a sewing machine

Abstract

The invention provides a sewing machine. The sewing machine comprises a main shaft, an upper shaft, a needle bar crank, a needle bar, a needle bar binding head, a tooth lifting shaft, a cloth feeding shaft, a tooth lifting eccentric wheel, a cloth feeding eccentric wheel and a connecting frame, the connecting frame is driven by the needle rod crank and moves up and down in the extending direction of the needle bar, the needle bar binding head is connected with the connecting frame, and the needle bar binding head and the connecting frame are relatively static; the tooth lifting eccentric wheel or the cloth feeding eccentric wheel is fixed to the main shaft, a first connecting part is arranged on the tooth lifting eccentric wheel, and a second connecting part is arranged on the cloth feeding eccentric wheel; the first connecting part and the second connecting part are connected with each other in a sleeved mode; when a cloth feeding mechanism is in a cloth feeding state, the first connecting part and the second connecting part are relatively static; when the cloth feeding eccentric angle is adjusted, the first connecting part and the second connecting part rotate relative to each other. Larger needle bar piercing force can be provided, the cloth feeding eccentricity time can be adjusted, and then the thick material adaptability of the sewing machine can be improved.

Description

technical field [0001] The present invention relates to a sewing machine. Background technique [0002] Currently, if figure 1 and figure 2 As shown, the needle bar driving mechanism in the sewing machine mainly includes an upper shaft 100, a needle bar crank 200 fixed on the upper shaft 100, a needle bar connecting rod 300, a needle bar 400 extending up and down, and a needle fixed on the needle bar 400. The two ends of the needle bar connecting rod 300 and the needle bar connecting rod 300 are respectively hinged with the needle bar crank 200 and the needle bar bar head 500; the upper shaft 100 is driven by a motor to rotate, and the upper shaft 100 drives the needle bar crank 200 to rotate synchronously, so the needle bar crank 200 makes a circular motion, and then drives the needle bar piercing head 500 to reciprocate up and down through the needle bar connecting rod 300, and finally drives the needle bar 400 and the machine needle 600 installed at the lower end of th...

AI Technical Summary

Problems solved by technology

In the above cloth feeding mechanism, the eccentric wheel is an integral part, which is fixed on the main shaft by screws, so that the relative position between the cloth feeding eccentricity and the tooth lifting eccentricity is fixed, and the time of cloth feeding eccentricity cannot be changed.

However, when sewing heavy materials, it is necessary to adjust the cloth feeding eccentric time several degrees later, otherwise there will be a situation of poor cloth feeding; obviously, the cloth feeding mechanism in the prior art cannot meet the above requirements

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