Deployment arrangement for elongated flexible connecting members

Abstract

In the embodiments described in the specification a deployment arrangement for elongated flexible members such as hoses and cables connected between spaced stationary and rotatable components includes two spaced cylinders of different diameter having walls defining an annular path in the space between the components and a support assembly on each component for supplying a flexible member into the annular space between the walls in a direction substantially perpendicular to the surface of the component facing the annular space. Each of the support assemblies includes a guide which limits the bending angle of the flexible member at the location in which it is introduced into the annular space.

Description

BACKGROUND OF THE INVENTION

[0001] This invention relates to arrangements for coupling elongated flexible members such as cables and hoses having a limited twisting ability between a stationary component and a rotatable component.

[0002] Flexible connecting members such as electrical cables and hoses, for example, are not designed to permit extensive twisting without loss of integrity. For couplings of convenient length, most such flexible members are subject to a limit of 400° of rotation between components to which they are connected. If more rotation is required slip rings have been used to transfer electrical power and control signals from one component to another but these must be centered on the axis of rotation and slip ring brushes are subject to wear which can result in failures. Also, rotatable mechanical seals have been used to permit relative rotation of hoses and conduits which transfer fluids between stationary and rotating components, but these also must be centered on the axis of rotation and are prone to leakage and require periodic adjustment. Various attempts have been made to overcome the disadvantages of such conventional arrangements.

[0003] The Betker et al. U.S. Pat. No. 5,566,900 discloses a cable takeup/payout system for a multi rotation assembly in which an interconnect cable is fixed at one end to a peripheral wall of a circular enclosure and at the other end to a mount located between two lobes of a central heart-shaped hub so as to enter the space between them in a radial direction. As the hub rotates with respect to the peripheral wall the cable can assume various configurations between the hub and the wall, including an S-shaped configuration.

[0004] The Obata U.S. Pat. No. 5,328,112 shows an arrangement for controlling motion of a flexible flat cable between a hub and a peripheral wall in which the flat cable extends around a planet roll which is fitted with a planet gear enmeshed with a sun gear attached to the hub so that the cable is guided between the hub and the peripheral wall during relative rotation of those components.

[0005] In the Fladung U.S. Pat. No. 5,358,190 connecting cables extending axially into a space between a fixed wall in a winding drum and a rotating wall pass through a central rotatable disc which divides the interior of the drum into two regions in which the connecting cables can be wound without interference with each other.

[0006] According to the Nagaoka et al. U.S. Pat. No. 5,841,069 a flexible flat cable extending between a central hub and a peripheral drum is confined by a C-shaped movable body disposed within the space between the hub and the drum to maintain the flexible cable in a desired orientation.

SUMMARY OF THE INVENTION

[0007] Accordingly, it is an object of the present invention to provide a deployment arrangement for elongated flexible members such as hoses, cables and the like extending between relatively rotatable components which overcomes disadvantages of the prior art.

[0008] Another object of the invention is to provide a simple and convenient deployment arrangement for elongated flexible members permitting relative rotation between components to which the flexible members are attached up to 400° or more of rotation or more without producing excessive bending or compression of the members.

[0009] These and other objects of the invention are attained by providing a deployment arrangement having an annular space defined by two cylindrical walls of different diameter extending between a stationary component and a rotating component along with couplings for a flexible member extending into the annular space from each of the rotating and stationary components in the direction toward the other component. In a preferred embodiment each of the couplings is shaped to assure that bending of the flexible member at the point of attachment is limited does not exceed the manufacturer's specification. If desired the flexible member or the cylindrical walls defining the annular space and the adjacent surfaces of the rotating and stationary components can be treated to reduce dragging or binding of the flexible members as they move through the annular space, for example, by applying anti-friction coatings or rolling members on surfaces subject to frictional contact.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Further objects and advantages of the invention will be apparent from a reading of the following description in conjunction with the accompanying drawings, in which:

[0011] FIG. 1 is a perspective view illustrating a representative embodiment of a deployment arrangement for flexible members in accordance with the invention;

[0012] FIG. 2 is a top perspective view schematically illustrating the components of the deployment arrangement in greater detail; and

[0013] FIG. 3 is a schematic side view of the deployment arrangement of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0014] In the typical embodiment of a flexible member deployment arrangement 10 shown schematically in the drawings, a rotating component such as a platform 12 is disposed in spaced relation to a stationary component such as table 14 and an elongated flexible member 16 is connected at one end to a support assembly 18 mounted on the platform 12 and at the other end to another support assembly 20 mounted on the stationary component 14.

[0015] The elongated flexible member 16 may, for example, be a hose carrying a liquid or a gas under pressure, or a cable or bundle of wires carrying electrical power or control signals. Such flexible members are normally subject to limitations which prevent twisting of more than about 400° over convenient connecting lengths.

[0016] In order to guide the flexible member between the two support assemblies 18 and 20 during relative rotation of the components 12 and 14 without permitting them to become kinked or tangled, two cylinders 22 and 24 of different diameter and are mounted on the platform 12 and spaced to define an annular region 26 which includes the locations of the support assemblies 18 and 20 between their facing surfaces 28 and 30, respectively.

[0017] As best seen in FIG. 3, the support assemblies 18 and 20 are arranged to introduce the flexible member 16 into the annular region 26 between the components 12 and 14 in a direction substantially perpendicular to the facing surfaces 28 and 30 of the platform 12 and the table 14, respectively, and each support assembly includes a guard 32 with a surface 34 which is inclined outwardly away from the adjacent surface 28 or 30 to prevent excessive bending of the member 16 in the region adjacent to the support assembly. As shown in FIG. 3 the outer edge of each guard 24 is spaced by a distance 36 from the adjacent surface 28 or 30 to prevent the flexible member from being bent at the location of the support assembly to an extent that exceeds the limit suggested by the manufacturer of the flexible member.

[0018] The walls of the annular space 26 confine the flexible connecting member 16 during relative rotation of the components so that the flexible connecting member can attain various configurations such as S-shaped configurations which will not interfere with relative rotation of the components 12 and 14 or cause damage to the flexible member. The width 38 of the annular space 26 increases with the overall width of the deployment arrangement, providing enough margin to permit relative motion of the flexible member. The height 40 of the cylindrical members 22 and 24, which, together with the length of the flexible member 16 between the support assemblies 18 and 20, limits the extent of relative rotation of the components, should preferably be greater than the sum of the distance 36 and four times the effective diameter of the deployment arrangement.

[0019] As best seen in FIG. 2 each of the support assemblies 18 and 20 also has a support section 42 affixed by a mount 44 to the corresponding stationary or rotatable component 12 or 14 to guide the member 16 into the annular space 26 in a direction substantially perpendicular to the surface 28 or 30 of the component facing the space 26.

[0020] As the rotatable component 12 turns with respect to the stationary component 14 the flexible member 16 follows a combination of movements which includes, for example, folding over in an S-shape. With this arrangement, it is possible to permit relative angular motion of the two components 12 and 14 of more than 200° in each direction without causing damage to the flexible component. If desired, the inner surfaces of the cylindrical members 22 and 24 defining the annular space 26 may be coated with an anti-friction material such as polytetrafluoroethylene or may contain rolling elements such as balls or rollers to reduce frictional resistance to motion of the flexible member within the annular space. Alternatively or in addition, the flexible member 16 may have an anti-friction coating or outer layer such as a Kevlar woven sleeve.

[0021] Although the invention has been described herein with reference to specific embodiments many modifications and variations therein will readily occur to those skilled in the art. Accordingly, all such variations and modifications are included within the intended scope of the invention.

Claims

1. A deployment arrangement for a flexible member comprising:

a fixed component and a rotatable component having facing surfaces disposed in spaced relation;

a support assembly mounted on each of the stationary and rotatable components and arranged to guide a flexible member toward the space between the components in a direction substantially perpendicular to the adjacent surface of the component on which that support assembly is mounted including a guide for limiting the extent of bending of a flexible member supported by the support assembly; and

a pair of generally cylindrical members disposed in the space between the facing surfaces of the stationary and rotatable components defining an annular space which encompasses regions adjacent to the support assemblies during relative rotation of the rotatable component and the stationary component.

2. A deployment arrangement according to claim 1 including a flexible member connected between the support assembly mounted on the stationary component and the support assembly mounted on the rotatable component and having a length between the support components which is great enough to permit relative rotation between the stationary component and the rotatable component through an angle of at least 400°.

3. A deployment arrangement according to claim 1 wherein the height of the cylindrical wall extending between the facing surfaces is at least four times the diameter of the annular space.

4. A deployment arrangement according to claim 1 including a friction-reducing arrangement to reduce friction between the walls of the annular space and a flexible member moving in the annular space.

5. A deployment arrangement according to claim 4 wherein the walls defining the annular space are provided with a low friction material.

6. A deployment arrangement according to claim 4 wherein the walls defining the annular space are coated with polytetrafluoroethylene.

7. A deployment arrangement according to claim 4 wherein the walls defining the annular space are provided with rolling members.

8. A deployment arrangement according to claim 4 including a flexible member covered with an anti-friction material.

9. A deployment arrangement according to claim 8 wherein the anti-friction material is a Kevlar sleeve.

10. A deployment arrangement according to claim 1 wherein the guide includes a surface inclined away from the adjacent component in the direction away from the support assembly.

11. A deployment arrangement according to claim 1 wherein the support assembly includes a support which confines the flexible member in an orientation substantially perpendicular to the adjacent surface of the component in a region between the facing surfaces.