GB2149052A

GB2149052A - Vernier control device

Info

Publication number: GB2149052A
Application number: GB8420552A
Authority: GB
Inventors: Michael Eugene Jones
Original assignee: Eaton Corp
Current assignee: Eaton Corp
Priority date: 1983-10-27
Filing date: 1984-08-13
Publication date: 1985-06-05
Also published as: GB8420552D0; DE3439453A1; JPS60113814A

Abstract

A vernier control device (60) for selectively moving an object in gross or incremental, vernier, amounts comprises a sleeve (6) disposed within an open-ended bore (5) of a housing (2) that is secured against movement with respect to the housing. One end of the sleeve is rotatably connected to the object and the sleeve is provided with at least one resilient portion (20) having thread engagement means (18) that is preferably caused to move radially outwardly to engage threads (4) on a wall (7) of the housing surrounding the sleeve by positioning an operating rod (12) in a first predetermined position within a bore (11) of the sleeve so that rotation of the sleeve moves the sleeve and the object in incremental amounts determined by the pitch of the threads and positioning the rod in a second position within the sleeve enables the resilient portion to urge the thread engagement means out of engagement with the threads enabling axial movement of the sleeve and the object in gross amounts. The device is particularly suited for controlling axial movement of a push-pull cable. <IMAGE>

Description

SPECIFICATION Vernier control device INTRODUCTION This invention relates generally to a control device for selectively moving an object in gross or vernier, incremental amounts and more particularly to such device for controlling axial movement of a push-pull cable.

BACKGROUND OF THE INVENTION Vernier control devices for use in controlling the direction and amount of axial movement of the core of a push-pull cable have been used for many years. Examples of various types of such vernier control devices are disclosed in United States Patents, 3,395,592; 3,405,567; 3,521,502; 3,643,523 and 4,050,327, the disclosures of which are incorporated herein by reference.

The control devices described in the above referenced patents and others used prior to the present invention generally feature a tubular open-ended sleeve slidably received within an open-ended bore of a housing which itself is characteristically secured against movement with respect to the cable and tubular in shape with some type of thread means secured to a wall of the housing intermediate the wall and the sleeve. The sleeve is typically able to both rotate and move axially within the bore and one end of the sleeve is operatively conected to the core of a push-pull cable having a surrounding casing that is secured to the housing.An operating rod is disposed within the sleeve that is generally able to move axially with respect to the sleeve and and the housing and is generally biased by a spring or the like into a first initial axial position within the sleeve and, upon moving the rod axially against the spring, can be moved to a predetermined second axial position within the sleeve. In other types of such controls, the operating rod does not move axially but rather can be rotated from an initial angular position within the sleeve to a second predetermined angular position within the sleeve or feature a pivotable rack and pinion arrangement such as disclosed in United States Patent 3,521,502.

All of such control devices, except the device disclosed in United States Patent 3,521,502, feature a ball that is moved radi ally outwardly through an aperture in the sleeve to engage the threads on the wall of the housing in response to either type of movement of the operating rod such that in one position, where the ball is disengaged from the thread, the sleeve is able to be moved in opposite axial directions in gross amounts along the bore and cause the cable core to be moved in corresponding gross amounts in opposite axial directions within the casing and, in the other position, when the ball is engaged with the threads, rotation of the sleeve causes the sleeve to move in opposite axial directions along the bore in more finely controlled amounts and accordingly move the cable core in finely controlled amounts in opposite axial directions within the casing.

The installation of such balls and pivotal rack and pinion arrangements in vernier control devices of the type described above is costly, time consuming and complex and a need has particularly existed for many years to provide a vernier control device for selectively controlling axial movement of a push-pull cable in gross and incremental amounts that eliminates such complex arrangements heretofore used in such devices.

SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide a vernier control device for selectively moving an object in gross or accurately fine, vernier, incremental amounts.

It is another object of this invention to provide a vernier control device for selectively moving a push-pull cable axially in gross or incremental amounts that is simpler to assemble than vernier control devices used for such purposes in the past.

It is yet another object of this invention to provide a vernier control device for selectively moving a push-pull cable axially in gross or incremental amounts that eliminates the complex and costly ball and pivotable rack and pinion assemblies heretofore used in such devices.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a cross-sectional view taken through the central longitudinal axis an embodiment of the vernier control device of the invention; Figure 1 shows a cross-sectional view taken along the central longitudinal axis of the sleeve used in the device of Fig. 1; Figure 3 shows a cross-sectional view taken along the central longitudinal axis of another embodiment of the sleeve that can be used in the vernier control device of the invention; Figure 4 shows a cross-sectional view taken along the central longitudinal axis of another embodiment of the sleeve that can be used in the vernier control device of the invention; and Figure 5 shows a partial side elevation view of the embodiment of Fig. 1 causing rotational rather than axial movement of the member being controlled.

DESCRIPTION OF SOME PREFERRED EM BODIMENTS Fig. 1 shows an embodiment of the vernier control device of the invention in the form of device 60 which is used to control gross and incremental axial movements of a push-pull cable having a core 34 reciprocally slidable within a casing 36.

Device 60 has a housing 2 having an openended bore 5 therethrough that is surrounded by wall 7 of housing 2. Although housing 2 may have any external shape, it commonly has a circular cross-sectional shape resulting in housing 2 having a substantially tubular configuration as shown in Fig. 1. Housing 2 is preferably provided with external threads 3 for securing housing 2 to a frame or the like.

Commonly spaced-apart nuts (not referenced) are threaded onto threads 3 of housing 2 and against opposite sides of a panel or the like through which housing 2 extends.

Sleeve 6 is disposed within bore 5 and is axially and rotatably moveable with respect to wall 7. Housing 2 may be secured to casing 36 by any suitable means. Preferably, housing 2 is removeably secured to casing 6 by means of a connecting member 38 as shown in Fig. 1 that has one end fixedly secured to casing 36 by crimping or swaging or the like and an opposite end secured to housing 2 by means of a rotatable nut 40 that is rotatably secured to connector 38 and is threadingly engaged with threads 41 disposed on the exterior of the end of housing 2 closest to casing 6.

Sleeve 6 is rotatably secured to the end of core 34 so that rotational movement of sleeve 6 does not apply a twist to core 34. Preferably, sleeve 6 does not apply a twist to core 34. Preferably, sleeve 6 and core 34 are releasably rotatably connected by means of lug 8 disposed at the end of sleeve 6 closest to core 34 that is removably disposed within cavity 9 of receptacle 32 secured to the end of core 34 as is well known to those skilled in the art. Alternatively, receptacle 32 may be secured to the end of sleeve 6 and lug 8 to the end of core 34 where such is desired.

Core 34 may be the core of the push-pull cable or it may be a rod like extension of the core as is well known to those skilled in the art of making push-pull cables. The vernier control device of the invention may also be used to control axial movement of a push-pull cable that is not enclosed within an outer casing.

Housing 2 is provided with thread means on wall 7 of bore 5. The thread means may be formed in form of threads 4 in wall 7 or may be in the form of a coiled spring that is secured to wall 7 intermediate wall 7 and sleeve 6 as is commonly practiced in the art.

The threads may be of any suitable type including acme or square threads where such is desired for a particular application.

Sleeve 6 is provided with knob 10 or the like at the end thereof of sleeve 6 furthest away from cable 34 for ease in moving sleeve 6 axially and rotatably within bore 5. Although knob 10 may be a separate part secured to sleeve 6, it is preferably an integral part of sleeve 6 as shown in Fig. 1.

As shown in Figs. 1 and 2, sleeve 6 is provided with at least one resilient portion 20 having at least one thread engagement means adapted to engage threads 4 on wall 7 of housing 2. In device 60, sleeve 6 has two diametrically opposed resilient portions 20 depending radially inwardly from the wall of sleeve 6.

Resilient portions 20 are preferably made by cutting spaced apart slots 21 through the wall of sleeve 6 to provide a strip of the wall of sleeve 6 that is preferably integral with the wall at one end and is formed into an arcuate surface of an opposite free-end that is adapted to engage threads 4 as shown in Figs. 1 and 2. Depending upon the particular application for which the control device of the invention is to be used, there may only be one resilient portion 20 or there may be a plurality positioned along sleeve 6 within bore 5 that may be disposed at one or more locations around the circumference of sleeve 6 along its length within bore 5. Resilient portions 20 may extend in a direction towards core 34 or they may extend in a direction away from core 34 as shown in the embodiment 70 of sleeve 40 of Fig. 3 or both.In Fig. 3, diametrically opposed resilient portions 42 are slotted from the wall of sleeve 42 in such a manner that they extend integrally from the wall of sleeve 40 in a direction away from the cable core to which the device of the invention is to be connected to respective free-ends that are formed into thread engagement means 44 that are respectively adapted to engage with the thread means associated with the wall surrounding the core of the housing into which the sleeve is moveably received.

Sleeve 6 has a bore 11 that is open-ended on the end of sleeve 6 furthest away from core 34 as shown in Fig. 1. Operating rod 12 is disposed within bore 11 and is axially moveable with respect to sleeve 6. The end of rod 12 closest to core 34 is provided with means 22 for engaging the thread engagement means 18 of resilient portions 20 and urging the engagement means into engagement with threads 4. Means 22 comprises a section of rod 1 2 preferably at the end thereof closest to core 34 that is larger in diameter than the rest of rod 1 2 and has a surface 24 adapted to engage and urge engagement means 18 radially outwardly into threaded engagement with threads 4 when rod 12 is in a predetermined position within bore 11 of sleeve 6. Moving rod 1 2 axially away from the predetermined position in a direction towards core 34 causes surface 26 of means 22, which is smaller in diameter than surface 24, to replace surface 24 enabling the resiliency of portion 20 to urge engagement means 18 radially inwardly away from threads 4 enabling sleeve 6 to be moved reciprocally axially in gross amounts along bore 5 and move core 34 reciprocally axially in gross amounts within casing 36.Alternatively, when rod 1 2 is positioned at the predetermined position along bore 5, surface 24 of means 22 establishes the threaded engagement between engagement means 18 and threads 4 sufficient to enable rotation of sleeve 6 by knob 10 in either direction to cause sleeve 6 to move axially in incremental vernier amounts in corresponding opposite directions along bore 5 and thus move core 6 axially reciprocally within casing 6 in corresponding incremental vernier amounts.

Device 60 is preferably provided with means for positioning rod 1 2 at the predetermined position in which engagement means 1 8 are engaged with threads 4. The means comprises a resilient member such as spring 14 disposed at the end of rod 1 2 closest to core 34 between the end and the end of sleeve 6 closest to core 34 as shown in Fig.

1. Spring 14 presses against the end of rod 1 2 and biases rod 1 2 in a direction away from core 34. A resilient cap 1 6 is secured to knob 10 and presses against the opposite end of rod 1 2 and urges rod 1 2 in a direction towards core 34 within sleeve 6. Alternatively, a stop such as stop 1 7 may be used either alone or in conjunction with cap 1 6 to maintain engagement between spring 14 and the end of rod 1 2 closest to core 34.As can readily be seen from Fig. 1, the length and spring force of spring 14 and the resilience of cap 1 6 and/or the position of stop 1 7 can be readily adjusted to ensure that rod 1 2 is at the predetermined within sleeve 6 when no additional external axial end force is applied to cap 16. Pressing cap 16 in a direction towards core 34 causes rod 1 2 to move towards core 34 which replaces surface 24 with surface 26 which in turn enables resilient portions 20 of sleeve 6 to urge engagement means 1 8 radially inwardly and disengage from threads 4 as previously described.

Although the opposed axially biasing of rod 1 2 by spring 1 2 and cap 1 6 as shown in Fig.

1 is preferred, it is to be understood that any means of biasing and the location of such means for biasing rod 1 2 into the predetermined position within sleeve 6 that enables the thread engagement means associated with rod 1 2 to urge the thread engagement means associated with resilient portions of the sleeve to engage with the thread means on the wall of the bore of the housing in which the sleeve is received is considered to be within the scope of the invention.Likewise, rod 1 2 may have a plurality of means such as means 22 or other means along its length that are positioned at the predetermined position of the rod to urge thread engagement means such as means 18 correspondingly disposed along sleeve 6 radially outwardly into engagement with threads on the wall of the base of the housing into which the sleeve is received.

Device 60 preferably includes means for securing sleeve 6 against movement with respect to housing 2 to provide a way of locking core 34 at a preferred position within casing 36. A preferred method well known in the art is shown in Fig. 1 where a compressible member 28 is able to be compressed between sleeve 6 and rod 1 2 by nut 30 which is rotatably secured to the end of housing 2 furthest from core 34 as shown in Fig. 1.

Fig. 4 shows an embodiment 80 of a sleeve 46 that may be used in device 60 of Fig. 1 without the need of operating rod 1 2. Sleeve 46 has a receptacle having a cavity 48 for releasably rotatably receiving a lug secured to the end of the cable rod to which the device is to be connected. Sleeve 46 has a single resilient portion 50 that is part of an insert 51 that is secured to sleeve 46 and is not integral with the wall as previously described with respect to Figs. 1-3. The free-end of resilient portion 50 extends radially outwardly from sleeve 46 and is formed into two spaced-apart arcuate surfaces adapted for engaging adjacent threads on the wall of the bore of the housing into which sleeve 46 is received.

Resilient portion 50 has sufficient resiliency to ensure the engagement of arcuate surfaces 52 with the threads when sleeve 46 is inserted into the bore of the housing so that rotation of sleeve 46 causes it and the cable core to which it is connected to move in axial incremental amounts in response to rotation of sleeve 46 as previously described. The application of an axial force against the end of sleeve 46 opposite to the end having cavity 48 sufficient to overcome the radial outward force of resiliency of portion 50 enables engagement means 52 to cross threads axially enabling sleeve 46 to move the cable core axially within its casing gross amounts as previously described.

Fig. 5 shows that the vernier control device of the invention can be used to control movement of an object other than a push-pull cable. In Fig. 5, device 60 of Fig. 1 is able to selectively move object 53 rotatably in gross, or vernier, incremental amounts by axial movement of sleeve 6 within housing 2 that is secured against movement with respect to object 53. Sleeve 6 is rotatably secured to object 53 as shown by reference 56 so that sleeve 6 can be rotated to move in incremental amounts as previously described. Object 53 understandably may be any device such as for example an automotive carburetor throttle control or choke plate.

Although the control device of the invention may be made from suitable metallic or polymeric materials or combinations of both, it is preferably made from one or more polymeric materials. For example, housing 2 may be molded form a suitable acetal copolymer such as sold under the trademark CELCON by the Celanese Company and rod 1 2 and sleeve 6 may each be molded in one-piece from a suitable polyamide polymer having sufficient resilience to provide the resilient portions hereinbefore described with sufficient resilience to perform in the manner described herein.

In applications where the resilient portions are not integral with the sleeve but are secured as inserts thereto as previously described, the insert may be made from a suitable polymer and the body of the sleeve from a suitable metal or alternatively the insert may be made from a suitably resilient metal and the body of the sleeve from a suitable polymeric material.

In cases where the sleeve of the control device of the invention is molded from a polymeric material, the thread means can be formed in the bore wall adapted to receive the sleeve during the moiding operation. The pitch and type of threads utilized will vary depending upon the application and, understandably, the finer the pitch, the smaller the axial incremental movement of the sleeve will be in response to rotation of the sleeve as previously described.

Although it is preferred to provide the resilient portions in the form of an arm extending from the sleeve to a free-end as described herein, it is to be understood that any resilient portions associated with the sleeve and having thread engagement means that are able to engage the threads with or without use of an operating rod in the manner described herein is considered to be within the scope of the invention for the resilient association between the thread engagement means and the sleeve itself by means of the resilient connection therebetween enables the elimination of the ball and pivotable rack and pinion arrangements used for such purpose in the past.

Claims

1. A vernier control device for selectively moving an object in gross or vernier, incremental, amounts, said control device comprising a housing secured against movement with respect to the object and having a substantially tubular open-ended bore extending therethrough that is surrounded by a wall of the housing, a control sleeve slidably received in the housing bore and able to both rotate and move axially in opposite directions with respect thereto, means rotatably connecting one end of the control sleeve to the object, thread means disposed on the wall of the housing surrounding the bore, and thread engagement means comprising at least one resilient portion of the control sleeve having means associated therewith adapted for engagement with the thread means that is urged radially outwardly by the resilient portion into engagement with the thread means to the extent necessary to cause the sleeve to move axially along the bore and move the object in vernier, incremental, amounts in response to rotation of the sleeve and that is caused to move radially inwardly in response to axial movement of the sleeve upon application of an axial force thereagainst sufficient to cause the thread engagement means to move axially across the threads and enable the axial movement of the sleeve resulting therefrom to move the object in gross amounts.

2. A vernier control device for selectively moving an object in gross vernier, incremental, amounts, said control device comprising a housing secured against movement with respect to the object and having a substantially tubular open-ended bore extending therethrough that is surrounded by a wall of the housing, a control sleeve slidably received within the housing bore and able to both rotate and move axially in opposite directions with respect thereto, means rotatably securing one end of the control sleeve to the object, thread means disposed on the wall of the housing surrounding the bore, thread engagement means comprising at least one resilient portion of the control sleeve having means associated therewith adapted for engagement with the thread means, and an operating rod disposed within a bore in the control sleeve and moveable axially with respect thereto, said rod having means associated therewith for engaging and urging the thread engagement means into engagement with the thread means when the rod is moved axially into a first predetermined position within the sleeve bore to the extent necessary to cause the sleeve to move axially along the housing bore and move the object in vernier, incremental, amounts in response to rotation of the sleeve, and said rod having means associated therewith for enabling the resilient portion to urge the thread engagement means radially inwardly away from the thread means when the rod is moved axially into a second predetermined position within the sleeve bore to the extent necessary to enable the sleeve to be moved axially within the housing bore and move the object in gross amounts.

3. The device of claim 2 including means for biasing the rod into the first predetermined axial position with respect to the sleeve.

4. The device of claim 3 wherein the biasing means comprises the combination of a resilient member disposed within the sleeve in such a manner as to urge the rod in a direction away from the object and against a stop secured to the sleeve.

5. The device of claim 3 wherein the biasing means includes a resilient member disposed against the rod in such a manner as to urge the rod in a direction towards the end of the sleeve secured to the object.

6. The device of claim 1 wherein at least one of said resilient portions comprises portion of the sleeve that extends therefrom to a free-end thereof disposed radially outwardly from the sleeve.

7. The device of claim 2 wherein at least one of said resilient portions comprises a portion of the sleeve that extends to a freeend thereof that is urged radially inwardly when the operating rod is in the second predetermined position.

8. The device of claim 1 or 2 wherein the sleeve and at least one of said resilient portions is made from a polymeric material.

9. The device of claim 1 or 2 wherein the sleeve and at least one of said resilient portions is made from a metallic material.

10. The device of claim 1 or 2 wherein the sleeve is made from a polymeric material and at least one of said resilient portions is made from a metallic material.

11. The device of claim 1 or 2 wherein the sleeve is made from a metallic material and at least one of said resilient portions is made from a polymeric material.

1 2. The device of claim 1 or 2 wherein the thread means comprises a coiled member secured to the housing wall intermediate said wall and the sleeve.

1 3. The device of claim 1 or 2 wherein the thread means comprises threads formed in the wall of the housing surrounding the sleeve.

14. The device of claim 1 or 2 wherein at least the wall of the housing surrounding the sleeve is made from a polymeric material.

1 5. The device of claim 1 or 2 wherein at least the wall of the housing surrounding the sleeve is made from a metallic material.

1 6. The device of claim 1 or 2 including means for securing the sleeve against movement with respect to the housing.

1 7. The device of claim 6 or 7 wherein at least one of said resilient portions extends in a direction towards the end of the sleeve secured to the object.

1 8. The device of claim 6 or 7 wherein at least one of said resilient portions extends in a direction away from the end of the sleeve secured to the object.

19. The device of claim 1 or 2 wherein the means adapted for engagement with the thread means comprises at least one arcuate surface on the resilient portion.

20. The device of claim 1 or 2 wherein the object is a push-pull cable.

21. The device of claim 20 wherein the push-pull cable is slidably received within a casing.

22. The device of claim 21 wherein the casing is secured to the housing.

23. A displacement control device comprising first and second members assembled with each other so as to be relatively rotatable and translatable and wherein one of said members has a screw-thread defining portion and the other of said members has a screwthread engaging portion, the arrangement being such that said first and second members are rotatable relatively to each other with said screw-thread engaging portion engaged with said screw-thread defining portion for translating said first and second members relative to each other in a fine adjustment mode and furthermore being such that said first and second members are directly translatable relative to each other without rotation in a coarse adjustment mode.

24. The displacement control device of claim 23 wherein said screw-thread engaging portion is resiliently biassed into engagement with said screw-thread defining portion so as to enable fine adjustment translation by relative rotation of said first and second members with said portions engaged and to enable coarse adjustment direct translation by application of a translating force such as to overcome said resilient bias.

25. The displacement control device of claim 23 wherein said screw-thread engaging portion is adjustable between positions where it engages with said screw-thread defining portion for enabling said fine adjustment and where it is out of engagement therewith for enabling said course adjustment.

26. The displacement control device of claim 23 or 24 or 25 coupled to a Bowden cable for determining the relative displacement between the inner core and the outer sheath thereof.

27. A displacement control device substantially as hereinbefore described with reference to any of the accompanying drawings.