Waterproof axle system for a boat trailer

A system is disclosed for a boat trailer which prevents water from entering the trailer's axle housing when the axle housing is submerged in water during loading or unloading of a boat from the trailer. The system includes a quantity of lubricating oil maintained in the axle housing by seals interposed between the trailers wheel axle and the axle housing and an elongated, hollow tubular member having one end in communication with said lubricating oil and the other end vented to the atmosphere when the axle housing is submerged.

BACKGROUND OF THE INVENTION AND OBJECTS 
This invention relates to boat trailers and more specifically to a system 
for preventing water from entering the wheel axle housing of the trailer 
when it is submerged in the water during loading or unloading of a boat 
from the trailer. 
Attempts to design systems for preventing water from entering and 
destroying axle bearings when a boat trailer's axle housing is submerged 
in water are numerous in the prior art. These include means to pressurize 
the inside of the axle hub with air from the trailer's tires to prevent 
water from entering the area adjacent the axle bearings such as disclosed 
in U.S. Pat. No. 3,226,162. Other devices apply positive pressure to the 
lubricant packing the hub of a bearing by springs and the like to prevent 
water from entering and damaging the bearings of a boat trailer hub as 
shown in U.S. Pat. No. 4,190,133. 
These devices are attached to the outside end of the hub and perform 
somewhat satisfactorily; however, due to the complexity of their 
construction, maintaining sealing of the lubricant under pressure is 
difficult and maintenance is costly. 
In contrast to the aforedescribed devices of the prior art as well as 
others, the subject invention solves the problem of preventing water from 
entering the axle housing and destroying the bearings by a simple and 
inexpensive means. Applicant has discovered that by connecting the 
bearings by an interconnecting tube, filling the tube with lubricating 
fluid and venting the inside of the tube to the atmosphere by means of a 
tubular member which extends a distance above the water level when the 
wheel hub is submerged prevents water from entering the housing and 
destroying the bearing. 
It is therefore the primary object of this invention to provide a superior 
means for the purpose of preventing water from entering a boat trailer 
axle housing when the housing is temporarily submerged thereby protecting 
the axle bearings from corrosion and damage. 
It is another object of the invention to provide a means for accomplishing 
the aforedescribed purpose which does not require attachment to the 
outside of the axle housing. 
It is yet another object of the invention to provide a means for 
accomplishing the aforedescribed purpose which is extremely simple in 
construction and efficient in use. 
It is a further object of the invention to provide a means for 
accomplishing the aforedescribed purpose which is economical to 
manufacture, capable of long operating life and inexpensive to maintain.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
Referring now to the drawings where like characters of reference indicate 
like elements in each of the several figures, numeral 10 refers generally 
to a boat 12 and conventional trailer 14 for transporting it. The trailer 
14 employs the novel watertight axle system 16 of the present invention 
which is supported by wheels 18. 
Referring specifically to FIGS. 2 and 3, the axle system 16 includes an 
axle housing 20 which has enlarged wheel hub member 22 with a flange 24 
integrally formed at the outer end of each hub member and interconnected 
at the inner ends 26 by means of an elongated hollow tubular member 28. 
The hub members 22 have an inner surface 30 that support the stub-axle 32 
by means of ball-bearings 34, 36 in a conventional manner. The stub-axle 
32 is integrally formed with the flange 38 carrying studs 40 for securing 
the wheel 42 and mounted tire 44 by means of nuts 46. The bearings 34, 36 
are mounted on the stub-axle 32 and maintained in spaced-apart 
relationship by means of spacer 48. The bearings 34, 36 and spacer 48 are 
held on the stub-axle 32 by means of washer 50 and nut 52 which is locked 
by a pin 54. The bearings 34, 36 engage the inner surface 30 of the hub 
member 22 and are held within the hub member 22 with the stub-axle 32 by 
means of hub cover plate 56 which is secured to the flange 24 by means of 
bolts 58. A seal 60 is interposed between the cover plate 56 and flange 24 
to prevent water from entering therebetween. The cover plate 56 also has a 
circular-shaped projection 62 which engages bearing 34 to prevent any 
axial movement of the stub-axle 32 within the hub member 22. The interior 
of the hub members 22 and interconnecting tubular member 28 is maintained 
substantially full of lubricating oil 64. To initially seal the hub member 
22 and tubular member 28 from the entrance of contaminants or the exit of 
lubricating oil during normal, over the road operation, circular seals 66 
are located on the stub axle 32 and are compressed against the stub axle 
32 and bearing 34 when the cover plate 56 is drawn toward the flange 24 by 
means of the bolts 58. 
Applicants have discovered that a hollow vent tube 70 as will be 
hereinafter described will prevent water from entering the hub member 22 
and tubular member 28 where it can cause damage to the bearings 34, 36 
whenever the hub and tubular members 22, 28 are submerged in water during 
on or off loading of the boat 12. More specifically, the hollow vent tube 
70 is of a sufficient length to have one end extend to the atmosphere 
above any anticipated depth of water that may be encountered during such 
loading or unloading operations and have the other end attached to and in 
communication with the interior of the hub and tubular members 22, 28 by 
means of a suitable fitting 72. By so venting the interior of the hub and 
tubular members 22, 28 to the atmosphere, the water in which the members 
are submerged is prevented from leaking past the seals 66. A valve 74 is 
provided on the underside of each hub member 22 for draining the 
lubricating oil 64 from the interior thereof when changing is required. 
It is to be understood that while I have illustrated and described a 
certain form of my invention it is not to be limited to the specific form 
or arrangement of parts herein described and shown.