2. Description of the Related Art Linear motion transports, such as, for example, conveyor systems, are known and are typically used for moving loads along an axis of the particular system.

These linear motion transports may be oriented on horizontal, vertical or angular planes.

Rotational motion transports are also known and typically include a turntable assembly for rotating a load carrying device about an axis defined by a spindle of the turntable.

These rotational motion transports may also be oriented on horizontal, vertical or angular planes.

In an attempt to increase the flexibility of translating systems, linear and rotational modes of motion have been combined to move a load from one point to another on a given path, then rotate the load and resume linear motion on a different

path. Alternatively, the use of linear motion in different directions permits movement of the load in a first given direction along a first path and then in a second direction, which differs from the first, along a second path.

The combination of the various motions creates inherent problems at a transition point, i. e., the point at which the load changes from motion in a first direction to motion in a second direction. More specifically, in the case where the load is moving along a conveyor or track for example, a gap is necessarily formed between two adjacent tracks to facilitate the transition from the first direction to the second direction. In the case of rotational motion, an even more pronounced gap exists between the tracks in the prior art to allow one track to rotate away from the other. Such a gap prevents the smooth transition of the load from one track to the other. Many applications, such as wafer handling, cannot tolerate such a rough transition is not desirable.

A need therefore exists for a method and apparatus for transferring a load in a plurality of different directions and between a plurality of rails configured in dissimilar orientations which permits a smooth transition between the rails.

SUMMARY OF THE INVENTION It is an object of the present invention to provide apparatus and methods of transferring a carriage assembly from a first position to a second position utilizing linear, angular and rotational movements while maintaining a smooth and accurate transfer of the load between the first and second positions.

In accordance with an embodiment of the present invention, an apparatus for transferring a carriage assembly between first and second rail assemblies is provided which includes a first rail assembly defining a first longitudinal axis oriented in a first direction and plane, the first rail assembly having distal and proximal ends; a second rail assembly defining a second longitudinal axis, the second rail assembly having distal and proximal ends; a carriage assembly configured for longitudinal motion along the first and second rail assemblies; and a turntable assembly mounted for vertical, lateral and rotational motion relative to the first rail assembly. The turntable assembly has proximal and distal ends and is positioned adjacent the first and second rail assemblies such that the proximal end of the turntable assembly can be moved from close longitudinal alignment with the distal end of the first rail assembly to a vertical position out of longitudinal alignment with the first longitudinal axis of the first rail assembly.

Subsequently the turntable assembly is moved into close longitudinal alignment between the distal end of the turntable assembly and the proximal end of the second rail assembly.

In another embodiment of the present invention the first rail assembly is positioned in the same horizontal plane as said second rail assembly. Alternatively, the first and second longitudinal axes may be oriented in different horizontal or angular planes.

In yet another embodiment of the present invention, the turntable assembly and the first rail assembly are positionable in axial alignment having a gap therebetween in a range of about 0.001 inches to about 0.090 inches, and preferably about 0.010 inches.

In accordance with still another embodiment of the present invention, an apparatus for transferring a carriage assembly between first and second rail assemblies is provided which includes a first rail assembly defining a first longitudinal axis oriented in a first direction and plane. The first rail assembly has distal and proximal ends. A second rail assembly defining a second longitudinal axis is also provided. The second rail assembly has distal and proximal ends as well. A carriage assembly is provided for longitudinal motion along the first and second rail assemblies and a turntable assembly is mounted for vertical, lateral and rotational motion relative to the first rail assembly. The turntable assembly has proximal and distal ends and is positioned adjacent the first and second rail assemblies such that the proximal end of the turntable assembly can be moved from close longitudinal alignment with the distal end of the first rail assembly to a vertical position out of longitudinal alignment with the first longitudinal axis of the first rail assembly. Subsequently the turntable assembly is moved into close longitudinal alignment between the distal end of the turntable assembly and the proximal end of the second rail assembly, wherein the turntable assembly and the first rail assembly are positionable in axial alignment having a gap therebetween in a range of about 0.001 inches to about 0.090 inches.

In accordance with still yet another embodiment of the present invention, a method of transporting a carriage assembly between first and second rail assemblies is provided which includes the steps of moving a carriage assembly from a proximal end to a distal end of a first rail assembly, the first rail assembly defining a first longitudinal axis oriented in a first direction and plane; traversing a gap between the distal end of the first

rail assembly and a proximal end of a turntable assembly which is mounted for vertical, lateral and rotational motion relative to the first rail assembly, with the carriage assembly; stopping the carriage assembly on the turntable assembly; moving the turntable assembly to a vertical position out of longitudinal alignment with the distal end of the first rail assembly; rotating the turntable assembly until it is in axial alignment with a second rail assembly; moving the turntable assembly to a vertical position in close longitudinal alignment between a distal end of the turntable assembly and a proximal end of the second rail assembly; traversing a gap between the distal end of the turntable assembly and the proximal end of the second rail, with the carriage assembly; and moving the carriage assembly from the proximal end to a distal end of the second rail assembly.

These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments, which is to be read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention, reference is made to the following description of exemplary embodiments thereof, and to the accompanying drawings, wherein: FIG. 1 is a perspective view of a portion of the combination turntable apparatus in accordance with the present invention illustrating various motions of the turntable;

FIG. 2 is an exploded perspective view of a carriage assembly which is configured to carry a load and slidably engage the rails of the combination turntable apparatus; FIG. 3 is a side view in partial cross-section of a portion of a rail illustrating a belt drive unit for moving the carriage assembly along the rail in accordance with an embodiment of the present invention; FIG. 4 is a side view in partial cross-section of a portion of a rail illustrating another embodiment of a belt drive unit for moving the carriage assembly along the rail in accordance with an embodiment of the present invention; FIGS. 5-8 are perspective views of a combination turntable apparatus illustrating movement of a carriage assembly and load from a first rail to a turntable assembly and from the turntable assembly to a second rail which is positioned substantially orthogonal to the first rail; FIG. 9 is a perspective view of the combination turntable apparatus _ FIGS. 5-8 illustrating movement of the turntable assembly to its initial position; FIG. 10 is a perspective view of the combination turntable apparatus illustrating a turntable assembly in position to receive a carriage assembly and load from a horizontally displaced rail; FIG. 11 is a top view of a combination turntable apparatus having a plurality of horizontally displaced rails and a plurality of vertically displaced rails in accordance with another embodiment of the present invention;

FIG. 12 is a side view of the combination turntable apparatus of FIG. 11 taken along lines 12-12; FIG. 13 is a side view of the combination turntable apparatus of FIG. 11 taken along lines 13-13; FIG. 14 is a top view of a combination turntable apparatus having a plurality of radially displaced rails in accordance with another embodiment of the present invention ; FIG. 15 is a side view of a carriage assembly and turntable assembly in accordance with another embodiment of the present invention; FIG. 16 is a side view of the carriage assembly and turntable assembly of FIG. 15 illustrating a piston in a partially extended position; FIG. 17 is a perspective view of another embodiment of a turntable assembly having additional angular movement capabilities, in accordance with the present invention; FIG. 18 is an exploded perspective view of the turntable assembly of FIG.

17; FIGS. 19-23 are side views of the turntable assembly of Fig. 17 illustrating the ability of the turntable assembly to move in a variety of directions; and FIG. 24 is an exploded perspective view of another embodiment of a turntable assembly having additional movement capabilities in accordance with the present invention.

DETAILED DESCRIPTION OF PF ; FFRRED EMRODIMENTS Referring initially to FIG. 1, a portion of a combination turntable apparatus 50 in accordance with the present invention illustrates the various motions of a turntable assembly 52, as indicated by arrows A, B and C. Combination turntable apparatus 50 generally includes turntable assembly 52, a plurality of fixed rails 54, a carriage assembly 56 for carrying a load 58 on rails 54 and turntable assembly 52, and a base rail 60 which defines a longitudinal guide track therein to guide turntable assembly 52 in a lateral direction as indicated by arrow B.

Turntable assembly 52 includes a rail portion 64, a piston 66 and a lower support block 68. Rail portion 64 includes a relatively horizontal base 70 and a pair of substantially parallel side walls 72 extending vertically upward from and substantially orthogonal to base 70. Two cylindrically shaped shafts 74 are mounted longitudinally along inner sides of walls 72 and are positioned to slidably engage longitudinal bores formed on carriage assembly 56, as will be discussed in further detail below.

Piston 66 is attached to a lower surface of horizontal base 70 and is provided to facilitate vertical and rotational movement of turntable assembly 52, as indicated by arrows A and C. Support block 68 is connected to a lower portion of piston 66 and serves to guide piston 66 along base rail 60, as support block 68 is slidably engaged with shafts 62 mounted in base rail 60, for lateral movement as indicated by arrow B. Thus, turntable assembly 52 is advantageously configured for vertical, lateral and/or rotational movement, the advantages of which will be discussed in further detail below. It is also contemplated that piston 66 may be replaced with a rotatable cylinder

having a cam groove which is engaged by a cam follower pin to cause the cylinder to move vertically, or piston 66 may be any other apparatus which combines vertical and rotational movement as is known to one having ordinary skill in the art.

The plurality of fixed rails 54 are positioned adjacent turntable assembly 52 such that a carriage assembly 56 traveling along a longitudinal axis of one of the plurality of fixed rails 54 may be transferred to turntable assembly 52 when the fixed rail 54 is axially aligned with rail portion 64 on turntable assembly 52. Each of the plurality of fixed rails 54 includes a proximal end, a distal end, a relatively horizontal base 76 and a pair of substantially parallel side walls 78 extending vertically upward from and substantially orthogonal to base 76. Two cylindrically shaped shafts 80 are mounted longitudinally along inner sides of walls 78 and are positioned to slidably engage longitudinal bores formed on carriage assembly 56, as will be discussed in further detail below. As used herein, the term"proximal end"refers to the end of the rail assembly at which the carriage assembly commences its longitudinal motion and the term"distal end" refers to the opposite end of the rail assembly (i. e., the end toward which the carriage assembly moves).

Referring now to FIGS. 1 and 2, an exploded view of carriage assembly 56 is shown. Carriage assembly 56 is configured to carry a load and slidably engage rail 64 of the combination turntable apparatus. More specifically, a load is received and carried within a container 82 which is removably mounted on an upper surface of carriage assembly 56. To facilitate mounting of container 82, four holes are formed in a bottom surface of the container and are configured to engage studs 86 extending from an upper

surface of carriage assembly 56. Alternatively, two longitudinal grooves 84 may be formed in the upper surface of carriage assembly 56 to receive two correspondingly shaped tracks extending from a bottom surface of container 82. It is also contemplated that container 82 may be secured to carriage assembly 56 by welding, epoxy, bolts or any other means known to one having ordinary skill in the art.

As discussed above, the plurality of rails 54 and the rail portion 64 of turntable assembly 52 each include two cylindrically shaped shafts 80,74, respectively, mounted longitudinally along inner sides of walls 78,72, respectively, which are positioned to slidably engage longitudinal bores formed on carriage assembly 56. In accordance therewith, as shown in FIG. 2, two longitudinal bores 88 are formed in the carriage assembly 56. Open-type linear motion bearings 90 are fitted within each end of longitudinal bores 88 to reduce the sliding friction between carriage assembly 56 and cylindrically shaped shafts 80 and 74.

As discussed above, load 58 may be carried within container 82 mounted on an upper surface of carriage assembly 56. The load may be, for example, cargo which must be conveyed from one location to another, or a piece of machinery which is transferred from one work station to another. For example, the piece of machinery may require several different operations to be performed on it, such as drilling, coating, hardening, etc., wherein each operation is performed at a station which is separate and spaced apart from the previous station.

Referring now to FIGS. 3 and 4, side views of a section of rail 64 are illustrated in partial cross-section to show preferred embodiments of apparatus for

moving carriage assembly 56 therealong. Referring initially to FIG. 3, load 58 (not shown) is positioned within container 82 on an upper surface of carriage assembly 56 which is slidably positioned between side portions of rail 64. As shown in the window formed in the side of rail 64, a conveyor belt drive unit 92 is positioned within a lower portion of rail 64. Conveyor belt drive unit 92 includes a drive belt 94, a drive shaft 96, pulleys 98 and means 100 for driving drive shaft 96 to rotate drive belt 94. A longitudinal groove is preferably formed along the axis of the base of rail 64 such that an upper surface of belt 94 contacts a lower surface of carriage assembly 56 to effect transitional movement thereof. Means 100 may be any means for driving a belt known to one having ordinary skill in the art including, but not limited to, an electric, pneumatic or hydraulic motor.

Although the apparatus for moving carriage assembly 56 along a rail is illustrated within rail 64 of turntable assembly 52, it is contemplated that the same apparatus may be utilized within the plurality of fixed rails 54 to further facilitate the movement of carriage assembly 56 along the rail structure of the combination turntable apparatus.

Alternatively, as shown in FIG. 4, a conveyor belt drive unit 102 may be housed within carriage assembly 56 and configured to engage the rail upon which the carriage assembly is situated. Conveyor belt drive unit 102 includes drive belt 104, a drive shaft 110, a pulley 112 and means 114 for driving drive shaft 110 to rotate drive belt 104. Furthermore, as illustrated in FIG. 4, instead of being a relatively smooth drive belt as illustrated in FIG. 3, drive belt 104 includes a plurality of teeth 106 extending

radially therefrom which are configured and dimensioned to engage a plurality of teeth 108 formed on an upper surface of the base portion of the rail upon which the carriage assembly is situated. Thus, as drive belt 104 rotates it will cause movement of carriage assembly 56 along an axis of the rail.

It is preferred that conveyor belt drive unit 102 may be housed within the rails as described above with respect to conveyor belt drive unit 92 shown in FIG. 3. In such a configuration, carriage assembly 56 may include teeth or transmission legs extending radially from a lower surface thereof to engage the teeth of the conveyor belt.

It is further contemplated that other linear motion transmission apparatus may be utilized to move carriage assembly 56, such as, for example, a rack and pinion configuration, electromagnetic rams, linear motors, chain drives, magnetic couplings, pneumatics, or hydraulics.

With reference to FIGS. 5 through 9, the operation of an embodiment of the combination turntable apparatus will now be described. Generally, FIGS. 5 through 9 are perspective views of a combination turntable apparatus in accordance with an embodiment of the present invention which illustrate movement of a carriage assembly and load from a first rail to the turntable assembly, and from the turntable assembly to a second rail which is substantially orthogonal to the first rail. In accordance therewith, carriage assembly 56, carrying load 58, is initially transmitted in the direction of arrow D from a proximal end to a distal end of fixed rail 54a toward turntable assembly 52. It is desired that load 58 is transferred, via carriage assembly 56, to a distal end of fixed rail 54b, thus requiring transmission along the longitudinal axis of fixed rail 54b. As carriage

assembly 56 approaches the distal end of fixed rail 54a, it is transferred to the proximal end of rail 64 on turntable assembly 52. As illustrated in FIG. 6, carriage assembly 56 then comes to rest on rail 64 to allow turntable assembly 52 to reposition itself such that rail 64 will be properly aligned with the proximal end of a desired destination rail.

In a preferred embodiment of the present invention, the gap X (shown in FIG. 5) between the ends of the shafts on rail 64 on turntable assembly 52 and the ends of the shafts on any of the fixed rails 54, axially aligned therewith and adjacent thereto, is minimized. The configuration of turntable assembly 52 permits such an important feature, as will be described in further detail below. The gap X is in the range of about 0.001 inches to about 0.090 inches and is preferably 0.010 inches to ensure a smooth transition of carriage assembly 56 between two axially aligned adjacent rails.

Since the gap X between two axially aligned adjacent rails is so small, turntable assembly 52 is physically restrained from rotating while at the same elevation as an adjacent rail (e. g., rails 54a and 54c). Therefore, in accordance with the present invention, as illustrated in FIG. 7, turntable assembly 52 must first move in a vertical direction to a position which is out of horizontal alignment with a plane defined by any of the adjacent fixed rails.. Although it may move vertically downward, turntable assembly 52 is illustrated moving vertically upward in the direction indicated by arrow E. Once turntable assembly 52 is out of horizontal alignment with each of the adjacent rails 54a and 54c, it is free to rotate in a direction indicated by arrow F until it is in axial alignment with the desired fixed output rail 54b.

When rail 64 on turntable assembly 52 is properly aligned with rail 54b, turntable assembly 52 is returned to its previous elevation and carriage assembly 56 may continue its intended direction of travel as indicated by arrow G in FIG. 8. Referring now to FIG. 9, after carriage assembly 56 has completely traversed the gap between a distal end of rail 64 and a proximal end of rail 54b, turntable assembly 52 may return to its initial position in anticipation of another carriage assembly from one of rails 54a, 54c, 54d and 54e.

Referring now to FIG. 10, as described above and in accordance with an embodiment of the present invention, turntable assembly 52 is configured to move laterally along cylindrical shafts mounted in base rail 60. Thus, as shown in FIG. 10, when turntable assembly 52 is positioned between rails 54a and 54c it is able to slide laterally within base rail 60 to a position to receive a carriage assembly 56 traveling along one of rails 54d and 54e.

FIG. 11 illustrates a top view of a combination turntable apparatus having a plurality of horizontally displaced rails 54 and a plurality of vertically displaced rails (not shown) in accordance with another embodiment of the present invention. The present invention has been described thus far utilizing an example wherein carriage assembly 56 entered from one of rails 54a, 54c, 54d or 54e, was rotated 90 degrees by turntable assembly 52, and exited via rail 54b at the same elevation as shown by dashed lines in FIG. 11. However, as illustrated in FIGS. 12 and 13, it is contemplated that carriage assembly 56 may enter rail 64 on turntable assembly 52 from a rail 54 at any one of a plurality of elevations, and be transferred to another rail 54 at a different elevation.

For example, carriage assembly 56 may enter rail 64 on turntable assembly 52 from rail 54j at a lower elevation, and be transferred to rail 54f, as indicated by arrow H in FIG. 13, at an upper elevation.

Referring now to FIG. 14, a top view of a combination turntable apparatus having a plurality of radially displaced rails 54m-r in accordance with another embodiment of the present invention is illustrated. In this embodiment, the gap X between axially aligned adjacent rails is advantageously minimized, as discussed above, since turntable assembly 52 is configured to move in a vertical direction prior to rotating, to avoid interference between rail 64 and an adjacent rail 54. Thus, in this embodiment, carriage assembly 56 is able to make a smooth transition from any one of rails 54m-r to rail 64 on turntable assembly 52, and back to a desired other one of rails 54m-r. It is contemplated that this embodiment may also include additional rails at a plurality of elevations.

FIGS. 15 and 16 are side views illustrating an alternative embodiment of a carriage assembly 56a. In this embodiment, piston 66a is located within carriage assembly 56a instead of within the turntable assembly as described in the previous embodiments. Additionally, piston 66a is illustrated in a fully retracted and a partially extended position. Proceeding with FIG. 15, load 58 is placed within container 82 on carriage assembly 56a. Turning now to FIG. 16, piston 66a is partially extended to facilitate vertical movement of container 82 and load 58 above carriage assembly 56a. As illustrated in this embodiment, piston 66a is of the telescoping type, connected at an upper portion thereof to the lower end of piston 166, and at a lower portion thereof it is

positioned on a stud 141 extending from an upper surface of support block 168. Yaw assembly 140 is configured to rotate turntable assembly 152 such that rail 164 may be repositioned adjacent another rail. Yaw assembly 140 includes a piston support plate 142, a motor 144, a pair of gears 146,147 and a bearing plate 148. During operation, gear 146 is fixed to stud 141 and is also configured to mesh with gear 147 which rotates in response to the operation of motor 144, thereby causing yaw assembly to rotate on bearing plate 148 as indicted by arrow J.

Referring now to FIGS. 17 and 18, there is shown a turntable assembly 152 in accordance with another embodiment of the present invention. Turntable assembly 152 maintains the features of the previously discussed turntable assembly embodiment, while adding structure which allows the assembly to rotate in place, adjust its height, and adjust the horizontal plane of its upper rail through a pitch/roll feature.

Accordingly, turntable assembly 152 generally includes a rail portion 164, a pitch/roll assembly 130, a piston 166, a yaw assembly 140 and a lower support block 168. Rail portion 164 includes a relatively horizontal base 170 and a pair of substantially parallel side walls 172 extending vertically upward from and substantially orthogonal to base 170.

Two cylindrically shaped shafts 174 are mounted longitudinally along inner sides of walls 172 and are positioned to slidably engage longitudinal bores formed on a carriage assembly 156 (not shown), as will be discussed in further detail below.

As best seen in Fig. 18, pitch/roll assembly 130 includes a motor 132 having a drive shaft 174, a pivot pin 136, a drive gear 138 and a fixed gear 139. Motor 132 is mounted to piston 166 such that drive shaft 134 is inserted into holes 135. Drive

gear 138 is mounted on drive shaft 134 such that operation of motor 132 will affect rotation of drive gear 138 through drive shaft 134. Fixed gear 139 is fixed to a lower surface of rotation mechanism 180 and is pivotally connected to piston 166. Holes 137 are positioned in relatively close proximity to and are axially aligned with holes 135 such that fixed gear 139 will mesh with drive gear 138. Accordingly, upon the operation of motor 132 which drives drive gear 138, fixed gear 139 will rotate about pivot pin 136 and will force rail 164 to pitch/roll in a direction indicated by arrows I, which is relative to the rotation of drive shaft 134.

Piston 166 is attached to a lower surface of pitch/roll assembly 130 and is provided to facilitate vertical movement of turntable assembly 152, as indicated by arrow H. Piston 166 is illustrated as a hydraulic or pneumatic type piston having hydraulic or pneumatic lines 167 connected thereto for operatively and selectively raising and lowering piston 166 in the directions indicated by arrow H.

Yaw assembly 140 is connected at an upper portion thereof to the lower end of piston 166, and at a lower portion thereof it is positioned on a stud 141 extending from an upper surface of support block 168. Yaw assembly 140 is configured to rotate turntable assembly 152 such that rail 164 may be repositioned adjacent another rail. Yaw assembly 140 includes a piston support plate 142, a motor 144, a pair of gears 146,147 and a bearing plate 148. During operation, gear 146 is fixed to stud 141 and is configured to mesh with gear 147 which rotates in response to the operation of motor 144, thereby causing yaw assembly to rotate on bearing plate 148 as indicated by arrow J. Although it is preferable to rotate turntable assembly 152 via yaw assembly 140, it is also possible to

rotate rail 164 via rotation mechanism 180, positioned between rail 164 and pitch/roll assembly 130, which operates in a similar manner as yaw assembly 140.

FIGS. 19-23 illustrate the ability of turntable assembly 152 to move rail 164 to a position such that it will be aligned with rails 154a and 154b which are not parallel with a horizontal plane. Thus, carriage assembly 156 is able to be transferred from rail 164 to rail 154a, in the direction indicated by arrow K. As illustrated in FIG.

20, subsequent to carriage assembly 156 being completely transferred to rail 154a, piston 166 is forced to move upward in the direction indicated by arrow L to move rail 164 out of axial alignment with rails 154a and 154b, thereby permitting rail 164 to rotate without interfering with either of rails 154a and 154b as illustrated in FIG. 21. FIG. 22 illustrates turntable assembly 152 with rail 164 returned to a horizontal plane and aligned with rails 154c and 154d. FIG. 23 illustrates, in phantom, the various planes rail 164 may be positioned in via pitch/roll assembly 130.

Referring now to FIG. 24, another embodiment of a turntable assembly 252 in accordance with the present invention is illustrated. Turntable assembly 252 is similar to turntable assembly 152 in operation, however a structural difference between the two embodiments is that pitch/roll assembly 230 on turntable assembly 252 is located at the bottom of piston 266 instead of at the top. Therefore, when pitch/roll assembly 230 is operated, both rail 264 and piston 266 move instead of just the rail.

Although the illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes

and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. For example, it is contemplated that alternative configurations of the combination turntable apparatus may be utilized including the use of more than one turntable assembly. Additionally, although the rails were described in a substantially horizontal plane, it is contemplated that they may be oriented in a plurality of positions and angles. Also, the character of the system may have additional embodiments, such as being configured from non-round rails, or where the rails are not mounted inside of the transporting system. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.