Mounting arrangement for outboard motor

An outboard motor mounting arrangement wherein the swivel bracket and clamping brackets have interengaging sliding surfaces that take side thrusts and minimize loading on the tilt pin during trim operation. In addition, certain electrical cables and hydraulic conduits are juxtaposed to the steering shaft and mounted so that they pass through the various brackets in a location close to the various pivotal axes to minimize flexure and reduce the necessary length therefor.

BACKGROUND OF THE INVENTION
 This invention relates to an outboard motor and more particularly to a
 mounting arrangement for the outboard motor that facilitates its tilt and
 trim movement to provide stability and good support and also that permits
 the use of conduits that extend from components carried by the lower
 portion of the outboard motor to external devices while minimizing length
 and permitting the tilt and trim movement without obstruction to the
 conduit.
 It is generally known that outboard motors are supported on the transom of
 a watercraft and the propulsion unit portion of the outboard motor is
 movable about a vertically extending steering axis for steering of the
 outboard motor and the associated watercraft and for tilt and trim
 movement so as to adjust the angle of attack of the propeller or
 propulsion unit and also so as to permit the propulsion unit so as to be
 raised out of the water. Thus, the movement of the propulsion unit
 relative to its connection to the watercraft requires movement in two
 distinct planes about two generally perpendicular axes.
 It is desirable that the steering and tilt and trim movement be permitted
 relatively freely but it is also necessary that the side thrust and side
 loading on the outboard motor be well absorbed so as to provide insurance
 against wear on the members that form both the tilt and the steering axes.
 Generally, the clamping bracket which is affixed to the transom of the
 watercraft has a pair of side plates that have a series of spaced
 apertures for receiving a trim pin for taking the forward thrust of the
 drive and for permitting trim adjustment in the maximum trim-down
 position. However, the pivot pin for the tilt operation must absorb large
 portions of the side thrust and this can placed unduly high wear on the
 trim pin.
 It is, therefore, a principal object of this invention to provide an
 improved mounting arrangement for an outboard motor.
 It is a further object of this invention to provide an improved side force
 taking arrangement that cooperates between the clamping bracket and the
 swivel bracket so as to accommodate side forces in the normal trim range
 of movement.
 It is a further object of this invention to provide an improved side thrust
 taking arrangement between the clamping bracket and the swivel bracket
 which does not restrict the degree of steering movement of the outboard
 motor.
 In addition to the thrust taking and wear problem, there is also the
 necessity to provide certain connections or conduits that extend between
 portions of the outboard motor and the interior of the watercraft. For
 example, a speed sensor of the pitot type is frequently used. In this type
 of device, the sensor is positioned at the forward portion of the lower
 unit. The sensor output is transmitted through either an electrical
 conductor or as a fluid pressure through a fluid conduit to an instrument
 mounted in the interior of the watercraft.
 The conduit or conductor must accommodate both the tilt movement, the trim
 movement and also the steering movement. This can present significant
 problems, particularly that of binding or damage to the transmitter.
 It is, therefore, a still further object of this invention to provide an
 improved conductor arrangement for conducting signals or electricity from
 the lower unit to the watercraft without binding or obstruction of the
 tilt and trim and steering movement.
 Many times the outboard motor is provided with an electro-hydraulic system
 for assisting in the trim and tilt movement. Generally, this includes a
 reversible electric motor that drives a reversible hydraulic pump for
 supplying hydraulic fluid to the tilt and trim mechanism. Again, this
 requires electrical conductors to extend from the electric motor to the
 interior of the watercraft for control purposes. These conductors should
 be neatly arranged but also should be constructed so that they do not
 provide binding or unsightly appearance when the outboard motor is steered
 or effects tilt and trim.
 SUMMARY OF THE INVENTION
 This invention is adapted to be embodied in an outboard motor having a
 propulsion unit comprised of a power head containing a powering internal
 combustion engine or other prime mover and a lower unit that contains a
 propulsion device driven by the prime mover and a transmission for
 effecting this driving connection. The propulsion unit is mounted on a
 steering shaft within a swivel bracket for permitting steering movement of
 the outboard motor about a generally vertically extending steering axis.
 The swivel bracket is, in turn, connected by a pivot pin to a clamping
 bracket that is affixed to the hull of an associated watercraft. This
 pivotal connection permits tilt and trim movement of the swivel bracket
 and propulsion unit relative to the clamping bracket and watercraft hull.
 The clamping bracket is comprised primarily of a pair of spaced apart side
 plates that extend along opposite sides of the swivel bracket.
 In accordance with a first feature of the invention, interengaging,
 thrust-taking pads are formed on the swivel bracket and side plates of the
 clamping bracket so as to take side thrusts during at least the trim range
 of movement of the outboard motor.
 In accordance with another feature of the invention, a conductor for
 conducting either fluid or electrical energy extends from a forward
 portion of the lower unit upwardly in an area contiguous to the axis
 defined by the steering shaft and passes through the protective cowling of
 the outboard motor for transmitting signals.
 In accordance with yet another feature of the invention, a hydraulic tilt
 and trim unit acts between the swivel bracket and clamping bracket for
 effecting the tilt and trim movement. This unit is electrically powered
 and electrical conductors extend from this unit generally upwardly to a
 position close to the trim and tilt pin axis and from there pass through
 the protective cowling for transmitting electrical power to the tilt and
 trim unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
 Referring now in detail to the drawings and initially primarily to FIGS. 1
 and 2, an outboard motor constructed in accordance with an embodiment of
 the invention is identified generally by the reference numeral 21. Except
 for the supporting arrangement for the outboard motor 21 and certain
 electrical and hydraulic connections therefor, the construction of the
 outboard motor 21 may be considered to be conventional.
 Therefore, the structure of the outboard motor 21, except for the
 aforenoted specific features will be described only generally. Where
 components of the outboard motor 21 are not illustrated or described,
 those skilled in the art can readily use any desired constructions with
 which to practice the invention.
 The outboard motor 21 is comprised of a power head at the upper end thereof
 which consists of a powering internal combustion engine that is not shown
 and which his contained within a protective cowling. This protective
 cowling is comprised of a lower tray portion 22 to which an upper main
 cowling portion 23 is detachably connected. These cowling portions 22 and
 23 contain and protect the engine and give a neat overall appearance to
 the outboard motor 21.
 A drive shaft housing lower unit assembly 24 depends from the power head
 and the upper portion thereof is at least partially encircled by the tray
 portion 22. This unit 24 includes a main drive shaft housing unit 25 and a
 lower unit housing 26 which are detachably connected to each other in any
 suitable manner.
 As is typical with outboard motor practice, the aforenoted, but
 unillustrated engine is mounted within the power head so that its output
 shaft rotates about a generally vertically extending axis. This is done so
 as to facilitate connection of this output shaft to a drive shaft 27 (FIG.
 1) which depends into the drive shaft housing 25 and which terminates in
 the lower unit housing 26.
 A driving bevel gear 28 is affixed to the lower end of this drive shaft 27
 and drives a pair of counter-rotating driven bevel gears 29 and 31 of a
 conventional reversing type transmission, indicated generally by the
 reference numeral 32. The transmission 32 is utilized so as to drive a
 propulsion unit such as a propeller shaft 33 and propeller 34 in selected
 forward or reverse conditions.
 The driven bevel gears 29 and 31 are suitably journaled for rotation on the
 propeller shaft 33. A dog clutching element 35 is splined to the propeller
 shaft 33 and is adapted to be shifted into engagement with corresponding
 clutching teeth formed on the driven bevel gears 29 and 31 so as to
 drivably couple selected of these gears with the propeller shaft 33 to
 accomplish the desired direction of drive.
 A shift rod 36 extends upwardly through the lower unit housing 26 and drive
 shaft housing 25 for control by a remote operator (not shown) so as to
 control the transmission 32 in a well-known manner.
 The manner in which the propulsion unit of the outboard motor 21 that is
 comprised of the power head and drive shaft housing lower unit 24 is
 connected to the associated watercraft will now be described making
 reference to additional of the figures. Initially, reference may be had
 primarily to FIGS. 3 and 4 in addition to FIGS. I and 2 to follow this
 description.
 A steering shaft 37 is mounted at the front of the drive shaft housing 26
 by means that include a pair of lower supporting brackets 38 which are
 affixed to opposite sides of the drive shaft housing 25 by means of
 fasteners 39 as best seen in FIG. 3. These brackets 38 are connected by
 elastomeric damping assemblies, indicated generally at 41, to a lower
 steering shaft bracket 42. This lower bracket 42 is, in turn, affixed to
 the lower end of the steering shaft 37.
 The upper end of the steering shaft 37 is connected to an upper bracket 43.
 The upper bracket 43 is connected by an elastomeric damping arrangement 44
 to an upper portion of the drive shaft housing 25 in a manner that is well
 known in this art.
 The steering shaft 37 and particularly the portion between the lower and
 upper brackets 42 and 43 is journaled within a swivel bracket assembly,
 indicated generally by the reference numeral 45. Hence, steering movement
 of the outboard motor 21 and specifically the propulsion portion thereof
 is accommodated by rotation of the steering shaft 37 within the swivel
 bracket assembly 45. The forward portion of the upper bracket 43 includes
 a tiller portion 46 so as to facilitate this steering operation.
 The swivel bracket 45 is connected to a clamping bracket assembly that is
 comprised of a pair of spaced apart clamping brackets 47. A pivot pin 48
 is fixed at its ends in these clamping brackets 47 and is journaled within
 suitable bearings of the swivel bracket 45 so as to accommodate tilt and
 trim up adjustment of the outboard motor 21. The clamping brackets 47 are
 suitably affixed to a transom 49 of the hull of a watercraft, indicated
 generally by the reference numeral 51.
 A hydraulic tilt and trim control mechanism, indicated generally by the
 reference numeral 52 and shown additionally in FIGS. 8, 9, and 13, is
 interposed between the clamping brackets 47 and the swivel bracket 45 so
 as to permit hydraulic trim and tilt adjustment. As is typical with these
 type of mechanisms, the hydraulic tilt and trim unit 52 also includes a
 damping mechanism so as to permit the outboard motor 21 and swivel bracket
 45 to "pop up" when an underwater obstacle may be struck by the lower unit
 26 to avoid damage. Once this underwater obstacle is cleared, the unit
 will return to its preset trim adjusted position, as is well known in this
 art.
 This tilt and trim adjusting mechanism 52, although it per se forms no part
 of the invention, will be described in some detail because the manner in
 which electrical power is delivered to it does form a part of the
 invention. The tilt and trim unit 52 is comprised of a tilt cylinder 53
 that has a trunion portion 54 that is pivotally connected to the lower
 ends of the clamping brackets 47 by means of a pivot pin 55. This pivotal
 connection may be either to a piston rod of the tilt cylinder 53 or to the
 cylinder body assembly, either of which constructions are well known in
 the art.
 The remainder of these two components (either the piston rod or cylinder
 body), has an upper trunion portion 56 that has a pivotal connection by
 means of a pivot pin 57 to the swivel bracket 45.
 This cylinder assembly 53 also includes the aforenoted shock absorbing
 mechanism so as to permit the outboard motor 21 to pop up when an
 underwater obstacle is struck and to return to its preset trim position
 once this underwater obstacle is clear. This is normally provided by a
 valving arrangement internally of the cylinder assembly 53.
 The trim position of the outboard motor 21 is primarily controlled by a
 trim cylinder 58 that has a piston 59 that is abuttingly engaged with a
 portion of the swivel bracket 45 for this purpose.
 The trim cylinder 58 and tilt cylinder 53 are controlled and supplied with
 hydraulic fluid under pressure by a reversible electric pump 61 and
 control valve assembly of any suitable and known type. Because the exact
 construction for this mechanism may be of any known type for the reasons
 aforenoted and the invention deals primarily with the way in which the
 electrical signals and controls are provided to the tilt and trim
 arrangement 52 and that will be discussed later, further description of
 the hydraulic circuitry is not believed necessary.
 Although the hydraulic tilt and trim mechanism 52 provides control of the
 tilt and trim position of the outboard motor, the maximum trim down
 condition is limited by a mechanism shown best in FIGS. 5, 8, and 9, and
 which includes a trim pin 62 that is received within selected ones of
 apertures 63 formed in the clamping bracket 47. FIGS. 5 and 8 show the
 trim pin 62 in the maximum trim down position while FIG. 9 shows the trim
 pin in the maximum trim up condition.
 The forward portion of the swivel bracket 45 is provided with a plurality
 of notched recesses 64 which cooperate with the trim pin 62 to provide
 this control. It should be apparent from this arrangement that the side
 thrust on the outboard motor are, with conventional type of mounting
 arrangements, borne primarily or entirely by the trim pin 48. This can
 cause wear and binding.
 In accordance with the invention, therefore, the clamping brackets 47 are
 each provided with a pair of lug portions or pads 65 which engage
 outwardly extending flanges 66 formed on the sides of the swivel bracket
 45. As may be seen in FIG. 10, it is desirable that the clamping brackets
 47 be relatively short in length rearwardly of the transom 49 of the
 watercraft so as to permit steering through a maximum steering angle
 .alpha.. Thus, the trailing edges 67 of the clamping brackets 47 are left
 with a clearance L from the drive shaft housing 25 in these extreme
 positions.
 Good side support is provided by the lugs or pads 65 and their engagement
 with their flanges 66 of the swivel bracket 45. In addition, and as best
 seen in FIG. 3, the sides of the swivel bracket 45 are provided with
 further lugs or pads 68 which extend outwardly a sufficient distance so as
 to engage planar facing surfaces of the clamping bracket 47 so that there
 is support at vertically spaced points along the vertical height of the
 swivel bracket 45 during the movement in the various trim adjusted
 positions which minimizes the loading on the trim pin 48.
 Conventionally, the lead wires for supplying the electrical power to the
 electric motor 61 of the tilt and trim unit 62 have passed upwardly along
 the swivel bracket and then have passed through openings formed therein
 quite far from the tilt and trim pivot pin 48. As a result, there has been
 a large extent of exposed wires and slack must be left in the wiring
 system in order to accommodate the relative movement between the swivel
 bracket and the clamping bracket during tilt and trim operation.
 Therefore, in accordance with another feature of the invention, the
 electrical cabling for supplying the power to and from the hull is
 simplified as best seen in FIGS. 4, 11, and 12. As may be seen, a wire
 harness, indicated generally by the reference numeral 69 extends upwardly
 from the electric motor 61 along one side of the swivel bracket. This wire
 then passes through an aperture 71 formed in one of the clamping brackets
 47 that is quite close to the tilt and trim pivot pin 48.
 In addition, a further conductor 72 extends from a trim condition sensor 73
 across the front of the clamping and swivel bracket assembly and is joined
 with the wire harness 69 by cable straps 73. These conduits then pass
 upwardly through with the wire harness 69 eventually passing through an
 opening 74 in the tray portion 22 that is surrounded by a grommet 75 for
 attachment remotely to the control assembly.
 The trim sensor conduit 72 extends upwardly to a fitting 76 that provides
 an external connection to the wiring system for the trim adjuster.
 Finally, as seen in FIG. 12, the harness 69 is interrupted and a pair of
 ground connectors 77 extend through it and have connections to the
 clamping brackets 47 as at 78 and to the swivel bracket as at 79.
 As may be best seen in FIGS. 1, 3, and 13, the watercraft 51 may be
 provided with a vessel speed indicator, indicated by the reference numeral
 77 that is mounted in proximity to the operator's portion of the hull.
 This speed sensor 77 is provided with a vessel speed signal from a pitot
 pickup 78 formed in the front of the lower unit outer housing 26.
 A conduit 79 extends upwardly from this pitot pickup 78 as seen in FIGS. 3
 and 13 and passes generally parallel to the axis of the steering shaft 37
 and quite close to it. The conduit 79 may be held in place relative to the
 swivel bracket by means of a clamp 81 and fastener 82. At its upper end,
 this conduit 79 passes through an opening in the tray 22 that is
 surrounded by a grommet 83. The conduit then can extend forwardly through
 the hull to a transducer assembly 84 that converts the pressure signal
 into a voltage signal for providing an indication of vessel speed.
 Thus, it should be apparent from the Foregoing description that the
 described construction and mounting arrangement for the outboard motor
 provides a neat, compact assembly in which side thrusts are taken between
 the swivel bracket and clamping bracket and not avoiding transmission of
 these forces to the tilt pin. In addition, the conduit and electrical
 circuitry is such that the wiring and pitot tube conduit are neat, can be
 kept of minimum length and will be subject to minimum flexures.
 Of course, the foregoing description is that of a preferred embodiment of
 the invention and various changes and modifications may be made without
 departing from the spirit and scope of the invention, as defined by the
 appended claims.