JPH0230733Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a backlash reduction device for a recording paper drive gear in which a driven wheel for rotating recording paper is driven by a main drive wheel via an intermediate wheel.

The recording paper drive gear mentioned above is used to rotate the recording paper at a speed different from that of the main drive wheel, and the intermediate wheel is used to rotate the driven wheel in the same direction as the main drive wheel. When the center position of the car is stationary, the effects of backlash at two points of engagement, the engagement between the main driving wheel and the intermediate wheel, and the engagement between the intermediate wheel and the driven wheel, are added together to record how the driven vehicle moves forward. This creates a gap in the paper in the forward direction, and as a result, when installing the recording paper, it is necessary to press the recording pen in the backward direction in order to align the position of the recording pen with the current time scale line on the recording paper. The recording paper advances by the amount of play due to vibrations, causing problems such as inaccurate recording.

This invention, whose front view and developed view are shown in FIGS. 1 and 2, respectively, is a conventionally known device for reducing the backlash of recording paper drive gears that reduces the play and alleviates such problems. Similarly to the embodiment, in a recording clock, a main drive wheel 2 is fixed to a mainspring shaft 1 that rotates as time progresses, and an intermediate wheel 5 is formed by fixing two gears 3 and 4 concentrically to each other.
The driven wheel 6 is driven in a decelerating manner and in the same direction as the main driving wheel 2, and a disc-shaped recording paper is removably attached to a paper scissor 8 fixed to one end of a driven shaft 7 to which the driven wheel 6 is fixed. There is a backlash reduction device which is provided with a biasing means 9 for biasing the intermediate wheel 5 in a direction in which its center approaches a straight line connecting the centers of the main drive vehicle 2 and the driven vehicle 6.

In this example, the intermediate wheel 5 is rotatably attached to an intermediate axle 12 fixed to the front end of a lever 11 fixed to a lever shaft 10 that is rotatable around a straight line parallel to its center line. is energized in the aforementioned direction by the energizing means 9.

In this way, due to the action of the biasing means 9,
There is no backlash in the meshing relationship of at least one of the gear 3 of the main drive wheel 2 and the intermediate wheel 5, or the gear 4 of the intermediate wheel 5 and the driven wheel 6, and the backlash in the meshing relationship of the other can be made very small. .

However, the force of the energizing means 9 is generally set to the minimum amount required to reduce the backlash in order to reduce the frictional resistance caused by sliding between the tooth surfaces. A sudden clockwise rotation of shaft 1 (counterclockwise rotation in Figure 1) or a sudden counterclockwise rotation of paper scissors 8 (first rotation)
(clockwise rotation in the figure), vibration, or impact, the lever 11 is displaced against the biasing means 9, and the intermediate wheel 5 and the main drive wheel 2 or the driven wheel 6 are disengaged, resulting in a state of engagement. There were disadvantages in that the tips of the teeth would press against each other and become deformed before returning to the original position, and the orientation of the recording paper could become erroneous after returning.

In order to eliminate this drawback, this invention provides a restraining means 13 that limits the displacement of the intermediate wheel 5 in the direction against the urging means 9 to such an extent that neither the main driving wheel 2 nor the driven wheel 6 disengages from the meshing state. This is a backup reduction device characterized by the following.

In the embodiment shown in FIGS. 1 and 2, the intermediate axle 12 is moved against the base plate 14 when the intermediate axle 12 is displaced in the direction against the biasing means 9.
The restraining means 13 is configured so as to come into contact with the inner surface of the through hole 15 provided in the.

As a result, the main drive wheel 2, intermediate wheel 5, and driven vehicle Since the meshing state of No. 6 is maintained, the above-mentioned drawback has been solved.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of this invention, and FIG. 2 is a developed view taken along the line A--A in FIG. 2... Main drive vehicle, 5... Intermediate vehicle, 6... Driven vehicle,
9... Enforcement means, 13... Restraining means.

Claims (1)

[Scope of utility model registration request] In a recording paper drive gear in which a driven wheel 6 that advances the recording paper is driven by the main drive wheel 2 via an intermediate wheel 5, the center of the intermediate wheel 5 is aligned with a straight line connecting the centers of the main drive wheel 2 and the driven wheel 6. This is a backlash reduction device that is provided with a biasing means 9 that biases in a direction toward which the intermediate wheel 5 engages with both the main drive vehicle 2 and the driven vehicle 6 to prevent displacement of the intermediate wheel 5 in a direction opposed to the biasing device 9. A device for reducing the backlash of a recording paper drive gear, characterized in that it is provided with a restraining means 13 for preventing the state from escaping.