Locating structure of expandable units of a rack

Information

  • Patent Grant
  • 6761274
  • Patent Number
    6,761,274
  • Date Filed
    Thursday, February 6, 2003
    21 years ago
  • Date Issued
    Tuesday, July 13, 2004
    19 years ago
  • Inventors
  • Examiners
    • Novosad; Jennifer E.
    Agents
    • Baxley; Charles E.
Abstract
A rack includes a horizontal framework for holding or displaying various things. The horizontal framework can be adjusted in height by a plurality of expandable units by which the horizontal framework is mounted on a base. The expandable units are formed of an outer tube, and an inner tube slidably fitted into the outer tube in conjunction with a locating structure having a cylindrical seat, a sleeve, and an elastic lock ring. The lock ring is retained in one end of the sleeve which is rotatably fastened to the cylindrical seat. The bottom end of the inner tube is slidably fitted into the top end of the outer tube and is embraced by the lock ring which is made compact to embrace tightly the bottom end of the inner tube when the sleeve is turned clockwise. The lock ring is relieved of the pressure when the sleeve is turned counterclockwise.
Description




RELATED U.S. APPLICATIONS




Not applicable.




STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT




Not applicable.




REFERENCE TO MICROFICHE APPENDIX




Not applicable.




FIELD OF THE INVENTION




The present invention relates generally to a rack, and more particularly to a structure by which each of the expandable units of the rack is located securely.




BACKGROUND OF THE INVENTION




The adjustable racks of the prior art comprise a plurality of expandable units, each being formed of an outer tube and an inner tube slidably fitted into the outer tube. The racks can be thus adjusted in height by locating the inner tube inside the outer tube. The locating of the inner tube is done by a locating knob, which is turned to press against the outer wall of the inner tube. Such a locating means as described above is rather primitive and ineffective at best. The locating knob is apt to become loosened upon being impacted. In addition, the locating knob undermines the aesthetic effect of the racks. Moreover, the outer wall of the inner tube is susceptible to damage that is resulted from the mechanical friction between the locating knob and the inner tube.




BRIEF SUMMARY OF THE INVENTION




The primary objective of the present invention is to provide the expandable units of a rack with a locating structure which is free of the drawbacks of the locating means of the prior art racks described above.




In keeping with the principle of the present invention, the foregoing objective of the present invention is attained by a locating structure comprising a cylindrical seat, a sleeve, and a lock ring. The cylindrical seat is fitted over the top end of an outer tube of an expandable unit and is provided in the top end thereof with a tapered receptacle. The sleeve is rotatably fastened with the seat for retaining the lock ring which has a tightening portion of a tapered construction. The bottom end of an inner tube of the expandable unit is fitted into the top end of the outer tube via the lock ring and the sleeve. As the sleeve is turned clockwise in relation to the seat, the lock ring is carried along to move downward such that the tightening portion of the lock ring is forcibly contained in the receptacle of the top end of the seat. As a result, the bottom end of the inner tube is securely embraced by the tightening portion of the lock ring. When the sleeve is turned counterclockwise, the lock ring is carried along to move upward such that the tightening portion of the lock ring is no longer forcibly contained in the receptacle of the seat. As a result, the bottom end of the inner tube is no longer intimately embraced by the tightening portion of the lock ring and can be therefore moved up and down inside the outer tube.




The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of a preferred embodiment of the present invention with reference to the accompanying drawings.











BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS





FIG. 1

shows a perspective view of the preferred embodiment of the present invention.





FIG. 2

shows an exploded perspective view of the expandable unit of the preferred embodiment of the present invention.





FIG. 3

shows an exploded sectional view of the expandable unit of the preferred embodiment of the present invention.





FIG. 4

shows a longitudinal sectional view of the expandable unit of the preferred embodiment of the present invention in the movable state.





FIG. 5

shows a longitudinal sectional view of the expandable unit of the preferred embodiment of the present invention in the fixed state.











DETAILED DESCRIPTION OF THE INVENTION




As shown in

FIGS. 1-3

, a coat rack


05


embodied in the present invention comprises a base


07


, two horizontal bars


06


, and four expandable units


10


which are uprightly mounted on the base


07


for supporting adjustably the two horizontal bars


06


. The two horizontal bars


06


are used to hold a plurality of coat hangers. The two horizontal bars


06


can be adjusted in height, thanks to the expandable units


10


.




The four expandable units


10


are formed of an outer tube


11


, an inner tube


12


, and a locating structure comprising a cylindrical seat


20


, a sleeve


30


, and a lock ring


40


. The outer tube


11


is uprightly fastened at the bottom end with the base


07


and is fitted at the top end into the bottom end of the cylindrical seat


20


. The inner tube


12


is fastened at the top end with one end of the horizontal bar


06


and is slidably fitted at the bottom end into the top end of the outer tube


11


through the cylindrical seat


20


in conjunction with the sleeve


30


and the lock ring


40


by which the bottom end of the inner tube


12


is securely located inside the top end of the outer tube


11


.




As shown in

FIGS. 2 and 3

, the cylindrical seat


20


is provided in the interior with a longitudinal slot


21


dimensioned to accommodate the top end of the outer tube


11


. The cylindrical seat


20


is further provided at the top end with a tapered receptacle


22


in communication with and in alignment with the longitudinal slot


21


. The cylindrical seat


20


is further provided with an outer threaded portion


23


.




The sleeve


30


is provided with an inner threaded portion


31


engageable with the outer threaded portion


23


of the cylindrical seat


20


. The sleeve


30


is further provided in the inner wall of the top end thereof with an annular retaining projection


32


. The sleeve


30


is rotatably fastened with the cylindrical seat


20


such that the inner threaded portion


31


of the sleeve


30


is engaged with the outer threaded portion


23


of the cylindrical seat


20


.




The lock ring


40


is made of an elastic material, such as rubber, and is provided with a flange


44


, and a tightening portion


43


of a tapered construction and extending from the flange


44


. The lock ring


40


is further provided in the outer wall with an annular retaining groove


42


which is located between the flange


44


and the tightening portion


43


. The lock ring


40


is retained in the top end of the sleeve


30


such that the retaining projection


32


of the sleeve


30


is retained in the retaining groove


42


of the lock ring


40


, and that the tightening portion


43


of the lock ring


40


is fitted into the receptacle


22


of the cylindrical seat


20


, as shown in

FIGS. 4 and 5

. It must be noted here that the lock ring


40


is provided with a center through hole


41


, which extends through the tightening portion


43


.




The expandable unit


10


is assembled in such a way that the bottom end of the inner tube


12


is slidably fitted into the top end of the outer tube


11


through the lock ring


40


, the sleeve


30


and the cylindrical seat


20


, and that the bottom end of the inner tube


12


is embraced by the tightening portion


43


of the lock ring


40


, as shown in FIG.


4


. The bottom end of the inner tube


12


can be moved up and down inside the top end of the outer tube


11


, so as to adjust the height of the horizontal bar


06


. The bottom end of the inner tube


12


is located by turning the sleeve


30


in the clockwise direction, as illustrated in FIG.


5


. As a result, the lock ring


40


is carried along with the sleeve


30


to move toward the cylindrical seat


20


so as to force the tightening portion


43


of the lock ring


40


to move further into the receptacle


22


of the cylindrical seat


20


. In light of the elasticity of the lock ring


40


, the tightening portion


43


of the lock ring


40


is pressed by pressure to embrace tightly the inner tube


12


, which is thus located securely. In another words, the bottom end of the inner tube


12


can not be moved up and down in the inside of the outer tube


11


. If a readjustment is called for, the sleeve


30


is turned in the counterclockwise direction, as shown in FIG.


4


. As a result, the lock ring


40


is carried along with the sleeve


30


to move in the direction away from the cylindrical seat


20


, so as to cause the tightening portion


43


of the lock ring


40


to separated from the receptacle


22


of the cylindrical seat


20


. The tightening portion


43


of the lock ring


40


is thus relieved of the pressure to become less compact. In another words, the inner tube


12


is no longer embraced tightly by the tightening portion


43


of the lock ring


40


and can be therefore moved up and down in the inside of the outer tube


11


.




The embodiment of the present invention described above is to be regarded in all respects as being illustrative and nonrestrictive. Accordingly, the present invention may be embodied in other forms without deviating from the spirit thereof. The present invention is therefore to be only by the scope of the following claims.



Claims
  • 1. A rack comprising:a base; a plurality of expandable units, each unit being fastened uprightly on said base and comprised of an outer tube, an inner tube, and a locating structure, said outer tube being fastened at a bottom end to said base, said inner tube being slidably fitted at a bottom end into a top end of said outer tube in conjunction with said locating structure; and one or more horizontal bars, each bar being adjustably supported by a top end of said inner tube of said expandable units; wherein said locating structure comprises: a cylindrical seat provided in an interior with a longitudinal slot, in a top end with a tapered receptacle in communication with and in alignment with said longitudinal slot, and in an outer wall with an outer threaded portion whereby said longitudinal slot is dimensioned to receive the top end of said outer tube, a sleeve comprised of an inner threaded portion, and in an inner wall of a top end, an annular retaining projection whereby said sleeve is rotatably fastened to said cylindrical seat such that said inner threaded portion of said sleeve is engaged with said outer threaded portion of said cylindrical seat; and a lock ring comprised of an elastic material and comprised of a flange, a tightening portion of a tapered construction and extending from said flange, an annular retaining groove located between said flange and said tightening portion, and a center through hole extending from said flange through said tightening portion, said lock ring being retained in the top end of said sleeve such that said retaining projection of said sleeve is retained in said retaining groove of said lock ring, and such that said tightening portion of said lock ring is extended into said receptacle of the top end of said cylindrical seat, and such that said tightening portion of said lock ring embraces the bottom end of said inner tube whereby said tightening portion is pressed thereagainst by said receptacle to become compact so as to embrace the bottom end of said inner tube when said sleeve is turned clockwise in relation to said cylindrical seat, said tightening portion of said lock ring being capable of relaxing when said sleeve is turned counterclockwise in relation to said cylindrical seat, thereby enabling the bottom end of said inner tube to be moved up and down inside the top end of said outer tube.
  • 2. The rack as defined in claim 1, wherein said lock ring is comprised of rubber.
US Referenced Citations (8)
Number Name Date Kind
5433551 Gordon Jul 1995 A
5492430 Jones Feb 1996 A
5727898 Lu Mar 1998 A
5823699 Austin et al. Oct 1998 A
5876011 Blasing Mar 1999 A
6003696 Hsiu-Chen Dec 1999 A
6488160 Wang Dec 2002 B2
6520192 Lo Feb 2003 B1
Foreign Referenced Citations (1)
Number Date Country
004020434 Jan 1991 DE