FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10; Rule 13)
TITLE OF THE INVENTION
Z-DRIVE SHORT TAIL ASSEMBLY FOR MOTION TRAVERSE OF A BOAT
APPLICANT(S)
Rocket Engineering Corporation Pvt. Ltd.
Nationality Indian
Plot No. D-19 M. I. D. C Shiroli,
Shiye-Bavada Road, Kolhapur - 416122,
Maharashtra, India.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
[0001] The present invention relates to controlling motion of watercrafts such as boat and more specifically related to allow a Z-drive short tail assembly to control motion of boat.
BACKGROUND OF THE INVENTION
[0002] In order to facilitate improving of maneuverability of watercrafts such as boats upon steering of the boat, power is driven with a single engine and propeller(s) driven by the single engine are installed at predetermined locations of a rear portion of the boat.
[0003] With conventional steering of boats with controllable propeller drive, a power transmission connected to an engine is used for propeller drive. An example of such conventional L type arrangement is driven by petrol engines. The engine is horizontally (piston movement is horizontal) and integral with ‘L’ type drive assembly to operate the boat. A rope start arrangement (2) is connected to the engine (1) to start the engine (1). The engine (1) is mainly water cooled and in-built water pump is used for engine cooling purpose. The ‘L’ type drive assembly includes an upper case (3) connected to a lower case (4). The lower case (4) is connected to a propeller (5). The ‘L’ type drive assembly also includes an operating handle (6) to operate the movements of the boat, a forward and reverse mechanism (7) to operate the boat in forward and reverse direction, and a mount bracket (8) to mount the arrangement on the boat. A drive shaft is connected to the engine (1) and the propeller (5) through bevel gears. The drive shaft is mounted on engine bearing and water pump ball bearing. The bevel gears are used at the bottom end of the lower casing (4) to give power or torque to the propeller (5). The drive shaft, ball bearings and the bevel gears are mounted inside aluminum casings. The propeller design of the conventional system is suitable for anticlockwise rotation of the engine (1). The

engine exhaust is directed out from the bottom end of the lower casing and the mixing in the water.
[0004] In the conventional propeller structure, when the engine (1) is started by using the rope start arrangement (2), power is transmitted from the engine (1) to the drive shaft. The bevel gear pair is used inside the lower casing (4) to reduce the speed and increase the torque. From the bevel gears power or torque is transmitted to the propeller (5) to generate thrust on the boat. Provision of operating handle (6) is done to operate the boat as per lad and speed requirements. The provision of the forward and reverse mechanism (7) is made to operate the boat in both the forward and the reverse directions.
[0005] Hence there remains a need for an improvised design and power operation for air cooled and water cooled design engine.
OBJECT OF THE INVENTION
The principal object of the embodiments herein is to provide a ‘Z’ type drive short tail assembly to control motion of boat.
[0006] Another object of the embodiments herein is to provide drive assembly for diesel engine for motion traverse of a boat. Alloy steel hardened spiral bevel gears are used in the ‘Z’ type drive short tail assembly for smooth power transmission.
[0007] Yet another object of the embodiments is to provide ‘Z’ type drive short tail assembly coupled to prime mover by using an universal coupling joint for better power transmission. The ‘Z’ type drive short tail assembly run with the prime movers for motion traverse of the boat.
[0008] Yet another object of the embodiments is to provide ‘Z’ type drive short tail assembly with prime mover mounting bracket that has provision for tilting

movement, sideways movement and locking arrangement for better operation flexibility to the ‘Z’ type drive short tail assembly.
[0009] Yet another object of the embodiments is to provide a gear box provision inside the upper case assembly of the ‘Z’ type drive short tail assembly for improved torque and better thrust.
[0010] Yet another object of the embodiments is to provide a lower case assembly of the ‘Z’ type drive short tail assembly with aerodynamic design for lower resistance to the boat and to get better speed.
[0011] Yet another object of the embodiments is to provide a reverse and forward mechanism with clutch dog inside the lower case assembly of the ‘Z’ type drive short tail assembly for both ways easy movement of the boat.
SUMMARY OF THE INVENTION
[0012] In one aspect the object is satisfied by providing Z- drive short tail assembly for engine for motion traverse of a boat. The Z-drive short tail assembly includes an upper case, a lower case assembly, a middle case assembly, a mounting bracket assembly, a shift cam assembly, and a steering handle assembly. The upper case assembly includes a horizontally oriented main drive shaft connected to the engine with a spiral gear, and a vertically oriented upper shaft with a spiral gear that receives gear driven power from the engine through the rotations of the main power shaft and rotates. The horizontally oriented main drive shaft is connected to the engine through an universal coupling joint. One end of universal joint coupling is coupled to flange coupling on prime movers like engine and motor and another end to the horizontally oriented main drive shaft. The lower case assembly includes a propeller mounted on a horizontally oriented lower propeller shaft with a spiral gear, a vertically oriented lower shaft with a spiral gear to receive the gear driven power through the rotations of the vertically oriented upper shaft and rotates to

provide the gear driven power to the propeller through the horizontally oriented propeller shaft. The middle case assembly includes a vertically oriented middle shaft connected to the vertically oriented upper shaft and the vertically oriented lower shaft. The propeller is connected to the horizontally oriented main drive shaft though the vertically oriented lower shaft, the vertically oriented middle shaft, and the vertically oriented upper shaft. The mounting bracket assembly is used to mount the drive assembly on the boat to control the motion travel of the boat. The shift cam assembly is connected to the mounting assembly to control forward and reverse movement of the boat. The steering handle assembly is connected to the mounting assembly to start the engine.
[0013] In an embodiment, when the engine is started using the steering handle assembly, the power is transmitted from the engine to the horizontally oriented main drive shaft with the spiral gear. The rotations of the horizontally oriented main drive shaft with the spiral gear generates the gear driven power that is transmitted to the propeller through the vertically oriented upper shaft with the spiral gear, the vertically oriented middle shaft, the horizontally oriented propeller lower shaft with the spiral gear, and the horizontally oriented propeller shaft with the spiral gear.
[0014] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the scope thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[0015] The proposed ‘Z’ type drive short tail assembly are illustrated in the
accompanying drawings, throughout which like reference letters indicate

corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0016] FIG. 1illustrates a L’ type drive assembly for a petrol engine, according to prior art;
[0017] FIG. 2 illustrates a ‘Z’ type drive assembly for a diesel engine, according to embodiments as disclosed herein;
[0018] FIG. 3 illustrates an upper case assembly for a diesel engine, according to embodiments as disclosed herein;
[0019] FIG. 4 illustrates an internal structure of a lower case assembly, according to embodiments as disclosed herein;
[0020] FIG. 5 illustrates an internal structure of a middle case assembly, according to embodiments as disclosed herein;
[0021] FIGS. 6a illustrates an internal structure of a mounting bracket assembly, according to embodiments as disclosed herein;
[0022] FIGS. 6b illustrates an internal structure of a swivel bracket assembly, according to embodiments as disclosed herein;
[0023] FIG. 7 illustrates an internal structure of a shift cam assembly, according to embodiments as disclosed herein;
[0024] FIG. 8 illustrates an internal structure of a steering handle assembly, according to embodiments as disclosed herein; and

[0025] It may be noted that to the extent possible, like reference numerals have been used to represent like elements in the drawing. Further, those of ordinary skill in the art will appreciate that elements in the drawing are illustrated for simplicity and may not have been necessarily drawn to scale. For example, the dimension of some of the elements in the drawing may be exaggerated relative to other elements to help to improve the understanding of aspects of the invention. Furthermore, the one or more elements may have been represented in the drawing by conventional symbols, and the drawings may show only those specific details that are pertinent to the understanding the embodiments of the invention so as not to obscure the drawing with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term “or” as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0027] Referring now to the drawings, and more particularly to FIGS. 2 through 8, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.

[0028] FIG. 2 illustrates a Z -drives short tail assembly for a diesel engine (10) for motion traverse of a boat, according to embodiments as disclosed herein. The drive assembly includes an upper case assembly (100), a lower case assembly (200), a middle case assembly (300), a mounting bracket assembly (400), a shift cam assembly (500) and a steering handle assembly (600).
[0029] The middle case assembly (300) is vertically connected to the upper case assembly (100) and the lower case assembly (200). The upper case assembly (100) is horizontally connected to the diesel engine (10) housed in a fabricated assembly (9). The mounting bracket assembly (400) is used to mount the drive assembly on the boat to control the motion travel of the boat. The shift cam assembly (500) is connected to the mounting assembly to control forward and reverse movement of the boat. The steering handle assembly (600) is connected to the mounting assembly to start the engine (10).
[0030] The connections between the lower case assembly (200), the middle case assembly (300), the mounting bracket assembly (400), the shift cam assembly (500) and the steering handle assembly (600) forms a ‘Z’ type drive short tail assembly outboard arrangement or a ‘Z’ type drive outboard drive assembly. The ‘Z’ type drive outboard drive is arranged at a rear portion of a watercraft such as a boat or the like so as to be well-balanced by causing a vertical center line of the outboard drive to be aligned with a center location of a longitudinal direction of the boat. The traveling of the boat on the water can be realized by rotation of propeller (207.1) (see FIG. 4) vertically connected to the lower case assembly (200). The propeller (207.1) is exposed to the exterior the lower case assembly (200) from a side.
[0031] Incidentally, as the engine (10), there may be employed various engines such as a two-cycle or four-cycle gasoline engine, a diesel engine and the like. Also, according to the degree of a horsepower of the ‘Z’ type drive outboard drive assembly, a fuel tank, a battery, a cooling device, suction and exhaust device,

lubrication system etc. can be housed within the ‘Z’ type drive outboard drive assembly.
[0032] FIG. 3 illustrates an internal structure of the upper case assembly (100) for the engine (10), according to embodiments as disclosed herein. The upper case assembly (100) includes circlip internals (101-103, 112), a gear lock washer (104), hex bolts (205), spacers (106, 111), a gear box breather cap (107), a gear box breather cap (107), a gear lock washer (108), bearings (109 and 110), a gear box oil level cap (113), oil seals (114), gasket for gear boxes (115), a spiral gear power shaft (116), a spiral gear driven upper shaft (117), a lock nut (118), a ball bearing (119), a vertically oriented upper shaft (120), a gear-box housing (121), a ball bearing (122), a horizontally oriented main drive shaft (123), dowel pins (124), and an oil seal (125).
[0033] The upper case assembly (100) includes the gear box housing (121) having the horizontally oriented main drive shaft (123) with the spiral gear (116) and the vertically oriented upper shaft (120) with the spiral gear (117).The spiral gear (116) is connected to one end of the horizontally oriented main drive shaft (123) using the ball bearings (119 and 122) and the lock nut (118). The ball bearings (119 and 122) is separated by the circlip internals (101). In an embodiment, the horizontally oriented main drive shaft (123) is connected to the engine (10) through an universal coupling joint (700). One end of universal joint coupling (700) is coupled to flange coupling on prime movers like engine and motor and another end to the horizontally oriented main drive shaft (123).
[0034] The spiral gear (117) is connected to one end of the vertically oriented upper drive shaft (120) using the ball bearings (109 and 110) and the spacer (106). The ball bearings (109 and 110) are separated by the circlip internals (102).
[0035] The horizontally oriented main drive shaft (123) is connected to the engine (10) with a spiral gear (116), and a vertically oriented upper shaft (120) with a spiral

gear (117). The horizontally oriented main drive shaft (123) receives the gear driven power from the engine (10) through the rotations of the main power shaft (123) and rotates further to provide the gear driven power the propeller.
[0036] The oil seal (125) is connected to another end of the horizontally oriented main drive shaft (123) using the spacer (111). The gear lock washer (104) is connected to spiral gear (116) to lock the spiral gear (116) using the dowel pin (124) and the bolt (125). The oil seal (114) is connected to another end of the vertically oriented upper drive shaft (120). The gear lock washer (108) is connected to the vertically oriented upper drive shaft (120) using the bolt (105).
[0037] The gear box housing (121) includes the gear box oil lever cap (113) connected to the gear box housing (121) using the gasket (115) and the hex nut (105). Further, the gear box housing (121) includes the gear box breather cap (107) connected to the gear box housing (121) using the gasket (115) and the hex nut (105).
[0038] FIG. 4 illustrates an internal structure of the lower case assembly (200), according to embodiments as disclosed herein. The lower case assembly (200) includes circlip internals (201), oil seals (202), a shifter rod (203), a coller (204), a gasket (205) for a lower casing (214), a snap lock (206), a fan assembly (207) having fan (207.1) and fan bush (207.2), a gasket (208) for the lower casing (214), a washer (209) for the fan (207.1), radial ball bearings (210), a spiral gear lower driven shaft (211), spiral gear propeller shafts (212), a propeller shaft (213), a shaft cam casing (215), a pipe (216) for the spiral gear lower driven shaft (211), a driven lower shaft (217), ball bearings (218, 222), a bearing bush (219), a thrust roller bearing (220), hex bolts (221), a castle nut (223), a pin for shifter (224), a coupling (225), a clutch dog (226), a cap lower casing (227), gear bushes (228), a clutch dog pin (229), shifter cam (230), a cotter pin (231), dowell pins (232), and a cam spring (233).

[0039] The lower case assembly (200) includes the propeller (207.1) mounted on the horizontally oriented propeller lower shaft (213) with the spiral gear (212), the vertically oriented lower shaft (217) with the spiral gear (211) to receive the gear driven power through the rotations of the vertically oriented upper shaft (120) and rotates further to provide the gear driven power to the propeller (207.1) through the horizontally oriented propeller shaft (213).
[0040] The lower case assembly (200) includes the lower casing (214), a first portion to connect with the middle case assembly (300) in a vertically direction, and a second portion to connect to the propeller (207.1) in a horizontally direction. The first portion includes the vertical shift rod (203), the pipe (216), the coller (204), and the coupling (225).
[0041] The vertical shift rod (203) is connected to the shift cam assembly (500) and the lower casing (214) using the shift cam (230) and the dowell pin (232) The pipe (216) to house the vertically oriented lower shaft (217) connected to the vertically oriented upper shaft (120). The coller (204) is connected to the pipe (216). The spiral gear (211) connected to the vertically oriented lower shaft (217) using the thrust roll bearing (220), the fan (207) and the bearing bush (219). The coupling (225) is connected to the vertically oriented lower shaft (217) using the circlip (201) and the ball bearing (210).
[0042] The second portion includes the shaft cam casing (215), the gear bush (228), the snap lock (206), the gear bush (228), and the cam spring (233). The shaft cam casing (215) having the ball bearing (218) for the pin (224). The gear bush (228) is connected to the pin for shifter (224) and the clutch dog (226). The snap lock (206) is connected to the clutch dog (226) and the spiral gear (212). The gear bush (228) is connected to one end of the horizontally oriented propeller shaft (213). The cam spring (233) is connected to another end of the horizontally oriented propeller shaft (213) to connect the horizontally oriented propeller shaft (213) to the propeller

(207.1) using the ball bearing (222), the cap lower casing (227), the cotter pin (231), the fan bush (207.2) and the castle nut (223).
[0043] FIG. 5 illustrates an internal structure of the middle case assembly (300), according to embodiments as disclosed herein. The middle case assembly (300) includes circlip internals (301), a gasket (302) for a middle housing (304), radial ball bearings (303), a vertically oriented middle shaft (305), a coupling (306), hex bolts (307), and dowel pins (308).
[0044] The middle case assembly (300) includes the vertically oriented middle shaft (305) connected to the vertically oriented upper shaft (120) and the vertically oriented lower shaft (217). The propeller (207.1) is connected to the horizontally oriented main drive shaft (123) though the vertically oriented lower shaft (217), the vertically oriented middle shaft (305), and the vertically oriented upper shaft (120).
[0045] The middle housing (304) and the gasket (302) is connected to the middle housing (304) using bolts (307) and pins (308). The middle housing (304) includes the radial ball bearings (303) connected to either sides of the vertically oriented middle shaft (305). The coupling (306) is connected to the vertically oriented middle shaft (305) using the circlip internal (301).
[0046] FIGS. 6a illustrates the internal structure of the mounting bracket assembly (400), according to embodiments as disclosed herein. The mounting bracket assembly (400) is used to mount the drive assembly on the boat to control the motion travel of the boat. The mounting bracket assembly (400) includes provision for tilting movement, sideways movement and locking arrangement to control the motion travel of the boat using the drive assembly.
[0047] The mounting bracket assembly (400) includes a swivel bracket assembly (401), a mount bracket assembly (402), a steering shaft bracket assembly (403), lower thrust plates (404), upper thrust plates (405), washers (406, 407, 413), a

steering shaft (408), hex nuts (409), a swivel bracket shaft (410), a left clamp bracket (411), a right clamp bracket (412), a plain washer (414), a distance stud (415), hex nuts (416, 422, 423), a clamp screw assembly (417), a thrust rod assembly (418), a dowel (419), a stud (420), and a steering handle assembly (421).
[0048] The steering shaft bracket assembly (403) is connected to the swivel bracket assembly (401) and the steering handle assembly (600). The steering shaft bracket assembly (403) is connected to the swivel bracket assembly (401) using the lower thrust plate (404) and the dowel pin (419). The lower thrush plate (404) includes a distance stud (415) connected the thrust upper plate (405) using the washer (406) and the nut (409). The steering shaft (408) whose one end is connected to the steering shaft bracket assembly (403) using the upper thrust plate (405). Another end of the steering shaft (408) is connected to the washer (406) and the nut (409). The right clamp bracket (412) is connected to the swivel bracket assembly (401) using the plain washer (414), the nut (416) and the clamp screw assembly (417). The swivel bracket shaft (410) whose one end is connected to the right clamp bracket (412) and another end is connected to the nut (422) and the washer (413). The left clamp bracket (411) is connected to the swivel bracket assembly (401) using the clamp screw assembly (417) and the nut (416). The thrust rod assembly (418) is connected to the left clamp bracket (411). The lower thrush plate (404) is connected to the left clamp bracket (411) using stud (420) through a mount bracket assembly (402). The stud (420) is connected to the left clamp bracket (411) using the washer (407) and the nut (423).
[0049] FIGS. 6b illustrates an internal structure of the swivel bracket assembly (401), according to embodiments as disclosed herein. The swivel bracket assembly (401) includes setting plate (424), a tilt stopper (425), a reverse lock (426), a cotter pin (427), plain washers (428), a reverse lock arm (429), a reverse lock arm bracket (430), a swivel bracket (431), a friction spring (432), a reverse lock rod (433), hex bolts (434), pivot bolts (435), a bush (436), a setting piece (437), an extension spring - A (438), plain washers (439), bushes (440), a plate (441), hex bolts (442),

bush for steering shafts (443), a reverse lock lever (444), a shoulder bolt(445), a spring pin (446), a washer (447), a link reverse lock (448), a spring plate (449), a lock washer (450), and an extension spring - B (451).
[0050] The tilt stopper (425) connected to the swivel bracket assembly (401) using the spring (432), the bush (436) and the setting piece (437). The tilt stopper (425) includes the setting plate (424) connected to the tilt stopper (425) using the washer (439) and the bolts (434). The swivel bracket (431) connected to the swivel bracket assembly (401) using the washer (428) and the pivot bolt (435). The bushes (443 and 440) connected to the swivel bracket assembly (401). The plate (441) is connected to the swivel bracket assembly (401) using the bolts (442). The reverse lock assembly includes the extension spring – A (438) connected to the reverse lock (426), the reverse lock bracket (430) having the reverse lock arm (429) with the reverse lock rod (433) connected to the cotter pins (427). The reverse lock lever (444) is connected to the swivel bracket (431) using the lock washers (447 and 450) and the shoulder bolt (445). The reverse lock lever (444) is connected to the link reverse lock (448) and the extension spring - B (451).
[0051] FIG. 7 illustrates an internal structure of the shift cam assembly (500), according to embodiments as disclosed herein. The shift cam assembly (500) is connected to the mounting assembly to control reverse and forward movement of the boat. The shift cam assembly (500) provide a reverse and forward mechanism with clutch dog inside the lower case assembly of the ‘Z’ type drive short tail assembly for both ways (forward and reverse) easy movement of the boat.
[0052] The shift cam assembly (500) includes a stud for shifter (501), a RNF shifter cam (502), a RNF shifter bracket (503), bushes (504), holding caps (505), hex bolts (506, 508), washers (507), circlip externals (509), a stud shifter locking (510), a shifter shaft (511), a shift rod extension (512), and a hex nut (513).

[0053] The shifter shaft (511) is connected between the RNF shifter bracket (503) and the two holding caps (505) using the washers (507) and the bolts (506 and 508). The stud (501) is connected to one end of the shifter shaft (511) using the stud shifter lock (510). The stud shifter lock (510) is connected to the shifter shaft (511) using the bolt (508), the nut (513), the circlip external (509). The RNF shifter cam (502) is connected to other end of the shifter shaft (511) using the bush (504) and the shift rod extension (512).
[0054] FIG. 8 illustrates an internal structure of the steering handle assembly (600), according to embodiments as disclosed herein. The steering handle assembly (600) is connected to the mounting assembly to start the engine (10). The steering handle assembly (600) includes a steering bracket (601), a steering handle (602), bush for steering handles (603), spring washers (604), plain washers (605), a spacer (606), a hex bolt(607), a hex nut (608), plain washers (609), studs (610), nut and washer (611), a guide (612), a plain washer (613), a nylon washer (614), a lock nut (615), and an allen bolt (616).
[0055] The steering bracket (601) two studs (610) is connected in parallel to the steering bracket (601) using nut and washer (611). The steering handle (602) whose one connected to the steering bracket (601) using the washers (604, 605 and 609), the spacer (606), bolts (607), and nuts (608). Another end of the steering handle (602) is connected to the guide (612) using the washers (613 and 614), the bolt (616), and the lock nut (615).
[0056] When the engine (10) is started using the steering handle assembly (600), the power is transmitted from the engine (10) to the horizontally oriented main drive shaft (123) that rotates through the spiral gear (116). The rotations of the horizontally oriented main drive shaft (123) with the spiral gear (116) generates the gear driven power that is transmitted to the propeller (207.1) through the vertically oriented upper shaft (120) with the spiral gear (117), the vertically oriented middle

shaft (305), the horizontally oriented propeller lower shaft (213) with the spiral gear (212), and the horizontally oriented propeller shaft (213) with the spiral gear (212).
[0057] The gear driven power from the horizontally oriented main drive shaft (123) is transmitted to the vertically oriented upper shaft (120). The vertically oriented upper shaft (120) rotates through the spiral gear (117) and further transmits the gear driven power to the vertically oriented lower shaft (217). The vertically oriented lower shaft (217) rotates through the spiral gear (116) to transmit the gear driven power to the horizontally oriented propeller shaft (213). The horizontally oriented propeller shaft (213) rotates through the spiral gear (212) to transmit the gear driven power to the propeller (207.1).
[0058] Unlike conventional drive units or arrangements, the proposed ‘Z’ type drive assembly operates on less cost due to use of high speed diesel instead of petrol and better efficiency of the prime movers. The proposed ‘Z’ type drive short tail assembly is indigenously designed and developed and is suitable for local diesel engines available in the market. Various ratings and types diesel engines can be coupled to the drive arrangement thorough the universal coupling joint (700). The ‘Z’ type drive short tail assembly is coupled to prime mover by using the universal coupling joint (700) for power transmission. The ‘Z’ type drive short tail assembly run with the prime movers (like engines and motors) for motion traverse of the boat.
[0059] Alloy steel hardened spiral bevel gears are used in the ‘Z’ type drive short tail assembly for smooth power transmission. The ‘Z’ type drive short tail assembly is coupled to prime mover by using universal joint for better power transmission. The ‘Z’ type drive short tail assembly with the prime mover mounting bracket has provision for tilting movement, sideways movement and locking arrangement for better operation flexibility to the ‘Z’ type drive short tail assembly. The gear box provision inside the upper case assembly of the ‘Z’ type drive short tail assembly for improved torque and better thrust.

[0060] The lower case assembly of the ‘Z’ type drive short tail assembly with aerodynamic design for lesser resistance to the boat and to get better speed. The proposed propeller design is suitable for clockwise rotations of the engine. Hence the proposed propeller design is opposite than the other propeller designs currently available in the market.
[0061] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.
[0062] List to reference numerals:

Sr. No. Description
1 Petrol engine
2 rope start arrangement
3 upper case
4 lower case
5 propeller
6 operating handle
7 forward and reverse mechanism
8 mount bracket

9 fabricated assembly
10 Diesel engine
100 upper case assembly
101-103, 112 Circlip internal
104 Gear lock washer
105 Hex bolt
106, 111 spacer
107 Gear box breather cap
108 Gear lock washer
109, 110 bearing
113 Gear box oil lever cap
114 Oil seal
115 gasket for gear box
116 Spiral gear power shaft
117 Spiral gear driven upper shaft
118 lock nut
119 Ball bearing
120 vertically oriented upper shaft
121 gear-box housing
122 Ball bearing
123 horizontally oriented main drive shaft
124 Dowel pin
125 Oil seal
200 lower case assembly
201 circlip internals
202 oil seals
203 shifter rod
204 205 coller
gasket for lower casing

206 snap lock
207 fan assembly
207.1 propeller
207.2 fan bush
208 gasket for cap lower casing
209 washer for fan
210 radial ball bearings
211 spiral gear lower driven shaft
212 spiral gear propeller shafts
213 propeller shaft
214 lower casing
215 shaft cam casing
216 pipe for lower driven shaft
217 driven lower shaft
218, 222 ball bearings
219 bearing bush
220 thrust roller bearing
221 hex bolts
223 castle nut
224 pin for shifter
225 coupling
226 clutch dog
227 cap lower casing
228 gear bushes
229 clutch dog pin
230 shifter cam
231 cotter pin
232 dowell pins
233 300 cam spring
middle case assembly

301 circlip internals
302 gasket for middle housing
303 radial ball bearings
304 middle housing
305 driven middle shaft
306 coupling
307 hex bolts
308 dowel pins
400 mounting bracket assembly
401 swivel bracket assembly
402 mount bracket assembly
403 steering shaft bracket assembly
404 lower thrust plates
405 upper thrust plates
406, 407, 413 washers
408 steering shaft
409 hex nuts
410 swivel bracket shaft
411 left clamp bracket
412 right clamp bracket
414 plain washer
415 distance stud
416, 422, 423 hex nuts
417 clamp screw assembly
418 thrust rod assembly
419 dowel
420 stud
421 steering handle assembly
424 425 setting plate tilt stopper

426 reverse lock
427 cotter pin
428 plain washers
429 reverse lock arm
430 reverse lock arm bracket
431 swivel bracket
432 friction spring
433 reverse lock rod
434 hex bolts
435 pivot bolts
436 bush
437 setting piece
438 extension spring - A
439 plain washers
440 bushes
441 plate
442 hex bolts
443 bush for steering shafts
444 reverse lock lever
445 shoulder bolt
446 Spring pin
447 washer
448 link reverse lock
449 spring plate
450 lock washer
451 extension spring - B
500 shift cam assembly
501 stud for shifter
502 503 RNF shifter cam RNF shifter bracket

504 bushes
505 holding caps
506, 508 hex bolts
507 washers
509 circlip externals
510 stud shifter locking
511 shifter shaft
512 shift rod extension
513 hex nut
600 steering handle assembly
601 steering bracket
602 steering handle
603 bush for steering handles
604 spring washers
605 plain washers
606 spacer
607 hex bolt
608 hex nut
609 plain washers
610 studs
611 nuts
612 guide
613 plain washer
614 nylon washer
615 lock nut
616 allen bolt
700 universal coupling joint

We Claim:
1. A Z-drive short tail assembly for engine (10) for motion traverse of a boat,
wherein the Z-drive short tail assembly comprises:
an upper case assembly (100) comprising a horizontally oriented main drive shaft (123) connected to the engine (10) with a spiral gear (116), and a vertically oriented upper shaft (120) with a spiral gear (117) that receives gear driven power from the engine (10) through the rotations of the main power shaft (123) and rotates;
a lower case assembly (200) comprising a propeller (207.1) mounted on a horizontally oriented propeller lower shaft (213) with a spiral gear (212), a vertically oriented lower shaft (217) with a spiral gear (116) to receive the gear driven power through the rotations of the vertically oriented upper shaft (120) and rotates to provide the gear driven power to the propeller (207.1) through the horizontally oriented propeller shaft (213);
a middle case assembly (300) comprising a vertically oriented middle shaft (305) connected to the vertically oriented upper shaft (120) and the vertically oriented lower shaft (217), wherein the propeller (207.1) is connected to the horizontally oriented main drive shaft (123) though the vertically oriented lower shaft (217), the vertically oriented middle shaft (305), and the vertically oriented upper shaft (120);
a mounting bracket assembly (400) to mount the drive assembly on the boat to control the motion travel of the boat;
a shift cam assembly (500) connected to the mounting assembly to control forward and reverse movement of the boat; and
a steering handle assembly (600) connected to the mounting assembly to start the engine (10).
2. The Z-drive short tail assembly as claimed in claim 1, wherein when the engine
(10) is started using the steering handle assembly (600), the power is transmitted
from the engine (10) to the horizontally oriented main driveshaft (123) with the
spiral gear (116), wherein the rotations of the horizontally oriented main drive

shaft (123) with the spiral gear (116) generates the gear driven power that is transmitted to the propeller (207.1)through the vertically oriented upper shaft (120) with the spiral gear (117), the vertically oriented middle shaft (305), the horizontally oriented propeller lower shaft (213) with the spiral gear (212), and the horizontally oriented propeller shaft (213) with the spiral gear (212).
3. The Z-drive short tail assembly as claimed in claim 1, wherein the mounting
bracket assembly (400) comprises provision for tilting movement, sideways
movement and locking arrangement to control the motion travel of the boat
using the drive assembly.
4. The Z-drive short tail assembly as claimed in claim 1, wherein the upper case
assembly (100) comprises:
a gear box housing (121) housing the horizontally oriented main drive shaft (123) with the spiral gear (116) and the vertically oriented upper shaft (120) with the spiral gear (117), wherein the spiral gear (116) is connected to one end of the horizontally oriented main drive shaft (123) using ball bearings (119 and 122) and a lock nut (118), and wherein the spiral gear (117) is connected to one end of the vertically oriented upper drive shaft (120) using ball bearings (119 and 122) and a spacer (106);
an oil seal (125) connected to another end of the horizontally oriented main drive shaft (123) using a spacer (111), and
a gear lock washer (104) connected to spiral gear (116)to lock the spiral gear (116) using dowel pin (124) and bolt (125);
an oil seal (114) connected to another end of the vertically oriented upper drive shaft (120); and
a gear lock washer (108) connected to the vertically oriented upper drive shaft (120) using a bolt (115).
5. The Z-drive short tail assembly as claimed in claim 5, wherein the gear box
housing (121) comprises:

a gear box oil lever cap (113) connected to the gear box housing (121) using a gasket (115) and a hex nut (105); and
a gear box breather cap (107) connected to the gear box housing (121) using a gasket (115) and a hex nut (105).
6. The Z-drive short tail assembly as claimed in claim 5, wherein the ball bearings (119 and 122) separated by circlip internals (101 and 103).
7. The Z-drive short tail assembly as claimed in claim 1, wherein the lower case assembly (200) comprises:
a lower casing (214), a first portion to connect with the middle case assembly (300) in a vertically direction, and a second portion to connect to the propeller (221) in a horizontally direction, where in the first portion comprises:
a vertical shift rod (203) connected to the shift cam assembly (500) and the lower casing (214) using a shift cam (230) using dowell pin (232),
a pipe (216) to house the vertically oriented lower shaft (217) connected to the vertically oriented upper shaft (120),
a coller (204) connected to the pipe (216), a spiral gear (211) connected to the vertically oriented lower shaft (217) using a thrust roll bearing (220), a fan assembly (207) and a bearing bush (219),
a coupling (225) connected to the vertically oriented lower shaft (217) using the fan assembly (207) and ball bearing (210); and wherein the second portion comprises:
a shaft cam casing (215) having a ball bearing (218) for a pin (224),
a gear bush (228) connected to the pint (224) and a clutch dog (226),
a snap lock (206) connected to the clutch dog (226) and the spiral gear (212),
a gear bush (228) connected to one end of the horizontally oriented propeller shaft (213);

a cam spring (233) connected to another end of the horizontally oriented propeller shaft (213) to connect the horizontally oriented propeller shaft (213) to the propeller (207.1) using a ball bearing (222), a cap lower casing (227), a cotter pin (231), and a castle nut (223).
8. The Z-drive short tail assembly as claimed in claim 1, wherein the middle case
assembly (300) comprises:
a middle housing (304); and
a gasket (302) connected to the middle housing (304) using bolts (307) and pins (308), wherein the middle housing (304) comprises:
radial ball bearings (303) connected to either sides of the vertically oriented middle shaft (305), and
a coupling (306) connected to the vertically oriented middle shaft (305) using a circlip internal (301).
9. The Z-drive short tail assembly as claimed in claim 1, wherein the mounting
bracket assembly (400) comprises:
a swivel bracket assembly (401);
a steering shaft bracket assembly (403) connected to the swivel bracket assembly (401) and the steering handle assembly (600), wherein the steering shaft bracket assembly (403) is connected to the swivel bracket assembly (401) using a lower thrust plate (404) and a dowel pin (419);
a steering shaft (408) whose one end is connected to the steering shaft bracket assembly (403) using an upper thrust plate (405), wherein another end of the steering shaft (408) is connected to a washer (406) and a nut (409);
a right clamp bracket (412) connected to the swivel bracket assembly (401) using a plain washer (414), nut (416) and a clamp screw assembly (417);
a swivel bracket shaft (410) whose one end is connected to the right clamp bracket (412) and another end is connected to a nut (422) and washer (413);
a left clamp bracket (411) connected to the swivel bracket assembly (401) using a clamp screw assembly (417) and nut (416);

a thrust rod assembly (418) connected to the left clamp bracket (411); and a lower thrush plate (404) connected to the left clamp bracket (411) using stud (420) through a mount bracket assembly (402), wherein the stud (420) is connected to the left clamp bracket (411) using a washer (407) and nut (423).
10. The Z-drive short tail assembly as claimed in claim 9, wherein the lower thrush plate (404) comprises a distance stud (415) connected a thrust upper plate (405) using a washer (406) and nut (409).
11. The Z-drive short tail assembly as claimed in claim 9, wherein the swivel bracket assembly (401) comprises:
a tilt stopper (425) connected to the swivel bracket assembly (401) using spring (432), bush (436) and setting piece (437), wherein the tilt stopper (425) comprises a setting plate (424) connected to the tilt stopper (425) using washer (439) and bolts (434);
a swivel bracket (431) connected to the swivel bracket assembly (401) using a washer (428) and bolt (435); bushes (443 and 440) connected to the swivel bracket assembly (401);
a plate (441) connected to the swivel bracket assembly (401) using bolts (442);
a reverse lock assembly comprising a spring (438) connected to a reverse lock (426), a reverse lock bracket (430) having a reverse lock arm (429) with a reverse lock rod (433) connected to cotter pins (427); and
a reverse lock lever (444) connected to the swivel bracket (431) using lock washers (447 and 450) and a shoulder bolt (445), wherein the reverse lock lever (444) is connected to a link reverse lock (448) and a spring (451).
12. The Z-drive short tail assembly as claimed in claim 1, wherein the shift cam
assembly (500) comprises:
a RNF shifter bracket (503); two holding caps (505);

a shifter shaft (511) connected between the RNF shifter bracket (503) the two holding caps (505) using washers (507) and bolts (506 and 508);
a stud (501) connected to one end of the shifter shaft (511) using a stud shifter lock (510), wherein the stud shifter lock (510) is connected to the shifter shaft (511) using bolt (508), nut (513), circlip external (509); and
a RNF shifter cam (502) connected to other end of the shifter shaft (511) using bush (504) and a shift rod extension (512).
13. The Z-drive short tail assembly as claimed in claim 1, wherein the steering
handle assembly (600) comprises:
a steering bracket (601) two studs (610) connected in parallel to the steering bracket (601) using nut and washer (611); and
a steering handle (602) whose one connected to the steering bracket (601) using washers (604, 605 and 609), spacer (606), bolts (607), and nuts (608), wherein another end of the steering handle (602) is connected to a guide (612) using washers (613 and 614), bolt (616), and lock nut (615).
14. The Z-drive short tail assembly as claimed in claim 1, wherein the horizontally
oriented main drive shaft (123) is connected to the engine (10) through an
universal coupling joint (700).
15. The Z-drive short tail assembly as claimed in claim 14, wherein the drive
assembly is coupled to prime mover by using the universal coupling joint (700) for power transmission, wherein the drive assembly run with the prime movers for motion traverse of the boat.