JP3039075B2 - Rotating head device and method of assembling the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head device for a VTR and a method of assembling the same, and more particularly to a technique for improving the accuracy and workability of adjusting the cylindricity of an upper drum and a lower drum. .

[0002]

2. Description of the Related Art Conventionally, as a rotary head device of this type, an upper drum and a lower drum are fixed by a drum support, and project from a gap between the two drums by about 50 to 100 .mu.m from a cylindrical surface formed by the two drums. One with a rotating video head is known. In the method of assembling the rotary head device, first, as shown in FIG. 4 (A), screw holes 1a, 1a opened in the side surface of the lower drum 1.
Then, the spacers 2 and 2 are brought into contact with each other. This spacer 2
Is a square plate having a predetermined thickness, and a hole for inserting a bolt 4 described later is formed at the center of the plate. A head rotation drive shaft 3 penetrates the lower drum 1 coaxially.

Next, as shown in FIG. 4 (B), an upper drum 6 is screwed to a substantially rectangular drum support 5 with bolts 7, and a bolt opened below the drum support 5. Bolts 4 and 4 are inserted into the insertion holes 5 a and 5 a, respectively, and the lower drum 1 and the drum support 5 are screwed through the spacer 2.

In this state, the cylindricity between the upper drum 6 and the lower drum 1 (the amount of protrusion of the upper drum outer peripheral surface with respect to the lower drum outer peripheral surface) is measured. As shown in FIG. 4C, the upper drum 6 is detached from the drum support 5, and a head assembly 9 having a video head 8 is attached to the head rotation drive shaft 3, and thereafter,
As shown in FIG. 4 (D), the upper head 6 is again
At 7 attaches to the drum support 5.

When the cylindricity does not satisfy the predetermined value, the upper drum 6, the lower drum 1, the drum support 5,
The spacers 2 and the like are all removed, spacers having different thicknesses are selected, and the above operation is repeated again to perform cylindricity to complete the assembly.

[0006]

However, in such a conventional rotary head device and its assembling method, in order to prevent the video head from being damaged by the upper drum 6 and the drum support 5, after adjusting the cylindricity, There is a problem that it is necessary to remove the upper drum 6, attach the head assembly 9, attach the upper drum 6 again, and measure the cylindricity again. At this time, if the measured value is out of the standard, the component must be removed and reattached again for retry. For this reason, there is a problem that parts are frequently damaged due to an operation error. In addition, there is a problem that the adjustment standard must be set narrower than the shipping standard in consideration of a margin that changes due to reattachment.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and a rotary head device which shortens the time required for adjusting the cylindricity and prevents parts from being damaged due to an operation error, and an assembly thereof. They want to get a way.

[0008]

According to the first aspect of the present invention, an upper drum and a lower drum are fixed by a drum support, and a video head rotatably driven is provided between the upper drum and the lower drum. In the rotary head device, a cylindricity adjustment spacer having a cutout portion extending across a screw fixing the drum and the drum support is interposed between the drum support and the drum. The solution.

According to a second aspect of the present invention, a head assembly provided with a video head is fixed to a head rotating drive shaft penetrating through the inside of the lower drum, and then a drum support is screwed to the lower drum. After the upper drum is screwed, a cylindricity adjusting spacer having a cutout portion that straddles the screw is inserted between the drum support and the drum from the side.

[0010]

[Function] Drum support and drum (upper or lower drum)
The cylindricity adjustment spacer interposed between the drum support and the drum is formed with a cutout portion that straddles a screw (male screw) for screwing the drum support and the drum, so that the drum support and the drum are assembled. However, since it can be pulled out to the side and can also be inserted from the side,
The cylindricity can be adjusted without removing the upper drum, the drum support, the lower drum, and the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of a rotary head device and a method of assembling the same according to the present invention will be described below with reference to the drawings.

FIGS. 1A, 1B, and 1C are perspective views showing each assembly process of this embodiment, FIG. 2 is a plan view of a cylindricity adjusting spacer, and FIG. 3 is a cross section of a rotary head device. FIG.

First, in this embodiment, as shown in FIG. 1 (A), a funnel portion 12a provided integrally with a head rotation drive shaft 12 provided coaxially through the lower drum 11 is provided with: The head assembly 13 on which the video head 14 is disposed is mounted by screwing the bolts 14 and 14 into the screw holes 12b.

Next, as shown in FIG. 1B, the upper drum 18 is attached to the drum support 15 using bolts 17, and the drum support 15 is attached to the lower drum 11 with bolts 1.
Attach by 6,16. The bolt 16 is screwed into a bolt hole 11 a formed in the lower drum 11 via a bolt insertion hole 15 a formed in the drum support 15. In this state, the cylindricity adjusting spacer 19 is inserted between the lower drum 11 and the drum support 15 from the side of the contact surface between the lower drum 11 and the drum support. At this time, the bolt 16 is slightly loosely fitted, and the cylindricity adjusting spacer 1 is set.
9 to facilitate insertion.

Then, the cylindricity of the upper drum 18 and the lower drum 11 is measured with the bolts 16, 16 properly tightened, and if the value is within the standard, the assembly is completed.

The cylindricity adjusting spacer 19 is formed as shown in FIG.
As shown in the figure, a U-shaped notch 16 straddling the bolt 16
b is formed, and a knob portion 19a is formed so that it can be easily held by hand when inserted from the side. For this reason, when a value out of the standard comes out in the measurement of the cylindricity, without removing the lower drum 11 and the drum support 15, only the cylindricity adjusting spacer 19 is pulled out with the knob portion 19 a and properly removed. Adjustment can be performed simply by replacing with another cylindricity adjusting spacer having a different thickness.

FIG. 3 is a sectional view of the rotary head device assembled according to the present embodiment. The lower drum 11 and the head rotation drive shaft 12 are rotatable via bearings 12 and 24, and the head rotation is performed. On the drive shaft 12 side and the lower drum 11 side, coils 21 and 22 constituting a rotary transformer are provided.
And a motor 20 for rotating and driving the head rotation drive shaft 12 is provided below the lower drum 11.

Although the embodiments have been described above, the present invention is not limited to the above embodiments, and various design changes accompanying the gist of the configuration are possible.

For example, in the above-described embodiment, the cylindricity adjusting spacer is interposed between the lower drum 11 and the drum support 15, but may be inserted between the upper drum 18 and the drum support 15. Of course.

The structure of the drive system, the structure of the head assembly and the like can of course be changed as appropriate.

[0021]

As is apparent from the above description, according to the present invention, when adjusting the cylindricity of the upper and lower drums, there is no need to attach and remove the upper drum and the drum support.
The time required for adjusting the cylindricity can be shortened, and parts can be prevented from being damaged due to a work error.

Further, since it is not necessary to remove and reattach the upper drum after adjusting the cylindricity, it is not necessary to allow for a margin for reattachment at the time of adjustment, and it is possible to widen the adjustment standard, thereby improving the accuracy of work. It has the effect of achieving improvement.

[Brief description of the drawings]

FIGS. 1A to 1C are perspective views showing an embodiment of a method of assembling a rotary head device according to the present invention.

FIG. 2 is a plan view of the cylindricity adjusting spacer according to the embodiment.

FIG. 3 is a sectional view of the rotary head device according to the embodiment.

FIGS. 4A to 4D are perspective views showing a conventional example.

[Explanation of symbols]

11: Lower drum, 12: Head rotation drive shaft, 14: Video head, 15: Drum support, 16: Bolt, 18: Upper drum, 19: Spacer for adjusting cylindricity, 19a: Notch.

Claims (2)

(57) [Claims] 1. A rotary head device in which an upper drum and a lower drum are fixed by a drum support, and a video head driven to rotate between the upper drum and the lower drum is provided. A rotary head device, wherein a cylindricity adjusting spacer having a cutout portion formed across a screw for fixing the drum and the drum support is interposed therebetween. 2. A head assembly provided with a video head is fixed to a head rotation drive shaft penetrating through a lower drum,
Then, the drum support is screwed to the lower drum, and the upper drum is screwed to the upper portion of the drum support. Then, a cylindricity adjustment spacer having a cutout portion that straddles the screw is provided between the drum support and the drum. A method of assembling a rotary head device, wherein the rotary head device is inserted from the side.