Tool for removing seals

A hand-held tool that may be used to quickly and accurately push a seal from an opening in a housing without causing damage to the inside surface of the housing. The tool includes a shaft having a handle at one end and a working head at the opposite end. The working head includes an angled surface from which a tooth extends outwardly. The tooth is spaced away from the end of the head to form a tip. During operation, the adjacent contact surfaces of the tip and the tooth engage the edge of a ring seal, such that the tool is used to push the ring seal through the opening without damaging the interior surface of the housing.

FIELD OF THE INVENTION 
This invention relates generally to seals and, more specifically, to 
hand-held tools for removing ring seals. 
BACKGROUND OF THE INVENTION 
Ring seals are used in numerous applications in motorized systems, 
including in vehicles. For example, semi-rigid ring seals are commonly 
used in vehicle transmission assemblies to prevent the escape of 
transmission fluid from the system. The seal is disposed within an inside 
cavity of the housing to prevent the passage of fluid along the adjacent 
surfaces. During repairs or maintenance, such a seal must often be moved 
from its assembled position so that a mechanic may repair or perform 
maintenance operations on the associated vehicle system. As the seal is 
often disposed deep within a cavity of the housing, it can be extremely 
cumbersome and difficult to remove. Furthermore, other components of the 
system, such as bearings, may also be disposed within the cavity of the 
housing; such obstructions further complicate removal of the seal and 
disassembly of the system. Often, mechanics wedge screw drivers or other 
makeshift tools against the seal to force the seal through the housing. As 
these devices are not designed for use in this situation, they often slip 
from position against the seal and score or otherwise damage the interior 
surface of the housing cavity. Such damage to the interior surface results 
in fluid leakage past the seal in a reassembled system. As damage to the 
interior of the housing generally cannot be repaired, the entire housing 
must be replaced. Such replacement is extremely time consuming and, of 
course, costly. In certain vehicle systems, as with the replacement of a 
damaged transmission housing, this cost can be prohibitive. For example, 
replacement of a front-wheel drive transmission housing in an automobile 
can exceed several thousand dollars. Thus, an otherwise uncomplicated and 
relatively inexpensive repair may result in a costly replacement of the 
housing if an inappropriate tool is utilized. 
SUMMARY OF THE INVENTION 
It is the primary object of the invention to provide a tool which 
facilitates the removal of a ring seal from an inside cavity of a housing 
without damaging the interior surface of the housing. 
An additional object is to reduce the costs and potential costs associated 
with repairs which require the movement or removal of the seal from the 
inside surface of a housing. A related object is to reduce the time 
required to perform repairs which involve the removal of a seal. 
Another object is to provide a tool that permits easy access to seals 
disposed deep within a cavity or within a cavity having additional 
components assembled therein. 
Other objects and advantages of the invention will be apparent from the 
following detailed description. 
In accordance with the present invention, there is provided a hand-held 
tool for removing a seal from a cylindrical opening in a housing by 
impelling the seal through the opening. The tool has an elongated shaft 
with a grip at one end and a working head at the opposite end. The working 
head has a surface that is disposed at an angle to the axis of the shaft. 
An integrally formed tooth extends outward from the surface and is spaced 
away from the outward end of the head so that a tip is formed at the end 
of the head. The junction or intersection of adjacent surfaces of the lip 
and the tooth form a seal seat (or notch) for engaging an edge of the seal 
so that it can be pushed from its position in the housing. During usage, a 
mechanic aligns the tooth and the lip with the edge of the seal so that 
the lip seats along the inside diameter of the seal and the tooth abuts a 
side of the seal. Holding the tool handle, the mechanic then uses the tool 
to push the seal through the opening in the housing so that it may be 
removed from the opposite end. 
Because the tooth and lip firmly seat against an inside edge of the seal, 
the mechanic can steadily impel the seal through the opening in the 
housing without the tool slipping from position and damaging the interior 
surface of the housing. Inasmuch as the height of the tooth is less than 
the side dimension of the seal, there is no danger of the tooth scoring 
the interior surface of the housing. Consequently, the tool reduces the 
time required for performing repairs in that the mechanic can quickly 
remove the seal in order to perform maintenance on the system. 
These and other features and advantages of the invention will be more 
readily apparent upon reading the following description of a preferred 
embodiment of the invention and upon reference to the accompanying 
drawings, wherein:

DESCRIPTION OF THE PREFERRED EMBODIMENT 
While the invention will be described in connection with certain preferred 
embodiments, it will be understood that it is not intended to limit the 
invention to those specific embodiments. Rather it is intended to cover 
all such alternative embodiment, modifications and equivalents as fall 
within the spirit and scope of the invention as defined in the appended 
claims. 
Turning now to the drawings, and referring first to FIG. 1, there is shown 
a tool 10 for removing a ring seal from an opening in a housing. The tool 
10 comprises a grip portion or handle 12 from which an elongated shaft 14 
projects. Disposed at the end of the shaft 14 is a head 16. Holding the 
handle 12, a mechanic may place the head 16 against the seal and use the 
tool 10 to push the seal through the opening of the housing. 
The grip or handle portion 12 may be of any appropriate shape or material 
that provides a comfortable and steady feel for the mechanic. It may have 
a hand-formed shape or may be corrugated for a firm grip, as shown in the 
embodiment illustrated in FIG. 1. Further, the handle may be of material 
such as plastic or a hard rubber molded directly onto the shaft 14 or 
assembled onto the shaft 14 as a separate component. Alternately, the 
handle 14 may be integrally formed with the shaft 14 such that the entire 
tool 10 is formed of a single material. 
The shaft 14 may likewise be of any appropriate material or cross-sectional 
shape. In a preferred embodiment, the shaft is a hardened steel, which 
provides a rigid and durable extension of the handle 12. In order to 
facilitate easy access to a seal disposed deep within a housing or to 
which access is obstructed by other components of the system, the shaft 14 
may be angled or bent. For example, in the tool 10 shown in FIG. 1, the 
shaft 14 is bent to form a center angle of 20.degree.-25.degree. from 
linear and, thus, the tool is particularly suited for easy access to 
differential seals seated deep inside a transmission housing, access to 
which is obstructed by the saddle bearings. It will be appreciated that 
alternate angles may be appropriate for utilization of the invention in 
other assemblies. 
In accordance with the invention, the head 16 includes a surface 18 which 
is disposed at an angle to the axis 20 of the shaft 14 such that the head 
16 tapers to a distal end 16a of reduced size. A tooth 22, which extends 
outward from the angled surface 18, is spaced away from the distal end 16a 
of the head 16 to define a working tip. The adjacent contact surfaces of 
the tooth and the tip form a seal seat (i.e., notch) at the distal end of 
the head 16. During use, a mechanic positions the contact surface of the 
tip along the inside surface of the seal and the contact surface of the 
tooth along the side of the seal. As the notch formed at the junction of 
the tip and tooth firmly seats against the seal, the mechanic may apply 
force to the tool 10 along the axis of the housing opening to impel the 
seal from its assembled position. 
According to an important aspect of the invention, the head 16, shown in 
the enlarged side and end views of FIGS. 2 and 3, respectively, seats 
firmly and steadily against the seal to prevent inadvertent undesirable 
scoring of the inside surface of the housing. As shown in the enlarged 
side view of FIG. 2, surface 18 of the head 16 is disposed at an angle to 
the axis 20 of the shaft 14 so that the head 16 tapers toward the distal 
end 16a of the tool 10. Additionally, a tooth 22, which may be integrally 
formed with the head 16, extends outward from the angled surface 18. The 
tooth 22 is spaced inward from the end of the head 16 to define a tip 24. 
Adjacent surfaces 26, 28 of the tooth 22 and the tip 24 provide contact 
surfaces (i.e., a notch) into which the seal seats or abuts during use. 
During use of the tool, the tooth 22 and tip 24 are situated so that the 
edge of the seal 26 is engaged at the juncture of the contact surfaces 26, 
28, as shown in FIG. 4. Consequently, the head 16 (and, therefore, the 
tool 10) firmly seats against the seal such that it will not slip from 
position during usage. 
The structure and function of the head 16 may be more clearly described 
with reference to FIG. 4, which shows the head 16 of the tool 10 
positioned in an opening 30 of a housing 32. While use of the tool 10 is 
described with reference to a specific type of automobile system, it will 
be appreciated that the tool 10 may likewise be used to facilitate removal 
of any type of ring seal from the interior of a housing 32. 
When used to remove a semi-rigid ring seal 34 from the inside of a housing 
32 of an automobile front wheel drive transmission system, as illustrated 
in FIG. 4, the drive shaft 36 (shown in phantom in FIG. 4) is first 
removed from the housing. Grasping the handle 12, a mechanic then inserts 
the head 16 and shaft 14 of the tool 10 into the opening 30 previously 
occupied by the drive shaft 36. When the head 16 is properly positioned 
within the opening 30, the angled surface 18 should abut against the 
inside surface of the ring bearing 38 with the tooth 22 extending toward 
the inside wall of the opening 30 of the housing 32 between the bearing 38 
and the seal 34. Furthermore, when properly positioned, the contact 
surfaces 26, 28 of the tooth 22 and tip 24 substantially abut the inside 
surface 40 and side 42 of the ring seal 34. Grasping the handle 12, the 
mechanic then moves the tool 10 in the axial direction of the housing 
opening 30 (as indicated by the arrow in FIG. 4) to impel the seal 34 
through the opening 30 in the housing 32 so that it may be removed from 
the opposite end. The mechanic is then free to remove the remaining 
components of the system from the inside of the housing 32. For example, 
the snap ring 44 and bearings 38 may be removed as maintenance of a 
transmission system requires. 
According to an important aspect of the invention, the tooth 22 and the tip 
24 are configured so as to substantially conform to the inside surface 40 
and edge of the ring seal 34 to ensure that the tool 10 seats firmly 
against the seal 34. Consequently, and as shown in FIG. 3, the radius of 
the contact surface 28 of the tip 24 depends upon the inside radius of the 
particular seal 34 for which the tool 10 is designed. As will be readily 
appreciated, the inventive tool may be manufactured in various sizes to 
accommodate ring seals of different sizes. For a proper fit, the radius of 
the surface 28 should be substantially the same as or slightly smaller 
than the inside radius of the seal 34 to ensure good contact. 
Similarly, the angled surface 18 may also be arcuate so that it 
substantially conforms to the inside surface of the housing 32 in which 
the seal 34 is seated. Alternately, the angled surface 18 may 
substantially conform to the inside surface of other components of the 
system, such as the bearing 38 shown in FIG. 4. Accordingly, the head 16 
mates well with the inside diameter of the bearing 38, and the contact 
surface 28 of the tip 24 may be easily positioned along the inside surface 
of the seal 34. 
In order to further provide easy and proper positioning of the head 16 
within the housing 32, the tooth 22 may be of a wedge shape, tapering as 
it extends outward from the angled surface 18. In this way, the relatively 
sharp edge of the tooth 22 may be reliably positioned between the bearing 
38 and the seal 34, as shown in FIG. 4. According to an important aspect 
of the invention, the height of the contact surface 26 of the tooth 22 (as 
represented by the letter A in FIG. 2) is smaller than the side dimension 
of the seal 26 (as represented by the letter B in FIG. 4). In this way, 
when the head 16 of the tool is properly seated against the seal 34, as 
shown in FIG. 4, the tooth 22 is spaced apart from the inside surface of 
the housing and cannot score the inside surface as the mechanic impels the 
seal 34 through the opening 30. 
It can be readily appreciated that the design of tooth 22 (along with its 
relationship to the contact surface 28 of the tip 24 and the angled 
surface 18 of the head 16) are dependent upon the relative dimensions (and 
the relationship) of the seal 34 to the bearing 38. The shape of the tooth 
22, including the dimensions (designated as the letters A and C in FIG. 2) 
of the surfaces 26, 46 and the angles at which the surfaces 26, 46 lie 
with respect to surface 28 of the tip 24 and the angled surface 18, should 
be such that the surfaces 18, 46, 26, 28 seat or abut against the inside 
and side surfaces of the seal 34 and bearing 38, as shown in FIG. 4. This 
results in proper positioning of the head 16 to ensure solid seating 
against the seal 34 and smooth removal thereof. 
As can be seen from the foregoing detailed description, the present 
invention provides a hand-held tool that may be utilized to quickly and 
accurately push a seal from an opening in a housing. The design of the 
inventive tool permits easy access to seals that are disposed deep within 
a housing or within a housing which has additional obstructions (such as 
bearings) therein, and facilitates removal of such seals without damaging 
(i.e., scoring) the inside surface of the housing.