GB2308756A - Earthing ring for head drum shaft - Google Patents
Earthing ring for head drum shaft Download PDFInfo
- Publication number
- GB2308756A GB2308756A GB9627039A GB9627039A GB2308756A GB 2308756 A GB2308756 A GB 2308756A GB 9627039 A GB9627039 A GB 9627039A GB 9627039 A GB9627039 A GB 9627039A GB 2308756 A GB2308756 A GB 2308756A
- Authority
- GB
- United Kingdom
- Prior art keywords
- head drum
- earth
- rotating shaft
- discharging device
- ring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05F—STATIC ELECTRICITY; NATURALLY-OCCURRING ELECTRICITY
- H05F3/00—Carrying-off electrostatic charges
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Recording Or Reproducing By Magnetic Means (AREA)
- Elimination Of Static Electricity (AREA)
- Accessory Devices And Overall Control Thereof (AREA)
Description
DISCHARGING DEVICE FOR A HEAD DRUM
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a discharging device for a head drum employed into a video cassette recorder (VCR), and more particularly to a discharging device for a head drum for discharging static electricity generated from the head drum to a base.
2. Description of the Prior Art
In a general VCR, a head reproduces signals recorded on a magnetic tape or records signals on the magnetic tape while the magnetic tape is closely attached to the outer circumference of the head drum. But, since the magnetic tape travels under the state of contacting the outer circumference of the head drum, static elasticity is generated between the surfaces of the head drum and magnetic tape. Such static elasticity impedes smooth travelling of the magnetic tape and adversely affects the playback or recording of the signals.
FIG. 1 illustrates a partial view in perspective of a conventional VCR installed with a discharging device for a head drum. As shown in FIG. 1, the discharging apparatus is installed around head drum 19 onto a main chassis 10 of the
VCR.
Head drum 19 is rotatable about a rotating shaft 18, and one end of a copper plate 17 is in contact with the upper end of rotating shaft 18. The other end of copper plate 17 is fixed to one end of a bracket 15, and the other end of bracket 15 is fixed to a drum base 12 by means of a screw 14. Drum base 12 is fixed onto main chassis 10.
FIG. 2 shows a partially enlarged view in perspective of the discharging apparatus shown in FIG. 1. As shown in FIG. 2, a graphite rod 13 is fixed to the tail end of copper plate 17.
The other end of copper plate 17 is fixed to bracket 15 by means of a rivet 16. A rubber 9 having elasticity is adhered to one side of copper plate 17.
The discharging device for the conventional head drum constructed as above is operated as below.
Once head drum 19 is rotated, the static electricity is generated between a magnetic tape (not shown) and head drum 19.
The static electricity is transmitted to bracket 15 via graphite rod 13 and copper plate 17. Then, the static electricity is delivered to drum base 12 and main chassis 10 to be emitted.
The discharging device for the conventional head drum constructed as above should be provided with the expensive graphite rod, and the operation of fixing the graphite rod to the copper plate is difficult to have drawbacks that the workability is lowered and the manufacturing cost is raised.
Furthermore, the graphite rod is closely attached to the rotating shaft by the elasticity of the rubber and copper plate to make the contacting status be inferior in case that the copper plate is deformed. The inferior contacting status results in a disadvantage of degrading the discharging effect of the head drum.
SUMMARY OF THE INVENTION
Therefore, the present invention is devised to solve the foregoing problems. It is an object of the present invention to provide a discharging device for a head drum for effectively emitting static electricity generated from the head drum by means of the discharging apparatus having a simple structure.
To achieve the above object of the present invention, there is provided a discharging device for a head drum including a head drum member installed for being rotatable about a rotating shaft onto a main chassis. Also, an earth ring forms earth plates which are inserted with the rotating shaft while maintaining a predetermined distance from the outer circumference of the rotating shaft and are partially cut for being inwardly curved to be in contact with the rotating shaft.
Preferably, the earth plates are elastically and closely attached to the rotating shaft. More preferably, the earth plates are provided by cutting the earth ring in the circumferential direction thereof. It is a characteristic that the earth plate is formed along the circumference of the earth ring by numbering three at equal distances.
It is preferable that the earth plate are provided by cutting the earth ring in the axial direction thereof, and the earth plates are formed along the circumference of the earth ring by numbering three at equal distances.
The discharging device for the head drum constructed as above is operated as below.
When the head drum is rotated, the static electricity is generated between a magnetic tape and the head drum. The static electricity is transmitted to the main chassis via the earth plate and earth ring to be emitted.
Consequently, the discharging device for the head drum according to the present invention can be quickly assembled with a single part without requiring a separate rivet operation to lower manufacturing cost and to enhance productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and other advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a partial view in perspective of a VCR installed with a discharging device for a conventional head drum;
FIG. 2 is a partially enlarged view in perspective of the discharging apparatus shown in FIG. 1;
FIG. 3 is a sectional view showing a discharging device for a head drum according to the present invention;
FIG. 4 is a perspective view of the horizontal earth ring according to a first embodiment of the discharging apparatus shown in FIG. 3; and
FIG. 5 is a perspective view of the vertical earth ring according to a second embodiment of the discharging apparatus shown in FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A discharging device for a head drum according to the present invention will be described in detail with reference to the preferred embodiments shown in accompanying drawings.
FIG. 3 is a sectional view showing the discharging device for the head drum according to the present invention. As shown in FIG. 3, a head drum member 20 is assembled onto a main chassis 33.
Head drum member 20 is formed by a fixedly-installed lower drum 24 and a rotatably-installed upper drum 22. A head 25 is installed between upper drum 22 and lower drum 24.
A rotating shaft 30 is installed to pierce through head drum member 20. An upper ball bearing 27 and a lower ball bearing 29 have shaft washers which are press-fitted with rotating shaft 30. An upper pre-load boss 32 and a lower preload boss 34 are respectively installed to both ends of upper ball bearing 27 and lower ball bearing 29, thereby permitting upper drum 22 to rotate without being shaken.
An earth ring 40 is installed between upper ball bearing 27 and lower ball bearing 29 while being elastically and closely attached to rotating shaft 30.
FIG. 4 is a perspective view of horizontal earth ring 40 according to a first embodiment of the discharging apparatus shown in FIG. 3. As shown in FIG. 4, horizontal earth ring 40 is a single part formed in a body.
An earth plate 42 is provided such that the circumference of horizontal earth ring 40 is partially cut in the circumferential direction for being inwardly curved to be in contact with rotating shaft 30. A free end portion of earth plate 42 is elastically and closely attached to rotating shaft 30. Respective earth plates 42a, 42b and 42c numbering three are formed along the circumference of horizontal earth ring 40 at equal distances.
FIG. 5 is a perspective view of vertical earth ring 50 according to a second embodiment of the discharging apparatus shown in FIG. 3. As shown in FIG. 5, vertical earth ring 50 is a single part formed in a body.
An earth plate 52 is provided such that the circumference of vertical earth ring 50 is partially cut in the axial direction for being inwardly curved to be in contact with rotating shaft 30. A free end portion of earth plate 52 is elastically and closely attached to rotating shaft 30.
Respective earth plates 52a, 52b and 52c numbering three are formed along the circumference of vertical earth ring 50 at equal distances.
The operation and effect of the discharging device for the head drum according to the first embodiment of the present invention will now be described.
When upper drum 22 of head drum member 20 is rotated, the static electricity is generated between a magnetic tape (not shown) and upper drum 22. The generated static electricity is transmitted to lower drum 24 via rotating shaft 30. The static electricity transmitted to lower drum 24 is delivered to main chassis 33 to be emitted.
Because of being inwardly curved, respective earth plates 42a, 42b and 42c are closely attached to the surface of rotating shaft 30 to be able to allow the static electricity to pass through. Consequently, horizontal earth ring 40 is fabricated by a metal substance capable of permitting the static electricity to pass through.
The assembling of horizontal earth ring 40 is completed by widening a space among respective earth plates 42a, 42b and 42c and then inserting rotating shaft 30 into the space.
The operation and effect of the discharging device for the head drum according to the second embodiment of the present invention will now be described.
When upper drum 22 of head drum member 20 is rotated, the static electricity is generated between the magnetic tape and upper drum 22. The generated static electricity is transmitted to lower drum 24 via rotating shaft 30. The static electricity transmitted to lower drum 24 is delivered to main chassis 33 to be emitted.
Because of being inwardly curved, respective earth plates 52a, 52b and 52c are closely attached to the surface of rotating shaft 30 to be able to allow the static electricity to pass through. Consequently, vertical earth ring 50 is fabricated by a metal substance capable of permitting the static electricity to pass through.
The assembling of vertical earth ring 50 is completed by widening a space among respective earth plates 52a, 52b and 52c and then inserting rotating shaft 30 into the space.
Therefore, the discharging device for the head drum according to the present invention can be quickly assembled since it does not require a separate riveting operation or adhering operation when assembling the discharging apparatus.
Also, the static electricity is swiftly discharged, so that the static electricity does not adversely affect the playback/recording of signals.
While the present invention has been particularly shown and described with reference to particular embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be effected therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (6)
1. A discharging device for a head drum comprising:
a head drum member installed for being rotatable about a rotating shaft onto a main chassis; and
an earth ring for forming earth plates which are inserted with said rotating shaft while maintaining a predetermined distance from the outer circumference of said rotating shaft, and are partially cut for being inwardly curved to be in contact with said rotating shaft.
2. The discharging device for a head drum as claimed in claim 1, wherein said earth plates are elastically and closely attached to said rotating shaft.
3. The discharging device for a head drum as claimed in claim 2, wherein said earth plates are provided by cutting said earth ring in the circumferential direction thereof.
4. The discharging device for a head drum as claimed in claim 3, wherein said earth plate is formed along the circumference of said earth ring by numbering three at equal distances.
5. The discharging device for a head drum as claimed in claim 2, wherein said earth plate are provided by cutting said earth ring in the axial direction thereof.
6. The discharging device for a head drum as claimed in claim 5, wherein said earth plates are formed along the circumference of said earth ring by numbering three at equal distances.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019950062757A KR100211876B1 (en) | 1995-12-29 | 1995-12-29 | Earthing structure of head drum assembly |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9627039D0 GB9627039D0 (en) | 1997-02-19 |
| GB2308756A true GB2308756A (en) | 1997-07-02 |
Family
ID=19446336
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9627039A Withdrawn GB2308756A (en) | 1995-12-29 | 1996-12-30 | Earthing ring for head drum shaft |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPH09204601A (en) |
| KR (1) | KR100211876B1 (en) |
| GB (1) | GB2308756A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB768797A (en) * | 1954-06-01 | 1957-02-20 | Coq Nv | Improvements in and relating to contact arrangements of electric switches |
| GB1544960A (en) * | 1975-04-30 | 1979-04-25 | Matsushita Electric Works Ltd | Electrical device having rotary current connecting means |
| GB2128420A (en) * | 1982-10-06 | 1984-04-26 | Sharp Kk | Rotatable socket for plug of microwave oven temperature probe |
-
1995
- 1995-12-29 KR KR1019950062757A patent/KR100211876B1/en not_active IP Right Cessation
-
1996
- 1996-12-27 JP JP8350721A patent/JPH09204601A/en active Pending
- 1996-12-30 GB GB9627039A patent/GB2308756A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB768797A (en) * | 1954-06-01 | 1957-02-20 | Coq Nv | Improvements in and relating to contact arrangements of electric switches |
| GB1544960A (en) * | 1975-04-30 | 1979-04-25 | Matsushita Electric Works Ltd | Electrical device having rotary current connecting means |
| GB2128420A (en) * | 1982-10-06 | 1984-04-26 | Sharp Kk | Rotatable socket for plug of microwave oven temperature probe |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9627039D0 (en) | 1997-02-19 |
| KR970050199A (en) | 1997-07-29 |
| KR100211876B1 (en) | 1999-08-02 |
| JPH09204601A (en) | 1997-08-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |