US2174692A

US2174692A - Translating device

Info

Publication number: US2174692A
Application number: US135885A
Authority: US
Inventors: Orville M Dunning
Original assignee: Thomas A Edison Inc
Current assignee: Thomas A Edison Inc
Priority date: 1937-04-09
Filing date: 1937-04-09
Publication date: 1939-10-03
Anticipated expiration: 1956-10-03

Description

Oct. 3; 1939. o. M DUNNING 2,174,692

TRANSLATING DEVICE Filed April 9, 1937 \INVENATOR OrvzlleMDunnmg BY f TTORNEY Patented Oct. 3 1939 UNE-ED sis TRANSLATING DEVICE Application April 9, 1937,'Serial No. 135,885

13 Claims.

This invention relates to translating devices, and more particularly to devices for translating acoustic or electric oscillations into mechanical oscillations, or vice versa. It is a broad object to provide improved such devices.

While not necessarily in all aspects limited thereto, the invention is of particular utility with devices wherein as active elements there are employed piezo-electric units, especially of the bending type. It is an object to provide improved translating devices employing such units.

A difficulty commonly encountered in the use of such units in translating devices is their fragility. It is an object of the invention to provide an improved translating device construction wherein the piezo-electric or other active unit is better proof against breakage and damage than heretofore.

The difiiculty of fragility is especially common in connection with translating devices such as phonographic recorders, Wherewith there is a continual necessity for eifecting, terminating and altering the mechanical contact of the device with a record, which further may be in motion,

, and for generally frequent handling of the device.

It is a particular object of my invention to provide a more sturdy recorder.

A broader object is the provision of a generally improved recorder and construction therefor.

Other and allied objects will more fully appear from the following description and the appended claims.

In the drawing and description I have chosen to illustrate and describe my invention in connection with a translating device adapted for use as a recorder and comprising as an active element a piezo-electric unit of the bending type as abovementioned; this is, however, intended as exemplary only and not as comprehensive of the various purposes and components for and with which my invention may be carried out, as will be obvious as the description proceeds.

In the description reference is had to the accompanying drawing, of which:

Figure 1 is a vertical cross-sectional view of a recorder embodying my invention;

Figure 2 is a bottom plan view of the recorder of Figure 1, the line l l in Figure 2 indicating the vertical plane upon which Figure 1 is taken; and

Figure 3 is a perspective view of the same recorder, showing the main frame and therewith associated components removed and drawn slightly away from its pivots, for the sake of clearer illustration.

In carrying out my invention I movably support, relative to a load (for example, a mechanical load in the form of a record to be cut or impressed with sound-representing undulations), a system vibratable in accordance with oscillations thereto supplied (for example, acoustic oscillations, or electric oscillations translated therefrom and suitably amplified). The vibratable system in the illustrated recorder is of cantilever form, and comprises the piezo-electric unit 'I the stylus 8 secured to the right-shown extremity thereof by means of the mounting 8 (in which the stylus is partially imbedded and which in turn is cemented about the unit extremity), and the unit base 2 of U-shaped cross-section, whichmay be of metal and in which the unit I is 'insulatedly cemented at its extremity opposite the stylus. The piezo-electric unit I may be of the so-Called bi-morph form-wherein two crystals are secured facc-to-face, electrically arranged for simultaneous voltage application, and further arranged so that one contracts longitudinally as the other expands (and vice versa) to result in a transverse (e. g., up-and-down) bending. The stylus 8 is shown engaging the surface of a record R, the stylus and record being of any mutually appropriate forms, and the record being for example arranged for continuous movement by means not necessary to show.

It will be obvious that the undulations in the record for the creation of which the illustrated system is arranged are vertical, although no limitation of broader aspects thereto is intended. In prior co-pen'ding applications of mine, for example Serial No. 701,247, filed December 6, 1933 (on which Patent No. 2,106,051 has since been granted), I have shown and claimed arrangements of the character of the illustrated one as so far de scribed. But in those structures the necessary bias of the vibratable system-more specifically, of the stylus-against the load .or record has been wholly or principally provided by mass or other force-applying means integral with or influencing the unit base; accordingly this force has been transmitted wholly or principally through the unit longitudinally. This construction imparts a steady bending strain on the unit throughout its length whenever the stylus is in position engaging a. record; this force is suddenly applied and relieved upon stylus placement upon and removal from the record, calling upon the unit to withstand abrupt strain changes and excessive impactive strains; and these undesirable influences are augmented by the observed likelihood of unskilled persons pressing upon and otherwise handling the stylus, with corresponding strain production through the unit. In short, an excessive tendency to breakage of the unit exists with such a structure, at least in the absence of certain special measures any necessity for which is obviated by the present invention.

The vibratable system has of course a principal vibratable portion (e. g., its stylus extremity) and a portion which tends to resist vibration (e. g., the base 2, in view of its mass). According to this invention I preferably by-pass the intervening or most fragile central portion of the system with the necessary force-applying means, for example connecting such means instead directly with the principal vibratable portion, or stylus extremity of the unit. I also may, and preferably do so apportion and so movably mount the base 2 as to minimize any significant contribution by its mass to record-ward stylus bias, and it will be understood that the mass of a typical bending unit 5 is very low. Accordingly the force-applying means which I employ to operate directly on the stylus extremity of the unit may supply the principal portion of a desired bias, and of this principal portion no part need be transmitted longitudinally through the vibratable system;

The force-applying means may be of any desired form, subject to the qualification that the vibration of the vibratable system portion shall not be thereby seriously interfered with; I have preferred and have iilustrated the force-applying means as comprising a resilient member or spring terminally associated with the stylus extremity of the unit. While the other terminal of this spring may be held stationary in position to create a suitable average compression in the spring, I have preferred to utilize the spring only as a coupling part of the force-applying means, the force ultimately being derived from a primary force-supplying part such asa movably supported and suitably positioned mass. An optional feature of my invention is the movable' supporting or pivoting of the vibratable system (e, g., of unit base 2) to a portion (preferably of low moment) of this mass. Having so generalized some of the aspects of my invention, I may refer back to the drawing in connection with a more detailed description.

The mass which I preferably employ as a forcesupplying means is seen as a generally horizontal and relatively heavy main plate or frame 3, with bent-down vertical ears 3 along its sides at its left-shown extremity. By brackets 5 secured to the top of the frame 3 the latter'is pivoted tomeans provided to the left of this extremity, as hereinafter is more detailedly described. The unit base 2 is seen pivoted between the ears 3' by the adjustable pivot screws 5 through the latter. The frame 3 extends rightwardly over the unit i to terminate a little beyond its stylus extremity; and between the stylus mounting ti and the frame 3 will be seen, in the form of spring 9, the resilient means which couples the vibratable system to the frame 3, and which with the latter makes up the force-applying means. The spring 9 is preferably (though, in view of its normal placement in compression, not necessarily) secured at its respective terminals.

It Will be understood that upon the application across the electrical terminals of the unit l (hereinafter more specifically mentioned) of a suitable voltage, for example sound-representing, the unit will vibrate vertically in correspondence therewith and at amplitude increasing along the length of the unit up to and including its stylus extremity;

the stylus accordingly is moved up and down to create a likewise corresponding sound track or undulating groove in the meanwhile-moved record. In view of the mass of the unit base 2 little of the vibratory force is dissipated in oscillatory rotation thereof about its pivot. In view of the high mass of frame 3 no appreciable vibration is dissipated in it. In view of the substantially pure compliance nature of the member (spring 9) which is immediately coupled to the principal vibratable system portion, the only impediment to vibration of the latter offered at this extremity by this construction is by the stiffness of this spring-which is simply additive to the necessarily present unit stifiness and effective record stiffness, and may in typical cases be a negligible fraction of these. The vibratory action of the vibratable system amounts to a modulation of the compression of spring 9, and of the steady bias imparted to the stylus principally through that spring, The mass of plate 3 will of course be fixed at whatever value produces a desired eifect of the stylus on the record in any given case; the compliance of spring 9 is desirably made as great consistent with reasonably small change of its length between no-compression and normalcompression conditions.

It will be obvious that now the vibratable system has been practically wholly relieved of the requirement of longitudinal force transmission and from attendant strains, abrupt changes of strain, etc. produced either by any intended use of the device or by any other pressure from beneath the stylus. Because of the considerations detailed in the preceding paragraph, however, there need be experienced no substantial change of efiiciency or performance throughout the desired frequency rangefor example, of audio frequencies-from simpler systems without these salient advantages.

The description of the illustrated recorder may be completed by attention to the pivoting of the main frame (through brackets 5), the electrical connections to the'unit I, etc. The brackets 5 are provided with the extending arms 5 through each arm near its extremity is passed a respective rivet l8 insulated from the arm by insulating bushings H. Held secure under each rivet, next to a respective bushing H, is a respective soldering lug ii; the electrical leads I from unit I are led insulatedly through the unit base 2 and connected to the respective lugs-so that the latter, or the rivets if! in contact therewith respectively, become in effect the terminals of the unit.

The means to which the frame 3 is pivoted may be a vertical member lwhich for example may be secured to a travelling carriage, not necessary to show; for rendering the track of the stylus on the rotating record a spiral one. On either side of the member ID are spacedly and insulatedly secured, as by suitable horizontal collar bushings I3 the vertical lug members ll; each of these may carry near its bottom extremity an outwardly extending horizontal pivot 12. These pivots are adapted to engage the centers of the respective insulated rivets iii in arms abovementioned, and thus both to pivot the frame 3 and to make possible electrical connections to the unit I simply by connections to the respective unpivoted lug members I l--for example by means of the screws l i in the folded-over top extremities i l of these lug members, The pressure against the pivots 52 of the arms 5 may be adjusted as by the screw i5 clearingly passed through one of the arms and threaded into the other, at intermediate regions along the arms.

A casing 4, suitable apertured for outward extension of the stylus mounting 8', may be provided to close substantially the end, sides and bottom of the device for appearance, dust elimination, and prevention of direct impact against the unit I. This casing also, in the event of non-securing of the extremities of spring 9, serves to prevent the excessive downward swinging of the unit I upon lifting of the frame 3 to disengage the stylus from the record. The bottom of this casing has been omitted from the bottom plan View of Figure 2, for the sake of clearer illustration.

A specific embodiment of my invention having been so described, it will be obvious to those skilled in the art that wide modifications in the components and purposes of the device may be made within the spirit of the invention. For example, it is apparent that certain of the hereinbefore stated objects of the invention will be attained where the desired bias of the stylus toward the record or at least the principal portion of such bias is derived from the vibratable system itself or any force-supplying means other than the plate or frame 3, or where an appreciable or the major portion of said bias is transmitted through the vibratable system. I accordingly intend no unnecessary limitations by virtue of the specific characteristics of this embodiment; rather, in the appended claims I undertake to express the scope of my invention broadly, limited only by the state of the art.

I claim:

1. In a translating device, a frame movably mounted adjacent a load and biased theretoward; a piezo-electric bending unit having a portion movably mounted to said frame; and means for coupling with said frame, for bias toward the load by said frame, a portion of said unit remote from said mounted portion.

2. In a translating device, a bending unit adapted to translate other oscillatory energy into oscillatory bending of the unit and vice versa, freely mounted in a first portion thereof for movement of a second portion thereof toward and away from a load; and means resiliently associated with said second portion for biasing the same toward the load.

3. In a translating device, a bending unit adapted to translate other oscillatory energy into oscillatory bending of the unit and vice versa, freely mounted in a first portion thereof for movement of a second portion thereof toward and away from a load; and means immediately associated with and influencing said second portion for biasing the same toward the load.

4. In a translating device, a bending unit adapted to translate other oscillatory energy into oscillatory bending of the unit and vice versa, freely mounted in a first portion thereof for movement of a second portion thereof toward and away from a load; and means by-passing at least a portion of said unit between said first and second portions for biasing said second portion to ward the load.

5. In a translating device, a bending unit adapted to translate other oscillatory energy into oscillatory bending of the unit and vice versa, freely mounted in a first portion thereof for movement of a second portion thereof toward and away from a load; means distinct from said unit for supplying a force toward the load; and means resiliently coupling said second unit portion with said force-supplying means for bias toward the load.

6. In a translating device, a frame movably mounted adjacent a load and biased theretoward; a bending unit adapted to translate other oscillatory energy into oscillatory bending of the unit and vice versa, having a portion freely mounted to said frame; and means for coupling with said frame, for bias toward the load, a portion of said unit remote from said mounted portion.

7. In a. translating device, a cantilever system comprising a piezo-ele'ctric bending unit supported at its base for movement of its extremity and for bending toward and away from a load, and means resiliently associated with said extremity for biasing the same toward the load.

8. In a translating device, a cantilever system comprising a piezo-electric bending unit supported at its base for movement of its extremity and for bending toward and away from a load, and means immediately associated with and influencing said extremity for biasing the same to" ward the load.

9.'In a translating device, a cantilever system comprising a piezo-electric bending unit pivoted at its base for movement of its extremity toward a load, and means by-passing at least the central portion of said unit for biasing said extremity toward the load.

10. In a translating device, a cantilever system comprising a piezo-electri'c bending unit supported at its base for movement of its extremity and for bending toward and away from a load; means distinct from said system for supplying a force toward the load; and means immediately associated with said extremity for coupling the the same with said force-supplying means.

11. In a translating device, a cantilever system comprising a piezo-electric bending unit having a vibratable extremity adjacent a load, and supported at its base for movement of said extremity and for bending toward and away from the load; a mass also supported adjacent and for movement toward the load; and means resiliently coupling said extremity with said mass for bias toward the load.

12. In a phonographic recorder adapted for cooperation with a record moved relative thereto, a frame movably mounted adjacent the record and biased theretoward; a piezo-electric bending unit having a portion movably mounted to said frame; a record-engaging stylus carried by a portion of said unit remote from said mounted portion; and means for coupling said remote unit portion with said frame for bias of said stylus against the record.

13. In a phonographic recorder adapted for cooperation with a record moved relative thereto, a frame movably mounted adjacent the record and biased theretoward; a bending unit adapted to translate other oscillatory energy into oscillatory bending of the unit, having a portion freely mounted to said frame; a record-engaging stylus carried by a portion of said unit remote from said mounted portion; and means for coupling said remote unit portion with said frame for bias of said stylus against the record.

ORVILLE M. DUNNING.