2. BACKGROUND ART Generally, a height of a tent may be varied by adjusting a height of a column, depending upon a shape thereof or application. An internal column of a small diameter is detachably inserted into an external column of a large diameter so as to adjust the height of the column.

The external column and the internal column are formed with a plurality of holes.

The external column and the internal column are arranged to have a desired height, with the hole of the external column being in line with that of the internal column. The fixing piece is protruded through the holes by resilience of a spring so as to fix the height of the columns.

When the fixing piece is released from the hole, it is difficult to release the fixing piece, because of the drawing force added due to vertical load of the columns and truss. Further, when the height of the column is adjusted by moving the fixing piece along several holes, the fixing piece is automatically protruded from the hole by the resilience of the spring whenever the fixing piece reaches the respective holes. Therefore, since a user should push down the fixing piece by a finger, it is a time consumption and it involves a risk of injuring to the finger.

Korean Utility Model No. 20-0278383 discloses one example of a structure capable of

adjusting the height of the tent, in which an external column is freely moved up and down by rotating a turning cap threadly fastened to an internal column through a hole of an external column. The utility model is adapted to easily handle a fixing piece using the turning cap, without a risk of injuring to a finger. The repeated usage of the fixing piece fastened threadly causes the fastening to be loose.

As shown in Figs. la and lb, Korean Utility Model No. 20-0275331 discloses another example of a structure capable of adjusting the height of the tent, in which a connector is provided with an inclined surface at one end and a knob at the other end. A nut is inserted into one side of the knob, and a fixing piece with one end formed with a nut and the other end formed with a latch. The bolt of the fixing piece is fastened to the nut, with biasing force of a spring applying to the fixing piece. If the inclined surface of the body is closed to the inclined surface of the knob by rotating the knob, the fixing piece integrally formed with the knob is moved toward one direction. Therefore, the fixing piece is not abutted against one side of the column, so that the connector can easily slide along the column to prevent damage of the column. However, when the knob is rotated, if the fixing piece is inserted into the column and is engaged thereto, while if the fixing piece is released, the fixing piece is caught by an upper end of the inclined surface, thereby interrupting the engagement of the fixing piece and the column.

Upon installing the tent, if the knob is rotated by a worker at regular intervals, the fixing piece is not inserted into the hole, and thus is not abutted against the column.

Therefore, it should identify whether the fixing piece is correctly inserted into the hole.

Further, when the worker operates by rotating the knob, the fixing piece may caught by one side of the hole by error and thus may not penetrate through the hole, so that the internal column is not fixed to the external column. Accordingly, the truss may be abruptly released from the column, thereby endangering the worker and users of tent when installing or removing the tent. In addition, a lot of power is required when the fixing piece is released from the column.

In particular, upon installing marquee or awning in the garden of a house or an excursion place, mistress or old and feeble persons may install the tent. Therefore, there is a need for an improved height adjusting device for a tent capable of being easily installed by stably engaging the fixing piece to the column.

3. BEST MODE FOR CARRYING OUT THE INVENTION Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

A height adjusting device for a tent according to one preferred embodiment of the present invention includes a handle 10 having a rod-type fixing piece 2 formed integrally with a knob 1 at one end of the fixing piece 2, a support block 3 for supporting the handle 1, an engaging protrusion 5 mounted to a bottom of the support block 3, a resilience spring 4 interposed between the support block 3 and the engaging protrusion 5, and a body 20 having a receptacle 11 corresponding to the engaging protrusion 5 and coupled to a connector.

The engaging protrusion 5 is formed to have a minimum contact area at a lower end of the engaging protrusion, and an inner periphery of the engaging protrusion 5 is formed to have a tapered cross-sectional shape The receptacle 11 is formed to have a minimum contact area at an upper end of the receptacle, and an inner periphery of the receptacle 11 is formed to have a tapered cross-sectional shape The basic structure of the handle 10 is widely known in the prior art, but the detailed mount of the present invention will now be described. As shown in Figs. 4a and 4b, the handle 10 has the rod-type fixing piece 2 formed integrally with the knob 1 at one end of the fixing piece 2. The support block 3 supports the fixing piece 2, and the engaging protrusion 5 is mounted to the bottom of the support block 3. The resilience spring 4 is interposed between the support block 3 and the engaging protrusion 5. The receptacle 11 is integrally formed with an inserting opening 12 of the body. The handle 10 is engaged to the receptacle 11 within a hollow connector 30.

As the conventional height adjusting device shown in Figs. la and lb, when the knob 11 is rotated, the fixing piece is moved down by the inclined surface formed at one end of the handle 10, so that the fixing piece 2 is inserted into holes formed at external and internal column to engage the external column with the internal column. If the knob 1 is reversely rotated, the fixing piece 2 is released from the hole to disassemble the internal column and the external column. Such a handle structure has disadvantages that if the hole of the internal

column is positioned in line with the hole of the external column and then the knob 1 is rotated, the fixing piece 2 is lowered, thereby requiring a lot of time, and that it should identify the engagement of the fixing piece 2. Accordingly, in order to solve the disadvantages, according to the present invention, the engaging protrusion 5 and the receptacle 11 are formed with the inclined surfaces and the upper and lower ends 13 and 6 to minimize the contact area, respectively. With the construction, when the upper end 13 is abutted against the lower end 6, the engagement is achieved in a moment by coinciding the holes of the internal and external columns.

Describing the operation of the engaging protrusion 5 and the receptacle 11, if the knob is rotated by an angle of 90 degrees, the fixing piece 2 is rotated, and then the lower end 41 of the engaging protrusion 5 is abutted against the upper end 61 of the receptacle 11 by the resilience of the spring 4 and the support block 3, as shown in Fig. 3a. If the knob 1 is further rotated by angle of 90 degrees, the lower end 41 of the engaging protrusion 5 is slid on the upper end 61 of the receptacle 11 along the inclined surfaces each formed the engaging protrusions 40 and 60, as shown in Fig. 3b. Specifically, the lower end 41 is perpendicularly abutted against the upper end 61 in the course of rotating the knob 1, and simultaneously, the lower and upper ends are slid along the inclined surfaces to increase restoring force and thus the fixing piece 2 protrudes into the body 20.

As shown in Figs. 5a and 5b, when the internal column is engaged to the external column, the hole of the external column is positioned in line with the hole of the internal column, and the engaging protrusion 5 is slid on the receptacle 11 by the restoring force and resilience of the spring 4 caused by the rotation of the knob 1. Simultaneously, the lower end 6 and the upper end 13 are point contacted and engaged along the inclined surfaces, so that the fixing piece 2 penetrates the body 20. At that time, the smaller the contact area of the upper and lower ends 6 and 13 becomes, the faster the sliding speed becomes. The more the point contact between the upper and lower ends 41 and 61 achieves, the faster the speed of sliding becomes, thereby minimizing the pulling force of the knob and thus reducing the energy of a user to be consumed. Specifically, when the fixing piece 50 is released from the hole, the engaging protrusion 5 is slid on the receptacle 11 along the contact surface by slightly pulling the knob 40, and then the fixing piece is spaced apart from the receptacle.

Therefore, it is possible to attach or detach the fixing piece 2 by using small power. Further, since one end of the fixing piece 2 is inserted into a bottom center of the knob 1, the fixing

piece is not detached from the knob 1 during the repeated use, thereby prolonging a life time of the component.

Accordingly, when the foldable tent is installed by using the height adjusting device according to the present invention, the pulling force acting on the knob 1 is minimized, and the restoring force of the handle 10 is maximized. The fixing piece can penetrate the external column and the internal column by turning the knob with the slight force, thereby stably and perfectly fixing the external column, the internal column and the truss at a desired height.

4. BRIEF DESCRIPTION OF DRAWINGS The above objects, other features and advantages of the present invention will become more apparent by describing the preferred embodiment thereof with reference to the accompanying drawings, in which: Figs. la and 1b are cross-sectional views of a conventional height adjusting device for a tent.

Fig. 2 is a perspective view illustrating a height adjusting device for a tent according to a preferred embodiment of the present invention.

Figs. 3a and 3b are cross-sectional views illustrating an operation of a height adjusting device for a tent according to a preferred embodiment of the present invention.

Figs. 4a and 4b are exploded perspective views illustrating a height adjusting device for a tent according to a preferred embodiment of the present invention.

Figs. 5a and 5b are cross-sectional views illustrating an operation of a height adjusting device for a tent according to a preferred embodiment of the present invention.

Fig. 6 is a view illustrating an application of the present invention.

<Numerals of Main Parts in Drawings> 1: knob 2: fixing piece 3: support block 4: resilience spring 5: engaging protrusion

6: lower ends 10: handle 11 : receptacle 12: hole 13: upper end 20: body 30: connector 5. INDUSTRIAL APPLICABILITY As apparent from the above description, since each contact area of the upper and lower ends of the engaging protrusion and the receptacle is minimized, the upper ends is abutted against the lower end, and simultaneously is slidingly engaged to each other, thereby maximizing the restoring force of the handle and rapidly and stably engaging the engaging protrusion and the receptacle. Further, the fixing piece is formed integrally with the knob, thereby prolong the life time of the component. In addition, when the fixing piece is released from the external and internal columns, the release can be performed by the slight force, thereby improving the efficiency of the operation.