US2424845A

US2424845A - Radio control unit

Info

Publication number: US2424845A
Application number: US497341A
Authority: US
Inventors: Alexander W Plensler
Original assignee: BELMONT RADIO CORP
Current assignee: BELMONT RADIO Corp
Priority date: 1943-08-04
Filing date: 1943-08-04
Publication date: 1947-07-29
Anticipated expiration: 1964-07-29

Description

y 1947- A. w. PLENSLER RADIO CONTROL UNIT Filed Aug. 4, 1943 2 Sheets-Sheet l July 29, 1947. I A, w PLENSLER 2,424,845

RADIO CONTROL UNIT Filed Aug. 4, 1943 2 Sheets-Sheet 2 29f fnUenZZn- 45a, 47 7 fk Patented July 29, 1947 RADIO CONTROL UNIT Alexander W. Plensler, Chicago, Ill., assignor, by

mesne assignments, to Belmont Radio Corporation, Chicago, 111., a corporation of Illinois Application August 4, 1943, Serial No 497, 34l

22 Claims.

The present invention relates to an improved control unit for controllable apparatus and more particularly to an improved mechanical control unit which is particularly adapted for use in selectively tuning a radio receiving set to desired signal channels.

Various push button actuated mechanical control devices are commercially available for selectively controlling the tuning elements of radio receivers. A device of this character conventionally includes a number of push button actuated selector structures which extend through slots in the escutcheon plate of the receiver; individually correspond to different signal channels; and cooperate with a treadl or linkage mechanism disposed within the receiver to selectively control the tuning element or elements of the receiver in accordance with the particular push button which is actuated. It is also common practice to provide adjustable push button actuated selector structures in order that each push button may be selectively adapted for use in tuning the receiver to any one of a large number of signal channels. In general, the prior art arrangements of this character utilize actuating mechanisms between the push button and the treadle mechanism which are relatively complicated, require expensive machine tool operations in the manufacture thereof, are relatively difficult to assemble, and require supplementary tools in adjusting the settings thereof to correspond to the desired signal channels. In small receivers, in particular, the push button actuating mechanisms must be located in. close proximity to each other in order to minimize the space which they occupy within the receiver, thus increasing the difiiculties of assembly and adjustment.

It is an object of the present invention, therefore, to provde for the control of controllable apparatus and particularly tunable radio receivers, an improved control unit which is so arranged that the above-mentioned difliculties are largely obviated.

It is another object of the invention to provide an improved push button actuated selector unit of the character described which is simple and rugged in construction, includes a small number of parts substantially all of which may be formed by a single stamping operation, may be easily assembled, and includes an adjustable portion which may be easily clamped in an adjusted position without the use of supplementary tools.

According to another object of the invention, a single member of unitary construction is utilized to movably support the adjustable portion 2 of the selector unit and also to clamp this portion of the unit in an adjusted position, thus eliminating the necessity of providing supplementary clamping members on the supporting member.

In accordance withstill another object of the invention, the number of parts in the selector unit is further reduced by utilizing the push button body as a camming element to lock the adiustable portion of the selector unit in any desired adjusted position.

It is a still further object of the invention to provide an improved selector unit of the character described in which only one piece is required in addition to the push button and the adjustable means, and in which the adjustable means may be easily and rapidly adjusted to any desired setting without the use of tools.

The invention, both'as to its organization and method of operation, together with further objects and advantages thereof will best be understood by reference to the following specification taken in connection with the accompanying drawings, in which:

Fig. 1 is a fragmentary plan view illustratingan improved control unit characterized by the features of the present invention;

Fig. 2 is a side sectional view taken along the lines 2-2'in Fig. 1;

Fig. 3 is a side sectional view corresponding to that of Fig. 2 illustrating the parts in changed positions;

Fig. 4 is a fragmentary detail view illustrating the manner of connecting two of the parts embodied in the control unit;

Fig. 5 is a top sectional view taken along the lines 5-5 of Fig. 4;

Fig. 6 is a fragmentary plan'view of one of the elements embodied in the control unit;

Fig. '7 is a side view, partially in section, illustrating a modified arrangement of certain of the parts embodied in the control unit;

Fig. 8 is a side sectional view corresponding to that of Fig. 7 showing the two illustrated parts in changed positions;

Fig. 9 is a side sectional view illustrating a further modification of certain of the parts embodied in the control unit;

Fig. 10 is a side sectional view corresponding to that of Fig. 9 but illustrating the parts in changed positions; and

Fig. 11 is a top sectional view taken along the lines llll of Fig. 10.

Referring now to the drawings and more particularly to Fig. 1 thereof, the improved control unit is there illustrated in its embodiment in a radio receiver for the purpose of adjusting the gang connected frequency changing elements which are utilized in a well known manner to tune the receiver to different signal channels, 1. e., to tune the receiver for the reception of signals radiated at different carrier frequencies. More specifically, the frequency changing means of the receiver comprises a tuning condenser Hi having a fixed frame H and a rotatable shaft i2 which carries the rotor plates of the condenser and is rotatable through 180 to provide the full tuning range for the receiver, This condenser is suitably electrically connected into the circuit of the receiver and the frame thereof is mounted upon the platform portion of the receiver chassis. The rotor shaft I 2 of the condenser carries a gear l3 through which rotary movement may be imparted to the shaft i 2 by the control unit for the purpose of tuning the receiver to any desired signal channel in the manner pointed out below.

Briefly considered, the control unit comprises a fram indicated generally at It which serves to support the movable parts of the control unit; is rigidly mounted upon the chassis of the receiver; and includes a front side member l5 and two end members I5 which are rigidly secured together at their abutting ends by means of screws or rivets i1. Rotary movement is imparted to the rotor shaft l2 of the condenser i through a shaft iB which is journaled at its opposite ends in centrally disposed bearings provided in the end members l6 and rigidly supports a treadle bar l9 and a gear sector 20. This shaft also rigidly mounts a driving gear 2i which meshes with the rotor shaft actuating gear l3 to drive the shaft i2 in response to rotation of the gear sector 20 and the treadle bar l9. Rotary movement may be imparted to the three rigidly connected elements [8, l9 and 20 either through operation of the knob actuated shaft 22 or through selective operation of any one of a plurality of push button actuated selector units 23a, 23b, etc. More specifically, the shaft 22 is provided with a section of reduced diameter which is journaled within aligned openings provided in the frame wall I and the legs of a U-shaped supporting bracket 24. This bracket is rigidly mounted upon the end member l6 of the frame and extends through registering opening provided in the abutting ends of the two frame members i5 and i6. At its inner end, the shaft 22 rigidly mounts a small gear 25 which meshes with the teeth of the gear sector 20 to impart rotary movement to the connected parts 20, i9, i8, 2|, i3 and I2 in response to rotation of the shaft 22. The outer end of this shaft is adapted to project through an opening in the front panel of the receiver and has an actuatingknob 26 rigidly mounted thereon.

The several push button actuated selector units 23 are slida-bly mounted upon the frame M between the frame end side members IB of the frame and a channel-shaped cross member 21 which is anchored at its ends within openings provided in the frame end members l5. They are evenly spaced apart along the two members drawings, the treadle bar I! is of one-piece hollow construction and is substantially V.-shaped in cross section, the adjacent angle or engaging portions Mia and i8b being connected by an integral slotted portion I90.

Referring now to the improved structural arrangement of the push button actuated selector units to which the present invention more particularly relates, it may be pointed out that these units are of identical construction. Considering the selector unit 230 by way of example, it will be noted that this unit comprises a carriage or supporting member 23, a push button 2!, a normalizing spring 30, a setting member or cam element 3|, and a combination lock and release lever 32. More specifically, the carriage member 28 is provided with an elongated portion 33 having an enlarged opening 34 at one end thereof for receiving a holding part in the form of a pivot pin 35 upon which the cam element Si is rigidly mounted in the manner shown in Fig. 5 of the drawings. The portion 33 of the carriage member 28 is also provided with an elongated slot 38 which opens into the opening 34 and extends throughout the length thereof to divide this portion of the member into two spaced-

apart parts

33a and 33?; which are integrally connected through a segment 330 of reduced cross-sectional area. With this construction, the edge surfaces defining the opening 34 act as holding or clamping surfaces within which the enlarged bearing portion of the pin 35 may be rigidly clamped.

At its right end, the part 3311 of the carriage member 28 rigidly supports the push button 29.

More specifically, this push button, which may be parts at points spaced longitudinally of the part 33a. The free end of the elongated part 33b, which is pivotally connected. to the part 33a through the segment 330, is freely movable in a vertical direction within the slot 29a, and is arranged to coact with the locking lever 32 to clamp the pin 35 within the edge surfaces of the opening 34 and thus set the cam element 3| in an adjusted position. To this end, the lever 32 which is also mounted within the slit 29a of the push button 29 by means of a, pivot pin 38, is provided with a rounded camming surface 32a which engages the lower edge surface of the carriage mem her part 33b. This lever may be pivoted about the pin 38 between the retracted position illustrated in the dashed lines, wherein the camming surface 32a is disengaged from the lower edge of the part 33b, and the locking position shown in full lines, wherein the camming surface 32a engages the under edge surface of the part 33?) to stress the connecting segment 330 of the member 23 and thus clamp the pivot pin 35 against pivotal movement. For the purpose of retaining the lever 32 in its locking position and for the additional purpose of indicating the particular station to which the selector unit 23a corresponds, a, tab 39 is slidably supported within guideways 4c and 4| provided at either side of the front wall of the push button. This tab, when moved to its depressed position within the guideways l0 and 4|, covers the opening of the slit 29a, and the lower edge thereof engages the lever 32 to maintain this lever in its locking position. At its outer surface, the tab 39 is provided with a suitable printed legend indicating the particular station to which the selector unit 2311 corresponds. When the tab 39 is removed from the

guideways

40 and 4|, the lever 32 may be pivoted to its retracted position wherein the upper edge thereof engages the stop surface defined by the inner slanting portion of the slit 29a.

From the abov'e explanation it will be understood that in order to-pivotally adjust the position of the cam element 3| relative to the carriage member 28 thereby to change the particular signal channel or station to which the selector unit 230, corresponds, it is only necessary to remove the tab 39 from the

guideways

40 and 4| and to pivot the lever 32 to its retracted position. Incident to the pivotal movement of the lever 32, the lower end of the carriage part 33b is moved away from the part 33a, permitting the lower edge surface of the opening 34 to move from the full line position to the dashed line position in the manner illustrated in Fig. 6 of the drawings. In other words, the normally stressed segment 330 of the carriage member 28, in relieving itself of the stress imposed thereon by the lever 32, moves the lower edge surface of the opening 34 away from the upper edge surface of this opening to remove the clamping pressure being exerted upon the bearing surfaces of the pivot pin 35. After this pressure is relieved, the rigidly connected cam element 3| and the pivot pin 35 may be easily pivoted within the opening 34 to impart any desired setting thereto. In this regard it will be understood from the following explanation that the particular setting imparted to the .cam element 3| during adjustmentthereof will determine the settings imparted to the treadle bar I9 and the'condenser l during slidable actuation of the selector unit 23a, and hence the particular station to which the receiver is tuned during such slidable actuation of this selector unit. After the cam element 3| has been adjusted to the desired setting by finge manipulation, the lever 32 may be pivoted from its retracted position to its locking position. Incident to this operation, the lever camming surface 32a engages the lower surface of the part 331) with the result that the free end of this part is pivoted toward the upper part 33a, the squeezing action upon the ends of the two named parts being exerted through the body of the push buttton 29. As the two elongated parts 33a and 33b are squeezed together at their ends, the connecting segment 33c therebetween is stressed and the lower edge surface of the opening 34 is moved toward the upper edge surface of this opening to rigidly clamp the bearing portion of the pin 35 therebetween. The extent of the clamping force exerted upon the pin 35 in the manner just explained is sufficient positively to prevent the cam element 3| from being rotated relative to the carriage member 28 during engagement of the camming surfaces thereof with the treadle member l9.

As indicated above, the carriage member 28 is slidably supported between the side member I6 and the cross member 21 of the frame I4. To this end, the side member I is provided with spaced-apart guide openings through which the two parts 33a and 33b of the carriage member extend, the lower opening 42 through which the part 33b extends being of sufficient vertical length to permit the required latitude of movement of this part during operation of the lever 32 between its retrac a d ocking positions. At its upper end, the carriage member 28 is provided with a transversely extending elongated part -43, the end of which extends through and is snugly received within an opening cut in the base portion of the channel-shapedcross member 21. The normalizing or retracting spring 30 is telescoped over the elongated part 43, with its left end in abutting engagement with the cross member 21 and its right end abutting the shouldered portion of the carriage member. This spring is normally' under slight compression so that the carriage member 28 and the parts supported thereon are normally urged away from the treadle bar I9. In order to prevent the carriage member 28 from being snapped against the inner surface of the frame member l5 under the influence of the spring 30, due to a sudden release of the selector unit 23a after it has been depressed to actuate the treadle bar I9, a cushioning stop 44 formed of sponge rubber or the like is cemented or otherwise rigidly secured to the inner surface of the frame member I5 opposite the adjacent vertically extending edge surface of the carriage member 28. This cushioning element may be in the form of a strip which extends throughout the length of the frame member I5 in order to act as a cushioning stop for the carriage members of the several selector units 23a, 23b, etc.

From the foregoing explanation it will be understood that in order to operate the tuning condenser ID to the particular setting corresponding to the selector unit 23a, thereby to tune the receiver to the particular signal channel or station which corresponds to this selector unit, it is only necessary to depress the selector unit inwardly by finger manipulation of the push button 29. Assuming that the treadle bar I9 and the cam element 3| occupy the positions illustrated in Fig. 2 of the drawings at the time this operation is started, the upper camming surface 3Ia of the cam element is initially brought into engagement with the angle portion |9a of the treadle bar as the selector unit 23a is slid to the left from the position shown in Figs. 2 and 3 of the drawings. During continued movement of the selector unit, the cam element 3| rotates the treadle bar I9 and the shaft I8 in a counterclockwise direction until the lower angle portion I9b of the treadle bar moves into engagement with the lower camming surface 3Ib of the camming element 3|, at which time movement of the selector unit and the treadle bar is arrested. With the treadle bar I9 occupying this position, the condenser III, which is driven through the gears I8 and I3 during rotation of the treadle bar and shaft I8, occupies a position such that the receiver is tuned to the particular signal channel or station which corresponds to the actuated selector unit 23a. This unit may now be released to be returned to normal under the influence of the normalizing or retracting spring 30 in an obvious manner.

From the above explanation it will be under stood that the cam elements of the respective selector units 23a, 23b, etc., respectively occupy different settings such that the treadle bar I9 and the rotor shaft I2 of the condenser are operated to different settings when the different selector units are respectively actuated. It will also be understood that the cam element of any selector unit may be set to any desired position corresponding to any particular station by adjusting the cam element relative to its associated carriage member 28 in the manner explained above. In the event the element 3| of the selector unit 23a, for example, is changed from a set- -7 ting corresponding to a particular station to a difierentsetting wherein it corresponds to a different station, the tab 33 which is slidably supported within the

guideways

40 and 4| of the push button 29 should be changed or the legend thereon altered in order that a true indication may be provided as to the particular station to which the selector unit corresponds.

In the modified arrangement of the selector unit illustrated in Figs. 7 and 8 of the drawings, the slotted elongated portion 33 of the carriage member 28 is substantially tong-shaped in outline and a different arrangement is provided for moving the ends ofthe two parts 33a and 33b relative to each other in order to clamp the pivot pin 35 within the edge surfaces. of the opening 34. Otherwise, the arrangement of the selector unit may be of the exact construction illustrated in Figs. 1, 2 and 3 of the drawings.

More specifically, the carriage member 28, as utilized in the arrangement shown in Figs. 7 and 8, is provided with a slot 36 which stops short of the opening 34, so that the two parts 33a and 33b are connected through a segment 33c of reduced cross section which is disposed at the inner side of the opening 34. A slot 3311 is also provided in the member 28 between the left peripheral edge thereof and the opening 34 so that the two parts 33a and 331) are connected only through the segment 33c. With this construction, it is necessary to spread apart the ends of the two parts 330 and 33b in order to cause the edge surfaces of the opening 34 clampingly to engage the bearing surfaces of the pivot pin 35 upon which the camming element 3| is mounted. To this end, the push button 29 is provided with two apertures 29b and 29c which extend longitudinally thereof and are separated by a camming portion 29d of tapering cross section, that may be projected between the ends of the two parts 33a and 33b to spread these parts apart. More particularly, the free end of the part 33a. is projected within the aperture 22b to slidably support the push button 29. For the purpose of limiting the movement of the push button 29 longitudinally of the two parts 33a and 33b, the part 33a is provided at its upper edge with an elongated slotted portion 33c the opposite ends of which are adapted to abut a pin 31a extending transversely of the push button 29 through the slot 3342. The lower edge surface of the aperture 29c tapers inwardly away from the lower edge surface of the aperture 291) to form a camming surface which bears against the tapered camming surface 33! of the part 33b, and is operative to spread the two parts 33a and 33b apart when the portion 29b of the push button is projected therebetween.

From the above explanation it will be understood that normally the .pushbutton 29 occupies the position illustrated in Fig. 7 of the drawings, such that the pin 31a abuts the left edge of the slot 33c and the major portion of the cam 29d is inserted between the end portions of the two parts 33a and 33b. With these two parts thus spread apart, the opposite edge surfaces of the opening 34 are pivoted inwardly toward each other to clampingly engage the bearing surfaces of the pivot pin 35 and thus rigidly hold the cam element'3l against pivotal movement relative to the carriage member 28. In this case also, the connecting segment 33c acts as the pivot point or pivot connection between the two parts 33a and 33b and is normally under stress. In Order to adjust the cam element 3| relative to the carriage member 28, thereby to change the signal channel to which this cam element is capable of tuning the receiver, the push button 29 is pulled outwardly until the pin 31a abuts the right edge of the slot 33c. Incident to this movement of the push button 28, the camming portion 29d of the push button is withdrawnfrom between the ends of the two parts 33a and 33b to relieve the connecting segment 330 of the stresses normally imposed thereon. Due to the inherent resiliency of this segment, the two parts 33a and 33b are pivoted toward each other and the oppositely disposed edge surfaces of the opening34 are moved away from each other as the camming portion 29d of the push button 29 is withdrawn from between the two parts 33:: and 331), Thus the clamping pressure exerted upon the bearing surface of the pivot pin 35 is relieved to permit this pin to be pivoted within the opening 34. Accordingly, the cam element 3| may be readily adjusted to any desired position or setting. After the desired setting of the cam element is established, the push button 29 may again be pushed inwardly until the pin 31a again abuts the left edge of the slot 33c, thereby to spread the two parts 33a and 33b apart and thus restore the clamping pressure normally exerted upon the bearing surface of the pivot pin 35. Thus the arrangement of the parts included in the embodiment of the selector unit shown in Figs. 7 and 8 of the drawings is such that the force exerted upon the push button 29 for the purpose of actuating the treadle bar IS, in no way tends to decrease the clamping pressure exerted upon the bearing surface of the pivot pin 35. On the contrary, the force exerted upon the push button 29 to set the treadle 'bar l9 has the effect of maintaining the camming portion 29d of the push button firmly wedged between the two parts 33a and 33b to prevent the pivot pin 35 from working loose within the opening 34.

In the third improved embodiment of the selector unit structure, as illustrated in Figs. 9, 10 and 11 of the drawings, the lower portion of the carriage member 28 cooperates with an additional member 45 to provide a pair of tongs within which the holding part or pivot pin 35 is clamped to restrain the cam element 3| against pivotal movement relative to the carriage member 28. More specifically, the carriage member 28 is provided with a holding blade 46 which cooperates with the blade portion 45a of the member 45 to define a, circular opening 34:: within which the pivot pin 35 may be inserted. The part 45 is pivotally mounted at 41 upon the blade portion 46 of the carriage member 28 and is provided with a handle 45b which extends substantially parallel with the elongated part 33a of the carriage member. With this construction, it is necessary to squeeze the two

parts

33a and 45a together in order to bring the edge surfaces of the opening 34a. into clamping engagement with the bearing surface oi'the pivot pin 35. To this end, a push button 29, having a construction substantially similar to that shown in Figs. 7 and 8 of the drawings, is slidably supported upon the part 33a and is provided with apertures 29!: and 29a within which the end portions of the two parts 33a and 45b respectively extend. The aperture 291) within which the end of the carriage member part 33a is slidably received, together with the arrangement for limiting movement of the push button 29 longitudinally of the two parts 33a and 33b, are exactly the same as de- 9 scribed above with reference to Figs. '1 and 8 of the drawings. In order to provide for pivotal movement of the two parts 33a and 45b toward each other as the end portions of these two parts left edge of the slot 33e, such that the pivot pin 35 is clamped between the opposite edge surfaces of the opening 34a. To release this pin for adjustment of the cam element 3|, the push button 29 is pulled outwardly until the pin 31a engages the right end of the slot 33e, thereby to permit the part 45b to move away from the part 33a and thus release the pin 35 for pivotal movement within the opening 34a. After the cam element 3| is thu adjusted to the desired setting, the push button 29 may again be pushed inwardly until the stop pin 31 engages the left end of the slot 33c. Incident to this movement of the push button 29 relative to the carriage member 28, the two parts 33a and 45b are pivoted toward each other to bring the inner edges of the

blades

45a and 34a into clamping engagement with the pivot pin 35 and thus restrain the cam element 3! against pivotal movement relative to the carriage member 28.

From the above explanation it will be understood that in each of the three embodiments of the control or selector unit, a construction of the utmost simplicity is utilized for adjustably supporting the cam element 3| upon the carriage member of the unit. Thus, in each of the three embodiments of the invention, screws, levers, springs, and the like, of the character normally utilized to permit adjustment of the cam element, are completely eliminated. In fact, in

. the two embodiments of the structure which are illustrated in the first eight figures of the drawings, the carriage member is of one-piece construction and is capable of being formed from fiat stock by a single stamping operation. Also, in the two embodiments of the invention shown in Figs. 7 to 11, inclusive, of the drawings, looking levers are completely eliminated by directly forming the camming structure as an integral part of the push button and the carriage member. If desired, a push button of the character illustrated in Figs. 9 and 10 of the drawings may be utilized in conjunction with the carriage member shown in Figs. 1 to 6, inclusive, of the drawings in order to eliminate the lever 32 from the selector unit structure. Not only is the improved selector unit simple in the extreme, but in addition, it occupies very little space and may readily be operated without supplementary tools for the purpose of adjusting the setting of the cam element provided therein.

While different embodiments of the invention have been disclosed, it will be understood that various modifications may be made therein, which are within the true spirit and scope of the invention.

I claim:

1. In a tuning device for a radio set, a movable selector unit including two elongated spaced apart and substantially parallel extending parts and another part connecting said two parts at corresponding ends thereof for relative movement therebetween, adjustable means including a pivot pin disposed between said two elongated parts at said corresponding ends thereof, and means including a push button substantially enclosing the opposite ends of said two parts and including means acting upon the opposite ends of said elongated parts to retain them in positions such that said pivot pin is clamped therebetween, thereby to holdsaid adjustable means in an adjusted position.

2. In a tuning device for a radio set, a movable selector unit including two elongated spaced apart and substantially parallel extending parts and another part connecting said two parts at corresponding ends thereof for relative movement therebetween, adjustable means including a pivot pin disposed between said two parts at said corresponding ends thereof, a push button supported upon one of said two parts at said opposite end thereof and operative to move said unit, 'and means including a portion of said push button for acting upon the opposite ends of said two parts to retain said two parts in positions such that said pivot pin is clamped therebetween, thereby to hold said adjustable means in an adjusted position.

3. In a tuning device for a radio set, a movable selector unit including two elongated spaced apart and substantially parallel extending parts and another part connecting said two parts at a point intermediate their ends for relative movement therebetween, adjustable means including apivot pin disposed between said two parts at corresponding ends thereof, a push button supported upon one of said two parts at said opposite end thereof and operative to move said unit, and means including a portion of said push button for producing relative movement between the opposite ends of said two parts in order to clamp said pivot pin between said corresponding ends of said two parts and thus hold said adjustable means in an adjusted position.

4. In a tuning device for a radio set, a movable selector unit including a pair of holding tongs having oppositely disposed holding surfaces adjacent one end thereof and provided with elongated handle parts, adjustable means including a pivot pin disposed between said holding surfaces, and,

means acting upon the ends of said handle parts and substantially enclosing said ends to maintain said pivot pin clamped between said holding surfaces, thereby to hold said adjustable means in an adjusted position.

5. In a tuning device for a radio set, a movable selector unit including a pair of holding tongs having oppositely disposed holding surfaces adjacent one end thereof and provided with elongated handle parts, adjustable means including a pivot pin disposed between said holding surfaces, a push button supported upon the end of one of said handle parts and operative to move said unit, and means including a portion of said push button for producing relative movement between said handle parts in order to clamp said pivot pin between said holding surfaces and thus hold said adjustable means in an adjusted position.

6. In a control device, a movable selector unit including a pair of holding tongs having oppositely disposed holding surfaces adjacent one end thereof and provided with elongated handles, adjustalble means including a part disposed between 11 said holding surfaces, an actuating member movably mounted upon at least one of said handles and enclosing a portion of at least one of said handles, and means including coacting camming surfaces of said member and one of said handles for producing relative movement between said handles in response to relative movement. between said member and said handles. thereby to clamp said part between said surfaces and thus hold said adjusting means in anaddusted position.

'1. In a control device, a movable selector unit including a pair of holding tongs having oppositely disposed holding surfaces adjacent one end thereof and provided with elongated handles, adjustable means including a part disposed between said holding surfaces, one of said handles being provided with a camming surface at one end thereof, and an actuating member in the form of an enclosure slidably mounted upon the end of the other handle and provided within said enclosure with a camming surface engaging the camming surface of said one handle, said camming surfaces being operative to produce relative movement between said handles in response to relative sliding movement between said member and said handles, thereby to clamp said part between said holding surfaces.

8. In .a control device, a movable selector unit including a pair of holding tongs having oppositely disposed holding surfaces adjacent one end thereof and provided with elongated handles, adjustable means including a, part disposed between said holding surfaces, an actuating member rigidly fastened to one of said handles, and means including coacting camming surfaces associated with said member and the other of said handles for producing relative movement between said handles in response to relative movement between said camming surfaces, thereby to clamp said part between said holding surfaces and thus hold said adjusting means in an adjusted position.

9. In a control device, a movable selector unit including a pair of holding tongs having oppositely disposed holding surfaces adjacent one end thereof and provided with elongated handles, adjustable means including a part disposed between said holding surfaces, one of said handles being provided with a camming surface at one end thereof, an actuating member slidably mounted p n the end of the other handle and substantially enclosing a portion of at least one of said handles provided with a camming surface engaging the camming surface of said one handle, said camming surfaces being operative to produce relative movement between said handles in response to relative sliding movement between said member and said handles, thereby to clamp said part between said holding surfaces, and means carried by said actuating member and coacting with portions of said other handle for limiting the relative sliding movement between said member and said handles.

10. A control unit for controllable apparatus, comprising a pair of parallel extending elongated parts having oppositely disposed clamping surfaces adjacent corresponding ends thereof, means connecting said parts for relativ movement therebetween, adjustable means including a pivot pin disposed between said clamping surfaces, and camming means coacting with the opposite ends of said two parts to produce relative separation of said opposite ends, thereb to clamp said pivot pin between saidclamping surfaces.

11. A control unit for controllable apparatus, comprising two parallel extending elongated parts '12 having oppositely disposed clamping surfaces adjacent corresponding ends thereof, means intermediate the ends of said par-ts connecting said parts for relative movement therebetween, adjustable means including a pivot, pin disposed between said .clamping surfaces, one of said two parts having a camming surface, and a camming member slidably mounted upon the other of said parts for movement longitudinally of said two parts, said camming member coacting with said camming surface to produce relative movement between said two parts in response to relative sliding movement between said two parts and said member, thereby to clamp said pivot pin between said clamping surfaces.

12. A control unit for controllable apparatus, comprising two parallel extending elongated parts having oppositely disposed clamping surfaces -adjacent corresponding ends thereof, means connecting said parts for relative movement therebetween, adjustable means including a pivot pin disposed between said clamping surfaces, one of said two parts having a camming surface and a push button slidably mounted upon the opposite end of the other of said parts for movement 1ongitudinally of said two parts, said push button having an apertured portion within which the opposite end of said one part is received and including an internal camming surface for coacting with said first-named camming surface to produce relative movement between said two parts in response to relative sliding movement between said two parts and said member, thereby to clamp said pivot pin between said clamping surfaces.

13. In a control device, a movable control unit including a member having two integrally formed parts positioned in the same plane and relatively movable therein and havin a clamping surface therebetween, adjustable means including a pivot pin disposed within said surface and solely clamped therein, and means including a push button for holding said two parts in relative posit-ions such that said pivot pin is clamped within said surface.

14. In a control device, a movable control unit including a flat member having two elongated parts which are integrally interconnected at corresponding ends thereof through a segment of small cross sectional area and are provided with cooperating clamping surfaces at said corresponding ends thereof, adjustable means including a pivot pin disposed within said surfaces, and means including an enclosure for the opposite ends of said two parts to stress said segment and clamp said pivot pin within said surfaces.

15. In a control device, a movable control unit including a flat member having two elongated parts which are integrally interconnected at corresponding ends thereof through a segment of small cross sectional area and are provided with cooperating clamping surfaces at said corresponding ends thereof, adjustable means including a pivot pin disposed within said surfaces, and an actuating button supported at the opposite ends of said two parts and provided with means acting at such opposite ends within said button for producing relative movement between said opposite ends, thereby to clamp said pivot pin within said surfaces.

16. In a control unit, adjustable means including a pivot pin, a fiat unitary movable member including an elongated portion provided with an opening at one end thereof for receiving said pivot pin and with a longitudinally extending slot which extends to the opposite end thereof and divides said portion into two substantially separated parts, and an enclosure means for said opposite end acting to squeeze said two parts toward each other, thereby to clamp said pivot pin within said opening.

1'7. In a control unit, adjustable means including a pivot ,pin, a flat unitary movable member including an elongated portion provided with an opening at one end thereof for. receiving said pivot pin and with a longitudinally extendingslot which opens into said opening and divides said portion into two substantially separated parts, and pivotally mounted means clampingly efl'ecting said two parts at the end of said elongated portion opposite said opening end, thereby to clamp said pivot pin within said opening.

18. In a control unit, adjustable means including a pivot pin, a flat unitary movable member including an elongated portion provided with an opening at one end thereof for receiving said pivot pin, said member having a slot extending from said opening to the outer edge thereof and with another slot extending longitudinally inward from the opposite end of said elongated portion to a point adjacent said opening, thereby to divide said elongated portion into two integral parts connectedvtogether by an integral portion positioned intermediately the two slots,

and means clampingly engaging said two parts,

thereby to clamp said pivot pin within said p nin 19. In a longitudinally movable selector unit for control apparatus, two elongated relatively movable parts connected at one end and sep-- arated at the other end, an adjustable member having a pivot pin supported by said two parts at said one end, a hollow push button with said two separated ends extending into said pu sh button, and means including said push button acting on said two separated ends within the push button to move said separated ends toward one another to move-said parts and clampingly engage the pivot pin at said one end.

20. In a. control device, a movable control unit including a flat member having two elongated parts, means for interconnecting said parts adjacent corresponding ends thereof, said correspending ends of said parts being provided with cooperating clamping surfaces, adjustable means including a pivot pin disposed between said clamping surfaces, and an actuating button supported at the opposite ends of said two parts and provided with means acting at said opposite ends within said button for producing relative movement between said opposite ends thereby to clamp said pivot pin between said clamping surfaces.

21. In a control unit, adjustable means including a pivot pin, a flat unitary member including an elongated portion provided with an opening adjacent one end thereof for receiving said pivot pin and with a longitudinally extending slot which extends to the opposite end thereof and divides said portion into two substantially separated parts, and an enclosure means for the opposite ends of said parts acting to cause relative movement of said two parts, thereby to clamp said pivot pin within said opening.

22. In a longitudinally movable selector unit for control apparatus, two elongated relatively movable parts connected at a point considerably.

closer to one corresponding end of each of said relatively movable parts than to the other corresponding end and separated atthe other end, an adjustable member having a pivot pin supported by said two parts at said one end, a hollow push button with said two separated ends extending into said push button, and means associated with said push button for acting on at least one of said two separated ends within "said push button to produce relative movement of said separated ends to move said parts and clampingly engage said pivot pin supported by said two parts.

. ALEXANDER W. PLENSIER.

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UNITED STATES PATENTS