Cabinet structure for a magnetic tape recorder

Abstract: Disclosed is a cabinet structure for a magnetic tape recorder having a rear-and-bottom structure (4 and 3) to which a deck (2) of the magnetic tape recorder is to be fixed. At least selected part or parts or the whole of the rear-and-bottom structure (4 and 3) are of a sheet of metal capable of providing a shielding effect.

Description: The present invention relates to a cabinet structure for a magnetic tape recorder, and particularly to such a cabinet structure capable of providing a shielding effect. The magnetic tape recorder is sensitive to exterior noise signals of high-frequency, such as electromagnetic wave produced by radio sets or hair dryers used in the vicinity of the magnetic tape recorder, allowing noise signals to appear in the pictures and sound reproduced on the screen. The cylinder unit installed in the deck of the magnetic tape recorder is very sensitive to such noise signals no matter how weak they may be in strength, causing a disturbance in reproduced pictures and sound. To prevent such a disturbance the cylinder unit is equipped with a shield plate. Fig.4 shows a conventional deck structure having a cylinder unit and surrounding electronics and electric parts enclosed with a relatively large shield plate "a". Fig.5 shows another conventional deck structure in which: a shield plate "b" is put behind a cylinder unit "c"; and another shield plate "d" is placed to protect some parts other than the cylinder unit. In both of such conventional deck structures the cylinder unit is located so remote from the rear plate of the cabinet that noise signals can hardly reach the cylinder unit. Incidentally the deck of the magnetic tape recorder is grounded to the cabinet, which makes up one part of the electronic circuit. To make sure of the grounding it is necessary that the deck be connected to the cabinet with metal or springs. This requires an extra work. The PCT publication WO 99/12161 relates to a device for reading, writing and storing data in a magnetic medium. The data storage device is preferably mounted inside a housing unit that seals out contaminants and shields the magnetic tape from electro-magnetic interference. The IBM Technical Disclosure Bulletin, vol. 32, no. 8b, 1990 pages 264-265 relates to a method of bonding metal assembly cases within metal housings designed to accept them to restrict the emission of electrical interference from the assemblies. Bonding clips which also serve the purpose of centralizing assemblies within their housings have been manufactured and implemented. The US-A-5,612,837 relates to a magnetic tape drive for reading and writing data on magnetic tapes wherein the drive has a one-piece molded chassis. The chassis is suspended at three points in a pan. At each point an interference fit between a planar mounting member on the chassis and a slot in a support member in the pan provides an easy snap-in mounting for the chassis. In view of the above one object of the present invention is to provide a cabinet structure for a magnetic tape recorder, which makes it unnecessary to use extra shield plates and grounding means. To attain this object a cabinet structure for a magnetic tape recorder according to the present invention comprises the features of claim 1. Other objects and advantages of the present invention will be understood from the following description of a cabinet structure for a magnetic tape recorder according to one preferred embodiment of the present invention, which is shown in accompanying drawings. Fig.1 is a perspective view of a deck of a magnetic tape recorder and a cabinet structure according to the present invention in the form of bottom frame; Fig.2 is a perspective view of the deck having notches made in its edges; Fig.3 shows how a selected hook rising from the bottom plate is caught by the notch formed in the chassis; Fig.4 is a perspective view of a conventional deck having shield plates equipped therewith; and Fig.5 is a perspective view of another conventional deck having different shield plates equipped therewith. Fig.1 shows a bottom frame 1 constituting a cabinet according to one preferred embodiment of the present invention and a deck of a magnetic tape recorder. The bottom frame 1 is made of a sheet of metal, comprising a bottom plate 3 and a rear or back plate 4, which is bolted or welded to the bottom plate 3. The bottom frame 1 may be made by stamping out from a sheet of metal and by bending the stamped metal sheet into a rear-and-bottom structure. The stamped bottom frame 1 has a resin plate or plates press-fitted in selected openings of its rear part, although not shown in the drawing. A base plate having a plurality of electronics mounted thereon (not shown) is fixed to the bottom part of the bottom frame 1. The base plate has posts standing upright therefrom, and the deck 2 is fixed to the bottom frame 1 via such posts. Fig.2 shows one example of such deck 2. As shown in the drawing, a cylinder unit 6, reels 7 and 8, a pinch roll block 9 and other parts are mounted on the chassis of the deck 2, but no shield plates for the cylinder unit 6 and other parts are mounted thereon. The bottom frame 1 is of a sheet of metal, and the metal rear part 4 provides a shield to protect the cylinder unit and other parts against the exterior noise signals. As seen from Fig.2, the chassis 5 has notches 10 formed on its rear side. The bottom plate 3 has hooks formed thereon to be caught by the notches 10 when the bottom plate 3 is applied to the chassis 5. Fig.3 shows how a selected hook 11 in the bottom plate 3 is caught by the notch 10 in the chassis 5 of the deck. The hook 11 is stamped out of the bottom plate 3. The stamped piece is raised, and its end is bent to be oblique relative to its upright leg. As shown in the drawing, the upright leg has a square opening made therein. The chassis has a rectangular cut 10 made on its edge, thus forming a projection 14 to be inserted in the square opening 13 of the hook 11. Specifically the hook 11 is applied to the notch 10 by inserting the projection 14 in the square opening 13 of the hook 11 while making the oblique end of the hook 11 to be yieldingly bent, thereby assuring that the hook 11 be put in contact with the chassis 5. As a matter of course the bottom plate 3 can be fixed to the deck by using female nuts and male-threaded posts standing upright from the bottom plate 3. As may be understood from the above, the cabinet structure according to the present invention is a stamped rear-and-bottom metal sheet effectively preventing the cylinder unit and other electronic or electric parts installed inside from exterior noise signals, thereby assuring that no noise signals appear in the recorded and reproduced pictures and sound. The cabinet structure has hooks rising from its bottom plate, thus permitting the cabinet structure to be integrally fixed to the deck of the magnetic tape recorder by allowing the hooks to be caught by the notches. At the same time it is assured that the deck be grounded without requiring any extra deck-to-cabinet connecting means.

Claims: A cabinet structure for a magnetic tape recorder comprising a rear-and-bottom structure (4 and 3) to which a deck (2) of the magnetic tape recorder is to be fixed, at least a selected part of the rear-and-bottom structure (4 and 3) being constituted of a sheet of metal capable of providing a shielding effect, characterized in that the rear-and-bottom structure (4 and 3) comprises a bottom part (3) and hooks (11) projecting upwardly from the bottom part (3), said hooks being arranged to engage in notches (10) formed in a chassis (5) of the deck (2) of the magnetic tape recorder; and that each of said hooks (11) includes an upright portion projecting up from said bottom part (3) of said rear-and-bottom structure, and an oblique end portion (12) extending from said upright portion and bent obliquely relative to said upright portion; and that each of said hooks (11) is a resilient hook to allow said oblique end portion (12) thereof to be yieldingly and resiliently bent upon engaging in a respective one of the notches (10) formed in the chassis (5) of the deck (2) of the magnetic tape recorder, and so as to cause said hooks (11) to be reliably contacted with the chassis (5) of the deck (2) of the magnetic tape recorder and to thereby cause the deck (2) of the magnetic tape recorder to be grounded to said rear-and-bottom structure (4 and 3), and that each of said hooks (11) is constituted by a stamped-out and raising-up portion of said bottom part (3) of said rear-and-bottom structure, such that said bottom part (3) has an opening there through directly adjacent said upright portion of each of said hooks.

Inventors: SASAKI KAZUO, SASAKI, KAZUO
Applicants: ORION ELECTRIC CO LTD, ORION ELECTRIC CO., LTD.
Application year: 2001
Main classification: G11B25
IPC codes: G11B33, G11B25