US3668937A

US3668937A - Key slide locking mechanism

Info

Publication number: US3668937A
Application number: US129882A
Authority: US
Inventors: Donald V O'neal
Original assignee: Motorola Inc
Current assignee: Motorola Solutions Inc
Priority date: 1971-03-31
Filing date: 1971-03-31
Publication date: 1972-06-13
Anticipated expiration: 1989-06-13

Abstract

A key slide locking mechanism for a pushbutton tuner having a boss located on the plunger rod which engages an interface of the pushbutton slide in the locked condition, and is disengaged from the pushbutton slide in the unlocked condition. With the slide and rod in the unlocked condition the rotatable presettable tuner cam joined to the plunger rod can rotate through an arc limited by an indexing slot and pressure pin in the cam. In the locked or contracted position the boss on the plunger rod engages the interface of the pushbutton slide biasing the rod and slide apart and causing the pressure pin indexed through the cam, plunger rod and pushbutton slide and secured by a ''''C'''' washer to clamp the cam to the plunger rod.

Description

United States Patent ONeal [4 1 June 13, 1972 [54] KEY SLIDE LOCKING MECHANISM Primary Examiner-Miton Kaufman 72 Inventor: Donald v. ONeal, River Grove, Ill. Awhele [73] Assignee: Motorola, Inc., Franklin Park, Ill. [57] ABSTRACT Filed: March 1971 A key slide locking mechanism for a pushbutton tuner having 1 L J 1 9 8 2 a boss located on the plunger rod which engages an interface [2 1 App No 2 8 of the pushbutton slide in the locked condition, and is disengaged from the pushbutton slide in the unlocked condition. [5 2] U.S. Cl. ..74/ 10.33, 334/7 w the Slide and rod in the unlocked condition the rotatable t "Fl6h presettable tuner cam joined to the plunger rod can rotate [58] Field of Search ..74/ 10.33, 10.31, 10.29, 10.27, through an are limited by an indexing Slot and pressure pin in the cam. In the locked or contracted position the boss on the plunger rod engages the interface of the pushbutton slide bias- [56] References cued ing the rod and slide apart and causing the pressure pin in- UNITED STATES PATENTS dexed through the cam, plunger rod and pushbutton slide and 3 960 R b k 74/10 33 secured by a C washer to clamp the cam to the plunger rod. 2,930,241 0 ac 5 Claims, 6 Drawing Figures 4 2 30 l4 I4 44 I 4 6 4| my fi rmttmumlm 3,668,937

Inventor FIG 5 B DONALD v. O'NEAL ATTYS.

KEY SLIDE LOCKING MECHANISM BACKGROUND OF THE INVENTION Locking mechanisms for key slides in pushbutton tuners have required some type of spring clamping means for locking a tuner cam to a preselected station. Some locking mechanisms used one or more strips of resilient metal in clamping the cam to preventrotation. Usually special means are used to secure them to the plunger mechanism wherein the total effect is a great number of small parts which are costly to assemble.

SUMMARY OF THE INVENTION One object of the present invention is to provide an improved key slide locking mechanism for a pushbutton tuner.

Another object of the present invention is to produce a more economical key slide locking mechanism for pushbutton tuners which can be easily and quickly assembled.

' In one embodiment of the invention the key slide locking mechanism includes a pushbutton slide and a plunger rod having a T slug on the plunger rod fitted through a guide slot in the pushbutton slide and a second guide means for maintaining longitudinal slideable engagement of the slide and rod. A presettable tuner cam is joined to the plunger rod by a rivet permitting rotation limited only by a pressure pin fitting through the cam slot. The pressure pin extends through the cam slot,a hole in the plunger rod and an indexing slot in the pushbutton slide. A C washer prevents the pin from disengaging from the slide, rod and cam.

In a first position, a boss on the plunger rod contacts the pushbutton slide and biases them apart with the clamping action of the pressure pin preventing the tuner cam from rotating. In the second position the rod and slide are extended and disengaged with the boss fitting into a detent in the pushbutton slide. The tuner cam is no longer locked and may consequently be adjusted to a different preselected channel fixed by the rotational position of the treadle mechanism which has been set by manual tuning.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view of the pushbutton tuner assembly of the invention in the locked condition;

FIG. 2 is a side elevation view of the locking mechanism in the unlocked condition;

FIG. 3 is a top plan view in cross-section of the locking mechanism in its locked condition taken along line 3-3 as shown in FIG; 2;

FIG. 4 is a top plan view of the locking mechanism in the unlocked condition;

FIG. 5 is a front elevation view of the tuner cam; and

FIG. 6 is a side cross-sectional view of the tuner cam taken along line 6-6 ofFIG. 5.

DETAILED DESCRIPTION Referring to FIG. 1 there is shown a pushbutton slide 14 which is connected to a pushbutton 12 shown installed in a radio 11. It is movable in an aperture in the face 10 of the radio. Several of these pushbuttons will normally be found in line, each being preset to a specific station.

To activate the tuner, pushbutton 12 is moved from the left to right. Pushbutton slide 14, the plunger rod 16, the cam 18 and other elements follow therewith. The cam 18 engages the

parallel bars

22 and 24 of a treadle structure 20. Pushing the pushbutton 12 further causes a series of gearing devices to either advance or reverse the tuning mechanism of the radio to the preselected station. After the pushbutton is released, the spring 26 returns pushbutton slide 14 and pushbutton 12 to inactive positions.

For presetting the key slide 16, the pushbutton 12 is pulled out, or moved from right to left in FIG. 1. This process unlocks the cam 18 by disengaging the boss 40 (FIG. 3) from contact with the pushbutton slide 14 interface at point 41. The boss settles into a detent 42 (FIG. 4). The pushbutton slide 14 and plunger rod 16 are extended and the presettable tuner cam is unlocked. The cam 18 may swing relatively freely around its securing means, rivet 32, through an arc permitted by the pressure pin 30 and slot 28 (FIG. 2). In this unlocked condition the head 48 of the pressure pin 30, although exerting some frictional force on the cam does not captivate or lock it relative to the plunger rod 16. By pushing in the pushbutton the cam becomes set to the position of the treadle bars as exemplified in phantom by lines 19 (FIG. 1). Pushing the pushbutton further locks the cam to the new preset position by causing the boss 40 to again engage the pushbutton slide 14 interface.

In FIG. 4 the key slide is shown in its unlocked position. The T lug 34 in the guide slot 36 of slide 14 and guide bracket, or means, 38 guiding the rod 16 accomplish longitudinal slidable engagement of the plunger rod 16 and button slide 14 as they are moved relative to one another. The cam is rotatable about the rivet 32 limited by the pressure pin joining the cam l8'to the pushbutton slide 14 and plunger rod 16. In this unlocked condition the boss is disengaged from the plunger rod 16 because of the clearance provided by the detent 42.

In FIG. 3 the boss 40 is shown engaging the pushbutton slide 14 at the interface 41 and biasing the plunger rod 16 away from the pushbutton slide 14 to lock the cam 18 in place. At all times the pressure pin 30 secured by a washer 44 (FIGS. 3 and 4) and C" washer 46 (FIGS. 3 and 4) loosely fastens the tuner cam, plunger rod, and pushbutton slide together, and it is the action of the rod 16 and slide 14 being biased apart which results in the cam 18 being clamped between the head of the pressure pin 30 and the plunger rod 16 so it cannot freely rotate. Separate securing and spring clamping devices are unnecessary since both functions are performed by the pressure pin 34 and C" washer 46, thereby reducing the number of parts resulting in a more economical key slide.

What we have, therefore, is an improved, more economical key slide for a pushbutton tuner which generally uses fewer parts than in previous devices of this kind.

I claim: I

1. In a key slide locking mechanism for use in a pushbutton tuner including in combination, a pushbutton slide, a plunger rod, means slidably joining said pushbutton slide to said plunger rod in a first position and a second position, a presettable tuner cam, pin means having a head portion and rotatably joining said tuner cam to said plunger rod and said pushbutton slide, cam means integral with said plunger rod and pushbutton slide, with said pushbutton slide and said plunger in said first position, said cam means moving said plunger rod and said pushbutton slide away from one another along said pin means thereby biasing said presettable tuner cam against said head portion of said pin to lock the same in position to prevent rotation thereof, with said slide and said rod in said second position said cam means permitting relatively free movement of said rod, slide and tuner cam along said pin whereby said tuner cam is free to rotate.

2. The key slide locking mechanism according to claim 1 wherein said means slidably joining said pushbutton slide to said plunger rod includes said pushbutton slide having a guide slot, a T slug on said plunger rod fitted into said guide slot, said pushbutton slide further having a guide bracket longitudinally displaced from said guide slot for guiding said plunger rod in spaced longitudinal motion.

3. The key slide locking mechanism according to claim 1, wherein said cam means integral with said plunger rod and said pushbutton slide includes projection means mounted to one of said plunger rod and said pushbutton slide and an interface on the other of said plunger rod and said pushbutton slide, said projection engaging said interface for biasing said plunger rod away from said pushbutton slide in said first position.

4. The key slide locking mechanism according to claim 3 wherein one of said pushbutton slide and said plunger rod includes a detent for loosely receiving said projection means on the other of said plunger rod and said pushbutton slide in said second condition.

5. A key slide locking mechanism for use in a pushbutton tuner including in combination a pushbutton slide having a guide slot and bracket guide means longitudinally displaced therefrom, a plunger rod having a T slug fitted into said guide slide and further being fitted to said bracket guide means for slidable engagement of said plunger rod with said pushbutton slide, said pushbutton slide and said plunger rod having first and second positions relative to one another, a presettable tuner cam, a pressure pin rotatably joining said tuner cam to said plunger rod and pushbutton slide, said pin being secured by a C washer to prevent disengagement of said tuner cam, plunger rod and pushbutton slide, a boss on said plunger rod being positioned for engagement with said pushbutton slide for biasing apart said rod and said slide in said first position with said pressure pin captivating said tuner cam and preventing rotational movement relative to said slide and said rod, and a detent in said plunger rod, said boss being disengaged from contact with said pushbutton slide in said second condition and being loosely received by said detent in said plunger rod with said tuner cam being rotatable relative to said slide and said rod.

* '0 I0! III II