US3572473A

US3572473A - Phonograph system

Info

Publication number: US3572473A
Application number: US828036*A
Authority: US
Inventors: Royal V Jones Jr; Clayton H Allen; Colin G Gordon
Original assignee: Bolt Beranek and Newman Inc
Current assignee: Bolt Beranek and Newman Inc
Priority date: 1967-02-13
Filing date: 1969-03-05
Publication date: 1971-03-30
Anticipated expiration: 1988-03-30

Abstract

Phonograph system with tensioned wire coupling between a needle engaging a drum-type record and a loudspeaker, and including a speed controller having a pair of coaxial conical members with a viscous liquid therebetween, the outer member being driven by the drum which carries the record and the inner member being driven by the outer member through the viscous liquid.

Description

United States Patent [72] Inventors Royal V. Jones, Jr.

Waltham; Clayton H. Allen, Wellesley; Colin G. Gordon, Bedford, Mass.

[21] Appl. No. 828,036

Division of Ser. No. 615,537. Feb. 13,1967, Pat. No. 3,480,283.

[22] Filed Mar. 5,1969

[45] Patented Mar. 30, 1971 [73] Assignee Bolt Beranek and Newman Inc.

Cambridge, Mass.

[54] PHONOGRAPH SYSTEM 2 Claims, 1 Drawing Fig.

Primary ExaminerDuane A. Reger AttorneyRines and Rines ABSTRACT: Phonograph system with tensioned wire coupling between a needle engaging a drum-type record and a loudspeaker, and including a speed controller having a pair of coaxial conical members with a viscous liquid therebetween,

[52] US. Cl 1851/220 the outer member being driven by the drum which carries the 46/ll7.274/17 record and the inner member being driven by the outer [51] Int. Cl ..F16d 57/00 memberthrough theviscousliquid.

I6 I21 I2 IO 4 8 P 4! I d 7 \4 1 i sy so 2 234 7 5 g *Jfiun 3 "4" R I6 i 20 b g s so I AW I \s f Is 6 EA 5% M 1 21 1:! l 9 J I, -34 11 Patented March so, 1971 3,512,473

5" n 5' I8 I 6 2 3' 5 I BY (1M1 W ATTORNEYS rnonoonxrn SYSTEM This is a division of application Ser. No. 615,537, filed Feb. 13, 1967 now US. Pat. No. 3,480,283.

The present invention relates to phonograph systems, being more particularly directed to self-powered sound-reproducing systems of compact and inexpensive construction for such applications as sound-producing toys and the like; it being understood, however, that certain of the novel features of the invention are more broadly applicable to other types of soundreproducing systems as well.

Dolls and other toys and similar devices have previously been equipped with small phonograph mechanisms of the selfpowered type wherein a needle is mechanically coupled to a sound-reproducing loudspeaker device such that by the pulling of a drawstring or the like, a spring device is energized to power the movement of a phonograph record against the needle. Prior art devices of this type have often required the use of circular record discs which, in combination with the requisite needle mounting structures, have introduced serious limitations in the number and length of messages that may be recorded on a small size record and have introduced problems in terms of the quality of reproduction resulting from varying groove speeds and the like. Such devices have also required in some cases the use of viscous coupling mechanisms between the needle and the loudspeaker for permitting movement of the needle relative to the record while yet allowing sound energy to be transmitted between the two. Such constructions, however, introduce complexities and limitations into the acoustic transmission path between the needle and the soundrepi'oducing loudspeaker. In addition, prior art recording devices have also been subject to the disadvantage that the position where the needle plays upon the disc record after each successive operation of the spring-tensioning device is a matter of random chance. In such system, therefore, the user has had no control over message selection and is unable to select different messages at will.

An object of the present invention, accordingly, is to provide a new and improved phonograph apparatus of the abovementioned type which shall not be subject to any of the previously described disadvantages, but that, to the contrary, removes the inherent restrictions accompanying the use of disc records and, if desired, the uncertainties of selection of desired recorded messages thereon.

A further object is to provide a novel sound-reproducing apparatus of more general utility as well.

Other and further objects will be hereinafter delineated, being more particularly set forth in the appended claims.

In summary, the invention contemplates the use of a preferably cylindrical drum record provided on its exterior surface with a plurality of circumferential or helically spiralled recorded grooves, preferably recorded in the lateral mode and representing multiple messages. A sound-reproducing loudspeaker means is provided at the bottom end of the drum. A needle holder is mounted outside the drum in a manner that allows it to slide parallel to the drum axis. It is normally pressed toward the drum to hold the needle within the record grooves. The vibrations transmitted to the needle holder from the recorded grooves are conveyed via Coulomb friction to a tensioned wire and thence to the loudspeaker. The tensioned wire is held between the loudspeaker and a tensioning spring. It rests against the needle holder but allows the needle holder to slide relative to it for positioning the needle in the groove and for allowing the needle to track freely. The wire, furthermore, is of configuration that folds back upon itself in that it runs up the outside of the cylinder, then along a radius and down the axis of the cylinder. This change in direction is achieved with insignificant loss of vibration transmission by a unique rocker arm device. A carriage is provide movable laterally with respect to the drum upon the operation of a tensioning drawstring or the like which not only serves to tension the drive means for the drum, but also in moving the carriage serves to move the needle out of engagement with and away from the drum record grooves during the operation of the tensioning of the spring drive means. Preferred constructional details and novel subcombination features particularly suited to the combination of the complete apparatus but useful also apart from the complete system, are hereinafter more fully explained.

The invention will now be described with reference to the accompanying drawing, the single FIGURE of which is aperspective view, partly sectionalized to illustrate details of construction, and showing the invention in a preferred form.

A substantially cylindrical drum record 1 is carried at the lower end of a cylindrical drum carrier 3 rotatable by a driving reel 5 about an axially disposed hollow shaft 5 bottomed at 5" under a transverse central plate 3. The driving reel 5 is powered by a spring Tshown in the preferred form of the wellknown negator"-type spring. The mechanical system, and particularly the hollow shaft 5', supporting the drum carrier 3, and the spindle carrying the spring reel 7 is supported upon an outer support frame 10 extending external to the lateral walls of the drum support 3 and over the top thereof. The spring 7 is tensioned through the pulling of a drawstring or the like 9 wound within a groove 20 at the upper end of the drum carrier 3. As the draw string 9 is pulled, the spring 7 becomes wound upon the drive reel 5. Upon release'of the spring 9, the spring thus wound upon the drive reel 5 causes the drum carrier 3 to rotate in one direction, say, to the right, so that the record grooves 1' circumferentially helically spiralled in the external surface of the record drum .1 are moved in one direction past a phonograph needle 11 carried in a needle holder 11'. The pulling of the spring 9 will, of course, move the drum-carried record grooves l in the opposite direction (to the left) for rewinding purposes.

The needle holder 11 is shown mounted within a slot 13 in a carriage support bracket 15, extending from the right-hand side of the apparatus (as illustrated in the drawing) over the top thereof, above the frame 10, such that the needle is constrained to move up and down in a direction parallel to the axis of the drum 1. The carriage support 15 is mounted on the support frame 10 in a manner later explained, such that it may be moved laterally with respect to the drum structure 1,3 and its axis upon the pulling of the string 9, so that the needle 11 is permitted to disengage the record grooves 1' and drop downward away from the drum record grooves under the influence of a reset spring 21. As before stated, this action will occur at the same time that the spring 7 is being tensioned upon the drive reel 5. A return spring 17 carried between the carriage bracket support 15 and the support frame 10 of the apparatus returns the carriage so that the needle 11 is engaged within the record grooves 1' at some circumferential position along the drum dependent upon the extent to which the drawstring 9 has been pulled.

The recorded messages upon the drum record 1 are preferably carried in a number of successive individual grooves, all of which start at one region of the drum, each, however, at a different circumferential position, and which spiral along the drum to the opposite region thereof. The user, by pulling the drawstring 9 different predetermined extents, as shown by the calibrations 9', may therefore preselect the desired record groove and thus the desired message that is to be played. The calibrations 9' may be color-coded or otherwise indicative of the different messages.

In order to obviate the before-described problems in connection with coupling the mechanical vibrations produced in the needle, through its engagement with the record grooves 1, to a sound-reproducing loudspeaker 2 disposed at the bottom end of the drum, and without the necessity for the viscous coupling mechanisms and other devices of the, prior art before, referred to, a novel sound-coupling system is provided. This involves a small diameter wire 4 that is mounted under tension between a spring 6 at the bottom of the slot 13 in the carriage support 15 and the loudspeaker 2. The tensioned wire 4 rests against the needle holder 11' with some positive pressure. Vibrational energy thatis transmitted to the needle holder 11 from the laterally recorded grooves 1, via the needle 11, is

passed to the tensioned wire 4 as a longitudinal vibration by Coulomb friction which limits small amplitude movement between the needle holder 11' and the tensioned wire. This construction, on the other hand, permits the large relative movements that are required for tracking and resetting purposes. The tension wire 4 thus frictionally presses against the stylus or needle-holding mechanism 11' with the needle engaging the grooves 1'. It is this frictional force which carries the vibrational signal from the record grooves l to the wire 4 and then by means of the wire 4 to the loudspeaker 2 with negligible loss of signal. It will be noted that this type of coupling avoids the losses that inherently appear in prior-art viscous and other sliding coupling mechanisms. This construction, moreover, compensates for warping and eccentricities and the like in the record, and minimizes the necessity for manufacturing tolerances of any high order, thus enabling the device to be built at very low cost for such purposes as toys and the like, if desired.

This method of coupling also avoids many of the disadvantages of such prior art devices, and, particularly, allows the needle to be remotely positioned from the loudspeaker. The resonances of conventional mechanical coupling structures in the audible frequency range are avoided since the thin wire 4 has a very small mass; and, when held under a high degree of tension, introduces mechanical resonances in its longitudinal, driving direction which are at highfrequencies lying outside the required reproducing range. The tensioned wire 4 is I susceptible to lateral resonance vibrations which lie in the audible frequency range, but these are poorly coupled to motion in the longitudinal driving direction and are easily damped out by a close fitting sleeve of damping material 18, disposed about the portion of the wire 4 within the hollow shaft 5, between the later-described rocker arm 8 and the speaker 2. The resonance of the system is thus controlled exclusively by the sound-reproducing loudspeaker 2 and the spring 6.

A further unique feature resides in the means by which the tensioned wire 4 is carried around a corner so that it may pass from the needle carrier 11, on the outside of the drum, to the loudspeaker 2, on the inside of the drum. This is achieved with insignificant loss of vibrational energy by the before-mentioned rocker arm 8, pivoted on the upper surface of the carriage support 15 and carrying the substantially radially inwardly extending portion of the tensioned wire 4 so that it may bridge between the point 4' outside the periphery of the drum where the wire extends upward from the needle holder 11' adjacent the side of the drum and the point 4" on the axis of the drum where the wire passes axially downward towards the loudspeaker 2.

Through this construction, and the particular positioning of the parts as above described, a very compact and inexpensive system is produced avoiding many of the disadvantages previously mentioned as inherent in prior art devices. As an example, a dozen three-second recordings can readily be provided on a recording drum surface 1, about one-half inch long and about l-iinches in diameter, rotated at a speed of about one revolution per second. Unlike disc records, it is observed that the groove speed is a constant, thus introducing a relatively high degree of similar reproducing quality for all messages and from beginning to end of each message.

The carriage support 15 is preferably supported from the support frame 10 upon small ball bearings 12 disposed in recesses 10' in the upper surface of the frame 10 and in corresponding ball rollways 12' in theundersurface of the carriage 15. The ball rollways 12' in the carriage also serve to stiffen the structure. The right-hand ball roller 12 is preferably located as shown, close to the pivot point P of the rocker arm 8 in order to give maximum support to the rocker arm. The support frame 10 also serves to support the loudspeaker 2 at its lower end by means of a clamping ring 14.

The grooves l are laterally recorded such that the needle 11 is caused to vibrate vertically up and downward in the direction of the tension wire 4. The tension wire is by this means highly insensitive to "hill and dale" motions such as might be caused by scratching, dirt, etc. It should be noted that when the needle 11 is removed from contact with the grooves 1 by operation of the pull drawstring 9, it disengages from the tensioning wire 4, as well.

The speed of the drum structure 1,3 during its playing period is controlled by a viscous speed controller 16 which is connected or coupled by an O-ring 16' passing within a groove 16" in the speed controller housing and circumferentially around the entire drum 3 within groove 3". While the speed controller has utility apart from the particular combination shown, it is particularly designed for and suited to the purposes of the invention. Within the housing 16, a conical recess 30 is provided, receiving a similarly shaped coaxial cone member 30 axially supported through sealed bearings at the top and bottom of the housing and rotatable within the recess I 30 with a viscous liquid, such as liquid silicones, in the space therebetween. Since the movement between the coaxial-

conical surfaces

30 and 30 increases with speed, as the housing 16 rotates with the drum 3 at an increased speed, the torque between the conical surfaces will. increase, balancing the torque of the spring 5 and thus acting to control the speed of the drum structure. A further feature of this construction resides in its inherent self-centering properties.

Further modifications will occur to those skilled in this art and all such are considered to fall within the spirit and scope of the invention as defined in the appended claims.

We claim:

1. Apparatus having, in combination, rotatable means the speed of which is to be controlled, and a speed controller including a pair of viscous-coupled coaxial rotatable members the torque between which increases upon increase in relative speed, one of said members being an outer member comprising a housing having an internal conical surface defining a conical recess and the other of said members being an inner member comprising an external conical surface separated from the said internal conical surface by a viscous liquid, both the inner and outer members being rotatably supported upon a frame, and means driven by said rotatable means for driving the outer member and for driving the inner member through the viscous liquid.

2. Apparatus in accordance with claim 1, and in which said driven means comprises a continuous ring passing about said outer member.