US3521502A - Vernier control device - Google Patents

Description

July 21, 1970 R. D. HOUK VERNIER CONTROL DEVICE 2 Sheets-Sheet 1.

Filed July 29, 1968 INVENTOR. RICHARD D. HOUK ATTORNEYS United States Patent VERNIER CONTROL DEVICE Richard D. Honk, Stow, Ohio, assignor, by mesne assignments, to North American Rockwell Corporation, Pittsburgh, Pa., a corporation of Delaware Filed July 29, 1968, Ser. No. 748,309 Int. Cl. F16c 1/10 US. Cl. 74-502 4 Claims ABSTRACT on THE DISCLOSURE A control device for moving the core of a push-pull control cable axially with respect to the casing thereof in gross amounts and, selectively, in accurately fine, or vernier, increments. The control device has a housing that is secured to the casing of the control cable. A guide sleeve is pivotally mounted in said housing and slidably receives an operating rod, one end of which is connected to the core of the push-pull control cable. The other end of the operating rod presents a control knob exteriorly of the housing. A spring means biases the pivotally mounted guide sleeve such that threads on the exterior surface of the operating rod are constantly urged toward engagement with mating tooth means presented from the housing. Rotation of said control knob, and thus said operating rod, provides vernier operation; a transverse force applied to said control knob sufficient to overcome said spring means and disengage the thread means from said tooth means followed by axial translation of said operating rod provide gross operation.

BACKGROUND OF THE INVENTION The present invention relates generally to controls for push-pull cables. More particularly, the present invention relates to a control device for actuating the core of a push-pull control cable with respect to the casing thereof. Specifically, the present invention relates to a control device for moving the core of a push-pull control cable with respect to the casing thereof in gross amounts, and, selectively, with accurately fine, or vernier, increments.

Push-pull control cables are generally well known to the art as devices capable of transmitting mechanical motion in either direction when at least the ends of the cable casing are satisfactorily clamped in position. Push-pull cables, being flexible, are particularly suitable for installations where the cable is required to extend through a number of bends between a control station and a remote, controlled station. Such cables are constructed to have a core slidably received in a support casing and are commonly utilized in conjunction with such devices as throttle controls. For many such installations it is imperative that the control be capable of providing not only quick, major adjustments in gross but also fine, accurate, Vernier adjustments. i

Heretofore, several known control devices have been employed to provide such a result. The most widely known construction is quite complex in that it requires that the tubular support attached to the cable casing slidably receive a tubular adjusting member attached to the cable core and in which is also slidably received a release rod for positioning a ball-like engaging member into and out of mating engagement with the threaded interior of the tubular support member. A primary control knob is secured to the adjusting member and coaxially receives a secondary control knob secured to the release rod. To make a Vernier adjustment the operator need only turn the primary control knob in the appropriate direction. How ever, for gross adjustment the operator is required to actuate the secondary control knob axially with respect to the 3,521,502 Patented July 21, 1970 primary knob and, while maintaining the secondary control knob actuated against the biasing action of the spring means, move the primary control knob axially in the desired direction.

Under even the most favorable conditions considerable manual dexterity is required to operate such a control. In moments of stress the results can be disastrous.

In order to alleviate the hazards imposed by the requirement of the aforementioned dextrous manipulation, many substitute constructions have been proposed. Exemplary of such proposals is a complex construction which eliminates the secondary control knob. The construction employs a control knob nonrotatably and axially slidably mounted on a tubular adjusting member which interacts with a release rod by a plurality of spring biased, pivotal dogs carried on the tubular adjusting member and engageable between the knob and release rod. For gross control the operator must always apply sutficient pressure to overcome the spring bias and thereafter move the control knob in the desired direction. Accordingly, approximation of incremental adjustments in gross are most difiicult, if not impossible, to obtain.

Similarly, another construction utilizes an annularly interrupted spring sleeve embracing a frame sleeve in which an operating rod is slidably received. The spring sleeve biases a ball into engagement with the thread means on the exterior of the opearting rod. Here too, in gross control can be eifected only after sufficient force is applied to the control knob to overcome the preloading resistance offered by the spring means to maintain the ball in engagement with the thread means.

In the afore-described configuration the operating rod Was, and could be, moved only axially. This factor itself engendered the necessity for complicated mechanisms to effect selection of in gross or Vernier operation.

There is one prior known construction that obviated the necessity for complex mechanisms to promote selected Vernier or in gross operation by eliminating the restriction that the operating rod move only axially. In that control the operating rod was mounted so that it could be first swung to select the type of operation desired and thereafter removed axially to effect the in gross or Vernier operation selected. This prior art construction connects the operating rod pivotally to the end of the core. The rod itself is threaded and swingable into and out of engagement with a half nut. When the rod is in engagement with the half nut, Vernier operation is accomplished by rotation of the control rod. When the rod is out of engagement with the half nut, gross operation is effected merely by translation of the control rod.

With such a control, however, the angle through which the operating rod must swing to change from vernier to gross operation varies directly with the particular setting. That is, when the pivotal connection between the operating rod and the cable core is remote from the half nut, the operating rod needs swing through only a modest angle to engage, or disengage, the half nut. This angle increases markedly as the pivotal connection between the rod and the cable core approaches the half nut.

The inherent disadvantages in such a control are readily appreciated. During in gross operation the angle must be constantly varied to assure that the control does not catch. Moreover, as the pivotal connection between the cable core and the operating rod approaches the half nut, the distance through which the knob, or handle, on the end of the rod must move to maintain gross control is compounded by the constantly increasing angularity. This exaggerated distance is a constant hindrance to facile operation, and this prior art control has not, therefore, met with favorable reception.

3 SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide, for the core of a push-pull control cable, a control device in which gross or vernier operation may be selected by swinging the operating rod through a fixed angle irrespective of the previous control setting.

It is another object of the present invention to provide a control device, as above, which employs only a single control knob.

It is a further object of the present invention to provide a control device, as above, that may be converted from vernier to gross operation merely by applying a modest transverse force to the control knob, in gross operation being thereafter effected by axial translation of the control knob with a return to vernier control occasioned merely by releasing the application of transverse force to the control knob.

It is a still further object of the present invention to! provide a control device, as above, that is relatively uncomplex and economical to manufacture and maintain.

These and other objects which will become apparent from the following specification are accomplished by means hereinafter described and claimed.

In general, a control device according to the concept of the present invention has a housing adapted to be connected to the casing of a push-pull control cable. A guide sleeve is mounted in the housing for pivotal movement about a fulcrum located substantially adjacent the connection of the control cable casing to the housing. An operating rod is slidably received Within the guide sleeve, and one end of the operating rod is connected to the core of a push-pull control cable. The other end of the operating rod is secured to a control knob located exteriorly of the housing.

A tooth means is presented from the housing for selective engagement with thread means on the exterior of the operating rod, the tooth means being preferably remote from the fulcrum about which the guide sleeve pivots. A spring means operatively connected between the housing and the guide sleeve biases the guide sleeve about its fulcrum so as to urge the thread means on the operating rod into engagement with the tooth means presented from the housing.

Vernier operation is effected by rotation of the control knob. Gross operation is selected merely by applying a transverse force to the control knob sufficient to overcome the spring means and thereby disengage the thread means on the operating rod from the tooth means presented from the housing. With gross operation thus selected it is effected by axial translation on the control knob.

One preferred embodiment is shown by way of example in the accompanying drawings and described in detail without attempting to show all of the various forms and modifications in which the invention might be embodied; the invention being measured by the appended claims and not by the details of the specification.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation, partly broken away and partly in section, depicting a pushull control cable operatively connected to a control device embodying the concept of the present invention with the mechanism positioned to provide vernier control;

FIG. 2 is a top plan view of the control device depicted in FIG. 1;

FIG. 3 is an enlarged cross section taken substantially on line 33 of FIG. 1;

FIG. 4 is an enlarged cross section taken substantially on line 4-4 of FIG. 1;

FIG. 5 is an enlarged cross section taken substantially on line 55 of FIG. 1 depicting the relationship of the mechanism during vernier operation in solid line representation and the relationship of the mechanism during gross operation in chain line representation; and

4 FIG. 6 is a view similar to FIG. 1 depicting the mechanism positioned to provide gross control.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings, the improved control embodying the concept of the present invention is indicated generally by the numeral 10 and is depicted as being operatively connected to a push-pull control cable 11. The push-pull control cable 11 includes a core 12 and casing 13 in which the core 12 is reciprocally slidable.

The prior art knows many casing constructions, one of which is depicted environmentally herein and comprises a plurality of wires 14 contiguously laid in the form of a helical coil about the radially outer surface of an inner, flexible tube 15 that extends the full length of the casing 13. An outer flexible cover 16 encases coil of wires 14 and extends along the entire casing to within a short distance from the ends of the wires 14.

A fitting 18 is received over the end of the coil of wires 14 and cover 16 and is securely attached thereto, as by swaging. The fitting 18, and thereby the casing 13, is connected to the housing 19 of control 10. The housing 19 may be secured to an instrument panel 20 as by bolts 21 that extend through both the panel 20 and mounting tabs 22 extending laterally from the housing 19.

The housing 19 is of generally inverted U-shaped cross section with two, opposed, spaced, side walls 23 and 24 extending downwardly from the web or base, wall 25. To secure the cable casing 13 within housing 19 an anchor bushing 26 may be employed. The anchor bushing 26 is closely fitted within the housing 19 with an aligning nub 28 extending outwardly therefrom matingly received within a bore 29 in the web wall of the housing 19.

The anchor bushing 26 is bifurcated with a pair of spaced legs 30 and 31 extending outwardly from the body portion 32 to define an arch 33 therebetween. The arch 33 engagingly receives a portion of the outer surface of the end fitting 18. A rib 34 extends from the arch 33 along at least a portion of the opposed legs 30 and 31 to mate with a portion of a corresponding annular recess 35 in the outer surface of the end fitting 13. A lock rivet 36 extends between the legs 30 and 31 and is received within the recess 35 in fitting 18 on the side thereof op posite to arch 33. With the fitting 18 so received, the cable casing 13 is anchored against axial displacement with respect to the control 10.

Also mounted within the housing 19 is a guide sleeve 40. The guide sleeve 40, which may be made in opposed, longitudinal sections 40a and 40b suitably riveted together as at 38 and 39, is mounted Within the housing 19 to pivot about a fulcrum located in preferably close proximity to the end fitting 18. As shown, a pin 41 adjacent the anchor bushing 26 may comprise the fulcrum. The fulcrum pin 41 extends between the opposed side walls 23 and 24 of the housing 19 and is rotatably received Within a bore 42 through a mounting ear 43 on one end of the guide sleeve 40.

The guide sleeve 40 is also axially bored, as at 44, slidably to receive an operating rod 45. One end of the rod 45 extends axially outwardly of the sleeve 40, and housing 19, to mount a control knob 46. The opposite end of the rod 45, within sleeve 40, is attached to the core 12 of the push-pull control cable 11.

Inasmuch as the operating rod 45 will rotate with respect to the housing 19 during vernier adjustment, as is more fully hereinafter described, and because the cable core 12 is often attached at the remote controlled station in such a Way that rotation thereof would be undesirable, it is preferable that the operating rod 45 be rotatably attached to the core 12. Exemplary of a construction that provides such a result, a cylindrical plug 4-8 may be swaged or otherwise afiixed to the core 12. The plug 48 is rotatably received within an axial bore 49 in rod 45. A

retaining washer 50 is positioned within the bore 49, in the axially outer end of plug 48, and may be retained therein by upsetting, or dimpling, the end of rod 45, as at 51.

Near the end of sleeve 40 opposite mounting ear 43 is a gate 52. The gate 52 comprises an aperture through the sleeve 40 to expose at least a portion of the operating rod 45. A tooth block 53 is secured to the housing 19 such that the teeth 54 thereof will extend through the gate 52 and intermesh with conforming threads 55 on the radially outer surface of the operating rod 45. The tooth block 53 is closely fitted within the housing with an aligning nub 56 extending outwardly therefrom matingly received within a bore 58 in the web wall 25 of the housing 19. A pin 59, that extends through registered bores 60 and 61 in the opposed side Walls 23 and 24, respectively, of the housing 19, is press fit within a bore 62 through tooth block 53 to retain the latter fixedly within the housing 11.

The ends of the pin 59 extend transversely beyond the side walls 23 and 2-4 to present pommels 63 and 64 behind which the end loops 65 and 66 of coil tension springs 68 and 69, respectively, can fasten. A similar pin 70 is press fit transversely through the sleeve 40 in spaced opposition to pin 59 and is similarly pomrneled, at 71 and 72, to retain the opposed end loops 73 and 74 of springs 68 and 69.

Suitable arcuate slots 75 and 76 are provided in the side walls 23 and 24 of housing 19 to permit the guide sleeve 40 to pivot about fulcrum pin 41 without interfering contact between the pin 70 and the housing 19.

Although a variety of designs for the teeth 54 on block 53 and the threads 55 on operating rod 45 may be utilized, the acme threads depicted work very well for this control.

With the teeth 54 intermeshed with the threads 55 critical axial translation of core 12 can be effected by rotation of knob 46. Should gross translation of the core be desired, or required, one merely applies a suflicient transverse force against knob 46 to overcome the biasing action of springs 68 and 69 and disengage the threads 55 on rod 45 from the teeth 54 on block 53. With the teeth and threads thus unmeshed the rod 45 may be translated axially in gross.

To convert from gross to vernier operation one releases the transverse force applied against the knob 46 and the biasing action of springs 68 and 69 swings the guide sleeve 40 so as to move the threads 55 on rod 45 toward the teeth 54 on "block 53. If acme threads 55 are utilized, they may not make instant meshing contact with teeth 54, but with the biasing action imparted by springs 68 and 69 as soon as the rod 45 is either partially rotated or moved axially the threads 55 will be swung into meshing engagement with the teeth 54 so that rotation of knob 46 effects vernier operation.

It should now be apparent that irrespective of the axial position of the control knob 46 disengagement of the threads 55 on rod 45 from the teeth 54 on block 53 will be accomplished by rotation of guide sleeve 40 through a fixed angle 80.

For example, to allow a 3" axial travel for the operating rod 45, and thereby core 12, a span of approximately three and one-half inches is required between the pivot pin 41 and the teeth 54 on block 53. Using a outer diameter operating rod with acme threads having a depth of approximately 0.05 6 inch an assured clearance between the threads 55 and teeth 54 is provided if the threads 55 are translated at least 0.075 inch away from tooth block 53 against the biasing action of springs 68 and 69i.e., the rod 45 will be swung through an angle of approximately 1 14 about pivot pin 41 to disengage the threads 55 from teeth 54. And, this angle Will remain constant throughout the 3" axial travel provided for rod 45.

However, should the operating rod be pivoted onto thecore, as is done in the prior art construction discussed earlier, the angle through which the rod must be swung to disengage the teeth will increase markedly as the operating rod approaches the outer extent of its travel. For example, should an identical operating rod with acme teeth be pivoted onto the core, the same clearance provided above would require a variation in angular displacement from approximately 114 at the innermost extent of its travel to approximately 8 32 at the outer extent of the 3" travel.

To thus compound the distance through which the knob 46 must, travel to change from vernier to gross control greatly decreases the facility with which the control is operated. A control embodying the concept of the present invention thus provides a fixed angular displacement through which the operating rod must be swung to change from vernier to gross operation and otherwise accomplishes the objects of the invention.

What is claimed is:

1. A vernier control device for a push-pull control cable, said control cable having a core and easing, said control device comprising a housing secured to said control cable casing, a guide sleeve pivotally mounted in said housing, an operating rod slidably received in said guide sleeve, said operating rod operatively secured to said cable core, thread means on said operating rod, tooth means presented from said housing, spring means biasing the teeth on said operating rod into engagement with the teeth presented from said housing.

2. A vernier control device, as set forth in claim 1, in which the guide sleeve is pivoted on a fulcrum, said fulcrum being located substantially adjacent the connection of said cable casing to said housing and remote from the teeth means presented by said housing for engagement with the thread means on said operating rod.

3. A vernier control device, as set forth in claim 2, in which the spring means is connected between said housing and said guide sleeve.

4. A vernier control device, as set forth in claim 3, in which a gate is provided in said guide sleeve and the tooth means engages said thread means through said gate.

References Cited UNITED STATES PATENTS 2,101,160 12/1937 Weber 74502 2,132,919 10/1938 Arens 74502 2,386,767 10/1945 Arens 74-502 2,848,902 8/1958 Hale 74502 WESLEY S. RATLIFF, JR., Primary Examiner 3 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 521 502 D t d July 21 1970 Inventor(s) RICHARD D. HOUR It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 1, after "in" insert engagement with Sibfifii Aim SEALED mv 1 mm M Hadron]- n 2 mm L m I- 1 Offioer Y Oomiaaiom of MI

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