1. Field of the Invention
This invention relates generally to a transmission device and, more specifically, to a transmission device of laminating machine that is controlled by a mechanism to release a document.
2. Description of the Prior Art
Heretofore, it is known that laminating machines apply heat to bind two laminating sheets between two rolling wheels and an inserted document into one body, the inserted document is sealed inside completely. The transmission device of the laminating machine as shown in FIG. 1 comprises a motor 11 for driving a lower gear 13 through an outer gear 12 and the lower gear 13 driving an upper gear 14; the axis of the upper and lower gear 14, 13 fixed onto an upper rolling wheel 16 and a lower rolling wheel 15 respectively; a document 17 passing between the upper and lower rolling wheels 16, 15 and the motor 11 driving the upper and lower rolling wheels 16, 15. Sometimes, the document 17 to be laminated along with the laminating sheets are entered between the upper and lower rolling wheels 16, 15; if the document 17 is not fed properly or affected by the rolling wheels 15, 16, wrinkles might occur. In the structure of the known laminating machine, users cannot pull the document out during the heating process; even if turning the power off, the document is still clipped between the rolling wheels; if users pull the document out by force, the surface of document will not be smooth, and the remedy that follows is tedious. The fundamental cause of the problem resides on the synchronization between the motor and the rolling wheels; if the motor stops, the rolling wheels will be stuck. As a result, the document can only be pulled out by force.