CONTROL UNIT BRAKING APPARATUS

Abstract: A control unit braking apparatus has a housing (6) in which a shaft (4) is rotatably supported and is capable of axial movement, has one end of the shaft (4) projecting from the housing (6) and connected to a control member (40). The braking apparatus incorporates a friction member (24) mounted on the end of the shaft (4) and urged by a spring (20) positioned between the housing (6) and the friction member (24) against the control member to effect a braking action. The braking apparatus prevents throttle creep when the unit is applied to the control of a gear selection and throttle operating mechanism operated by a single lever.

Description: Control Unit Braking Apparatus This invention relates to control unit braking apparatus in which the control unit comprises a housing rotatably supporting a shaft projecting at one end from the housing and connected to a control member externally of the housing. The control unit can further include in the housing a driven member engageable with the shaft so as to be driven therewith, the shaft being axially movable to disengage it from the driven member. The present invention finds its principal application to single lever control units which sequentially operate a transmission and throttle and also permit independent operation of the throttle when the transmission is not engaged. Such control units find particular use in marine applications. Examples of-previous pertinent patents are United States Patents 2,254,144; 3,127,785; 3,511,117; 3,581,603; 3,842,695 and 3,929,039. In US Patent 3,842,695, the lever and shaft are not capable of axial movement, but a slider shaft in the lever assembly can be retracted. When the transmission is in the neutral position, retraction of the slider shaft disengages key 96 having projection 100 from the driving gear 56 and pulls pin 108 into hole 110. US Patent 3,581,603 discloses a similar mechanism. US Patent 3,842,695 differs from the present invention in several ways: first, the lock is on the slider shaft, not the lever; second, the slider shaft is nonrotatable; and third, the lock is not spring biased. In Patent 3,581,603, the slider shaft is rotatable. US Patents 3,511,117 and 3,127,785 disclose control levers which can be pulled outward when in neutral position, to open the throttle independently of the shift function. The control lever is spring biased. In US Patent 3,511,117, a blocking flange 134 locks curved portion 133 of interlocking plate 131 against reverse to prevent accidental shift while in the neutral throttle mode. Lateral wings 135 or 136 are interposed between the blocking flange 134 and gear 38 to prevent axial translation of the control lever 18 except in the neutral position. US Patent 3,127,785 has a similarly functioning plate 70 and flange 37. The lever in US Patent 3,929,039 contains a springloaded coupling shaft which can be disengaged while the lever is in a neutral position. The coupling shaft has radially extending pins 25 which couple the main shaft to the throttle gear. Pressing in the coupling shaft against the spring disengages the pins from the gear, and the gear from the shaft. In operation, this mechanism functions in the reverse manner from the present invention. It is useful to be able to operate control units so that a braking effect is put on the control member operating the throttle opening to ensure that once set to a specific opening it remains at its setting and that no throttle creep occurs which may cause the throttle either to open or close from the set position. This risk of throttle creep particularly manifests itself where vibration occurs and where this vibration is transmitted to the control unit. It is an aim of the invention to prevent any substantial throttle creep. In control units which are directly associated with gear transmission controls, i.e. where the unit also selects a reverse or advance gear position as well as applying throttle control, it is an advantage to be able to ensure that when it is desired only to apply throttle control the gear transmissions cannot inadvertently be engaged and are able to be locked -in neutral. The present invention prevents or reduces throttle creep by providing braking apparatus in a control unit which comprises a housing rotatably supporting a shaft which projects from one end of the housing and is connected on its projecting end to a control member externally of the housing, which apparatus incorporates a friction member mounted on a shaft adjacent the control member with spring means positioned between the housing and the friction member to urge the friction member into frictional braking engagement with the control member. The action of the spring is thus to create a resilient force on the friction member biassing towards the control member so that there is resistance to the movement of the control member by the shaft and the control member is thus only moved deliberately. Any creep or slippage due to vibration will not occur since the friction member, under the action of the spring means, will hold the control member firmly in its set position. The most convenient form of spring means is a helical spring which surrounds the end of the shaft with one end of the spring abutting the housing, and preferably circumscribing a shoulder thereon, and the other end abutting a friction plate which preferably has a relatively large radial surface area and is configured to abut the control member over substantially the entire radial surface of the control member. In a preferred form of control unit where a driven member is included in the housing and is able to be engaged by the shaft and driven with it and the shaft is made axially movable to disengage it from the driven member and to move the friction member towards the housing to compress the spring means, locking means may be connected to the friction member so as to be moved by axial movement of the shaft to engage and lock the driven member. This locking means is advantageously used where it is required to hold the driven member in a neutral or nondrive position whilst the throttle only is operated via the throttle member. The locking member preferably comprises a member connected to the friction member and extending towards an opening in the housing, and the driven member also preferably has a notch which is able to be aligned with the opening in one position only of the driven member so as to receive the locking member therein to lock the driven member when the shaft is moved axially to bring the friction member towards the housing. The spring means may be connected to the locking means for supporting the locking means and for resiliently urging it away from the driven member when the control member is moved by axial movement of the shaft away from the housing. The spring means may have a radial projection which is received within the locking means. A friction member may be secured in the housing adjacent the driven member which is provided with a surface configured frictionally to engage the friction member sufficiently to provide a relatively large frictional braking resistance to the movement of the surface across the friction member. A recessed portion in the surface may provide an area of smaller frictional resistance. The friction member is preferably adjustable. This friction member helps to offset a brake to stop throttle creep when the driven member is in an operative position and the throttle is operated. One example of a control unit braking apparatus will now be described with reference to the accompanying drawings which illustrate one form of the apparatus. In the drawings Figure 1 is a longitudinal cross section through the control unit braking apparatus; Figure 2 is a top plane view of a retainer plate; Figure 3 is a top plan view and Figure 4 is a sectional side view taken on the line 4-4 of Figure 3 of a collar, Figure 5 is crosssectional detail of the hand lever shown in Figure 1, Figure 6 is top plan view of a detail of a throttle gear included in Figure 1, Figure 7 is a rear plan view of the apparatus shown in Figure 1, and Figure 8 is scrap sectional detail of an additional braking feature of the apparatus. Referring to Figure 1, a single lever control unit 1 is shown attached to a mounting board 2. Preferably, the unit is adapted to operate sequentially a transmission and throttle and, selectively, to operate the throttle independently of the transmission. The control unit 1 has a shaft 4 mounted in a housing 6 for rotational and axial movement. The shaft 4 is provided with keys 8 adjacent an annular flange 10. The keys 8 are shaped to engage keyways 12 in a hub 14 rotatably mounted in th housing 6. The flange 10 abuts an annular shoulder 16 on the hub 14 when the keys 8 and keyways 12 are engaged. The shaft 4 communicates rotary actuating forces to the hub 14 through the keys 8. A space 18 is provided adjacent the shaft 4 above the annular flange 10 to permit axial movement of the shaft 4. When the shaft is moved axially, the keys 8 and keyways 12 disengage, thereby permitting rotation of the shaft 4 without consequent rotation of the hub 14. The lower surface of the keys 8 abut the upper surface of the hub 14 until further rotation of the shaft 4 causes the keys 8 to realign with the keyways 12. One end of the shaft 4 projects beyond the housing 6 and a spring 20 surrounds this end. One end of the spring 20 abuts an annular shoulder 22 on the housing 6. The lower end of the spring 20 abuts friction plate 24 mounted on the shaft 4 adjacent a throttle actuating member 26 rigidly connected to the end of the shaft 4. The spring 20 continuously urges the keys 8 automatically to engage the keyways 12 when the shaft 4 rotates the keys 8 into alignment with the keyways 12. The hub 14 has a throttle gear portion 30 and constitutes a driven member. The throttle gear 30 is a Geneva type wheel which operatively engages a Geneva wheel 32 rotatably mounted in the housing 6. The Geneva wheel 32 is rigidly connected to a shift control arm 34; the arm 34 and wheel 32 rotating simultaneously. As shown in Figure 6, rotation of the throttle gear 30 causes rotation of the Geneva wheel shift gear 32 only when the teeth of the gears 30 and 32 are meshed. Substantial rotation of the throttle gear 30 in either direction causes the teeth of the throttle gear 30 and shift gear 32 to disengage. Continued rotation of the throttle gear 30 causes a reversed curve portion 34 of the shift gear 32 to mate with a curved surface 36 on the throttle gear 30 to prevent rotation of the shift gear 32. The sequential shifting and throttling operations of the control unit as well as the selective independent throttling operation of the control unit can now be readily understood. A throttle control arm 40 is connected to an engine throttle operator (not shown). Similarly, the shift control arm 34 is connected to a transmission operator (not shown). The connections are made in a manner to permit neutral idling of the engine when the throttle gear 30 and shift gear 32 are aligned as in Figure 6. Rotation of the shaft 4 in one direction rotates the throttle gear 30 in the same direction. Initially, the shift gear 32 is also rotated in the same direction. When the reversed curve portion 34 of the shift gear 32 abuts the curved portion of the throttle gear 30, the shift gear 32 stops rotating. At this point, the shifting of the transmission from neutral to an operative gear, for example, forward gear, is complete. Continued rotation of the shaft 4 causes rotation of the throttle gear 30 and throttle actuating member 26. Consequently, the engine is throttled. When the shaft 4 is rotated in the opposite direction, the throttle gear 30 and throttle actuating member 26 also rotate in the opposite direction. Initially, engine throttle is reduced. Continued rotation of the shaft 4 causes the teeth on the throttle gear 30 and shift gear 32 to mesh. The transmission is shifted from forward gear to neutral. If the shaft 4 is further rotated, the transmission is shifted from neutral to reverse gear. Reverse throttle is then applied by continued rotation of the shaft 4. In order to prevent throttling while the shifting gear 32 is rotating, the throttle control arm 40 is connected to the throttle operator by an appropriate lost motion device, or any similarly functioning device. A locking arm 42 is connected to the friction plate 24 and is received within an opening 44 in the housing 6. The end 46 of the spring 20 projects through an opening in the locking arm 42 and is thereby connected to the locking arm 42. The throttle gear 30 is provided with a notch 48 formed to receive the locking arm 42 when the notch 48 is aligned with the opening 44 in the housing 6. The notch 48 is positioned to align with the opening 44 in the housing 6 when the throttle gear 30 and shift gear 32 are in neutral alignment. Axial movement of the shaft 4 in neutral disengages the keys 8 from the keyways 12 and projects the locking arm 42 into the notch 48 in the throttle gear 30, thereby locking the throttle gear 30 and shift gear 32 in neutral position. Rotation of the shaft 4 throttles the engine. The spring 20 urges the friction plate 24 into frictional engagement with the throttle actuating member 26 to prevent throttle creep. When the shaft 4 is rotated to the neutral position, the keys 8 automatically engage the keyways 12 and the locking arm 42 automatically disengages the notch 48 in the throttle gear 32 by means o-f axial loading created by the spring 20. The end 46 of the spring 20 connected to the locking arm 42 facilitates removal of the arm 42 from the notch 48 in the throttle gear 30 and supports the arm 42. When the throttle gear 30 is rotated from neutral alignment, the notch 48 in the throttle gear 30 is moved from alignment with the opening 44 in the housing 6. The locking arm 42 prevents axial translation of the shaft 4. A detent 50 is mounted in the housing 6 adjacent the throttle gear 30. The detent has a spring 52 which continuously urges a roller 54 against the side of the throttle gear 30. The gear 30 is provided with spaced notches 56, 58 and 60 configured to receive the roller 54. The central notch 58 is positioned to receive the roller 54 when the throttle gear 30 is in neutral alignment. The side notches 56 and 60 are positioned to receive the roller 54 when the reverse curved portion 34 of the shift gears 32 is first rotated into contact with the curved portion 36 of the throttle gear 30. Engagement of the roller 54 with the notches 56, 58 and 60 tends to lock the throttle gear 30 against rotation. The operator of the control unit 1 is thereby given indications that the engine is in neutral or forward or reverse gear. Additionally, the side notches 56 and 60 are positioned to engage the roller 54 when the control unit 1, operating in sequential mode, completes the shifting operation and begins the throttling operation. A friction pad 61 is connected to the end of a screw 62 threadedly mounted in the housing 6. As best shown in Figure 8, the pad 61 is positioned to abut a specially profiled surface 64 of the throttle gear 30. The surface 64 has a portion 66 recessed from the friction pad 60; the arc length of the portion 66 corresponding to the amount of angular displacement of the throttle gear 30 during which the throttle gear 30 rotates the shifting gear 32. When the control unit 1 operates in the shifting mode, the friction pad 60 offers relatively little frictional resistance to the rotation of the throttle gear 30 since the friction pad 60 is aligned with the recessed portion 66 of the throttle gear 30. In the throttling mode, however, the friction pad 61 is aligned with the portion 67 of the profiled surface 64 of the gear 30 closely adjacent the inward surface of the housing 6, thereby offering a relatively large frictional resistance to the rotation of the throttle gear 30. The amount of frictional resistance offered by the pad 61 to the rotation of the gear 30 can be adjusted by the screw 62. It is appreciated that the control unit 1 is readily adaptable for use with power boat engines. Consequently, sleeve bearings 68, 69 and 71 are provided to seal the unit 1 and to prevent damage to the components of the unit 1 due to the environment. Referring now also to Figures 2, 3 and 4 an interlock collar 70 and a collar retainer 72 are connected to the control unit 1 prior to mounting the control unit 1 on the mounting surface 2. A neutral interlock hand lever 74 is connected to the end of the shaft 4 projecting through an opening 76 in the mounting board 2. The lower end of a hand lever cap 78 surrounds a portion of the interlock collar 70 and is provided with means to lock the hand lever 74 against further rotation when the hand lever 74 is moved to a neutral position. As shown most clearly in Figure 5, the hand lever 74 has a block 80 slidably mounted within the cap 78. The block 80 is connected to a release button 82 by an arm 84 slidably mounted within the shaft 86 of the hand lever 74. A spring 88 connected to the arm 84 and the shaft 86 urges the block 80 toward the centre of the cap 78. A screw 90 projects through a slot in the arm 84 and is received-within a sliding block 92 formed inside the shaft 86 to keep the arm 84 in proper alignment. Moving the button 82 in the direction indicated by the arrow 94 slides the block 80 toward the side of the cap 78. When the button 82 is released the spring 88 causes the block 80 to automatically move toward the centre of the cap 78. The cap 78 is positioned on the collar 70 in a manner which enables the radially inward surface of the block 80 to abut the radially outward surface of the upper axial portion 102 of the collar 70 (Figures 3 and 4). The cap 78 is connected to the shaft 4 and rotates with the shaft 4. Rotation of the shaft 4 causes the block 80 to move along the surface 102 of the collar 70. A notch 100 provided in the upper axial portion 102 of the collar 70 is shaped to receive the block 80 when the block 80 is aligned with the notch. Preferably, the notch 100 is positioned to engage the block 80 when the hand lever 74 and shaft 4 are rotated to a neutral position. Engagement of a block 80 and notch 100 prevents further rotation of the hand lever 74 and shaft 4. Moving the button 82 in the direction indicated by arrow 94 moves the block 80 toward the side of the cap 78, thereby disengaging the block 80 and the notch 100. The hand lever 74 and shaft 4 can then be rotated from the neutral position. When the hand lever 74 and shaft 4 are returned to the neutral position, the spring 88 causes the block 80 automatically to engage the notch 100 thereby automatically preventing further rotation of the hand lever 74 and shaft 4. The collar 70 is held against the housing 6 by the retainer 72 which overlies an annular flange 104 on the lower axial portion 106 of the collar 70. The retainer 72 is provided with serrations 108 shaped to engage serrations 110 on the lower axial portion 106 of the collar 70 adjacent the flange 104. The serrations 108 and 110 prevent rotation of the collar 70 when engaged. Prior to mounting the control unit 1 on the mounting plate 2, the collar 70 is orientated in the retainer 72 in any desired position. Preferably, the collar 70 is orientated in a manner which positions the interlock notch 100 to engage the block 80 when the hand lever 74 is in an appropriate neutral orientation. Cap 78 is provided with an annular shoulder 112 which abuts the outward surface of the mounting board 2 when the keys 8 on the shaft 4 engage the keyways 12 in the hub 14. When the shaft 4 is moved axially to disengage the keys 8 and keyways 12, the shoulder 112 is spaced from the surface of the mounting board 2 thereby providing an indication to the operator that the control unit 1 is in the neutral throttle mode of operation. In an alternative embodiment, the cap 78 is positioned on the collar 70 in a manner which enables the axially inward surface of the block 80 to abut the axially outward end of the upper axial portion 102 of the collar 70 when the hand leve-r 74 is rotated from the neutral position while the control unit 1 is in the neutral throttle mode of operation. When the hand lever 74 is rotated to the neutral position, the block 80 engages the notch 100, thereby permitting axial movement of the shaft 4 and engagement of the keys 8 with the keyways 12 under loading from the spring 20. The hand lever 74 is rotated from the neutral position in the manner previously described.

Claims: Claims: 1. Control unit braking apparatus in which the control unit comprises a housing (6) rotatably supporting a shaft (4), the shaft (4) projecting at one end from the housing (6) and being connected to a control member (40) externally of the housing 67 Characterised by the braking apparatus incorporating a friction member (24) mounted on the shaft (4) adjacent the control'member (40), spring means (20) positioned between the housing (6) and the friction member (24) to urge the friction member (24) into frictional braking engagement with the control member (40). 2. Control unit braking apparatus as claimed in Claim 1 in which the spring means (20) is of helical form and surrounds the end of the shaft (4) projecting from the housing (6), one end of the spring means (20) abutting the housing (6) and the other end abutting the friction member (24). 3.- Control unit braking apparatus as claimed in Claim 1 or Claim 2 in which the friction member comprises a plate (24). 4. Control unit braking apparatus as claimed in any preceding claim in which the control member (40) has a relatively large radial surface adjacent the friction member (24), the friction member (24) having a radial surface configured to abut the control member (40) over substantially the. entire radial surface of the control member (40). 5. Control unit braking apparatus as claimed in any preceding claim, in which the housing (6) is provided with an external shoulder (22) concentrically spaced about the shaft (4), the end of the spring means (20) adjacent the housing (6) closely circumscribing the shoulder (22). 6. Control unit braking apparatus as claimed in Claim 5 in which the shoulder (22) is an annular shoulder. 7. Control unit braking apparatus as claimed in aPy preceding claim in which the control unit further includes in the housing (6) a driven member (14, 30) engageable with the shaft (4) so as to be driven therewith, the shaft (4) being axially movable to disengage it from the driven member (14, 30), and to move the friction member (24) towards the housing (6) to compress the spring means (20), characterised by a locking means (42) connected to the friction member (40) so as to be moved by axial movement of the shaft( to engage the lock the driven member (14, 30). 8. Control unit braking apparatus as claimed in Claim 7 in which the locking means comprises a member (42) connected to the friction member (40) and extending towards an opening (44) in the housing (6), and in which the driven member (30) has a notch (48) which is able to be aligned with the opening (44) in one position of the driven member (30) so as to receive the locking member therein when the shaft (4) is moved axially to bring the friction member (40) towards the housing (6) to lock the driven member (30). 9. Control unit braking apparatus as claimed in Claim 7 or Claim 8 in which the spring means (20) is connected to the locking means (42) and for resiliently urging it away from the driven member (30) when the control member (40) is moved by axial movement of the shaft (4) away from the housing (6). 10. Control unit braking apparatus as claimed in Claim 9 in which the spring means (20) has a radial projection (46) received within the locking means (42). 11. Control unit braking apparatus as claimed in any one of Claims 7 to 10 characterised by further including a friction member (61), secured in the housing (6) adjacent the driven member (30), the driven member (30) having a surface (67) configured frictionally to engage the friction member (61) sufficiently to provide a relatively 'large frictional braking resistance to the movement of the surface (67) across the friction member (61). 12. Control unit braking apparatus as claimed in Claim 11 in which a recessed portion (66) is provided in the surface (67) to provide an area of relatively small frictional resistance across the friction member (61). 13. Control unit braking apparatus as claimed in Claim 11 or 12 in which the friction member (61) is supported by adjusting means (62) in the housing (6). 14. Control unit braking apparatus as claimed in Claim 11 in which the surface is a radial end surface of the driven member (30).

Inventors: CANTLEY, GEORGE, OLSEN, ROGER F.
Applicants: INCOM INTERNATIONAL INC.
Application year: 1978
Main classification: G05G9
IPC codes: B63H21, G05G9