US2927551A - Steering mechanisms and the like - Google Patents

Description

March 8, 1960 G. E. BEVIS EI'AL STEERING MECHANISMS AND THE LIKE Filed NOV. 7, 1957 INVENTORS 6, E, BEV J' P C lv ulvqs fioeb JR. r

United States Patent 10 STEERING MECHANISMS AND THE LIKE George E. Bevis, Chagrin Falls, and Philip C. Hungerford, Jr., Cleveland Heights, Ohio, assignors to Curtlss- Wright Corporation, a corporation of Delaware Application November 7, 1957, Serial No. 694,956

8 Claims. (Cl. 115-18) The invention relates to an improved steering control mechanism (eg for dirigible equipment such as represented by outboard motor and propeller units for boats) and to improvements in bidirectional friction braking devices of a generally known type capable of enabling transmission of torque therethrough, as from a control shaft to a load, while effectually preventing back drive bidirectionally as from the load to such control shaft.

A further specific object is to provide a new or improved anti-back-drive installation in an outboard motor assembly for boats wherein the unit comprising the engine, main drive shaft for the propeller and a rigid housing therefor including support for propeller and rudder or other steering means, is pivotly supported, to enable steering, on an axis transversely offset from that of the main drive shaft of the unit.

A further object is to provide an improved steering or similar control mechanism for motor boats and other dirigible equipment whereby external surface conditions (e.g. water currents in the case of boats) can be effectually prevented when desired from transmitting forces to a control member operable as for steering and, optionally, can be enabled to transmit such forces for affording what is called operator feel in steering and analogous control operations.

Other objects and features of the invention will become apparent from the following description of the illustrative forms of the invention shown in the accompanying drawing. The essential characteristics are summarized in the claims.

In the drawing, Fig. 1 is an assembly side view of an outboard motor or power unit A arranged as referred to above and showing exterior portions of the anti-backdrive or no-back coupling 10 hereof, together with the preferred arrangement for operating the input of the coupling for steering and for connection of its output to the power unit.

Fig. 2 is a fragmentary longitudinal cross sectional view through the no-back coupling mechanism 10 and associated portions of the unit A in larger scale than Fig. l, the section being taken along the line 22 on Fig. 1.

Fig. 3 is a further enlarged cross sectional view of the no-back coupling, turned at a right angle relative to Fig. 2, and taken along the line 33 on Fig. 2.

Figs. 4 and 5 are transverse sectional fragmentary assembly views taken along the lines 4-4 and 5-5 on Fig. 3.

Referring to Fig. 1, the outboard motor unit A, as one example of a di-rigible device or structure, includes a power head (motor and fuel tank housing) portion B and a propeller drive shaft housing C having rigid or integral pivot bracket members or portions D and E at the forward portions thereof. A rudder and gear case portion R of the drive shaft housing C carries a conventional propeller P.

In order to enable steering by swinging of the outboard motor unit A about a generally vertical axisL (Fig. 1) avhich isofiset forwardly from the axis L of the propeller drive shaft (not shown) the customary (and only manner heretofore employed, so far as we know), has been to attach a tiller or its operating equivalent to a power head portion such as B of the unit A. The present subject invention includes replacement of the usual main upright portion of the pivotally suspended bracket (not shown but situated between bracket members such as D and E), by, in part, atubular housing represented at F and containing the essential parts of the no-back coupling mechaism 10 hereof and, additionally, providing an operating hub or steering head 1 between the housing F and (e.g.) the upper bracket D, the head 1 having a tiller 1' or equivalent steering means (e.g. linkage for remote control) attached to it. Thereby angular motion of the tiller or the like necessary for steering can transmit the forces applied for steering along such axis L through the noback coupling to the unit A at one of the bracket portions of the unit A (e.g. lower bracket portion E).

The support for the housing member F comprises, as illustrated in Fig. 1, a clamp device S of conventional form which is rigidly secured, as to the transom of a boat by clamp screws S, one being shown. To enable the propeller and rudder portions of the unit A to be lifted out of the water at desired times and swung in an inboard direction without having to remove the clamp attachment S, the housing F is pivotally attached to the main body of the clamp S on a horizontal axis, as at S". The clamp S, since it is operatingly rigid with the transom, not shown, may be taken as representing part of the framework of the vehicle, to be steered, or in this case part of the hull of the boat.

The bidirectional no-back coupling mechanism hereof, generally indicated at 10 in Figs. 1, 2 and 3 will usually be hereinafter abbreviated BDNB.

As shown in Figs. 2 and/or 3, the steering head 1 is rigidly secured to a tubular input member 6 of the BDNB coupling 10 as by a stub shaft 4 and a cross pin 6'. The input member 6, Fig. 3, extends into a guide or pilot counterbore 30, 31 of a generally cylindrical head portion 8 of tubular output member 9 of coupling 10 occupying a sleeve 11 turnably mounted in the housing F. Output member 9 is rigidly connected via stub shaft 5 to the bracket E of propeller shaft housing C. The sleeve 11 is in effect a rigid part of housing F in the normal operation of coupling 10. End portions of the head 8 of output member 9 are supported for rotation within the sleeve 11 by cup shaped collars or bushings 12 and 14 turnable in counterbores 12 and 14 of the sleeve 11 and fixed to the head 8 as by screws 50 in threaded openings 51 formed, after assembly of the parts already mentioned, in the collars 12 and 14 and head 8 (drilled and tapped).

Sleeve 11 has a generally smooth internal cylindrical drum surface portion 15 of substantially the same diameter as cylindrical inner drum surface portions 16 and 17 of the collars or bushings 12 and 14. The collars 12 and 14 are axially fixed in position in the sleeve 11 as by snap rings 40 and 41; and a pair of identically wound helical friction springs-20 and 22 are preloaded in or resiliently seated radially against the pairs of drum surfaces 15 and 16 and 15-1'7 respectively in bridging relation to associated pairs of drum surfaces.

The helical springs 20 and 22 are secured, as will-be described later, at their relatively opposite ends to the output member 9 of the coupling 10, via the bushings 12 and 14, so that the output member 9 and shaft 5 are normally tightly locked against any possible rotation in the sleeve 11, hence housing F, by conjoint action of the two helical springs 20 and 22. Relatively adjacent more or less free ends of the two springs 20 and 22 have respective lugs or toes 20' and 22; and a key 34 snugly occupying a slot 34 in the input member 6 and secured to that member as by a cross pin 35, extends loosely through n estate;

a. radial slot (iderltiiiedby its walls 36 and 37, fig. in the head 3 so as to lie closely between the toes'20 and 22'. Thereby turning movement or the steering head 1 and input member 6 in either direction operates, through the key 34, to deenergi'ze whicheverspring wouldotherwis'e block rotation of the output member 9 and shaft It is only necessary to deenerg'ize one of the springsZt) or'22 foreach direction of input operation, because the other spring will then simply overrun on the drum surface as is usual in BDNB devices employing two helical locking springs.

In order, individually, to adjustably secure the helical springs and 22 to the outputrnember 9, so that, in operation, the input toward output backlash will be minimized, end disc portions 12" and 14" of the bushings 12 and 14 support the head portion 8 of output member 9 at reduced end circular surfaceportions '8' and 8" of the head 8; and between the disc portions 12 and 14 of the bushings and axial shoulders 24 and 25 of the head 8 are fiat friction locking ring'members zfi and 27 (cf. FigI -S, showing a portion of ring 27), which rings lie fiat against the inner faces of the idisc portions 12" and 14" of the bushings 12 and 14. The rings 2 6 and 27 are identical and have radial slots 26' and 27' (see Fig. 5 which snugly receive axial toe portions 28 and 29 at the relatively outer ends of the respective helical springs Ztland The screws 50, when inserted during assembly of. the coupling as previously indicated, loclc the bushings to said-head '8 and clamp the rings 26 and 27 to the head in individually angularly adjusted positions. 7.

Through comparison of Figs. 2 through 5 it will be apparent that when the input member 6, as shown in Fig. 4, is turned in a counterclockwise direction by torque applied thereto, coils of the spring 29 associated with the stationary drum surface 15 of sleeve 11 will be deenergized by operation of key 34 acting against the spring toe 20 so that the springwill slide easily on the fixed drum surface 15. Concurrently, by reason of the lug and slot connection at 27, 29 (upper right Fig. 3) the coils of the other spring 22) will be caused to overrun onthe drum surface 15. The design and previously described adjustment are such thatas soon as deenergization-of-the coils of spring 20 has taken place, the key 34 will abut the slot surface 36 of output member 9 for positive transmission of torque thereto. Clockwise input-toWard-output operationof the coupling is essentially the same as that-just described except for direction.

Assuming torque ceases to be applied to the input-member 6, the outputmember 9 will be arrested in whatever position it then occupies due to expandingmovementot the helical spring 20 and 22 into tightly seated position against the drum surfacelS which movementreturns the key 34 into theposition illustratedin-Fig. 4 betweenthe slot faces 36 and 37 ofthe output memberhead 8 whenever torque ceases to be applied to the input member 6.

For mounting of the coupling 10 and steering head assembly into operating association with'au outboard'motor unit haying mutually integral bracket portions (such as D'and E, Fig. 2) a readilyretractable, spring loadedpin Shaving a releasing stem'SA may be slidably securedin the'steering head 1 to constitute -a releasable mounting pivot. If the upper bracket 1) ofmotor assembly A- is demountably secured to unit A then the pivotpin 3-can be rigid or integral with steering head 1, or as shown in Fig. '1. I A

Withthe above described arrangement, as shown in Figs. 1 and 2, steering is efiected by swingingof the head 1 linc'e'the shaft 4 about the axis Lot aligned shafts-4 and 5, and the latter shaft'causes swinging of the outboard motor unit A and'its propeller and rudderaportions P and R about such axis L. Whenever the tiller-l'lor othersteering device connected with theheadl) is released temporarily or otherwise by -the--operator-othe 'erafL the BDNB coupling 10-functions 'to preventtheoutpertain-s, hence the outboard-motor unit A andihe rudder from being moved out of position as by water current forces acting on the rudder.

To enable external forces to be transmitted to the tiller, (i.e. for enabling control feel by the operator or for other reasons), the sleeve 11 of the coupling 10 is freed by the readily releasable latching device 11a. The latch 11a is suitably designed to be self-retaining in latching and unlatching positions by known or suitable detent means, not shown; and, when in release or unlatching position, the mechanism of coupling 10 per se offers no resistance to back drive from output to input in either direction'atany time, and the coupling 10 acts as a solid connectionbetween its :output and input elements.

We claim:

1. In a steering mechanism, a diri'gible-element adapted for steering, a tubular housing adapted for support in approximately fixed position on a vehicle, a circular drum turnably journalled in the housing about the principal axis thereof, a bidirectional no-back coupling including an input torque transmitting member and a cooperating .output member, said members extending into coaxial relationship to the drum, the output member being operatingly connected to the dirigible element, self-energizing friction braking means connected to the output member and capable of automatically locking against the drum normally-to prevent back drive from the output member tothe input member, deenergizing means for the braking means operatingly connected between the input member and braking means and including a lost motion positive torque-transmitting connection between the input member and output member, and readily releasable latch means between the drum and said housing and normally preventing the drum from turning in the housing, the latch :means being operable topermit the drum to turn and render the n'o-back coupling ineffective to prevent back drive.

In aportable power unit for a motor boat, said unit having propulsion means and-steering surface means for contactwith water, means including a tubular housing connected tossupport the unit for swinging movement about "the-axisof the tubular housing, and a bidirectional no-back coupling in the housing and comprising a normally stationary drum journalled in the housing for angular movement about the housing axis, relatively angularly movable torque transmitting input and output member in the housing coaxialtherewith, the output member being operatingly connected to said unit for steering, self-energizing helical friction spring means engaging the drum and connected with the output member to lock it against-rotation, means between the input member and the helical spring means forreleasing the spring means from lockingcontact with the drum as functions tit-turning the input means in opposite directions, and latch means rleasably securing the drum in the housing forvpermitting approximately free angular movement of the drumt in the housing so as to .render the no-back coupling ineffective.

3. In-combination with an outboard motor unit of the typewhe'rein a-rigid housing, containing a main drive 'shaftandsupp'ortin'g a propeller driven thereby and rudder' surfaces, is pivotally secured on a generally upright axis for steering to a support adapted for demountably attaching the unit to a boat, a bidirectional no-back coupling having input and output members relatively :an- .gularly movableabout-said pivotal axis, a normally'stationarydrumon said axisand turnably mounted .on. said support, self-energizing braking means capable of automatically lock-ing on the-drum and connected to the out- .put member to block ba'clt-drive from the output tothe input-member while permitting torque transmission. in the -opposite.-direction from the-input to theoutputmember for steering, and releasable means capable ofiholdinglhe -drurn against -tur-ningon :said support.

4. in combination witheanl.outboardfmotornnit tot the :type wbereimarigidhousingforiagenerally.upright main drive shaft of a propeller is pivotally secured on an axis transversely offset from the drive shaft axis, to a support adapted for attaching the unit to a boat, a bidirectional no-back coupling having input and output members relatively angularly movable about said pivotal axis, the unit being connected to the output member to be turned thereby for steering, and means connected to turn the input member, said coupling including means bidirectionally blocking back drive from the output member to the input member.

5. In combination with a main housing of an outboard motor unit and which carries a propeller and rudder, a bracket adapted to support the housing and having a tubular main body portion connected to the housing forwardly thereof on a generally upright pivot axis coincident with that of the tubular portion, a steering head, means supporting the steering head to swing about said axis, and a bidirectional no-back coupling in the tubular body of the bracket, said coupling having a.

rotary input member connected to be turned by the steering head and a coaxial rotary output member connected to the main housing, and releasable, two way acting friction braking means in the coupling operating to prevent back drive from the output member to the input member and steering head.

6. In a steering mechanism, a dirigible element adapted for steering, a tubular housing adapted for support in fixed position on a vehicle, a normally stationary circular internal drum coaxial therewith internally of the housing, means releasably connecting the drum to the housing but capable of permitting the drum to turn at times in the housing, a bidirectional no-back coupling including an input torque transmitting member and a cooperating output member, said members having portions disposed inside of the drum in coaxial relationship thereto, the output member being operatingly connected to the dirigible element, helical friction spring coil elements internally of the drum and having, respectively, normally free end coils in interference fitting relationship to the drum and having, respectively, coil portions axially opposite the normally free end coils anchored to the output member without free play so as to be capable of preventing back drive from the output member to the input member in opposite angular directions with substantially zero backlash, de-

6 energizing means for the normally free end coil portions of the spring elements operatingly connected between the input member and the normally free end coil portions of the spring elements, the deenergizing means including a lost motion positive torque-transmitting connection between the input member and the output member.

7. A steering mechanism for, vehicles, comprising a tubular housing adapted for connection to a frame portion of a vehicle, an input or steering shaft having a portion extending into one end of the housing concentric therewith, a tubular output member in the housing and containing at least a portion of the input shaft, a selfenergizing friction braking means including a brake drum member within the housing concentric therewith and two-way-acting brake elements frictionally connecting the output shaft and said drum member and respectively releasable from the drum member by the input shaft but not by the output member, one of said members being journalled for support and angular movement in the housing by inner wall surface portions of the housing.

8. A steering mechanism for vehicles comprising a tubular housing adapted for connection to a frame portion of a vehicle, an input or steering shaft concentric with the housing, a tubular output member having an angular lost motion connection with the input shaft within the housing, a self-energizing friction braking means including a brake drum directly supported by the housing for angular movement relative thereto, two-wayacting friction brake elements between the output member and said drum and respectively releasable from the drum by the input shaft but not by the output member, a radial opening in the housing, a socket in the drum normally aligned with the opening, and a latching plunger slidably supported in the radial opening and capable of holding the drum against angular movement or releasing it to permit its angular movement.

References Cited in the file of this patent UNITED STATES PATENTS 1,689,962 Peck Oct. 30, 1928 2,458,441 Starkey Jan. 4, 1949 2,819,777 Kosch Jan. 14, 1958 2,819,778 Kosch Jan. 14, 1958

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