JPS6040992Y2 - Upper drum removal jig - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an upper drum removal jig used when replacing the upper drum of a VTR.

In a VTR, there is a video head for recording video signals on a magnetic tape and reproducing recorded video signals, and the part that holds this video head is an upper drum.

Figures 1 and 2 show a portion of the drum motor of a VTR. 1 is the drum motor, 1a is the shaft of the drum motor, 1b is the lower drum attached to the drum motor 1, and 1c is the drum motor 1 and the lower drum. An upper drum 1b is attached above the upper drum 1b, and a video head 1d is attached to the upper drum 1c at intervals of 180 degrees and has a plurality of minute gaps.

A video head performs the functions of recording video signals on magnetic tape and reproducing video signals from magnetic tape.

The video head comes into contact with the magnetic tape each time it is recorded on or reproduced from the magnetic tape, causing wear and tear, resulting in poor images on the monitor television.

Furthermore, during recording, sufficient video signals cannot be recorded, and during playback, the above-mentioned condition occurs, so it is necessary to replace the upper drum that holds the video head.

Conventionally, in order to remove the upper drum 1c from the shaft 1a of the drum motor 1, the lower drum 1b and the upper drum 1c are removed by hand, but the fitting accuracy is high and there is no risk of scratches on the lower drum 1b or rust due to finger squeezing during removal. This is causing a problem.

This invention provides an upper drum removal jig that can easily remove the upper drum attached to the shaft of the drum motor.

This invention will be explained below with reference to FIGS. 3, 4, and 5, which are examples.

In the figure, the upper drum removal jig consists of a push rod 2 with a thread formed on its outer periphery, a handle 3 provided at one end of this push rod 2, an arm mounting piece 4 screwed onto the push rod 2, and an arm mounting piece. A pair of fixing pins 9 provided at two points symmetrical about the push rod 2 in 4, a pair of arms 8 rotatably attached via each fixing pin 9, and each arm 6 A pair of curved plates 5 are provided to face each other in a semicircular manner, a sheet 7 is attached to the inner surface of the semicircular curved plates 5, and the semicircular curved plates 5 are moved in opposite directions and opposite directions. In particular, the circular plate 5 is arranged at the tip of the arm 6, and the circular plate 5 is arranged at the tip of the arm 6.
A fixing screw 8 with a flat knob with the shaft center facing the circumferential direction is screwed between each end of the curved plate 5.A pair of flat knobs of the fixing screw 8 are screwed between each end of the curved plate 5 in the same direction in the circumferential direction. towards the direction.

The upper drum 1c is placed against the inner surface of the semicircular curved plate 6, and the fixing screws 8 of the semicircular curved plate 6 are tightened at two places to fix it.

Turn the handle 3 provided at one end of the threaded push rod 2 by hand to align the threaded tip 2a of the push rod with the shaft 1a of the drum motor, and turn the handle 3 further to tighten the shaft 1a of the drum motor. Push down.

As described above, the upper drum 1c can be easily removed without causing scratches, fingerprints, etc. on the lower drum 1b.

In particular, not only is the curved plate 5 disposed at the tip of the arm 6, but also a fixing screw 8 with a flat knob that can be directly manually operated is screwed between each end of the curved plate 5.
The fixing screw 8 is also arranged at the height of the tip of the arm 6 like the curved plate 5, and as a result, the rotational operating force of the fixing screw 8 acts as a clamping force as it is. Therefore, on the contrary, clamping can be performed quickly and with a light operating force.

Although a strong clamping force is generated here, since the curved plate 5 is semicircular and the sheet 7 is pasted, the pressure per unit area acting on the upper drum 1c is light, and the upper drum 1c is , while the entire body is strongly clamped, it is not easily damaged.

Moreover, no bending force is applied to the arm 6. Therefore, not only can the arm 6 be made of a sufficiently thin and light material, but also the clamping surface can be twisted against the surface of the upper drum 1c as the arm 6 bends. There is also the advantage that there is no risk of local contact.

Further, a fixing screw 8 of the flat knob is screwed together between each end of the circular curved plate 5, and one of the flat knobs of the fixing screw 8 is screwed together.
Since the pairs are oriented in the same direction with respect to the circumferential direction of the curved plate 5, for example, in FIG. It becomes possible to simultaneously operate the screws 8 by turning them with the right hand.

This is effective in allowing the circular plates 5, 5 to approach each other equally in parallel at the same time when clamping, and since the entire plate opens evenly when the clamp is released, the gripped upper drum 1c is not tilted and pried. prevent it from falling.

In particular, when both fixing screws 8 are operated at the same time, the torques act so as to cancel each other out when viewed from each torque direction, so that the clamp opening operation can be performed stably.

Moreover, the fixing screws 8 are directly screwed into the tongue pieces of the curved plate 5 and are oriented not only in the radial direction but also in the circumferential direction, so that the setting positions of these screws 8 are near the outer periphery of the jig. Not only is the outer diameter of the device small and compact, but the simultaneous operations described above are also easily accessible.

[Brief explanation of the drawing]

Figures 1 and 2 are a front view and a top view of a part of the drum motor, Figures 3 and 4 are a front view and a top view of the upper drum removal jig of this invention, and Figure 5 is a front view and a top view of a part of the drum motor. It is a front view showing a state of use. In the figure, 2 is a push rod, 3 is a handle, 4 is an arm attachment piece, 5 is a curved plate, 6 is an arm, 7 is a seat, 8 is a fixing screw, and 9 is a fixing pin.

Claims (1)

[Scope of utility model registration request] A push rod with a thread formed on the outer periphery, a bundle provided at one end of this push rod, an arm mounting piece that screws onto the push rod, and a bundle provided at two points on the arm mounting piece that are symmetrical about the push rod. A pair of fixing pins, a pair of arms rotatably attached via each fixing pin, a pair of curved plates provided to each arm to face each other in a semicircular shape, and a semicircular It has a sheet affixed to the inner surface of the curved plate, and fixing screws that move the semicircular curved plates in opposite directions and opposite directions, and the circular plate is placed at the tip of the arm, and Screw together a fixing screw with a flat knob with the shaft center facing the circumferential direction between each end of the curved plate, and insert a pair of the flat knobs of this fixing screw in the same direction with respect to the circumferential direction of the curved plate. An upper drum removal jig characterized by the fact that it is aimed at the upper drum.