Hand operable tool used in installing piston assemblies into an engine block

A hand operable tool (10) used in installing pistons and piston rod assemblies (PR) into an engine block (EB) includes magnets (170, 172,232) for securing the device to the engine block and engine dowel pin receiving holes (190,226) for receiving cylinder head dowel pins (200) to accurately and precisely orient and position the tool with respect to an engine block cylinder bore. A method of installing pistons and piston rod assemblies into an engine block utilizing the hand operable tool is also disclosed.

DESCRIPTION 
1. Technical Field 
The present invention relates, in general, to installing piston and 
connecting rod assemblies into an engine block, and, more particularly, to 
a tool and method used in the process of compressing piston rings around 
pistons and introducing piston assemblies into engine block cylinder 
bores. 
2. Background Art 
The introduction of a piston assembly into a cylinder bore of a combustion 
engine is a complex and awkward process wherein the piston rings must be 
compressed and seated while the piston assembly is maintained properly 
oriented and positioned with respect to the engine block cylinder bore. 
The inherent awkwardness of the parts being handled, as well as the 
necessity of compressing the piston rings into grooves in the piston with 
a substantial degree of pressure while simultaneously introducing the 
piston assembly into the engine block cylinder bore, creates problems in 
handling and coordination of tools which have not been adequately solved 
by presently known devices. 
The problems associated with the complexity and awkwardness of the process 
of installing a piston assembly into an engine block cylinder bore are 
aggravated by a requirement that the installation process be carried out 
without damaging any of the parts being assembled that might cause blow-by 
conditions. Therefore, extreme care must be taken not to damage any of 
these elements as blow-by may detrimentally affect engine efficiency and 
performance. 
While piston assembly installation can be automated, such as disclosed in 
U.S. Pat. No. 3,952,393 to von Ravenzwaay et al, such machinery tends to 
be complex, expensive to install and difficult to maintain in a proper 
operating condition. One particular problem associated with automated 
machinery involves the extreme difficulty in achieving accurate 
orientation and positioning of a piston assembly with respect to an engine 
block cylinder bore during the installation step. In fact, machinery used 
in such automated processes is generally designed to tolerate some spatial 
variation between magazines holding the piston assemblies and the engine 
block cylinder bores. Establishing low tolerances for the spatial 
variation in automated process machinery may be extremely expensive, and 
furthermore, may not be maintained during successive operating cycles. 
Many of the problems discussed above in connection with automated processes 
used in installing piston assemblies into an engine block cylinder bore 
can be avoided by using hand operable tools, such as those tools disclosed 
in Winter U.S. Pat. No. 861,342, Linton, U.S. Pat. No. 1,458,067, Koza, 
U.S. Pat. No. 1,892,989 and Wenk et al U.S. Pat. No. 2,716,272. However, 
the presently known hand operable tools, while not being subject to many 
of the problems associated with those devices used in automated piston 
assembly installation processes, have their own problems which have 
militated against the acceptance of and further development of these 
tools. For example, a great deal of manual dexterity is required of an 
assembler to coordinate all of the motions and equipment involved in the 
installation of piston assemblies into an engine block using these known 
hand operable tools, and this severely disadvantages them with respect to 
automated processes. Known hand operable tools often require a piston 
pusher to install a piston assembly in an engine block, and thus an 
assembler must coordinate two tools as well as the piston assembly during 
the installation process. The problems arising as a result of such 
multi-device coordination are evident, and the dexterity and coordination 
skills required to operate these known hand operable tools must be 
acquired thereby necessitating some sort of assembler training. Such 
assembler training may be expensive in terms of time as well as in terms 
of economics, and some assemblers will still not be able to execute the 
installation process steps as well as others thereby creating problems in 
producing products of uniform quality. 
Still a further, and perhaps most serious, drawback to known hand operable 
piston assembly installation tools arises because such tools usually have 
no means for accurate orientation and support with respect to the engine 
block cylinder bore. The accuracy of orientation and placement is 
dependent upon the skill and eye of the assembler, and can then be lost 
due to the lack of means for supporting the hand operable tool once it has 
been located and oriented thereby creating problems of uniform production 
as well as the above discussed acquired-skill related problems. In 
addition, the lack of any orienting and supporting means on known hand 
operable tools slows the installation process as an assembler must orient 
and support the tools while manipulating all of the elements associated 
with the piston assembly installation process. 
Most designers of prior art hand operable tools have been concerned with 
the ease with which the piston rings can be seated, and have not tended to 
recognize that a problem may arise because the tools cannot be accurately, 
reliably, precisely and easily oriented and supported with respect to the 
engine block cylinder bore. Since such problems have not been generally 
recognized, the prior hand operable tools certainly do not account for 
such problems. 
Accordingly, there is need for a hand operable tool used in installing 
piston assemblies into an engine block which overcomes the problems of the 
known hand operable tools so that hand operable tools can be used to 
install a piston assembly into an engine block while meeting the 
requirements of modern engine technology and manufacture. 
DISCLOSURE OF THE INVENTION 
It is a primary object of the present invention to provide a novel and 
improved hand operable tool and method used in installing a piston in an 
engine block which permits accurately and precisely orienting and locating 
a piston assembly with respect to an engine block cylinder bore and which 
has the hand operable tool attachable to the engine block. The hand 
operable tool includes mounting means thereon for attaching the apparatus 
to an engine block and accurately and precisely orienting and locating the 
hand operable tool with respect to an engine block cylinder bore. Accurate 
and precise location and orientation of the hand operable tool is 
automatically accomplished by the attaching means on the tool and thus 
there is no need to depend on the skill of an assembler for establishing 
an accurate and precise position and orientation of the hand operable 
tool. Furthermore, the mounting means frees the assembler's hands so he 
can perform additional tasks. The awkwardness and complexity associated 
with prior hand operable tools is removed by the mounting means of the 
hand operable tool embodying the present invention. The mounting, 
orientation and locating of the presently disclosed tool can be effected 
using essentially one single motion, and thus, the piston assembly process 
is expeditiously carried out even by an unskilled laborer. 
It is a further object of the present invention to provide a novel and 
improved hand operable tool and method used in installing a piston in an 
engine block wherein the tool can be quickly and easily attached to an 
engine block without endangering the piston, the piston rings, the engine 
block or the engine block adjacent to the cylinder bore. The hand operable 
tool of the present invention includes a pair of movable jaw portions each 
having thereon means for receiving an engine dowel pin and at least one 
permanent magnet. The magnets attach the tool to the engine block in a 
stable manner, and the means receiving the engine dowel pins are located 
on the tool to accurately and precisely position and orient that tool with 
respect to an engine block cylinder bore when the tool is in the closed 
configuration. The tool includes handles and a hinge which control the 
movement of a pair of movable jaw portions. The jaw portions surround 
piston seated piston rings to compress those piston rings against the 
piston with sufficient pressure to properly seat those piston rings on the 
pistons. 
It is yet a further object of the present invention to provide a novel and 
improved hand operable tool and method used in installing a piston in an 
engine block which permits a piston assembly to be moved into an engine 
block cylinder bore by hand. The need for a piston pusher is eliminated, 
along with the disadvantages associated with such tool. 
It is still another object of the present invention to provide a novel and 
improved hand operable tool and method used in installing a piston in an 
engine block wherein the tool is automatically locked in a piston-ring 
compressing configuration. The hand operable tool of the present invention 
includes a self-closing lock located on handles used to manipulate the 
tool. The self-closing lock is adapted to close when the tool has been 
properly positioned around piston mounted piston rings thereby freeing an 
assembler's hands to manipulate the tool. The self-closing lock includes a 
swing arm on one handle with the swing arm being designed to close about a 
latch pin located on another handle as soon as the tool is in a 
configuration to compress piston rings with a proper amount of force. In 
this manner, errors resulting from the exertion of too much or too little 
force on the piston rings will be avoided. 
It is another object of the present invention to provide a novel and 
improved hand operable tool and method used in installing a piston in an 
engine block wherein the tool causes the piston mounted piston rings to be 
compressed gradually as the piston assembly is advanced into an engine 
block cylinder bore through the tool. The hand operable tool has a tapered 
bore which is chrome plated to reduce ring friction and surface wear. The 
tool therefore reduces the possibility of damaging the piston rings and is 
long lived due to the wear coating. The tapered bore is designed and 
shaped to compress the piston rings with the proper amount of force when 
the hand operable tool is in a closed configuration. The taper of and 
coating on the tool assist the hand installation of the piston assembly. 
It is another object of the present invention to provide a novel and 
improved hand operable tool and method used in installing a piston in an 
engine block wherein a piston-piston rod assembly having piston rings 
thereon can be initially located by hand in an engine block cylinder bore 
prior to seating the piston rings on the piston. Lubricating and 
positioning the piston rings can also be carried out prior to compressing 
the piston rings. Once the piston rings have been lubricated and 
positioned, the tool of the present invention is manually operated to 
place a pair of movable jaw portions in locked configuration around the 
piston rings to compress those rings. The tool has means for accurately 
and precisely orienting and placing the piston assembly with respect to 
the engine block cylinder bore and for securing the tool to the engine 
block. Once the tool is secured to the engine block, the piston assembly 
is accurately and precisely oriented and positioned with respect to the 
engine block cylinder bore and the piston assembly is easily advanced into 
the engine block cylinder bore by hand. 
These objects are accomplished by providing a hand operable tool and method 
used in the manual installation of piston assemblies into an engine block 
wherein a plurality of permanent magnets and a plurality of engine dowel 
pin receiving holes are located on the tool for accurately and precisely 
orienting, locating and supporting the tool on an engine block. Cylinder 
head dowel pins are received in bushings located in the engine dowel pin 
receiving holes as the permanent magnets pull the tool towards the engine 
block to orient and locate the tool with respect to the engine block 
cylinder bore with extreme accuracy and precision. The permanent magnets 
then affix the accurately and precisely oriented and positioned tool to 
the engine block. The tool has a self-closing lock to lock the tool in the 
piston ring compressing configuration and the tool has a coated tapered 
bore through which the piston and piston rings pass when being installed 
into the piston cylinder bore of the engine block via a closed tool. The 
self-closing lock locks the hand operable tool in the closed configuration 
thereby freeing the assembler's hands to carry out other tasks. A method 
of installing a piston assembly into an engine block using the hand 
operable tool includes steps of locating a piston having piston rings 
thereon in an engine block, surrounding the just-located piston assembly 
with the hand operable tool and then mounting the hand operable tool on an 
engine block in accurate and precise orientation and placement with 
respect to the engine block cylinder bore. Appropriate lubrication and 
piston ring placement can be carried out prior to surrounding the piston 
and piston rings with the hand operable tool. Preferably, the hand 
operable tool and method of the present invention are applied to 
installing piston assemblies into engine blocks of diesel engines.

BEST MODE FOR CARRYING OUT THE INVENTION 
A tool 10 is hand operable and is shown in FIGS. 1-4 as including a pair of 
jaw portions 12 and 14 pivotally connected together by a hinge 16 and 
having handles 18 and 20 respectively thereon for moving the jaw portions 
12 and 14 together around a piston to compress piston rings with 
sufficient force to properly seat those piston rings on the piston. Each 
of the jaw portions 12 and 14 has an entrance section 30 and an exit 
section 32, with entrance and exit locations being taken with reference to 
the movement of a piston through the tool 10 into an engine block cylinder 
bore. A mounting means 40,40' attaches the tool 10 to an engine block, and 
accurately and precisely orients and locates the tool 10 with respect to 
the engine block cylinder bore so that an assembler's hands are free for 
moving a piston assembly surrounded by the tool 10 into the engine block 
cylinder bore, and the assembler need not support the tool 10 while 
coordinating other tools and activities. However, the mounting means 
40,40' maintains the piston assembly oriented and positioned with respect 
to that cylinder bore with extreme accuracy and precision. 
Each of the jaw portions 12 and 14 is semi-circular in peripheral shape 
(FIG. 4) and includes a surface 44 which is the inner surface of the 
respective jaw portion when the tool 10 is closed and which tapers from an 
entranceway 46 connecting the surface 44 to an entrance section rim 48 to 
a shoulder 50 which connects the tapered section of the surface 44 to a 
cylindrical section 54 which extends to an exit section rim 56. The exit 
section rim 56 is located to be adjacent to an engine block surface when 
the tool 10 is operatively mounted on an engine block. The surface 44 is 
coated to reduce piston ring friction and surface wear, and is preferably 
chrome plated. The taper of surface 44 of jaw portions 12 and 14 causes 
piston rings seated on a piston being advanced through a closed tool to be 
gradually compressed as a piston assembly is moved into an engine block 
cylinder bore liner through tool 10. The length of the tapered section of 
a closed tool 10, as measured from the entrance section rim 48 to the 
shoulder 50, as well as the diameter defined by the tapered section at any 
location thereon, is selected to establish proper piston ring compressing 
force against a surrounded piston ring while permitting movement of the 
piston assembly into the entranceway 46, through the closed tool 10, then 
to and through the exit section 32 of the tool 10. 
Each of the jaw portions 12 and 14 includes end edges 60 and 62 extending 
from the entrance section rim 48 to the exit section rim 56. The end edge 
62 of jaw portion 12 is spaced from the corresponding end edge 62 of the 
jaw portion 14 to establish a gap 66 when the tool 10 is in the closed 
configuration so the jaw portions 12 and 14 can be hingeably moved with 
respect to each other into an open configuration for the tool 10 as shown 
in FIG. 3. The end edges 60 and 62 have rounded shoulders 68 and 70 so 
that there are no sharp edges located within the circumference of the tool 
10 in the closed configuration. Sharp edges may damage a piston ring as a 
piston assembly is moved through that tool 10, thereby creating a 
condition wherein blow-by may occur. 
The hinge 16 includes a pair of hinge leaves 71 and 72 attached, as by 
welds 74 and 76, or the like, to surfaces 78 and 80 of the jaw portions 12 
and 14 respectively. The surfaces 78 and 80 define the outer surfaces of 
the jaw portions 12 and 14 respectively when the tool 10 is closed. The 
hinge 16 further includes a barrel portion 84 having a liner located 
therein and a pivot pin 88 mounted in the liner. The hinge 16 is mounted 
on the tool 10 to straddle jaw portion end edges 62 and gap 66 so the tool 
10 can be closed with the hinge 16 located beneath a cylindrical piston 
oriented to have the longitudinal axis thereof extending horizontally, 
whereby the horizontally oriented piston can be supported in the tool 10 
as that tool is being closed about that horizontally oriented piston. 
Manipulation of the tool 10 with the hinge 16 located beneath a 
horizontally oriented piston is easier than if the hinge 16 were located 
to be above or beside such horizontally oriented piston. It is to be noted 
that while the disclosed orientation for a piston assembly installed using 
the tool 10 is horizontal, such orientation is not to be considered as 
limiting. 
Each of the handles 18 and 20 is elongate and includes a foot section 90 
attached, as by welds 92, or the like, to the jaw portion outer surfaces 
78 and 80, and a hand grip 94 on the end of the handle remote from the 
foot section 90. The hand grip 94 of each handle includes a pair of 
knurled sections 96 and 98 connected together and to the handle by 
fastening means, such as socket head screws 99. The handles are used to 
move the jaw portions 12 and 14 toward and away from each other, and are 
mounted on the jaw portions 12 and 14 in a location to make the tool 10 
balanced and easily manipulated. 
A self-closing lock 100 includes a swing arm 102 pivotally mounted on 
handle 18 by a pivot pin 104 and a latch pin 108 affixed to handle 20 and 
passing through that handle 20 to extend outwardly of the handle 20 on 
both sides of that handle. The swing arm 102 includes a proximal end 110 
attached to the pivot pin 104 and a split distal 112 having a first side 
portion 114 which is located on the entrance side of the tool 10, and a 
second side portion 116 which is located on the exit side of the tool 10. 
As can be seen by comparing FIGS. 1 and 2, the handle 20 is sandwiched 
between the first side portion 114 and the second side portion 116 when 
the lock 100 is closed. Arcuate slots 120 are defined in the swing arm 
distal end side portions 112 and 114 and extend from a swing arm edge 124 
along an arc centered at a position which is near the pivot pin 104 when 
the swing arm is mounted on that pivot pin 104 so the slots 120 in each 
side portion 114 and 116 are oriented to properly and smoothly receive the 
latch pin 108 during a lock closing operation. The swing arm 102 is 
weighted and mounted to be biased to swing into a latch pin engaging 
position to close lock 100 when the jaw portions 12 and 14 of the tool 10 
are closed sufficiently to exert the proper amount of force on piston 
rings captured in the tool 10. This self-closing feature of the lock 100 
permits an assembler to use both hands to manipulate the tool 10 to 
properly compress piston rings on a piston. 
The mounting means 40 includes a pair of boot-shaped members 150 and 152 
mounted on the jaw portions 12 and 14 respectively. Each of the mounting 
members 150 and 152 includes a heel section 156 and a toe section 158 with 
the heel sections of the members 150 and 152 being formed and shaped to be 
in abuttment when the tool 10 is in the closed configuration. Each of the 
mounting members 150 and 152 includes a first face 160 located on the 
entrance side of the tool 10 and a second face 162 located on the exit 
side of the tool 10, with the face 162 being flush with the exit section 
rim 56 of the jaw portions 12 and 14 to be located adjacent to an engine 
block when the tool 10 is in an operative position on the engine block. As 
best shown in FIGS. 2 and 4, the mounting members 150 and 152 have 
permanent magnets 170 and 172 respectively mounted thereon in the toe 
sections 158. The magnets 170 and 172 are cylindrical and are accommodated 
in bores such as bore 174, defined in the mounting member toe sections 158 
and are held in place by fasteners, such as set screw 180 and hex nut 182. 
The permanent magnets 170 and 172 extend beyond face 162 of each of the 
mounting members 150 and 152 to have engine block engaging faces 186 which 
are coplanar with each other and which are spaced from a plane containing 
the tool exit section 30 so the faces 186 of the magnets 170 and 172 
engage an engine block while the exit section 30 of the tool is spaced 
from that engine block. 
In addition to the magnets 170 and 172, the mounting member 150 of the 
mounting means 40 includes a hole 190 defined therein adjacent to the heel 
section 156 of the mounting member 150 to receive a cylinder head dowel 
pin when the tool 10 is located closely adjacent to an engine block. A 
bushing 192 having a cylindrical tubular body 194 is securely seated on 
the mounting member 150 in the hole 190 and is sized to snugly engage a 
cylinder head dowel pin 200 at the outer side surface 200 of that engine 
dowel pin 200. There are a plurality of cylinder head dowel pins 200, and, 
as best shown in FIG. 6, each of the cylinder head dowel pins 200 includes 
a chamfer 204 which extends from distal end 206 of the cylinder head dowel 
pin 200 to the outer side surface 202 thereof and defines a diameter less 
than the diameter defined by the inner surface of body 194 of the bushing 
192. The purpose of this relative sizing for the bushing 192 and the 
engine dowel pins 200 will be discussed below. 
The mounting means 40' includes boot-shaped mounting members 220 and 222 
located on the tool 10 adjacent to the hinge 16. The mounting member 222 
includes a toe section 224 having a cylinder head dowel pin receiving hole 
226 defined therein and a heel section 228 located to be adjacent to the 
end edges 62 of the jaw portions 12 and 14 when the tool 10 is closed. The 
mounting member 220 includes a toe section 230 having a permanent magnet 
232 mounted thereon in a manner similar to the above-disclosed mounting of 
the magnets 170 and 172 on the mounting members 150 and 152. The mounting 
member 220 further includes a heel section 236 located to be adjacent to 
the end edges 62 of the jaw portions 12 and 14 when the tool 10 is closed. 
The magnet 232 is cylindrical, is similar to the magnets 170 and 172 and 
includes an engine block engaging face 240 which is coplanar with engine 
block engaging faces 186 of the permanent magnets 170 and 172 and is 
spaced from the plane containing the exit section 30 of the tool 10 a 
distance equal to the spacing between the engine block engaging faces 186 
of the magnets 170 and 172 and the exit section rim 56 so all of the 
magnets 170, 172 and 232 can engage the engine block and hold the tool 10 
so that the plane containing the exit section rim 56 of the tool 10 is 
parallel to the engine block surface to which the tool is secured. 
The mounting member 222 has a bushing 246 seated thereon in the cylinder 
head dowel pin receiving hole 226 The bushing 246 includes a cylindrical 
tubular body 248 which engages the outers side surface 202 of a cylinder 
head dowel pin 200 in a member similar to that discussed for the 
engagement of a cylinder head dowel pin 200 in the bushing 192 located in 
engine dowel pin receiving hole 190. 
As can be seen in the figures, and in particular, FIGS. 1 and 5, with 
respect to a closed tool 10, the engine dowel pin receiving hole 190 is on 
one side of a line extending through jaw portion end edges 60 and along a 
diameter of such a closed tool, and the engine dowel pin receiving hole 
226 is on the other side of that line. As will be evident from this 
disclosure, such relative positioning of the engine dowel pin receiving 
holes 190 and 226 contributes to the stability with which a tool 10 is 
held affixed to an engine block. 
The permanent magnets 170, 172 and 232 attach the tool 10 to the engine 
block and are powerful enough to strongly attract the tool 10 toward that 
engine block when the tool 10 is positioned near the cylinder head dowel 
pin distal ends 206 but is still spaced from the engine block. Since the 
distal ends of the cylinder head dowel pins 200 are chamfered, there is 
some margin of error for the alignment of the tool 10 with respect to 
these cylinder head dowel pins 200. However, once the cylinder head dowel 
pins 200 are received in the bushings 192 and 246, and the tool 10 is 
moved toward the engine block manually and under the influence of the 
magnets 170, 172 and 232, the cylinder head dowel pin outer side surfaces 
202 will engage the bushing tubular bodies 194 and 248 to move the tool 10 
into a precise and exact orientation and position on the engine block. 
Thus, the engine dowel pin receiving holes 190 and 226 are machined in the 
mounting members 150 and 220 at positions on the movable jaw portions 12 
and 14 to cause those jaw portions 12 and 14 to be precisely and 
accurately located and oriented with respect to an engine block cylinder 
bore when cylinder head dowel pins 200 are fully engaged and received in 
the bushings 192 and 246 mounted in those dowel pin receiving holes 190 
and 232. 
It is, therefore, clear from the foregoing disclosure that the mounting 
means magnets 170, 172 and 232 secure the tool 10 to the engine block, 
and, while the tool 10 is being thus secured, that tool 10 is being 
accurately and precisely oriented and positioned relative to the engine 
block cylinder bore by the engagement of cylinder head dowel pins 200 and 
the bushings 192 and 246. In this manner, mounting means 40, 40' effects 
accurate and precise orientation and positioning as well as secure 
attachment of the tool on the engine block in one movement of the tool 10. 
Thus, an assembler need only move the tool 10 into an approximate position 
and orientation with respect to an engine block cylinder bore, then allow 
the magnets 170, 172 and 232 and the bushings 192 and 246 to guide the 
tool 10 into the proper position and orientation on the engine block, as 
the engagement of cylinder dowel pins 200 in the bushings 192 and 246 
corrects any errors in alignment, orientation and positioning of the tool 
10 with respect to the desired alignment, orientation and position on the 
engine block. Once the tool 10 is secured to the engine block, the 
assembler's hands are completely free to carry out other tasks associated 
with the installation of a piston assembly into an engine block. 
Furthermore, accurate and precise alignment and orientation of tool 10 on 
the engine block is not dependent on the skill, eye or dexterity of the 
assembler, and an unskilled worker can produce extremely accurate and 
precise placement of tool 10 with the same facility as can a skilled 
assembler. In fact, an unskilled worker can orient and locate the tool 10 
with respect to an engine block cylinder bore to within a tolerance of 
plus or minus axes system having an origin at the center of an engine 
block cylinder bore and being located in a plane containing the engine 
block surface to which the tool 10 is attached. 
The installation of a piston and piston rod assembly into an engine block 
EB having a cylinder liner CL is illustrated in FIGS. 7-9, and attention 
is directed thereto. A plurality of piston and piston rod assemblies PR 
can be located convenient to an assembler and can be placed in an engine 
block EB by hand. The assemblies are shown in FIG. 9 to be next to an 
engine block EB, but can be in any other convenient location as necessary. 
The assemblies PR can be left resting on the engine block EB while the 
other steps are carried out if necessary as indicated in FIG. 7. Piston 
rings P of placed piston assemblies PR are lubricated and positioned, and 
a tool 10 is positioned with the jaw portions 12 and 14 thereof 
surrounding the piston and piston rings of the piston rod assembly PR. The 
tool 10 is closed by manually moving the handles 18 and 20 together until 
the self-closing lock 100 closes to lock the tool in a piston ring 
compressing configuration. 
The tool 10 with a piston assembly PR therein is moved toward the engine 
block EB, and the magnets 170, 172 and 232 pull the tool toward the engine 
block EB while the cylinder headed dowel pins 200 engage the bodies of 
bushings 192 and 246 to accurately and precisely orient and position the 
tool 10 and the piston assembly PR with respect to the engine block 
cylinder bore. The magnets then secure the tool 10 to the engine block EB, 
and the assembler is not required to hold onto the tool 10 so his hands 
are free for other tasks. 
As shown in FIG. 9, the assembler then presses the piston and piston rod 
assembly PR into the engine block cylinder liner CL by hand via the tool 
10 which causes the piston rings P to be gradually compressed as the 
piston passes through the tapered bore defined by the closed jaw portions 
12 and 14 of the closed tool 10. The piston assembly PR is inserted into 
the engine block cylinder bore to a proper position with a connecting rod 
bearing B seated on a crankshaft journal J (FIG. 5), and rod cap bolts 
(not shown) are then torqued into position to complete the installation of 
the piston and rod into the engine block EB. 
INDUSTRIAL APPLICABILITY 
This invention has particular utility to the installation of piston 
assemblies into an engine block of a diesel engine and, most specifically, 
a Cummins K series engine manufactured by the Cummins Engine Co. of 
Columbus, Ind., but can be useful for installing pistons in an engine 
block of any combustion engine. Furthermore, the hand operable tool 
embodying the present invention can be used in the installation of piston 
assemblies in engine blocks wherein the engine block piston cylinder is 
not horizontally oriented during the installation process, and the engine 
block cylinder bore can be oriented so the piston assembly is vertically 
oriented during the installation process as well as any orientation 
between horizontal and vertical without departing from the scope of the 
present disclosure. Other types of securing means can be used in place of 
the permanent magnets, such as electromagnets, or the like, also without 
departing from the scope of the present disclosure.