Abstract:
A tilt-steering mechanism for a vehicle including a steering shaft, a steering wheel, universal joint interconnecting the steering shaft and the steering wheel wherein rotation of the steering wheel correspondingly rotates the steering shaft, the universal joint including a yoke defining a cavity therein and a shaft having a first end pivotably supported within the cavity in the yoke, and a locking structure for selectively locking the shaft of the universal joint at a predetermined angle to the steering shaft.

Description:
RELATED APPLICATIONS 
     This is a divisional of Ser. No. 09/481,294, filed on Jan. 11, 2000, now U.S. Pat. No. 6,293,167B1, which in turn is a continuation of Ser. No. 09/168,757, filed on Oct. 8, 1998, which is abandoned. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to vehicle steering systems and, more particularly, to tilt-steering mechanisms for vehicle steering. 
     BACKGROUND OF THE INVENTION 
     Vehicle steering systems having tilt-steering mechanisms are commonly used in both land and water vehicles. For example, in a land vehicle such as an automobile, a driver may tilt the steering wheel to its maximum upward position to facilitate the ingress and egress for the vehicle. The smaller the vehicle, the more convenience that is afforded by the tilt-steering mechanism. 
     Similarly, tilt-steering mechanisms for marine vehicles facilitate a driver&#39;s ingress and egress to the helm seat. However, the application of a tilt-steering mechanism to a marine vehicle presents significant challenges for designers due to the wide spread use of hydraulic steering in such vehicles. 
     In a typical hydraulic steering arrangement, the steering wheel of the marine vehicle is mechanically coupled to a hydraulic pump. The turning of the steering wheel delivers pressurized oil from one of two pump ports depending on the direction of the turn. The pressurized oil is delivered to one of two ends of a hydraulic cylinder that, in turn, pivots an outboard engine, a rudder or the like. 
     An example of an improved tilt-steering mechanism for marine vehicle is shown in U.S. Patent application Ser. No. 08/798,832 filed on Feb. 12, 1997, assigned to the assignee of the present invention, and incorporated herein by reference. In the &#39;832 application, the steering shaft is interconnected to the driving shaft of a hydraulic pump by a universal joint. As is known in the art, the universal joint includes two cross pins that ride in a trunnion block. While universal joints of this type are acceptable in most marine applications, the cost of such universal joints can be significant. Consequently, it is highly desirable to develop a low-cost alternative to prior art universal joints, and improved vehicle tilt-steering mechanisms with universal joints. 
     OBJECTS OF THE INVENTION 
     Therefore, it is a primary object and feature of the present invention to provide an improved tilt-steering mechanism using a universal joint which is less expensive to manufacture. 
     It is a further object and feature of the present invention to provide an improved tilt-steering mechanism which is stronger and less likely to fail in response to large loads. 
     It is a still further object and feature of the present invention to provide a tilt-steering mechanism which minimizes the “play” of a steering wheel. 
     It is a still further object and feature of the present invention to provide a tilt-steering mechanism with a universal joint that can be easily assembled. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention, an improved tilt-steering mechanism with a universal joint is provided. The universal joint includes a generally cup-shaped yolk having a ball-receiving cavity therein. A shaft extends along a longitudinal axis and has first and second ends. A ball is mounted to a first end of the shaft. The ball is receivable within the ball-receiving cavity in the yolk. A connection structure is provided for interconnecting the ball and the yolk. 
     The ball may include a slot extending therethrough along an axis perpendicular to the longitudinal axis of the shaft. An insert is receivable within the slot of the ball. The insert includes a passageway extending therethrough. The connection structure, such as a pin, extends through the passageway in the insert and inter-connects the yolk to the shaft, thereby allowing the shaft to be pivotable about the pin. 
     It is contemplated that the insert be generally disc-shaped and have a predetermined diameter which is less than the width of the slot in the ball. 
     In order to connect the shaft of the universal joint to a steering wheel, the second end of the shaft may be threaded. Further, the base of the yolk may include a key-receiving slot therein for receiving the keyed end of the driving shaft of the hydraulic pump. 
     In accordance with a still further aspect of the present invention, a universal joint is provided having a generally cup-shaped yolk. The cup-shaped yolk includes a base and a generally cylindrical wall projecting therefrom. The wall partially defines a cavity therein. A shaft extends along a longitudinal axis and has a ball at a first end thereof. The ball is receivable in the cavity of the yolk. Mounting structure is provided for pivotably supporting the ball in the cavity of the yolk. 
     The ball may include a slot extending therethrough for receiving an insert therein. The mounting structure includes a pin which extends through a passageway in the insert so as to interconnect the cylindrical wall of the yolk to the ball. 
     The tilt-steering mechanism of this invention includes a driving shaft and a steering wheel interconnected by the universal joint described herein such that rotation of the steering wheel correspondingly rotates the driving shaft. As noted, the universal joint includes a yolk defining a cavity therein, and a shaft having a first end pivotably supported within the cavity in the yolk. A locking structure is provided for selectively locking the shaft of the universal joint at a predetermined angle to the driving shaft. 
     The shaft of the universal joint may include a slot therein in order to accommodate a woodruff key. It is contemplated that the steering wheel include a central hub having a passageway for receiving the shaft of the universal joint therethrough. The passageway is defined by a generally cylindrical inner wall of the central hub. The inner wall of the hub includes a recess therein for receiving a portion of the woodruff key in a conventional manner. The recess communicates with the passageway through the central hub. 
     It is further contemplated that the first end of the shaft of the universal joint include an enlarged head thereon. The enlarged head including a slot therethrough. An insert is receivable within the slot in the enlarged head of the shaft of the universal joint. The insert includes a passageway therethrough. The shaft of the universal joint is pivotably mounted to the yolk by a pin extending through the yolk and through the passageway in the insert. The insert is generally disc-shaped and has an predetermined diameter approximating the diameter of the enlarged head of the shaft of the universal joint. 
    
    
     Various other features, objects and advantages will be made apparent from the following description taken together with the drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate a preferred construction of the present invention in which the above advantages and features are clearly understood as well as others which will be readily understood from the following descriptions. In the drawings: 
     FIG. 1 is a partially exploded, isometric view of a steering unit having a tilt-steering mechanism incorporating the universal joint of the present invention. 
     FIG. 2 is an exploded, isometric view of the tilt-steering mechanism of FIG.  1 . 
     FIG. 3 is an exploded, isometric view of the universal joint of the present invention. 
     FIG. 4 is a side elevational view of the universal joint of the present invention. 
     FIG. 5 is an end view of the universal joint of the present invention. 
     FIG. 6 is a top plan view, partially in section, showing the universal joint of a present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a tilt-steering mechanism  10  incorporating the universal joint  12  of the present invention is shown. Tilt-steering mechanism  10  includes a helm unit  14  extending along a longitudinal axis. As is conventional, helm unit  14  includes a hydraulic pump, pilot check valve assembly, relief valve and reservoir supported within front and rear housing components  16  and  18 , respectively. Front housing  16  includes a yolk-receiving cavity  20  into which a driving shaft  22  extends for driving the hydraulic pump (not shown) of helm unit  14 . 
     Referring to FIG. 3, universal joint  12  includes a steering shaft  24  extending along a longitudinal axis and a yolk  26 . Steering shaft  24  includes a first threaded end  28  adapted for receiving steering wheel  30  thereon, FIG. 1, in a manner hereinafter described. A tapered body portion  32  interconnects threaded end  28  with a generally cylindrical central body portion  34  of steering shaft  24 . Tapered body portion  32  includes a slot  36  having an arcuate cross-section for receipt of a woodruff key  38  therein in a conventional manner. 
     Central body portion  34  of steering shaft  24  includes a groove  40  extending about the outer cylindrical surface  42  thereof at a location adjacent tapered body portion  32 . Groove  40  is adapted for receiving a retaining ring  44 , FIG. 2, for reasons hereinafter described. Central body portion  34  of steering shaft  24  further includes an enlarged neck  46  which extends about the outer periphery of external surface  34  at a location adjacent an opposite end  48  of steering shaft  24 . Neck  46  defines a shoulder  50  in external surface  42  of central body portion  34 . It is preferred that neck  46  be dimensioned for receipt in swivel housing  100 . 
     An enlarged head or ball  52  is mounted on opposite end  48  of steering shaft  24 . Ball  52  includes an elongated slot  54  having a predetermined width defined between side walls  55   a  and  55   b , and a predetermined height defined between side walls  57   a  and  57   b . Slot  54  extends along an axis transverse to the longitudinal axis of steering shaft  24 , and is dimensioned for receiving a generally disc-shaped insert  56  therein. 
     Insert  56  includes first and second opposite faces  58  and  60 , respectively, interconnected by an outer edge  62 . The height of insert  56  is slightly less than the predetermined height of slot  54  in ball  52  so as to provide minimal clearance between faces  58  and  60  of insert  56  and corresponding walls  57   a  and  57   b  in ball  52 . The diameter of insert  56  is slightly less then the predetermined width of slot  54  in ball  52  so as to provide minimal clearance between outer edge surfaces  62  and sidewalls  55   a  and  55   b  in ball  52 . 
     Insert  56  further includes a pin-receiving passageway  64  therethrough having a length generally equal to the diameter of insert  56 , and a second passageway  66  extending between faces  58  and  60  which communicates with pin-receiving passageway  64 . Second passageway  66  is intended to carry grease for lubricating the pivotal connection hereinafter described between steering shaft  24  and yolk  26 . 
     Yolk  26  includes a base portion  68  having a generally cylindrical wall  70  projecting therefrom. Cylindrical wall  70  includes first and second axially aligned apertures  76  and  78 , respectively, therein and has an inner surface  72  which partially defines a ball-receiving cavity  74  in yolk  26 . Ball-receiving cavity  74  has a diameter slightly greater than the diameter of insert  56  so as to provide minimal clearance between inner surfaces  72  of yolk  26  and the outer edge surface  62  of insert  56  when ball  52  is received therein, FIG.  6 . 
     Base  68  of yolk  26  includes an inner surface  80  which partially defines ball-receiving cavity  74 , and a generally flat outer surface  82  which is perpendicular to cylindrical wall  70 . A slot  84  extends between the inner surface  80  of base  68  and the outer surface  82  of base  62  and communicates with ball-receiving cavity  74  in yolk  26 . Slot  84  has a predetermined configuration to form a mating relationship with a keyed end  86  of driving shaft  22 . 
     In order to assemble universal joint  12 , insert  56  is positioned within slot  54  in ball  52  of steering shaft  24  such that pin-receiving passageway  64  is perpendicular to the longitudinal axis of steering shaft  24 . Ball  52  of steering shaft  24  is inserted into ball-receiving cavity  74  in yolk  26  such that pin-receiving passageway  64  is axially aligned with first and second axially aligned apertures  76  and  78 , respectively, in cylindrical wall  70  of yolk  26 . Pin  90  is inserted through aperture  76  in cylindrical wall  70  of yolk  26  such that a first end  92  of pin  90  is seated within apertures  76  in cylindrical wall  70  of yolk  26  and a second end  94  is seated within aperture  78  in cylindrical wall  70  of yolk  26  so as to capture insert  56  thereon. As a result, steering shaft  24  may pivot about pin  90 . The grease carried in second passageway  64  in insert  56  is intended to lubricate pin  90  and facilitate the ability of steering shaft  24  to pivot with respect to yolk  26 . 
     It is contemplated that end  92  and  94  of pin  90  be retained in corresponding apertures  76  and  78  of yolk  26  in any suitable manner such as by staking, welding or the like. 
     With steering shaft  24  pivotably mounted to yolk  26  as hereinafter described, yolk  26  is inserted into yolk-receiving cavity  20  in front housing  16  of helm unit  14  such that keyed end  86  of driving shaft  22  is received within slot  84  in base  62  of yolk  26 . Rotation of yolk  26  results in the turning of driving shaft  22 . Depending upon the direction of the turn, pressurized oil is delivered to one of two ends of a hydraulic cylinder that, in turn, pivots an outboard engine, a rudder or the like. 
     Referring to FIG. 1, tilt-steering mechanism  10  further includes a mounting plate  96  which is interconnected to front housing  16  of helm unit  14  so as to capture control panel  98  therebetween. Tilt-steering mechanism  10  further includes a swivel housing  100  having a steering shaft passageway  102  extending therethrough. Swivel housing  100  is slid axially over universal joint  12  such that threaded end  28  of steering shaft  24  extends through swivel housing  100  and such that neck  46  is seated within the interior of passageway  102  in swivel housing  100 . Swivel housing  100  is interconnected to the forward end  106  of front housing  16  of helm unit  14  through springs  108  and  110 . First ends of springs  108  and  110  are interconnected to swivel housing  100 , while the second, opposite ends of springs  108  and  110  are interconnected to a spring anchor  112  which is mounted on the forward end  106  of front housing  16  of helm unit  14 . Springs  108  and  110  bias swivel housing  100  toward the forward end  106  of front housing  16  of helm unit  14 . 
     Swivel housing  100  further includes trunnions  114  which project laterally therefrom. Trunnions are adapted for receipt in corresponding recesses  116  in the forward end  106  of front housing  16  of helm unit  14  so as to allow swivel housing  100  to pivot with respect thereto. 
     Retaining ring  44  is seated in groove  40  in the central body portion  34  of steering shaft  24  so as to maintain swivel housing  100  on steering shaft  24 . 
     Two C-shaped locking clamps  120  are mounted to the forward end  106  of front housing  16  of helm unit  14  so as to capture swivel housing  100  therebetween. Each locking clamp  120  extends approximately 180° around swivel housing  100 , and includes an inner surface having a plurality of grooves  122  alternating with a plurality of ridges  124 . The grooves  122  and the ridges  124  converge at a pivot axis extending through trunnions  114  of swivel housing  100 . 
     Tilt-steering mechanism  10  further includes a latch  126  having a grasping plate  128  with a tubular locking device projecting pivotably therefrom. Tubular locking device  130  includes first and second wedged-shaped locking members which are circumferentially spaced 180° from one another and which are generally parallel to longitudinal axis of steering shaft  24 . A compression spring  132  fits into an annular groove  134  in latch  126  and into a corresponding annular groove in retaining ring  136 . Compression spring  132  urges latch  126 , and hence, wedged-shaped locking members into engagement with corresponding grooves  122  into a respective C-shaped clamps  120  so as to secure swivel housing  100  at a fixed angle with respect to the longitudinal axis of helm unit  14 . 
     In order to mount steering wheel  30  onto helm unit  14 , woodruff key  38  is positioned within corresponding slot  36  in steering shaft  24  of universal joint  12  such that flat side  38   a  of woodruff key  38  faces outward from steering shaft  24 . As is conventional, steering wheel  30  has a central hub  140  and an outer grasping portion  142  having a plurality of spokes  144  extending therebetween. Spokes  144  are circumferentially spaced about the outer surface  146  of central hub  140 . Central hub  140  further includes a passageway  148  therethrough for receipt of the steering shaft  24  of universal joint  12 . Passageway  148  in central hub  140  includes a groove for accommodating woodruff key  38 . 
     To mount steering wheel  30  on steering shaft  24  of universal joint  12 , groove in passageway  148  of central hub  140  is axially aligned with woodruff key  38  positioned within slot  36  in steering shaft  24 . Steering wheel  30  is axially pushed over the threaded end  28  of steering shaft  24  such that the threaded end  28  projects through passageway  148  in central hub  30 . Washer  150  is positioned over threaded end  28  of steering shaft  24  and nut  152  is threaded thereon so as to secure steering wheel  30  to steering shaft  24  of universal joint  12 . 
     It is contemplated that a boot  154  be positioned over the forward end of helm unit  14  between central panel  98  and steering wheel  30  in order to discourage access thereto. 
     In order to change the angular position of steering wheel  30  and hence, swivel housing  100  relative to helm unit  14 , the user grasps the grasping portions  128  of latch  126  with the fingertips (while retaining the grasp of central hub  140  of steering wheel  30 ) and urges the latch  126  toward the steering wheel  30  until latch  126  and its locking members disengage from corresponding grooves  122 . After such disengagement, the swivel housing  100  and steering wheel  30  may be tilted to a different angle. After reaching its desired angle, the latch  126  is released, the spring  132  biases the latch  126  to re-engage its locking members with corresponding grooves  122  in clamps  120 . The pivot connection between steering shaft  24  and yolk  26  of universal joint  12  allows steering wheel  30  and swivel housing  100  to pivot over the desired range of angles with respect to helm unit  14 . 
     As is evident from the above description, rotation of steering wheel  30  turns steering shaft  24  of universal joint  12  therewith, which in turn, rotates yolk  26 . Insert  56  distributes the load of ball  52  of steering shaft  24  during rotation of yolk  26 . As a result, universal joint  12  may accommodate additional load thereon. As heretofore described, yolk  26  is interconnected to the keyed end  86  of driving shaft  22  such that rotation of yolk  26  rotates driving shaft  22  in a common direction. 
     As is conventional, rotation of driving shaft  22  drives a hydraulic pump. Hence, turning steering wheel  30  delivers pressurized oil from one of two pump ports depending on the direction of the turn. The pressurized oil is delivered to one of two ends of a hydraulic cylinder, which in turn, pivots an outboard engine, a rudder or the like. 
     While universal joint  12  has been shown for use in connection with a tilt-steering mechanism incorporating a hydraulic pump, is contemplated as being the scope of the present invention to incorporate universal joint in other types of steering or load transmitting mechanisms such as a conventional cable and pulley system. 
     Various modes of carrying out the invention are contemplated as being within the scope of the following claims, particularly pointing out and distinctly claiming the subject matter regarded as the invention.