US2926001A - Anti-friction guide - Google Patents

Description

Feb. 23, 1960 R. F. MACK E'rAL ANTI-FRICTION GUIDE Filed Feb. 7. 1957 INVENTOR5 `C j( BY "MJU ATTORNEY5 United States Patent M' 2,926,001 ANTI-FRICTION GUIDE Richard F. Mack, Albany, and John D. Smith, Selkirk, N.Y., asslgnors to Anti-Corrosive Metal Products Co., Inc., Schodack, N.Y., a corporation of New York Application February 7, 1957, Serial No. 638,786 12 Claims. (Cl. 254-190) This invention relates to an anti-friction guide and more particularly to a guide for a cable or wire which may be used for control purposes.

Push-pull cables of the Bowden wire type are widely used in remote control. For example, such cables are employed in automobiles fork releasing the hood latch and for controlling the heater. In some applications of the push-pull control cable, it is found necessary to bend the cable around one or more curves in order to span the distance between the controlling and controlled elements along a convenient path. The axially movable control wires of the cables of the prior art are commonly encased in an outer sleeve or sheath that has substantially more lateral resistance to bending than vthe Wire, so that the wire will not buckle or kink when compressional forces are exerted on it. Cables thus constructed work well when the path between the controlling and controlled elei ments is substantially straight, but when the cable is bent around one or more curves, particularly fairly sharp curves, the effort required to move the wire along its axis greatly increases because of the frictional forces applied to the wire at the bends. The greater the number of bends and the sharper the curvature of the bends, the greater the force required to move the wire. Increasing the clearance between the axially movable wire and its sheath does not vsolve the problem, because when the wire is placed in compression, it is forced against the outside curvature of -the sheath, and when it is placed in tension, it is forced against the inside curvature of the sheath. The frictional forces are thus not materially reduced; moreover, increasing the clearance between the wire and the sheath allows the wire to buckle and kink under the influence of substantial axial loads.

Because of the foregoing diilculties it has heretofore been necessary to avoid substantial bending of push-pull control cables, thereby making it necessary for the cable to follow Ian inconvenient path in many cases, lor preventing the use of push-pull cables Where curves in the cables would be necessary. The present invention obviates the foregoing problems by providing a unique cable guide.

`It is accordingly a principal object o-f the invention to provide an anti-friction guide which overcomes the foregoing failings of the prior art.

Another object of the invention is to provide a cable guide having the desired characteristics and yet which is simple and economical to manufacture.

A further object of the invention is to provide a cable guide which may be adjusted to many different coniigurations.

An additional object of the invention is to provide a l cable guide of the aforesaid type which employs unique bearing units.

A still further object of the invention is to; provide a cable guide of the aforesaid type which includes means for receiving and gripping the sheath of the axially movable wire.

These and other objects of the invention will become more readily apparent upon consideration of the follow- 2,926,001l Patented Feb. 23, 1960 'of the invention;

Figure 3 is an elevation view of the device of Figure 2, shown with an outer covering removed;

Figure 4 is -a plan view of the device of Figure 2 as it appears when curved and illustrating in more detail the connection of the cable to the cable guide; and

Figure 5 is a transverse sectional view taken along line 5-5 in Figure 2.

Briey stated, the invention comprises a pair of flexible strips between which a plurality of bearing units are mounted. The bearing units are fixed at one end thereof to one of the strips and are movable with respect to the other strip. At least one end of one of the strips is adjustable longitudinally with respect yto the other strip and is arranged to be fixed with respect to the other strip to maintain the guide in a predetermined curved configuration. The strips are joined by end pieces, at least one of which is arranged to receive the sheath of the cable.

Figure l of the drawing illustrates the use of a pushpull cable 10 in controlling a power boat 12, as more fully described in another application of one of the applicants herein, entitled Remote Control System for Power Boat. The boat may be of the outboard motor type and may have a motor 14 and a steering wheel 16. Control cables of the type to be described may be used to adjust the orientation of the outboard motor 14 in response to movement of the steering wheel. In order to provide a convenient, unobtrusive path for the control cable 10, it is necessary to provide at least two bends in the cable, as indicated at 18 and 20. It is at these bends that the cable guide 22 of the invention is employed.

Referring to Figure 2, each cable guide in the preferred form comprises a pair of resilient strips 24, 26, which may be formed of spring steel or other suitable material. The strips are joined in substantially parallel relationship by a pair of end pieces or blocks 28, 30 as described herenafter. Each block has a central passage 32 for guiding the axially movable wire 34 of the control cable 10.

The control cable may assume many different forms, but the axially movable Wire 34 commonly has a solid core encased in a helically wound strip. The axially movable wire thus constituted is commonly guided in an outer metallic sheath 36, which may be formed of helically wound wires. The inner and outer members of the cable may then be encased within a tubular covering (not shown) of rubber, plastic, or similar material. The ends of the control cable are conventionally provided with suitable fittings for coupling the cable to the controlling and controlled elements.

Bach of the end pieces 28, 30 may be provided with means for receiving and gripping the sheath or stationary member 36 of the control cable. As shown in Figure 4, an exemplary end piece 28 has an enlarged bore 38, for receiving a pair of concentric sleeves, 40, 42, the inner surface of sleeve 40 and the outer surface of sleeve 42 converging inwardly of the bore. The sleeve 40 and the sheath 36 are formed of a hard material, such as steel, while the sleeve 42 is formed of a relatively soft material, such as aluminum. End piece 28 may also be provided With a washer 44 that is arranged to be secured to the end piece as by machine screws 46, and through which the cable passes.

When the cable guide of the invention is assembled with a cable of the type described, the outer sheath 36 of the cable is terminated or cut back so that the naked inner member 34 passes into the cable guide beyond the end piece 28. Sleeve 42 is then slipped over sheath 36, and Sleeve 40 is slipped into bore 38. The sheath is then gripped just beyond sleeve 42 by a tool or clamp, and the end piece, which is not yet attached to strips 24, 26, is hammered onto the sheath, forcing sleeve 42 and the end of thesheath into sleeve 40. Washer 44, which may have been slipped onto the cable previously, is then se cured to the end piece, preventing any possibility of dislodging the cable. The compression of the soft sleeve 42 between sleeve 4t) and sheath 36 securely swages the cable to the end piece. Further details of the cable holder may be found in the afore-mentioned companion application, but the use of the particular sheath receiving and holding device is not essential to the guide construction of the invention, and other types of such devices may be employed. One of the end pieces may be constructed without the sheath holding device, for installations in which the corresponding end of the cable guide is close to the controlling or controlled element and wherein the inner or axially movable member of the cable is coupled directly to such element. Moreover, in some instances the cable guide may be utilized in conjunction with a cable which does not have an outer sheath, such applications of the invention making the use of a sheath holding device obviously unnecessary.

At least one end of one of the strips 24, 26 is arranged to be adjustable longitudinally with respect to the other strip and to be fixed in Selected positions. In the form shown, both ends of strip 26 are provided with slots 48 (Figure 3) which may reciprocate with respect to machine screws 50, which fix the strip ends to the respective end pieces 28, 30 when the screws are threaded tightly into the end pieces. -In the form shown, strip 24 is xed to the respective end pieces by machine screws 52.

In Figure 2 the strips are shown straight, and screws 50 are located at the inner ends of the associated slots 48. If the screws 50 are loosened, the strips may be curved as shown in Figure 4, strip 24 forming the inner and strip 26 the outer curvature. The screws may then be tightened to retain the curved configuration of the guide. It will be observed that in the bending of the guide, the ends of strip 26 move longitudinally relative to the strip 24 and the end pieces 28 and 30, screws 50 sliding along slots 48. If screws 50 are loosened again, the guide may be allowed to return to its original straight configuration by virtue of the naturalresiliency of the strips 24 and 26.

Mounted transversely between strips 24 and 26 are a plurality of spaced bearing units 54. These units are arranged in succession, and each unit may comprise a rectangular yoke 56 tixed at one end to strip 24, as by rivets 5S or machine screws. The opposite ends of the yokes are not secured to the strip 26, but instead are movable with respect thereto. Thus, the yokes, which are substantially parallel when the guide is straight, as shown in Figure 2, may diverage or fan out when the guide is curved, as shown in Figure 4, clearance being provided between strip 26 and the yokes for this purpose.

Each yoke constitutes a bearing support member for bearing elements which, in the form shown, are constituted by roller bearings 60. Each yoke may support a pair of such bearings arranged to rotate about axes transverse to the yokes on pins 62 iixed to the yokes. The bearing surfaces are contoured as shown so thatthe opposed surfaces of each pair of bearings 60 form a substantially circular cross-section. The curvature and spacing of the bearings is chosen in accordance with the diameter of the wire 34 that is to be guided. The bearing elements may be formed of nylon or other suitable material.

lf both ends ot strip 26 are to be adjusted with respect to the end pieces 2S and 30, an odd number of `hearing units may be employed, and the central unit of the series of units may be fixed to strip 26 as well as to strip 24.

In some instances, both strips may be iixed to one end piece, and the adjustment described above may be restricted to the other end piece. If a reversely curved guide is desired, some of the bearing units may be iixed to one of the strips and other bearing units to the other strip, with both strips being adjustable. Reverse curvature may also be provided by using two guides in sequence.

It will thus be apparent that with the use of the invention, the push-pull member of the control cable is supported at spaced points along the length of a curve and. that rotary bearings are provided at these points to reduce greatly the frictional drag exerted on the pushpull member. With the use of the invention, a substantial number of curves may be employed without unduly increasing the force which must be exerted to move the control cable.

A suicient number of bearing units is employed inthe guide to prevent any tendency of the push-pull member to buckle or kink. In order to protect the bearing units, the entire guide structure described may be covered by a Flexible boot 64 (Figure 2) formed of plastic, rubber, or other suitable material. The boot may be accordion pleated, as shown, to increase its exibility.

While there has been described and shown what is now believed to be a preferred form of the invention, it will be apparent to those skilled in the art that changes may be made in this form without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims. Accordingly, this form is to be considered illustrative rather than restrictive of the invention and those modifications which come within the meaning and range of equivalency of the claims are intended to be included therein.

We claim:

1. A cable guide comprising a pair of substantially parallel flexible strips, means for adjusting the position of at least one end of one of said strips with respect to the corresponding end of the other strip and for xing said position, whereby said strips may be curved, and bearing means mounted between said strips for guiding the movable member of a cable between said strips.

2. The cable guide of claim l, wherein a pair of end pieces joins the corresponding ends of said strips, and wherein said adjusting means comprises means for sliding said one end with respect to the corresponding end piece.

3. The cable guide of claim l, wherein said bearing means comprises a plurality of bearing units iixed to one of said strips but movable along the other strip.

4. The cable guide of claim 3, wherein each of said units has a bearing element supporting member transverse to said strips, each member being fixed at one end thereof to one of said strips.

5 The cable guide of claim 4, wherein each supporting member has a pair of opposed rollers rotatable about axes transverse thereto.

6. The cable guide of claim 1, wherein said strips are surrounded by a ilexible covering.

7. The cable guide of claim l, further including means connected to at least one end of said strips for receiving the end of a sleeve in which said movable member moves beyond the guide.

8. A cable guide comprising a flexible bearingsupport ing strip, a plurality of bearing units xed in succession along said strip, a pair of means secured, one to each end of said strip, and fastening means cooperating with each of said pair of means for holding said strip in curved configuration.

9. The combination of claim 8 wherein each of said pair of means is provided with a cable-guiding channel for guiding the cable into the bearing units, said channels being axially aligned with the two cndmost of said bearing units respectively.

l0. The cable guide of claim 8, wherein each of said bearing units has a rotary bearing element arranged to rotate about an axis transverse to the associated member.

11. A cable guide comprising a flexible bearing-supporting strip, and a plurality of bearing units xed in succession along said strip and including a second strip having at least one end thereof adjustable longitudinally 5 with respect to the lirst-mentioned strip, and means for fixing the ends of the second strip With respect to the iirstmentioned strip to hold said strips in a selected curved conguration.

12. The cable guide of claim 11, wherein said bearing units are xed at one end thereof to therst-mentioned strip and are movable with respect to the second strip so that said units may diverge when the strips are curved.

References Cited in the file of this patent UNITED STATES PATENTS 2,442,817 Lyle June 8, 1948

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