the stroke movement.

The pulling cord 49 has an anchoring end 491 which is led into the retaining cavity 421 through the guiding slot 422. A retained block 494 is connected to the anchoring end 491 and is received in the retaining cavity 421 so as to secure the anchoring end 491 in the retaining cavity 421. The pulling cord 49 further has a cord body 493 which extends from the anchoring end 491 in the longitudinal direction to terminate at a connected end 492. The connected end 492 is secured on the reel member 43 such that, by means of rotation of the reel member 43, the cord body 493 is reeled in or out to shorten or lengthen a distance between the first and second surrounding shell bodies 10,20.

Reference is made to FIGS. 5 and 6 which illustrate the expandable shell of the suitcase in a non-expanded state, i.e., having a smallest volume. In this state, the second surrounding shell body 20 is stacked on the first surrounding shell body 10, the extension spring 35 is in a compressed state, and a major portion of the cord body 493 is reeled in on the cord reeling portion 431.

Referring again to FIGS. 2 and 4, when it is desired to extend the expandable shell to increase the volume of the suitcase, a pressing force is applied to the pushbutton 47 to actuate the force-transmitting end 452 of the pawl 45 so as to move the pawl 45 to the free-rotating position. The second surrounding shell body 20 can be pushed away from the first surrounding shell body 10 by the biasing force of the extension spring 35, while the cord body 493 is permitted to be reeled out from the reel member 43 against the biasing force of the reel spring 44. Once the pressing force is released from the push button 47 to result in engagement between the retaining end 451 of the pawl 45 and one of the ratchet teeth 433 of the reel member 43, the reel-out movement (R′) of the reel member 43 is prevented so as to position the first and second surrounding shell bodies 10,20 in place. Thus, the volume of the expandable shell can be adjusted readily.

When it is desired to reduce the volume of the suitcase, the user can press the first and second surrounding shell bodies 10,20 toward each other against the biasing force of the extension spring 35. By virtue of the biasing force of the reel spring 44, the reel member 43 can perform a reel-in movement (R) to reel in the pulling cord 49, and the ratchet teeth 433 can alternately slap against the retaining end 451 of the pawl 45 to provide audible and tactile feedback to the user until the tubular unit is placed in the retracted position as shown in FIGS. 5 and 6. If the user inadvertently releases the first and second surrounding shell bodies 10,20, due to the engagement between the pawl 45 and the reel member 43, relative movement between the first and second surrounding shell bodies 10,20 can be restricted.

As illustrated, the expandable shell according to this invention is extendable and retractable to adjust the volume of the suitcase. In addition, with the provision of the first and second surrounding shell bodies 10,20 and the guiding units 30, the structural strength of the suitcase can be enhanced.

While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.

Claims

1. An expandable shell of a suitcase, comprising: a first surrounding shell body surrounding a longitudinal axis in a longitudinal direction;a second surrounding shell body surrounding the longitudinal axis and configured to mate with and to be stackable on said first surrounding shell body so as to cooperate with said first surrounding shell body to define an expandable accommodation chamber for increasing volume of the suitcase;a control unit including a pulling cord having an anchoring end which is secured to said first surrounding shell body, a cord body which extends from said anchoring end in the longitudinal direction to terminate at a connected end,a reel member which is rotatably mounted to said second surrounding shell body about a reel axis that is transverse to the longitudinal direction, and which is configured to permit said connected end to be secured thereon such that, by means of rotation of said reel member, said cord body is reeled in or out to shorten or lengthen a distance between said first and second surrounding shell bodies, said reel member having a flange which surrounds the reel axis and which is formed with a plurality of ratchet teeth that are angularly displaced from one another,a reel spring disposed to bias said reel member to perform a reel-in movement,a pawl having a retaining end and movable relative to said reel member between a blocking position, where said retaining end is engaged with one of said ratchet teeth so as to guard against a reeling-out movement of said reel member, and a free-rotating position, where said retaining end is disengaged from said reel member to permit said reel member to reel out said cord body, anda pawl spring disposed to bias said pawl to the blocking position; andan extension spring disposed to bias said second surrounding shell body away from said first surrounding shell body in the longitudinal direction so as to enlarge said expandable accommodation chamber, and having a biasing force larger than that of said reel spring such that, once said pawl is moved to the free-rotating position, said second surrounding shell body is pushed away from said first surrounding shell body by the biasing force of said extension spring, while said cord body is permitted to be reeled out from said reel member against the biasing force of said reel spring.

2. The expandable shell according to claim 1, wherein said control unit further includes a push button configured to be manually operable to perform a stroke movement in the longitudinal direction relative to said second surrounding shell body so as to move said pawl to the free-rotating position.

3. The expandable shell according to claim 2, wherein said control unit further includes a mount which is secured to said second surrounding shell body and which has an axle extending along the reel axis for mounting said reel member thereon, and a guide rail which extends in the longitudinal direction for guiding said push button to perform the stroke movement, anda button spring which is disposed between said mount and said push button to bias said push button against the stroke movement.

4. The expandable shell according to claim 3, wherein said control unit further includes a positioning mount which is secured to said first surrounding shell body and which has a retaining cavity and a guiding slot that is in spatial communication with said retaining cavity to permit said anchoring end to be led into said retaining cavity, and a retained block which is retained in said retaining cavity, and which is configured to secure said anchoring end in said retaining cavity.

5. The expandable shell according to claim 1, further comprising: first and second tubular members which are disposed to extend respectively from said first and second surrounding shell bodies in the longitudinal direction toward each other and which are telescopically fitted to each other to form a tubular unit which is movable between retracted and extended positions;said extension spring being disposed in said tubular unit so as to bias said tubular unit toward the extended position.