JPH117675A - Vtr cylinder base attaching structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a VTR cylinder base attaching structure capable of properly fixing a cylinder base to a bent and deformed chassis and preventing a reproduced image from being disturbed by keeping the fixed position traveling of a magnetic tape. SOLUTION: This structure is made in such a manner that a plurality of leg parts 8, 9 and 10 are integrally formed to be protruded from the bottom surface 1c of a cylinder base 1 and have nearly equal mutual intervals, the lower surfaces 8a to 10a of the leg parts 8 to 10 are abutt on the upper surface 3a of a chassis 3, attaching screws are inserted into screw insertion holes penetrating the upper surface of the cylinder base 1 to the leg parts 8 to 10, fitted into the screw holes of the chassis 3 side and then the cylinder base 1 is fixed to the chassis 3. In this case, the lower surfaces 8a to 10a of the leg parts 8 to 10 are formed on a slope where an outer peripheral edge side located in a diameter outside direction with respect to the center M of the holding part 1d of a cylinder 2 is highest and an outer peripheral edge side of a diameter inner direction is lowest.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder base mounted on a chassis of a video tape recorder and rotatably holding a cylinder, and more particularly to a VTR capable of properly fixing a cylinder base without affecting the deformation of the chassis. The present invention relates to a cylinder base mounting structure.

[0002]

2. Description of the Related Art A cylinder constituting a traveling system of a VTR (Video Tape Recorder) is rotatably held by a cylinder base. In a helical scan type rotary cylinder 2 shown in FIG. It is held inclined. The cylinder base 20 is formed in an annular shape, and its opening 20a and upper side 20b are cylinder holding portions 20d, and three screw holes are provided at equal intervals on the inner peripheral edge. A pair of left and right overhangs 25 and 26 and an unillustrated extension are integrally formed on the outer peripheral edge of the cylinder base 20 so as to protrude radially outward from the cylinder holding portion 20d. I have. As shown in FIG. 11, the lower surfaces 28a, 29a are integrally formed with flat legs 28, 29 on the bottom surfaces of the left and right overhanging portions 25, 26 and the extending portion. Screw insertion hole 28
b and 29b are respectively formed. The chassis 3 has an accommodation hole 3b near the corner, and the accommodation hole 3b is formed.
b, the screw insertion holes 2 of the legs 28 and 29
Screw holes 3d are provided corresponding to 8b and 29b.

When assembling the cylinder base,
With the lower side of the cylinder 2 shown in FIG. 10 covered by the lead member 4, the cylinder motor side (not shown) is arranged in the cylinder holding portion 20 d, and the mounting screws are moved from the screw insertion holes on the cylinder 2 side to the screw holes on the cylinder base 20. The screw is inserted to fix the cylinder motor and the lead member 4 to the cylinder base 20. Thereafter, the lower side of the cylinder holding portion 20d is inserted into the housing hole 3b of the chassis 3, and the mounting screw 16 is screwed into the screw hole 3d from the screw insertion holes 28b and 29b as shown in FIGS. Thereby, the cylinder base 20 is firmly fixed to the chassis 3. Thereby, while the cylinder 2 is held rotatably, the lead member 4 is held with a small gap between itself and the cylinder 2. Since the upper end edge 4a of the lead member 4 is below the magnetic head of the upper drum and a step 4b is formed between the lead member 4 and the outer peripheral surface of the lower drum, the magnetic tape is fixed along the outer peripheral surface 2d of the cylinder 2. It can be run in position.

[0004]

By the way, in the chassis 3, since the side wall 3c hangs down from the peripheral edge and the accommodation hole 3b is opened near the corner, the strength around the accommodation hole 3b is reduced. For this reason, an upwardly curved chassis 3 that is difficult to maintain a deviated plane is often manufactured. As shown in FIG. 11, even if such a curved deformation is on the order of several tens of microns with respect to the deviated plane, a cross section that crosses between the legs 28, 29 of the overhangs 25, 26 of the cylinder base 20 is formed. , The chassis 3 is bent upward with respect to the linear reference line A shown by the dashed line. If the chassis 3 is slightly bent, when the cylinder base 20 is placed on the chassis 3, the outer peripheral edges 28c, 29c on the lower surfaces 28a, 29a of the flat legs 28, 29 are higher than the upper surface 3a of the chassis 3. It will be in a slightly floating state. If the mounting screw 16 is strongly tightened in this state, the chassis 3
Since the lower surfaces 28a, 29a of the legs 28, 29 are in close contact with the upper surface 3a, the cylinder base 20 is bent along the curved shape of the chassis 3. Then, the cylinder base 20 after being fixed becomes a one-dot chain line B as shown by a two-dot chain line C in FIG.
Is deformed upward with respect to the cylinder base 20 before fixing shown in FIG. As described above, when the cylinder base 20 is slightly deformed in a curved manner, the entire lead member 4 fixed to the cylinder holding portion 20d is also distorted and deformed. When the whole is deformed, the step portion 4b formed between the upper end edge 4a of the lead member 4 and the outer peripheral surface 2d of the cylinder 2 is also distorted, so that when the magnetic tape runs along the outer peripheral surface 2d of the cylinder 2, the constant The position running is not maintained, and a state of waving up and down occurs. Even if the undulation phenomenon is extremely small, the magnetic tape is displaced from the magnetic head, so that accurate tracing is not performed and a reproduced image is disturbed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and enables a cylinder base to be properly fixed to a curved chassis, and a reproduced image is disturbed while maintaining a fixed position of a magnetic tape. It is an object of the present invention to provide a VTR cylinder base mounting structure that does not cause any problems.

[0006]

In order to achieve the above object, according to the present invention, a substantially cylindrical cylinder is rotatably held on an upper side and extends along an outer peripheral surface of the cylinder. A plurality of legs projecting from the bottom surface of the cylinder base and having substantially equal intervals are integrally formed on the outer peripheral edge of the cylinder base to which a lead member forming a step portion for moving the magnetic tape at a fixed position is attached. The lower surface of the part is in contact with the upper surface of the chassis, the mounting screw is inserted from the upper surface of the cylinder base into the screw insertion hole that passes through each leg, and is screwed into each screw hole on the chassis side to attach the cylinder base to the chassis. In the cylinder base mounting structure of the VTR to be fixed, the lower surface of each leg portion is the highest on the outer peripheral side that is radially outward with respect to the center of the holding portion of the cylinder, and the radially outer peripheral side It is characterized in that the side is formed in the lowest inclined surface. The present invention described in claim 2 is characterized in that the cylinder in the structure of claim 1 is a helical scan type rotary drum, which is held inclined at the upper side of the cylinder base. The present invention described in claim 3 is characterized in that the leg portion described in claim 1 or 2 is integrally formed at three locations on the outer peripheral edge of the cylinder base.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a cylinder base of a VTR according to the present invention, FIG. 2 is a plan view showing the cylinder base, and FIG. 3 is a rear view showing the cylinder base. The cylinder base mounting structure of the VTR will be described for a case where a cylinder base 1 for rotatably holding a helical scan type cylinder 2 is mounted on a chassis 3. The cylinder base 1 is substantially annular and made of a metal material, and the inner wall of the opening 1a is inclined at a required angle. The opening 1a and the upper side 1b constitute a cylinder holder 1d for holding the cylinder 2 at an angle. In the vicinity of the inner peripheral edge of the opening 1a, screw holes 1e inclined in the same direction as the opening 1a are provided at three places at equal intervals. Also, on the outer peripheral edge of the cylinder base 1,
As shown in FIG. 2, the cylinder holding portion 1 at the center of the opening 1a
A pair of left and right protruding portions 5, 6 and an extending portion 7 are integrally formed so as to protrude radially outward from the center M of d. Then, as shown in FIG. 3, legs 8, 9, and 10 are integrally formed on the bottom surface 1c of the left and right overhang portions 5, 6 and the extension portion 7 so as to abut on the upper surface 3a of the chassis 3. It protrudes. The three legs 8 to 10 have substantially the same distance from each other, and the lower surfaces 8a to 10a are inclined, and screw insertion holes 8b to 10b are formed in the center.

The lower surfaces 8a to 10a of the legs 8 to 10 will be described with respect to the left and right overhanging portions 5 and 6, respectively. The IV portion in FIG. 1 is shown in FIG. 4 and the V portion in FIG. Outer peripheral edges 8c, 9c which are radially outward with respect to the center M of the cylinder holding portion 1d.
Side is the highest, and the outer peripheral edges 8d and 9d in the radially inner direction are the lowest inclined surfaces. These inclined surfaces 8a and 9a have an inclination angle θ with respect to the straight reference line A. When the legs 8 to 10 abut against the upper surface 3a of the curved chassis 3 and are screwed, the cylinder base 1 Can be prevented from being bent. Further, although not shown, the lower surface 10a of the leg 10 on the side of the extension 7 is also formed as an inclined surface having the same inclination angle θ. In addition, catching parts 11 and 12 are formed in both overhang parts 5 and 6, and one ends of left and right arms 13 and 14 are attached as shown in FIG. The other ends of the arms 13 and 14 extend toward the moving guide 15. The chassis 3 is a metal plate, and has a side wall 3c extending downward from a peripheral edge. The chassis 3 has an accommodation hole 3b for accommodating the cylinder holding portion 1d near a corner. Further, screw insertion holes 8 of the legs 8 to 10 are provided near the periphery of the accommodation hole 3b.
Three screw holes are provided corresponding to b to 10b. By the way, this chassis 3 hangs down the side wall 3c from the peripheral edge,
Since the accommodation hole 3b is opened near the corner, the strength around the accommodation hole 3b is reduced even if it is made of metal. For this reason, the manufactured chassis 3 is generally curved upward by several tens of microns. When this chassis 3 is shown in a cross section that crosses between the two leg portions 8 and 9 of the cylinder base 1 as shown in FIG. . In the cylinder base 1, the annular portion is indicated by a dashed-dotted line B, and the left and right extending portions 5, 6 are shown in cross section.

When assembling the cylinder base,
First, as shown in FIG. 8 and FIG.
d holds a cylinder 2 composed of an upper drum 2a and a lower drum 2b. At this time, the lead member 4 covers the outer periphery of the lower drum 2b, and the cylinder motor 2c mounted on the lower drum 2b is disposed in the cylinder holder 1d. Then, a mounting screw is inserted through a screw insertion hole formed on the cylinder 2 side, and a screw hole 1e of the cylinder base 1 is formed.
To fix the cylinder motor 2 c and the lead member 4 to the cylinder base 1. Thereafter, the lower side of the cylinder holding portion 1d is housed in the housing hole 3b of the chassis 3, and the screw insertion holes 8b and 9 are inserted into the screw holes 3d as shown in FIG.
b, the cylinder base 1 is placed on the upper surface 3a of the chassis 3. Then, as shown in FIG. 7, the cylinder base 1 is fixed to the chassis 3 by inserting the mounting screw 16 from the screw insertion holes 8 b and 9 b and screwing the leading end screw portion into the screw hole 3 d. At this time, even if the chassis 3 is curved upward as described above, since the lower surfaces 8a to 10a of all the legs 8 to 10 are inclined surfaces, the cylinder base 1 has the lower surfaces 8a to 8a as shown in FIG. 10 a follows the curved shape of the chassis 3. That is, since the chassis 3 is bent upward, the upper surface 3a has a tapered surface that is higher on the accommodation hole 3b side and lower on the peripheral edge side. On the other hand, the lower surfaces 8a to 10a of the legs 8 to 10
The outer peripheral edges 8c and 9c, which are radially outward with respect to the center of the cylinder holding portion 1d accommodated in b, are the highest and the radially outer peripheral edges 8d and 9d are the lowest inclined surfaces.

Therefore, since the inclination angles of the two 3a and 8a to 10a are substantially equal, the mounting screw 16 is
b-10b, and screwed into the screw hole 3d and tightened tightly, the upper surface 3a of the chassis 3 has the lower surface 8a of the legs 8-10.
The cylinder base 1 is firmly fixed to the chassis 3. As a result, the cylinder base 1 after the fixing is not deformed, and the same shape as the cylinder base 1 before the fixing shown by the one-dot chain line B in FIG. 6 is maintained, and as shown in the one-dot chain line B in FIG. Linear one-dot chain line A indicating a plane
And become parallel. As described above, when the cylinder base 1 is fixed without being curvedly deformed as in the related art, the lead member 4 fixed to the cylinder holding portion 1d is not deformed and deformed as shown in FIGS. Upper edge 4 of member 4
Also, no distortion occurs in the step portion 4b formed between the a and the outer peripheral surface 2d of the cylinder 2. For this reason, when the magnetic tape travels along the outer peripheral surface 2d of the cylinder 2, the home position travel is maintained and the vertical waving phenomenon is avoided. Accordingly, accurate tracing is performed without the magnetic tape being displaced from the magnetic head 2e, and a reproduced image without disturbance is obtained. In the above embodiment, the case where the helical scan type rotary cylinder 2 is held on the cylinder base 1 has been described. However, the same operation and effect can be obtained when a type of rotary cylinder other than the helical scan type is attached. Can be The left and right overhangs 5, 6 and the extension 7 are integrally formed on the cylinder base 1, and three legs 8 to 10 are provided on the lower surface thereof. When two or more chassis are provided, it is needless to say that the influence of the deformed chassis can be avoided by inclining the lower surface.

[0011]

As described above, according to the first aspect of the present invention, the lower surface of each of the plurality of legs abutting on the upper surface of the chassis is formed as an inclined surface. When fixing the cylinder base with the mounting screw, tightening with the mounting screw causes the inclined surface to be evenly along the curved surface, so that the cylinder base is properly fixed without bending. Therefore, no distortion occurs in the step formed between the outer peripheral surface of the cylinder and the upper end edge of the lead member, so that the magnetic tape travels at a fixed position along the outer peripheral surface of the cylinder and does not deviate from the magnetic head. In addition, there is an effect that the problem that the reproduced image is disturbed is solved. According to the second aspect of the present invention, the helical scan type cylinder is inclined and held on the upper side of the cylinder base, but the fixed position traveling of the magnetic tape traveling along the outer peripheral surface of the cylinder is maintained. Therefore, there is an effect that a trouble such as a disorder in a reproduced image does not occur. According to the third aspect of the present invention, since the legs are integrally formed at three locations on the outer peripheral edge of the cylinder base at substantially equal intervals, the cylinder base is fixed to the chassis in which the cylinder base is bent by mounting screws. In this case, uniform tightening is performed around the holding portion of the cylinder, and there is an advantage that the cylinder base can be properly mounted and fixed without being affected by deformation of the cylinder.

[Brief description of the drawings]

FIG. 1 is a side view showing a cylinder base of a VTR according to an embodiment of the present invention.

FIG. 2 is a plan view showing the cylinder base.

FIG. 3 is a rear view showing the cylinder base.

FIG. 4 is an explanatory view showing a leg portion obtained by enlarging an IV portion of FIG. 1;

FIG. 5 is an explanatory view showing a leg portion obtained by enlarging a V portion in FIG. 1;

FIG. 6 is an explanatory view showing a chassis and a cylinder base before fixing.

FIG. 7 is an explanatory view showing the chassis and the cylinder base after being fixed.

FIG. 8 is a side view showing a state where the cylinder is held on the cylinder base.

FIG. 9 is a plan view showing a state where the cylinder is held on the cylinder base.

FIG. 10 is a side view showing a cylinder base of a conventional VTR.

FIG. 11 is an explanatory view showing a chassis and a cylinder base before the fixing.

FIG. 12 is an explanatory view showing the chassis and the cylinder base after the fixing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder base 1b Upper side 1c Bottom 1d Holding part 2 Cylinder 2d Outer peripheral surface 3 Chassis 3d Screw hole 4 Lead member 4b Stepped part 8-10 Leg 8a-10a Lower surface 8c Outer peripheral edge side 8d Radial outer periphery Edge 16 Mounting screw

Claims (3)

[Claims] 1. A cylinder base to which a substantially cylindrical cylinder is rotatably held on an upper side and to which a lead member forming a step for moving a magnetic tape at a fixed position along an outer peripheral surface of the cylinder is attached. A plurality of legs protruding from the bottom surface of the cylinder base and having substantially equal intervals are integrally formed on the outer peripheral edge, and the lower surface of each leg abuts against the upper surface of the chassis, so that each leg portion extends from the upper surface of the cylinder base. In a VTR cylinder base mounting structure for fixing a cylinder base to a chassis by inserting a mounting screw into a screw insertion hole that penetrates the cylinder and screwing the screw into each screw hole on the chassis side, A VTR syringe characterized in that the outer peripheral side, which is radially outward with respect to the center of the holding portion, is formed on the highest inclined surface, and the outer peripheral side in the radially inner direction is formed on the lowest inclined surface. Base mounting structure. 2. The VT according to claim 1, wherein the cylinder is a helical scan type rotary drum, and is held at an upper portion of a cylinder base in an inclined manner.
R cylinder base mounting structure. 3. The VTR cylinder base mounting structure according to claim 1, wherein the leg portions are integrally formed at three positions on an outer peripheral edge of the cylinder base.