Stretching assembly for cloth

A stretching assembly for cloth has a heating furnace, a pressing device and a shaping device. The heating furnace has two opposite sidewalls and a channel. The channel is formed through the opposite sidewalls of the heating furnace and has an inlet and an outlet. The pressing assembly is set to face the inlet of the heating furnace and has a first pressing wheel and a second pressing wheel. The first pressing wheel has multiple annular protruding segments formed on an external surface of the first pressing wheel. The second pressing wheel parallel the first pressing wheel to form a curved clearance between the pressing wheels and has multiple annular concave segments formed on an external surface of the second pressing wheel. The shaping device is set to face the outlet of the heating furnace, aligns with the pressing device and has two shaping wheels.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a stretching assembly, and more particularly to a stretching assembly for cloth to change the width of cloth and provide a high quality of cloth after stretching.

2. Description of Related Art

A conventional stretching assembly can stretch cloth to change the width of cloth to a desired level. With reference toFIG. 7, a conventional stretching assembly70for cloth has a heating furnace60, a first transporting assembly61, a second transporting assembly62and a rolling wheel80. The heating furnace60has an inlet and an outlet. The first transporting assembly61is set on a side of the heating furnace60in which the inlet is formed to transport cloth70into the heating furnace60via the inlet. The fibers of cloth70are heated in the heating furnace60and may become soft, adhesive and deformable. The second transporting assembly62is set on a side of the heating furnace60in which the outlet is formed to transport cloth70out of the heating furnace60via the outlet. In use, the rotating speed of the second transporting assembly62is higher than that of the first transporting assembly61. Thus, cloth70can be stretched due to the speed difference between the transporting assemblies61,62to change and reduce the width of cloth to a desired level. After the stretching process, the cloth70with a desired width is reeled on the rolling wheel80.

However, the deformation on the sides of the cloth70is larger than that on the middle of the cloth70, so this will cause the density of cloth non-uniform and will influence the quality of the stretched cloth70.

Therefore, the present invention provides a stretching assembly for cloth to mitigate or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

The main objective of the present invention is to provide a stretching assembly for cloth that can change the width of cloth and provide a high quality of cloth after stretching.

The stretching assembly for cloth in accordance with the present invention has a heating furnace, a pressing device and a shaping device. The heating furnace has two opposite sidewalls and a channel. The channel is formed through the opposite sidewalls of the heating furnace and has an inlet and an outlet. The pressing assembly is set to face the inlet of the heating furnace and has a first pressing wheel and a second pressing wheel. The first pressing wheel has multiple annular protruding segments formed on an external surface of the first pressing wheel. The second pressing wheel parallel the first pressing wheel to form a curved clearance between the pressing wheels and has multiple annular concave segments formed on an external surface of the second pressing wheel. The shaping device is set to face the outlet of the heating furnace, aligns with the pressing device and has two shaping wheels.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference toFIGS. 1A and 1B, a stretching assembly for cloth40in accordance with the present invention has a heating furnace10, a pressing device20and a shaping device30.

The heating furnace10has an interior, two opposite sidewalls, a heater and a channel. The heater is mounted in the interior of the heating furnace10. The channel is formed through the opposite sidewalls of the heating furnace10, communicates with the interior of the heating furnace10and has an inlet11and an outlet12. The inlet11is formed in one of the sidewalls of the heating furnace10. The outlet12is formed in the other sidewall of the heating furnace10and aligns with the inlet11. The pressing assembly20is set to face the inlet11of the heating furnace10and has a first pressing wheel21and a second pressing wheel22.

The first pressing wheel21faces the inlet11of the heating furnace10and has an external surface, a middle, two ends and multiple annular protruding segments211. With reference toFIGS. 2 to 5, the annular protruding segments211are formed around the external surface of the first pressing wheel21and each annular protruding segment211has a width and a height. The widths of the annular protruding segments211are increased from the middle to the ends of the first pressing wheel21. The heights of the annular protruding segments211may be the same or be increased from the middle to the ends of the first pressing wheel21. With reference toFIG. 2, the annular protruding segments211are continuously formed around the external surface of the first pressing wheel21. With further reference toFIGS. 3 to 5, the annular protruding segments211are formed around the external surface of the first pressing wheel21at intervals. The external surface of the first pressing wheel21is smooth at the intervals. Preferably, with reference toFIGS. 3 and 4, one of the annular protruding segments211is defined at the middle of the first pressing wheel21. In addition, the heights of the annular protruding segments211may be the same as shown inFIGS. 2,3and5and may be increased from the middle to the ends of the first pressing wheel21as shown inFIG. 4. Alternatively, with reference toFIG. 5, one of the intervals is defined at the middle of the first pressing wheel21.

The second pressing wheel22is set over or below the first pressing wheel21, is parallel with the first pressing wheel21to form a curved clearance between the pressing wheels21,22and has an external surface, a middle, two ends and multiple annular concave segments221corresponding respectively to the annular protruding segments211on the first pressing wheel21. With further reference toFIGS. 2 to 5, the annular concave segments221are formed around the external surface of the second pressing wheel22and each annular concave segment221has a width and a depth. The widths of the annular concave segments221are increased from the middle to the ends of the second pressing wheel22. The depths of the annular concave segments221may be the same as shown inFIGS. 2,3and5and may be increased from the middle to the ends of the second pressing wheel22as shown inFIG. 4.

The shaping device30is set to face the outlet12of the heating furnace10, aligns with the pressing device20and has two shaping wheels31and a rolling wheel50. The shaping wheels31face the outlet12of the heating furnace10, are parallel with each other and can be rotated in opposite direction, and each shaping wheel31has a smooth external surface. The rolling wheel50is set to face the shaping wheels31at a position opposite to the outlet12of the heating furnace10. In operation, with reference toFIGS. 1A and 6, the pressing wheels21,22of the pressing device20can be driven in the opposite directions to pull the cloth40into the pressing device20between the assorted annular protruding segments211and the annular concave segments221, the compressing deformation of the cloth40are increased from the sides to the middle of the cloth40due to the structural characters of the widths of the annular protruding segments211and the annular concave segments221being increased from the middle to the ends of the pressing wheels21,22.

After the pressing process of the pressing device20, the cloth40is moved into the heating furnace10, the heating temperature of the heating furnace10is set between the heat distortion point and the melting point of the cloth40. Thus, the fibers of cloth40can be heated to become soft, adhesive and deformable. After the heating process of the heating furnace10, the shaping wheels31of the shaping device30are driven in opposite directions to pull the cloth40into the shaping device30with a rotating speed higher than that of the pressing wheels21,22. Accordingly, the cloth40can be stretched due to the different rotating speeds of the pressing device20and the shaping device30. During the stretching process, the drawing deformation on two sides of the cloth40is larger then that on the middle of the cloth40. Therefore, after the pressing and shaping processes of the pressing device20and the shaping device30, the density of the stretched cloth40will be uniform to provide a high quality of cloth40due to the balance of the compressing and drawing deformations of the cloth40on the sides and the middle.