US3788648A

US3788648A - Locking device for tone arms

Info

Publication number: US3788648A
Application number: US00208864A
Authority: US
Inventors: K Kawai
Original assignee: Pioneer Electronic Corp
Current assignee: Pioneer Corp
Priority date: 1970-12-17
Filing date: 1971-12-16
Publication date: 1974-01-29
Anticipated expiration: 1991-01-29
Also published as: JPS4934805Y1

Abstract

A locking device for a tone arm comprising a tone arm lifter and a tone arm rest. The arm lifter is arranged so that the outer end portion of the lift plate is formed with a curved hook-like portion, the outer end of which is bent inwardly. The seating plate of the arm rest is provided with a rising curved portion, at least in its inner side part. The hook-like portion of the arm lifter and the rising portion of the arm rest form an aperture having a restricted opening between the outer end of the hooklike portion and the top of the rising portion, wherein the tone arm is captively located and clamped when the arm is out-of-use.

Description

United States Patent 1 Kawai Jan. 29, 1974 LOCKING DEVICE FOR TONE ARMS Pn'mary Examiner-Louis R. Prince 7 Ka 51 Inventor Klyoshl wal Tokyo Japan Assistant Examiner-Charles E. Phlihps Assigneer Pioneer e onic Corporation, Attorney, Agent, or Firm-Sughrue, Rothweli, Mion,

Tokyo, Japan Zinn and Macpeak [22] Filed: Dec. 16, 1971 [21] Appl. No.: 208,864 [57] ABSTRACT A locking device for a tone arm comprising a tone [3()] Foreign Application Priority Data arm lifter and a tone arm rest. The arm lifter is ar- Dec. 17, 1970 Japan 45/126317 ranged 80 that the outer end Portion of the lift Plate is formed with a curved hook-like portion, the outer end 52 US. Cl 274/23 B of which is bent inwardly- The Seating plate of the arm 51 1111. c1. G1 lb 3/10 rest is Provided with a rising eurved Portion, at least in 58 Field of Search 274/23 B, 23 R its inner Side p The hook-like portion of the arm lifter and the rising portion of the arm rest form an ap- 5 References Cited erture having a restricted opening between the outer end of the hook-like portion and the tOp Of the rising portion, wherein the tone arm is captively located and 3,271,035 Johnston 274/23 R clamped when the arm is oubotluse' FOREIGN PATENTS 0R APPLICATIONS 559,312 6/1958 Canada 274 23 R 2 Clams 12 Draw PATENTEDJANEQIW 3,788,648

Q h L 3 F lGh4 R FIG. 3 PRIOR ART PRIO A T PATENTEUJANZQIBH 3. 788,648

sum 2 0f 2 FIG. 8

FIG. 7

3W FIG 9 FIG IO FIG. H FIG. l2

LOCKING DEVICE FOR TONE ARMS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a locking device for a tone arm, and more particularly to a simple and improved arrangement for locking a pick-up tone arm in its out-of-use position to prevent damage due to accidental displacement.

2. Description of the Prior Art In the prior art, automatic record changers or record player units having tone arm returning devices, the tone arm I is, as shown in FIGS. 1-3, rested only on a tone arm rest 3 by means of a lifting device 2 or socalled arm lifter or arm elevator, without locking or damping, so that the arm 1 is in unstable condition and in danger of unexpected falling off the arm rest 3 and subject to damage. There have been proposed and practiced various kinds of locking devices, wherein some of them are electrically operated, which are unduly complex to get out of order and are also expensive. Others are, as shown in FIG. 4, manually manipulated to maintain the arm 1 in engagement with the arm rest 3 by means of an arm clamper 3'. These types of locking devices are, however, not suitable to an automatic record changer and are liable to remain inadvertently unlocked.

SUMMARY OF THE INVENTION In order to eliminate such limitations and disadvantages of the conventional devices, the present invention has an object to provide a simple and effective locking device without any additional parts, wherein the tone arm may be locked or unlocked on the arm rest only by manipulating the arm lifter without need of any other particular operation for locking the same.

In accordance with the present invention, there is provided a tone arm lifter and a tone arm rest. The arm lifter has a lifting plate and the outer end portion thereof is formed with a curved hook-like portion, the outer end of which is bent inwardly. The arm rest has a seating plate,which is provided with a rising curved portion at least within the inner side portion thereof. The rising portion of the resting plate is complementary to the hook-like portion of the lifting plate of the arm lifter to form an aperture having a restricted opening between the top of the seating plate rising portion and the outer end portion of the hook-like portion, wherein the tone arm is captively located and clamped for preventing the arm from disengaging from rest position when the arm is out-of-use. The terms inwardly or outwardly and inner or outer as used hereinabove and throughout this specification refer to directions relative to the turntable, in which in is close thereto and out is far therefrom.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and features of the present invention, as well as advantages thereof, will become more apparent from the following description of the examplary embodiment taken in conjunction with the accompanying drawing in which:

FIG. I is the top view of the tone arm resting on an arm rest of a conventional record player unit.

FIG. 2 is a side view of the tone arm of FIG. 1.

FIG. 3 is the cross sectional view substantially on the line A-A of FIG. 2, in which the rear portion of the arm and the arm supporting device are omitted.

FIG. 4 is the front elevational view of a conventional arm rest having a locking device, and the dotted line illustrates the arm locked by the locking device.

FIG. 5 is the top view of the tone arm locked by the locking device of the present invention.

FIG. 6 is the side view of the tone arm of FIG. 5.

FIG. 7 and FIG. 8 are the cross sectional views suly stantially on the lines BB and C-C respectively of FIG. 6, in which the rear portions of the arm and the arm supporting device are omitted.

FIGS. 9, l0, l1 and 12 are front views, respectively, illustrating the relation between the tone arm, the arm lifter and the arm rest of the embodiment in various operating conditions.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 5 12, there are shown a tone arm 1, a vertically movable arm lifter 2, and a fixed arm rest 3. The outer end portion (further portion from the turn table T) of the lifting plate 21 of the arm lifter 2 is, as best seen in FIG. 8, formed with a curved hook-like portion, the outer end a of which bends inwardly so as to arrest the upward movement of the tone arm 1. The seating plate 3 of the arm rest 3 is, as best seen in FIG. 7, provided with a curved rising portion at least at its inner side (closer portion to the turn table T). When the tone arm 1 is placed on the arm rest, as shown in FIG. 9, the rising portion of the seating plate 3' cooperates with the curved hook-like portion of the lifting plate 2 to form an aperture having an opening C between the top b of the rising portion and the outer end a of the hook-like portion so that the tone arm 1 may be captively located in the aperture, that is, since the dimension C is less than the diameter of the tone arm 1, the arm can not be withdrawn from the opening.

In operation, the tone arm 1 is, as shown in FIG. 10, elevated vertically to up position, by manipulating the arm lifter 2, and then, as shown in FIG. 11, the arm 1 is turned in the clockwise direction to bring it into a record-playing position along the lifting plate 2'. Next, the arm lifter 2 is manipulated, as shown in FIG. 12, for lowering the tone arm 1 so that the stylus of the pick-up (not shown) mounted thereto may contact a record (not shown) at any selected position. After finishing play of the record,'the tone arm 1 is elevated again by operating the arm lifter 2, and turned outwardly along the lifting plate 2' until the arm 1 enters into the booklike portion. Then, the tone arm is lowered onto the arm rest 3 and left intact in the hook-like portion. This state is illustrated in FIG. 9, and thus, the tone arm 1 is locked.

From the foregoing, it may be appreciated that the present invention provides a novel and improved arrangement of locking device for a tone arm, in which the tone arm may be assured of being locked at its rest position and unlocked at the beginning of playing only by usual manipulation of the tone arm and the arm lifter without any special operation for locking or unlocking. Thus, there is no chance that the tone arm can remain unlocked inadvertently, and damaged by accidental displacement. Furthermore, this arrangement need not require any additional parts, so that the manufacturing cost is inexpensive.

While the above describes the preferred embodiment of the present invention, it is clear that various modifications can be made by those skilled in the art and, accordingly, the scope of the present invention should be measured solely from the following claims in which:

What is claimed is:

l. A locking device for a tone arm for a record player or the like comprising:

a turntable mounted for rotation about a vertical axis,

a tone arm mounted adjacent said turntable and pivotable about a vertical axis and a horizontal axis from a position of rest adjacent the turntable to a position of play on the turntable,

a vertically movable arm lifter having a lifting plate underlying said tone arm for contact therewith,

an arm rest fixed to said record player and having a seating plate underlying said tone arm at a longitudinal position spaced from said lifting plate when said arm is pivoted to the side of said turntable,

the outer end portion of said lifting plate being formed with a curved hook-like portion, the end of which is remote from said turntable being bent inwardly,

the seating plate of said arm rest being provided with a rising curved portion, at least at its inner side relative to said turntable, whereby, when said tone arm is retracted from a playing position, the tone arm comes to rest on said arm lifter in an uppermost position with the tone arm resting within said hook-like portion, whereupon said arm lifter is lowered to seat said tone arm on said arm rest, the hook-like portion of said lifting plate and the rising portion of said seating plate then forming an aperture having a restricted opening between the outer end of said hook-like portion and the top of said seating plate rising portion with the dimension of the opening being less than the diameter of the tone arm.

2. The locking device of claim 1, wherein said seating plate is U-shaped in cross section.

Claims

1. A locking device for a tone arm for a record player or the like comprising: a turntable mounted for rotation about a vertical axis, a tone arm mounted adjacent said turntable and pivotable about a vertical axis and a horizontal axis from a position of rest adjacent the turntable to a position of play on the turntable, a vertically movable arm lifter having a lifting plate underlying said tone arm for contact therewith, an arm rest fixed to said record player and having a seating plate underlying said tone arm at a longitudinal position spaced from said lifting plate when said arm is pivoted to the side of said turntable, the outer end portion of said lifting plate being formed with a curved hook-like portion, the end of which is remote from said turntable being bent inwardly, the seating plate of said arm rest being provided with a rising curved portion, at least at its inner side relative to said turntable, whereby, when said tone arm is retracted from a playing position, the tone arm comes to rest on said arm lifter in an uppermost position with the tone arm resting within said hook-like portion, whereupon said arm lifter is lowered to seat said tone arm on said arm rest, the hook-like portion of said lifting plate and the rising portion of said seating plate then forming an aperture having a restricted opening between the outer end of said hook-like portion and the top of said seating plate rising portion with the dimension of the opening being less than the diameter of the tone arm.