| 摘要 |
The device is inserted into the cover plate (1) forming the working surface (A) of the sewing machine, specifically at one corner point of the diagonal of an imaginary square (y), at the other corner point of which the needle-pricking point (x) is located. A first clamping disc (8) is connected in one piece via an edge web (4c) to the shank part (4a) of the holding bush (4). The clamping disc (8), rounded on all sides, projects only a little above the working surface (A); it is inclined slightly relative to the latter. Pressed against the inner face (9) of the clamping disc (8) by a spring (14) is the corresponding end face (12) of a second clamping disc (11) which is seated on a bolt (13) guided in the shank part (4a). The introduction gap (15) for the threads (F) is located at the highest point of the clamping plane formed by the clamping faces (9, 12). The fall line of this clamping plane is approximately at right angles to the said diagonal (x - b). The edge, further from the pricking point (x) and lying on a generatrix of the holding bush (4), of the edge web (4c) of sickle-shaped cross-section is formed directly under the first clamping disc (8) as a cutting edge (10). The entire device can be countersunk completely into the working surface (A) counter to a spring effect (7); however, otherwise, it still projects only slightly and does not disturb the flow of the sewing material. <IMAGE> |
