Brake apparatus for a rotating shaft

A brake apparatus for a rotating shaft. The apparatus comprises a fluid-tight housing in which is disposed a shaft rotational engagement gear having an exteriorly-accessible portion thereof rotatably engageable with a shaft. A plurality of compartments are formed by a plurality of walls within the housing, and the compartments are in fluid communication with each other through openable and closable valves. The housing is substantially filled with a fluid which is flowable through the valves in direct relation to the openness of the valves. A plurality of compartment-divider rotational gears are disposed inside the housing. These compartment-divider gears are rotatably engaged with the shaft rotational gear and are situated in cooperation with the walls forming the compartments to create at their respective sites restriction seals between the compartments. Upon activation, the brake apparatus operates through closure of the valves, thereby retarding the flow of fluid amongst the plurality of compartments and initially increasing fluid pressure. The initially increased fluid pressure slows the gears which, in turn, slow the velocity of a rotating shaft rotatably engaged with the rotational engagement gear and simultaneously gradually decreases fluid pressure.

BACKGROUND OF THE INVENTION 
This invention relates in general to braking devices, and in particular to 
a brake apparatus for slowing a rotating shaft such as, for example, the 
drive shaft of a moving vehicle. 
Rotating shafts are associated with concurrent movement of many devices and 
mechanisms. Important non-limiting examples include transportation 
vehicles employing drive shafts, axles, and the like, all being associated 
with vehicle movement. Often, it is important to be able to slow movement 
in a controlled and timely manner, and such need to retard movement is 
highly exemplified in motor vehicles whose manufacturers have worked to 
improve traditional wheel-braking systems by developing disk brakes, 
ventilated brakes, greater surface areas for braking action, etc. However, 
as is evident, emphasis has been placed on the rotating wheel rather than 
on the rotating shafts that deliver power and movement to the rotating 
wheel. Thus, rotating drive shafts, rotating axle components, etc. 
generally are ignored as objects in and of themselves for braking action. 
It is therefore apparent that a need is present for a brake apparatus that 
can work independently from traditional brakes to achieve the slowing of a 
moving object where a rotating shaft carries responsibility for such 
movement. Accordingly, a primary object of the present invention is to 
provide a brake apparatus that operates to slow a rotating shaft 
responsible for delivering power to an operating mechanism. 
Another object of the present invention is to provide a brake apparatus for 
a rotating shaft wherein a component of the brake apparatus is 
rotationally engaged with the shaft and is rotationally slowable. 
Yet another object of the present invention is to provide a brake apparatus 
for a rotating shaft wherein slowing of the shaft is accomplished through 
positive and negative fluid pressure. 
These and other objects of the present invention will become apparent 
throughout the description of the invention which now follows. 
SUMMARY OF THE INVENTION 
The present invention is a brake apparatus for a rotating shaft. The 
apparatus comprises a fluid-tight housing in which is disposed a shaft 
rotational engagement means having an exteriorly-accessible portion 
thereof rotatably engageable with a shaft. A plurality of compartments are 
formed by a plurality of walls within the housing, and the compartments 
are in fluid communication with each other through openable and closable 
valve means. The housing is substantially filled with a fluid which is 
flowable through the valve means in direct relation to the openness of 
these valve means. A plurality of compartment-divider rotational 
engagement means are disposed inside the housing. These 
compartment-divider rotational engagement means are rotatably engaged with 
the shaft rotational engagement means to create at adjacent sites 
restriction seals, and are situated in juxtaposition with the walls 
forming the compartments to also create at adjacent sites therewith 
restriction seals which act to separate the compartments. The terms 
"restriction seal" and "restriction sealing" as used herein are defined as 
the minimum clearance distance required between two adjacent bodies such 
that the two bodies can pass by each other without touching. 
In a preferred embodiment, the shaft rotational engagement means is a 
wheel-shape gear having an exteriorly accessible center opening 
therethrough. The center opening accepts the shaft, while the wheel-shape 
gear has a rim from which a plurality of cogs project outwardly. These 
outwardly projecting cogs engage the plurality of compartment-divider 
rotational engagement means which, themselves, are preferably wheel-shape 
gears having respective rims from which a plurality of cogs project 
outwardly for such engagement. The shaft is secured to the shaft 
rotational engagement means with a conventional spline device. 
Upon activation, the brake apparatus of the present invention operates 
through closure of the plurality of valve means, thereby retarding the 
flow of fluid amongst the plurality of compartments. Because the 
compartment-divider rotational engagement means create at their respective 
sites restriction seals between the compartments, their rotation rate 
decreases as the fluid flow rate decreases and positive and negative 
pressure within the compartments initially increases and then gradually 
decreases with the slowing of the shaft. Since these compartment-divider 
rotational engagement means are in engagement with the shaft rotational 
engagement means, the rotation rate of the shaft rotational engagement 
means likewise decreases. Therefore, because this shaft rotational 
engagement means is in rotational communication with the rotating shaft, 
the rotation rate of the shaft is decreased, and braking action is thereby 
provided. As is evident, continued closure action on the valves 
continually decreases the flow rate of fluid which continually decreases 
the rotation rate of the shaft. In this manner, rotational braking of a 
shaft occurs independently of any other braking system such as that which 
may be employed for a mechanism energized through the rotational movement 
of the shaft being so braked. When so used as an adjunct braking 
apparatus, resultant rotational braking can greatly enhance a conventional 
braking system traditionally in place.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2, a brake apparatus 10 is illustrated. The 
apparatus 10 has an outer fluid-tight housing 12 constructed of a front 
casing member 14 and a rear casing member 16 held together at a mating 
periphery site 18 with a plurality of screws 20 through aligned threaded 
openings, as well as at aligned threaded openings at interfacing interior 
wall top edges, described below, with a plurality of screws 21. A 
rotatable shaft 22 is shown running through the center of the apparatus 10 
through an exteriorly accessible opening 24. This rotatable shaft 22 can 
be associated with any mechanism to which it transmits resulting 
rotational power, with a primary example of the shaft 22 being a drive 
shaft of a vehicle (not shown). In that instance, the drive shaft 
transmits rotational power to an axle which in turn rotates wheels and 
moves the vehicle. The housing 12 is here constructed of aluminum, with 
each of the front and rear casing members 14, 16 matched to provide 
sealingly-close internal tolerances whose importance will become apparent 
below. 
Referring to FIG. 3, wherein the front casing member 14 is removed, a shaft 
rotational engagement means here being a bearing-mounted wheel-shape 
central gear 26 having an exteriorly accessible center opening 28 in 
spline rotatable engagement as known in the art with the rotatable shaft 
22 is shown. The interior cavity 30 is divided into four compartments 32, 
34, 36, 38, with the compartments 32, 34 divided from each other by 
T-shaped wall 40a. In like manner, the compartments 36, 38 are divided 
from each other by T-shaped wall 42a. Further division of the compartments 
32, 34, 36, 38 from each other is accomplished by respective 
compartment-divider rotational engagement means here being respective 
wheel-shape divider gears 44, 46 rotatably bearing-mounted on respective 
spindles 48, 50. Respective valve-housing base walls 52a, 54a of 
respective valves 56, 58 complete division of the compartments 32, 34, 36, 
38. As shown in FIG. 4, the interior of the front casing 14 has 
complimentary respective walls 40b and 42b whose top edges seal with the 
top edges of walls 40a and 42a when the casing 14 is in place. In a 
similar manner the front casing 14 has therein complimentarily-shaped 
valve-housing base walls 52b, 54b whose top edges seal with the top edges 
of base walls 52a, 54a when the casing 14 is in place. 
As is apparent in FIG. 3, the central gear 26 has a plurality of cogs 64 
projecting outwardly from its rim. The divider gears 44, 46 are 
constructed substantially identically to the central gear 26 and therefore 
likewise have respective pluralities of cogs 66, 68 projecting outwardly 
from their respective rims. All gears 26, 44, 46 in the preferred 
embodiment are constructed of bronze. The gears 26, 44, 46 are arranged 
such that they engage with adjacent gears. Simultaneously, the tips of the 
respective cogs 66, 68 almost contact adjacent tops of the T-shaped walls 
40a, 42a to thereby produce restriction sealing, while the tips of the 
cogs 64 almost contact the valve-housing base walls 52a, 54a to also 
produce restriction sealing. Of course, when the front casing 14 is in 
place, the tips of the respective cogs 66, 68 almost contact adjacent tops 
of the T-shaped walls 40b, 42b to likewise produce restriction sealing, 
while the tips of the cogs 64 almost contact the valve-housing base walls 
52b, 54b to also produce restriction sealing. 
In operation, the brake apparatus 10 is filled with a fluid such as oil, 
and is situated such that a rotatable shaft 22 resides via spline 
connection through the center of the apparatus 10 as shown. As shown in 
FIG. 3, bearing-mounted valves 56, 58 each have therethrough respective 
openings 60, 62 through which the oil can flow when the valves 56, 58 are 
in an open position. Operation of the valves 56, 58 is directed by a user 
through employment of any control mechanisms such as a solenoid switch or 
any other appropriate means as recognizable by a skilled artisan and 
working in combination with respective valve shafts 74, 76 extending from 
the housing 12 to rotate the valves 56, 58 between open and closed 
positions. Thus, when the valves 56, 58 are open, the oil can move freely 
among the compartments 32, 34, 36, 38. When the rotatable shaft 22 is 
rotating and the valves 56, 58 are open, shaft rotation is unimpeded. A 
conventional pressure gauge 69 can be included to monitor pressure within 
the housing 12. Also included in the preferred embodiment are two 
conventional spring-and-ball pressure bypass relief valves 70, 72 shown in 
FIGS. 1 and 4 for releasing to the exterior any untoward pressure build-up 
within the housing 12. When an operator wishes to slow the rotating shaft 
22, the operator closes the valves 56, 58 by rotating them 90.degree. for 
complete closure or less for incomplete closure. Such action causes oil 
pressure build up because the oil can no longer flow freely among the 
compartments 32, 34, 36, 38. This increased pressure build up causes the 
gears 26, 44, 46 to slow. As the gears 26, 44, 46 slow down because of 
pressure build up, rotational velocity of the rotating shaft 22 also 
slows, thus producing a braking action on the shaft 22 and consequently on 
any mechanism powered by the rotational velocity of the shaft 22. As the 
gears 26, 44, 46 slow, pressure within the housing 12 decreases to 
thereafter allow the shaft 22 to rotate more freely at its new reduced 
speed. This pressure reduction because of shaft slowing and consequent 
freeing of shaft rotation provides anti-lock braking characteristics for 
the shaft 22. In this manner a braking action is effectively applied on a 
rotating shaft responsible for delivering rotational power to another 
mechanism such that consequent braking action occurs on that other 
mechanism. 
While an illustrative and presently preferred embodiment of the invention 
has been described in detail herein, it is to be understood that the 
inventive concepts may be otherwise variously embodied and employed and 
that the appended claims are intended to be construed to include such 
variations except insofar as limited by the prior art.