CA1176139A

CA1176139A - Self-aligning swivel assembly for push-pull cable control lever assembly

Info

Publication number: CA1176139A
Application number: CA000405632A
Authority: CA
Inventors: Jacob Kobelt
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-06-21
Filing date: 1982-06-21
Publication date: 1984-10-16

Abstract

Kobelt 34 c/w SELF-ALIGNING SWIVEL ASSEMBLY FOR PUSH-PULL
CABLE CONTROL LEVER ASSEMBLY

ABSTRACT OF THE DISCLOSURE

A control lever assembly for actuating a control cable, particularly a cable of the type capable of transmitting compressive forces as well as tensile forces, known as a push-pull cable. The assembly has a lever journalled for rotation relative to a body thereof, and a core anchoring structure adapted to rotate with the lever and to be subjected to relative lateral movement during such rotation. The core anchoring means anchors one end of a core of the control cable, and a sheath retaining means retains a portion of a sheath of the cable to restrict axial movement of the sheath following actuation of the cable. A connecting structure, which is struc-turally independent of the control cable, cooperates with the sheath retaining structure and the core anchoring structure to swivel the sheath retaining structure in response to rotation of the core anchoring structure. Thus, the sheath retaining structure swivels to accomodate the lateral movement of the core anchoring structure to maintain approximate alignment of the sheath with the core so as to reduce a tendency of the core to buckle under compressive loads.

Description

~76~39 (1) '1 BACKGROUND OF THE INVENTION
:
Field of the Invention The invention relates to a control lever assembly for ac-tuating a control cable, particularly a cable capable of transmitting com-pressive forces RS well as tensile forces, commonly called a push-pull cable, which has applications in the marine control industry.

10 Prior Art 3 Control heads for controlling devices remotely have been used for many years in the marine industry, for example, for controlling an engine and gearbox of a marine vesseL Bowden cables have been used 15 successfully in certain applications, the Bowden cable having a sheath and a cable core slidable within the sheath. The core is relatively flexible and thus is prone to buckling when subjected to compressive forces, and preferably this type of cable is used only in situations where it is subjected to a tensile force.

The limitations of the Bowden cable to transmitting force in one direction, namely as a tensile force, have been recognized for many years and now a cable having a stiffer core has been developed, such cable being known as a push-pull cable which is capable of carrying a degree of compressive forces before buckling when extending from an end of the sheath 25 and being unsupported by the sheath. The tendency of a push-pull cable to buckle under compressive force is proportional to the length of usupported coPe extending from the sheath, and also, to some extent, the alignment of the sheath with the core itself and the line of action and direction of the compressive force applied to the core. Commonly, a core of a cable is 30 anchored to a rotatable member at a position spaced from the axis of rotationthereof so that as the member is rotated the core anchoring means, and with it the core, is subjected to swinging and lateral movement which shifts the cable core from a position aligned with an adjacent end portion of the sheath.
To reduce buckling and binding tendencies of the sheath on the core, the 35 adjacent end of the sheath swivels to accomodate the lateral swinging of the 1~7~i139

(2) core. This is attained by several different methods in the prior art, for example, see United States Patent 2, 975,653 (Morse) and United States Patent #3,101,821 ~Henry). In both of these prior art structures, an adjacent end portion of the sheath enclosing the core is swung laterally by direct 5 movement of the core itself acting on the sheath, which swivels on a sheath swivelling connection. Whilst this arrangement is satisfactory for some applications, where there is a relatively long length of unsupported core extending from the outer portion of the sheath to the core connection and a compressive force is applied to the core, as in the pushing mode, buckling of 10 the core can result due to the inability of the sheath to follow wide swings of the core and to become aligne~ therewith.

SUMMARY OF THE INVENTION
The difficulties and disadvantages of the prior art are re-duced by providing a control lever assembly according to the invention in which the sheath of the control cable has an adjacent end portion which is swivellable positively by means other than the lateral force of the core acting 20 on the sheath itself. As the anchored end of the core swings through an arc due to rotation of the lever, a positive connection between the lever and the sheath swivels the adjacent end portion of the sheath to accomodate the lateral movement to maintain approximate alignment of the sheath with the core without excessive lateral forces acting on the core, thus reducing a 25 tendency of the unsupported core to buckle under compressive forces.

A control lever assembly according to the invention is for actuating a control cable having a cable sheath and a cable core slidable within the sheath, the assembly having a body, a lever and a core anchoring 30 means. The lever is journaUed for rotation relative to the body about a lever axis and the core anchoring means cooperates with the lever to rotate therewith relative to the body so as to be subjected to relative displacement during such rotation. The core anchoring means also is adapted to anchor one end of the core of the control cable. The assembly is further characterized 35 by a sheath retaining means and a connecting means. The sheath retaining

(3) means cooperates with the sheath to retain a portion of the sheath to restrict axial movement of the sheath following actuation of the cable. The connecting means, which is structurally independent of the control cable, cooperates with the sheath retaining means to swivel the sheath retaining 5 means in response to rotation of the core anchoring means. This causes the sheath retaining means to swivel to accomodate the relative displacement of the core anchoring means to maintain approximate alignment of the sheath with the core.

A detailed disclosure following, related to drawings, des-cribes a preferred embodiment of the invention which is capable of expression in structure other than that described and illustrated.

Figure 1 is a simplified fragmented side elevation of a control lever assembly according to the invention, some portions being shown in section or in broken outline, Figure 2 is a simplified fragmented end elevation of the assembly of Figure 1, Figs. 3, 4 ~ 5 are simplified sequence diagrams showing the control lever assembly in a central position, an intermediate position and an extreme outer position respectively, showing progressive swivelling of a sheath retaining means.

Figures 1 and 2 A control lever assembly 10 according to the invention has a 35 body 12 and a manually actuated lever 14 extending from a lever spindle 15.

`" i~761~9

(4) The spindle is journalled relative to the body in a pair of spaced journals 16 for rotation relative to the body about a lever axis 18. The body is adapted to be secured to a table surface 21, and carries a cable support 23 extending below the table to a lower end 25.
A control cable 27 has a cable sheath 29 and a cable core 30 slidable within the sheath, the cable core being sufficiently stiff to permit transmission of compression forces relative to the sheath, and is commonly called a push-pull cable. A sheath retainer member 32 is journalled on a bolt 34 at the lower end 25 so that the retainer member is journalled for rotation relative to the body about a retainer axis 36 whîch is disposed parallel to the lever axis. This is accomplished by means of a generally U-shaped sheath clamp 38 secured by bolts 40 to the retainer member 32 so as to essentially prevent longitudinal movement of the sheath 29 relative to the retainer member 32. Thus the retainer member 32 and the clamp 38 and associated structure serve as sheath retaining means cooperating with the sheath to retain a portion of the sheath to restrict axial movement of the sheath following actuation of the cable.

A rotatable member 43 is disc-like and is secured to the lever spindle 15, and thus cooperates with the lever to rotate therewith. A
support member 45 is securable by three screws, severally 47, to the support member so as to rotate therewith and to provide a clearance 49 between the rotatable and support members. The support member 45 is a four-sided plate-like member which has a series of axially disposed recesses, severally 52, which face inwardly into the clearance 49 and are aligned with a similar series of axially disposed recesses 54 in the rotatable member 43. The rotatable member has an outer cam surface 56 with which a cam follower 58 cooperates to actuate a limit switch 80 so as to control electrical devices, not shown, as required. Clearly, other structures can cooperate with the rotatable member for particular functions. A cable fitting 63 is fitted at an outer end of the cable core 30 and has a cylindrical bore therein to receive a spindle 65. The spindle 65 has opposite ends carried in a pair of the aligned recesses 52 and 54, and fits in the clearance between the members 43 and 45.
Thus, an intermediate portion of the spindle journals the cable fitting ~176:139

(5) between the members and serves as a journalling means which is a cylindrical element cooperating with the cable fitting and journalled in the aligned recesses. Clearly, the cable fitting could have other means to cooperate with the members 43 and 45 in which only one OI the members 43 or 45 requires a 5 recess. The rotatable member 43, the support member 45, the spindle 65 and the cable fitting 63 serve &S core anchoring means 66 cooperating with the lever to rotate therewith relative to the body so as to be subjected to relativedisplacement or lateral movement during such rotation. It can be seen that the core anchoring means is adapted to anchor one end of the core of the 10 control cable and clearly, equivalent structures can be devised. A particularadvantage of the core ancho~ing means as described herein is that the cable can be secured relative to the lever means by a simple structure which does not require cotter pins, bolts with locking nuts, etc. to retain the end of the cable. Also, the anchoring means is a relatively compact structure which, by 15 providing the series of aligned recesses, permits easy adjustment of the moment arm or lever effect of the core anchoring means relative to the lever AxiS. As shown, the spindle 65 is fitted in the second pair of recesses of the series, and thus provides a relatively large cable core axial movement for a particular rotation of the lever, with a correspondingly large relative 20 displacement or lateral movement of the core anchoring means 66.

The structure as above described is adequate for applying tensile force to the core 30 of the cable because the sheath retainer member 32 could be made to be free to swivel to some extent about the retainer axis 25 36 in response to lateral movement or relative displacement of the outer end of the core or the core anchoring means which occurs when the lever rotates more than a few degrees. A full range of movement of the lever of between 50 and 60 on either side of an intermediate or central position as shown in Figures 1 and 2 would result in a corresponding swinging of the sheath up to 30 about 15 on either side of an aligned central position, as shown in Figures 3 through 5.

However, if the above structure were used to apply com-pressive forces to the core of the cable, it is likely that the adjacent end of 35 the sheath would not be sufficiently aligned with the core or anchoring means ~l~G139

(6) to avoid excessive out of alignment forces on the core that would likely result in buckling of the core followed by permanent bending or breakage. The present invention is particularly adapted to essentially eliminate problems that result in the buckling of the core under compressive forces that occur in 5 a pushing mode. This is accomplished by a simple structure which extends between the lever and sheath retaining means to positively align the adjacent end of the sheath with the unsupported portion of the core, as follows.

A circular cam 67 has a cam center 69 disposed laterally of 10 a longitudinal plane 71 passing through the lever axis 18 and the retainer axis 36 when the lev~sr is in an intérmediate position thereof as shown. In effect, the cam center 69 is disposed in a transverse plane 73 which is disposed approximately at right angles to the longitudinal plane 71 when the lever is in the intermediate position. The cam means is disposed on a face of the 15 support member 45, and is mounted eccentrically relative to the lever axis 18for rotation with the core anchoring means so that rotation of the cam means results in a circular movement of the cam center. It can be seen that rotation of the cam means results in movement of the cam center out of the transverse plane 73, which movement has a component parallel to the 20 longitudinal plane 71, as will be described. A connecting link 76 has an upper end having a circuler recess 77 complementary to the circular cam 67 and a lower end connected by a hinge pin 79 to the sheath retainer member 32. The connecting link 76 thus serves as a cam follower having adjacent one end thereof a circular recess complementary to the circular cam to be accepted 25 thereon and is connected to the sheath retaining member adjacent an opposite end thereof.

OPERATION

In Figures 1 through 3, the lever 14 is shown in a central or intermediate position midway between two extreme positions and the control cable 27 is aligned with the longitudinal plane 71 and the spindle 65 of the cable anchoring means. In Figure 4, the lever 14 is swung through an angle 84, 35 of about 30, to a position shown at 14.1 in which the support means 45 and ~!L76139

(7) ,~
the spindle 65 have assumed corresponding displaced positions ~5.1 and 65.1 disposed laterally of the longitudinal plane 71. The cam center 69 has swung through a similar angle 84 to a raised position 69.1 which results in a corresponding upward movement of the upper end of the connecting link 76 5 which results in a corresponding rotation of the sheath retainer member 32 in direction of an arrow 86. Rotation of the retainer member 32 causes a corresponding swinging of the adjacent end of the control cable 27, so that an axis 88 of the control cable which is aligned with a portion of the core 30 leaving the she~th, passes closely adjacent, or intercepts, the spindle 65.
10 Because the spindle 65 is fitted in the second recess of the series of recesses, the axis 88 passes closely thereto, as it would pass through a position about midway between the series of four recesses. It can therefore be seen that the connecting link 76 serves as a portion of a connecting means 89 which is structurally independent of the control cable and cooperates with the sheath 15 retaining means, ie. the member 32, and the core anchoring means to swivel the sheath retaining means in response to rotation of the core anchoring means. Thus, the sheath retaining means swivels to accomodate the lateral movement or relative displacement of the core anchoring means 66 to maintain approximate alignment of the sheath with the core. It can be seen 20 that, in this position, if the direction of rotation of the lever 14 is reversed so that a compressive force is applied to the core of the cable, the core maintains substantial alignment with the sheath as the support member 45 swings back towards the plane 71. It can be seen that the connecting means 89 also includes a driver means, n~mely the cam means, which is journalled 25 for rotation with the core anchoring means, an-3 also a driven means, namely the cam follower or connecting link 76, which cooperates with the driver means and the retainer member so that lateral movement or relative displacement of the core anchoring means is reflected approximately by a corresponding rotation of the retainer member about the retainer axis. In 30 effect, the connecting link 76 or cam follower provides Q rigid positive connection between the retainer member and the cam to reflect movement of the cam in either direction, and thus, eliminates some problems of the prior art where the necessary lateral swivelling force is normally applied to the sheath itself to cause- the swinging of the sheath. With some earlier 3S structures, the lateral swivelling force would tend to aggravate the tendency 1~7Ç~139

(8) of the core to buckle under compressive loads.

Referring to Figure 5, the lever 14 is swung through an angle 90 to assume an extreme position 14.2, between 50 and 60 from the central 5 position. This produces a corresponding rotation of the support means to an extreme position 45.2 in which the spindle 65 assumes an extreme position 65.2. The cam center 69 assumes an extreme raised position 69.2 after swinging through the angle 90 and this causes a corresponding additional upwards movement of the connecting link 76 to further rotate the sheath 10 retainer member in direction of the arrow 86. This rotation produces an additional swivelling OI the sheath 27 so that the axis 88 of the core 30 is maintained to be substantially aligned with the core anchoring means on the spindle 65.

It is assumed that the central position of the lever, as shown in Pigure 3, is in fact an intermediate position of the lever disposed equally between two outer extreme positions. The description above discusses swinging of the lever, with a corresponding rotation of the sheath anchoring means to one extreme position, and by inspection, it can be seen that rotation ao of the lever in the opposite direction to an angle equal to the angle 90 would result in a corresponding swinging of the retainer member 32 in an opposite direction, so as to maintain alignment of the core with the core anchoring means for essentially all positions of the lever.

Claims

(9) CLAIMS:

1. A control lever assembly for actuating a control cable having a cable sheath and a cable core slidable within the sheath, the assembly having a body, a lever journalled for rotation relative to the body about a lever axis, and a core anchoring means cooperating with the lever to rotate therewith relative to the body so as to be subjected to relative displacement during such rotation, the core anchoring means also being adapted to anchor one end of the core of the control cable, the assembly being further characterized by:
(a) a sheath retaining means cooperating with the sheath to retain a portion of the sheath to restrict axial movement of the sheath following actuation of the cable, (b) connecting means, structurally independent of the control cable, cooperating with the sheath retaining means and the core anchor-ing means to swivel the sheath returning means in response to rotation of the core anchoring means, so that the sheath retaining means swivels to accomodate the relative displacement of the core anchoring means to maintain approximate alignment of the sheath with the core.

2. A control lever assembly as claimed in Claim 1 in which the sheath retaining means is a retainer member journalled for rotation relative to the body about a retainer axis disposed parallel to the lever axis.

3. A control lever assembly as claimed in Claim 2 in which the connecting means includes:

(a) driver means journalled for rotation with the core anchoring (10) means, (b) driven means cooperating with the driver means and the retainer member, so that the relative displacement of the core anchoring means is reflected approxi-mately by a corresponding rotation of the retainer member about the retainer axis.

4. A control lever assembly as claimed in Claim 3 in which:
(a) the driver means is a cam means, (b) the driven means is a cam follower.

5. A control lever assembly as claimed in Claim 3 in which:
(a) the driver means is a circular cam mounted eccentrically relative to the lever axis for rotation with the core anchoring means, (b) the driven means is a cam follower having adjacent one end thereof a circular recess complementary to the circular cam to be accepted thereon, and being connected to the sheath retaining member adjacent an opposite end thereof, so that the cam follower provides a rigid connection between the retainer member and cam to reflect movement of the cam in either direction.

6. A control lever assembly AS claimed in Claim 5 in which:

(a) the body has a longitudinal plane passing through the lever axis and the retainer axis, (11) (b) the cam means has a cam center disposed laterally of the longi-tudinal plane when the lever is in an intermediate position there-of, so that rotation of the cam means results in movement of the cam center, which movement has a component parallel to the longitudinal plane.

7. A control lever assembly as claimed in Claim 6 in which:

(a) the intermediate position of the lever is disposed equally between two outer positions, (b) the cam center is disposed in a transverse plane which is disposed approximately at right angles to the longitudinal plane when the lever is in the intermediate position, so that rotation of the cam means results in movement of the cam center out of the transverse plane.

8. A control lever assembly as claimed in Claim 1 in which the core anchoring means includes:

(a) a rotatable member cooperating with the lever to rotate there-with, (b) a support member securable to the rotatable member so as to rotate therewith and to provide clearance between the rotatable and support members, (c) a cable fitting fitted in the clearance between the members and adapted for securing to the core of the cable, (d) journalling means cooperating with the cable fitting and with the members to journal the cable fitting between the members.

(12)

9. A control lever assembly as claimed in Claim 8 in which:

(a) the rotatable member and the support member both have recesses, the recesses being aligned with each other, (b) the journalling means being a cylindrical element cooperating with the cable fitting and journalled in the aligned recesses.

10. A control lever assembly as claimed in Claim 9 in which:

(a) the cable fitting has a cylindrical bore therein, (b) the journalling means is a spindle having opposite ends carried in the recesses of the rotatable member and the support member, and an intermediate portion journalling the cable fitting.