Drive apparatus for one or more supplemental apparatuses driven by an internal combustion engine

A drive shaft for driving supplemental apparatuses is disposed in or penetrates an oil pan disposed under an engine in order to provide a compact supplemental apparatus layout or arrangement. In the oil pan, a supplemental apparatus drive unit, including the drive shaft, an idle gear meshing with an output gear fixed on an engine crankshaft, and a chain for transmitting drive power from the idle gear to the drive shaft, is supported, and is simultaneously assembled so as to be linked with the idle gear and the output gear when the oil pan is assembled to the engine. The output gear is preferably fixed on the inner side of an endmost journal of the crankshaft to reduce vibrations from the crankshaft. Moreover, providing a damper associated with the output gear fixed to the crankshaft reduces the vibrations from the crankshaft. By providing supplemental appartuses on both ends of the drive shaft, by placing an oil pump near an oil filter, and by placing the oil pump in the oil pan and a water pump out of the oil pan, a compact engine and supplemental apparatus structure, a low oil flow resistance, a reduction in the number of required parts, and so on, are produced.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a drive apparatus for one or more supplemental 
apparatuses driven by an internal combustion engine. 
Supplemental apparatuses used in conjunction with an automotive vehicle 
engine are generally driven by power produced by the engine. Consequently, 
in order to realize maximum performance and use available space 
efficiently, both the structure linking the engine and the supplemental 
apparatuses and the layout of the engine and the supplemental apparatuses 
are very important. 
Typically, in an engine and supplemental apparatus combination, a compact 
supplemental apparatus having a low drive load requirement, such as an oil 
pump for a lubrication and/or a water pump, is disposed near a front end 
of the engine and is directly linked to, or otherwise engaged via gearing 
with, a crankshaft of the engine. By contrast, a supplemental apparatus 
having a high drive load requirement, such as a power steering pump, a 
compressor for an air conditioner, and/or an alternator, is typically 
disposed on a side of the engine and near either a front end or a rear end 
of the engine. This type of supplemental apparatus is also typically 
driven by a belt or a chain connected with an end of the engine 
crankshaft. 
2. Description of Related Art 
As described in, for instance, the specification of West German Patent 
Publication No. 3,838,073, an engine may be mounted at a backward slant or 
a tilt so that it leans toward a rear end of a vehicle. The engine of the 
disclosure of this publication is mounted parallel to a transmission so as 
to extend transversely of the body of the vehicle, and has a supplemental 
apparatus disposed in a space located in front of the engine. This space 
is formed by the backward slant or tilt of the engine. A belt, linked to 
the engine crankshaft, drives the supplemental apparatus disposed in the 
space located in front of the engine. 
There is a demand to compactly mount the supplemental apparatus in the 
volume available for the engine. Such a demand is met by using an unused 
space, which is located at a front or rear side of an oil pan of the 
engine. In order to locate the supplemental apparatus in the dead or 
unused space around the oil pan, however, it is necessary to reinforce a 
supporting portion or bearing of the supplemental apparatus in order to 
provide it with a sufficient rigidity to resist tension applied by the 
belt. It is also necessary to provide a space in which to locate a drive 
shaft, which links the supplemental apparatus with the engine crankshaft. 
These requirements undesirably force the volume of the oil pan to be 
reduced; therefore, the volume of oil available to the engine may be 
insufficient in some cases. Consequently, as is clear from the 
specification of the West German publication mentioned above, it is 
difficult to receive the supplemental apparatus in the dead or unused 
space around the oil pan in the desired manner. Another requirement is 
that it must be possible to assemble the supplemental apparatus to the 
engine readily. More particularly, in order to assemble a plurality of 
supplemental apparatuses and their drive mechanism to the engine in a 
fully automated assembling line, it is essential to provide the 
supplemental apparatuses and their drive mechanism as a single unit. 
However, it is difficult to unite conventional belt-driven supplemental 
apparatuses and their drive mechanism as a single unit. In addition, for 
such belt-driven supplemental apparatuses, it is also essential to improve 
the structural rigidity of a supporting element or supporting elements for 
the drive shaft, due to the presence of a considerably increased belt 
tension. Providing such a supporting element or supporting elements, 
however, results in both an increased engine weight and the occurrence of 
some vibrations. 
Particular problems associated with an oil pump of an engine of the prior 
art also exist. In a layout of a supplemental apparatus and its drive 
mechanism according to the prior art, an oil passage or "sub-gallery" 
between the oil pump and its associated oil filter is required to be 
relatively long. As a result, a loss of pressure is present in the 
sub-gallery. This is because the oil pump is generally disposed near a 
crankshaft and is driven by the crankshaft through gearing. Further, 
because a limited space is present, it is difficult for an oil filter to 
be located near both the oil pump and the crankshaft. Disposing the oil 
pump and its associated oil filter separately from each other results in a 
long distance between the oil pump and the oil filter and in an increased 
oil flow resistance, or pressure loss. 
The layout of the oil pump cannot be considered alone without also 
considering the layout of a water pump, which also serves as a 
supplemental apparatus. Both the oil pump and the water pump provide a low 
load to drive, as mentioned above, and the oil pump and the water pump can 
be provided close to each other in a layout. In order to provide a compact 
supplemental apparatus layout and drive as many of the supplemental 
apparatuses as possible by a single drive shaft, at least the oil pump and 
the water pump must be driven by the same drive shaft and disposed inside 
the oil pan. The number of bearings for these pumps should also be reduced 
so that no more of these bearings than are necessary are provided. 
Additionally, the oil pump should be disposed in a location in which an 
oil leak will never happen. It is important for a compact and satisfactory 
layout of the supplemental apparatuses to satisfy all these conditions or 
considerations. 
In an arrangement such as that described above, a flywheel of the engine is 
generally connected to rear end of the crankshaft at which a clutch is 
coupled. A pulley for driving a supplemental apparatus, through a belt, is 
generally fixed at a front end of the crankshaft, opposite to the end of 
the crankshaft which is connected with the clutch. Furthermore, the pulley 
on the front side of the crankshaft may have a built-in damper mechanism 
which dissipates twisting vibrations of the crankshaft. Since the pulley 
on the front end of the crankshaft itself typically has considerable 
weight, putting the damper in the pulley so as to surround an axis 
portion, or a portion around the center axis of the pulley, and an outer 
mass portion, or an outside ring portion, helps damp the crankshaft 
against twisting vibrations. The damper may, for example, be formed of an 
elastic member made of rubber. The amplitude of the twisting vibrations is 
at a maximum on the front end of the crankshaft, while a vibration node is 
located at the rear end of the crankshaft on which the flywheel is mounted 
and connected to the transmission via the clutch. Consequently, the 
twisting vibration of the crankshaft is effectively dissipated by the aid 
of the pulley on the front end of the crankshaft, which drives the 
supplemental apparatus. 
The provision of such a damper in a pulley mounted on the front end of the 
crankshaft is effective in dissipating twisting vibrations, but is 
ineffective for dissipating bending vibrations of the crankshaft. Because 
the crankshaft bends between the journals, especially at its rear end 
portion where the flywheel is attached, due to vibrations of the rearmost 
end cylinder, it causes the flywheel t o vibrate, so that bending of the 
crankshaft increases noise and is produced. Accordingly, providing the 
damper on the front end of the crankshaft, located far from the rear end 
thereof, where bending is the most serious, cannot effectively reduce the 
bending vibration. In addition, although the damper on the front end of 
the crankshaft lessens the vibrations of the crankshaft more effectively 
as it is made heavier, since a natural frequency of the damper is lowered 
with an increase in weight of the flywheel, the range of vibrations of the 
crankshaft which can be damped, by an inverted phase, is narrowed. 
Consequently, the rigidity of the crankshaft against twisting is decreased 
in the range of the same phases of vibration of the crankshaft as of the 
flywheel. 
Twisting vibration problems typically arise in engines having supplemental 
apparatuses. If a supplemental apparatus is driven by a chain or a belt 
linked with a crankshaft, a shift in angular velocity of the crankshaft is 
transmitted to the supplemental apparatuses through the chain or the belt. 
Twisting vibration will be transmitted to the supplemental apparatuses, 
even if a structure is used which provides drive power for the 
supplemental apparatuses which is supplied from the rear end or minimum 
point of the twisting vibration so as to eliminate twist vibration 
influences. As a result, extraordinary gear engagement noise may occur at 
the connection between the gears. 
SUMMARY OF THE INVENTION 
It is one object of this invention to provide a drive apparatus for a 
supplemental apparatus or supplemental apparatuses which is compact and 
arranged around an oil pan. 
It is another object of this invention to provide a drive apparatus for a 
supplemental apparatus or supplemental apparatuses driven by an internal 
combustion engine which is constructed so that the supplemental apparatus 
or apparatuses and the drive mechanism can be assembled as a single unit 
to the engine. 
It is a further object of this invention to provide a drive apparatus for a 
supplemental apparatus or supplemental apparatuses of an internal 
combustion engine in which bending vibrations of a crankshaft of the 
engine are reduced effectively. 
The forgoing objects are accomplished, according to present invention, by 
providing a particular drive apparatus for at least one supplemental 
apparatus driven by an internal combustion engine. The drive apparatus 
includes a drive shaft for driving the supplemental apparatus, and power 
transmission means for transmitting drive power from an output shaft of 
the engine to the drive shaft. The drive shaft and power transmission 
means are disposed in an oil pan located under the engine. 
According to a preferred embodiment of the invention, the power 
transmission means comprises an output gear fixed to the output shaft, an 
idle gear in mesh with the output gear, and a chain for coupling the idle 
gear and the drive shaft. Preferably, the idle gear is located at a 
position at which no force couple is produced by forces from the chain and 
the output gear. A supporting portion for the idle gear extends in a 
direction of these forces. 
In accordance with another aspect of the invention, a drive apparatus for 
at least one supplemental apparatus driven by an internal combustion 
engine includes drive power deriving means for deriving drive power from 
an output shaft of the engine, and a supplemental apparatus drive unit 
supported in an oil pan disposed under the engine and simultaneously 
assembled so as to be linked with the drive power deriving means when the 
oil pan is assembled. The supplemental apparatus drive unit includes a 
drive shaft for driving at least one supplemental apparatus and power 
transmission means for linking the drive power deriving means with the 
drive shaft. 
In accordance with yet another aspect of the invention, a drive shaft for 
driving supplemental apparatuses driven by an internal combustion engine 
penetrates an oil pan disposed under the engine. 
According to another preferred embodiment of the invention, the 
supplemental apparatuses are disposed on both ends of the drive shaft. The 
oil pan is preferably disposed not only under the engine but also under a 
transmission placed beside the engine. 
In accordance with yet another aspect of the invention, a supplemental 
apparatus system includes an oil pump mounted on an inner side wall of an 
oil pan and driven by a drive shaft disposed in the oil pan, and filtering 
means for filtering oil mounted on an outer side of the oil pan and placed 
so that an inlet of the filtering means is located in the vicinity of an 
outlet of the oil pump. 
In accordance with yet another aspect of the invention, a drive apparatus 
is structured with a crankshaft having a flywheel fixed on one end thereof 
and an output gear for deriving drive power fixed on the inner side of an 
endmost journal of the crankshaft. 
According to another preferred embodiment of the invention, either or both 
of the output gear and a gear in mesh with the output gear have a damper 
filled between gear ring and a mounting ring. 
According to yet another preferred embodiment of the invention, a phase and 
order of pulsation of a supplemental apparatus such as an oil pump is 
adjusted to an inverted phase and order of change in angular velocity of 
the crankshaft to cancel the pulsation. 
In accordance with another aspect of the invention, a supplemental 
apparatus structure includes a water pump disposed outside of an oil pan, 
a oil pump disposed inside of the oil pan, and a drive shaft connecting 
both of the oil and water pumps to drive both of the pumps.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIG. 1, an engine, generally indicated by reference number 1 
and shown as an in-line four cylinder engine, is mounted in an appropriate 
location at the front of a vehicle body (not shown). A crankshaft 2 of the 
engine 1 is disposed so that it extends in the direction of the width of 
the vehicle body. The engine 1 is mounted so that it slants backward or 
tilts toward the rear end of the vehicle. A transmission 3 is disposed 
behind and close to the engine. The transmission 3 is placed with its 
lengthwise axis parallel to the engine crankshaft 2. A single oil pan unit 
4 is disposed under and secured to the engine 1 and the transmission 3. A 
surge tank 6 is disposed in front of the engine 1 near a lower block 5 
forming a skirt portion of an engine block. An intake pipe 7, connecting 
the surge tank 6 with a combustion chamber formed by the respective 
cylinder, extends and curves upward, and is connected to a cylinder head 
8. 
Since the engine slants backward or tilts toward the rear end of the 
vehicle, a space, having an approximately triangular sectional shape, as 
viewed from the front end of the engine 1, is formed under the engine 1. 
The oil pan 4 is configured so that it substantially fills the 
rectangularly shaped space formed under the engine 1. In order to provide 
the oil pan 4 with a sufficient volume, the oil pan 4 is extended. More 
particularly, the oil pan 4 is formed so that it extends, in the same 
direction as the engine 1, from the vicinity of an engine clutch housing 9 
to an inner position, located before a front end position of the engine 1. 
The oil pan is also formed so that it extends under the transmission 3 and 
covers substantially the entire underside of the transmission 3, as is 
clear from FIG. 3. 
Referring to FIG. 2, a drive shaft 10 for at least one supplemental 
apparatus is disposed under the engine 1 and extends parallel to the 
crankshaft 2 so as to penetrate the oil pan 4. An oil pump 11 for an 
automatic transmission is disposed at the rear side of the engine 1, near 
the oil 4, under the engine clutch housing 9. A pump 12 for power steering 
is disposed after and coaxially with the oil pump 11 for the automatic 
transmission 11. The oil pump 11 for the automatic transmission and the 
pump 12 for power steering are connected, in series, with one end of the 
drive shaft 10 so that they receive drive power from the drive shaft 10. 
On the front end side of the engine 1, a water pump 13 is disposed in a 
casing placed, on the front side of the oil pan 4, under the engine 1. The 
water pump 13 is connected with the other end of the drive shaft 10. An 
oil pump 14 for lubricant is disposed inside the oil pan 4 under the 
engine 1 adjacent the water pump 13. The oil pump 14 for lubricant is free 
from oil leakage, because the oil pump 14 is itself located in the oil pan 
4. The oil pump 14 for lubricant is connected with the drive shaft 10. All 
these pumps 11, 12, 13 and 14, which are supplemental apparatuses, are 
mounted on, or "shared by," the drive shaft 10 penetrating the oil pan 4. 
As a result, a compact layout or arrangement of the engine 1, utilizing 
the dead or unused space provided by the backward slant of the engine, is 
realized. 
The oil pan 4 is provided with an open-ended, generally thin box-shaped 
buffer wall 15, formed in the oil pan 4 closer to the rear wall of the oil 
pan 4 than the front wall of the oil pan 4 and adjacent to a partition 
wall 4C of the oil pan 4 dividing the oil pan into two o chambers, namely 
an engine oil chamber 4A and a transmission oil chamber 4B, penetrated by 
the drive shaft 10. A sprocket 16, mounted on the drive shaft 10, is 
located within the box-shaped buffer wall 15. The oil pan 4 is further 
provided with a buffer extension 15a located laterally adjacent the oil 
chamber 4B and extending toward the rear end of the engine 1. In an upper 
portion of the buffer extension 15a, a supporting member 19 is formed so 
as to support rotatively a shaft 18 of an idle gear 17 disposed so as to 
face an endmost web, for instance, the eighth web, in the case of an 
in-line, four-cylinder engine. Such an endmost web or connecting rod throw 
20 is located at the rear end of the crankshaft 2. The idle gear shaft 18 
is fixed, at its one end, with a drive sprocket 21 positionally 
corresponding to the driven sprocket 16. The drive sprocket 21 and the 
driven sprocket 16 are operationally connected by a drive chain 22. The 
crankshaft 2 is provided with an output gear 23 integrally formed on the 
outer periphery of the endmost web 20 and in mesh with the idle gear 17 so 
as to transmit rotation to the drive shaft 10 through the idle gear 17, 
the drive sprocket 21, and the driven sprocket 16. 
Referring to FIGS. 2 and 5, the output gear 23, formed as a gear ring 47 
with external gear teeth, is fixedly mounted on a mounting ring 45, having 
a generally L-shaped cross section and press fitted onto the endmost web 
20 of the crankshaft 2, through a rubber ring 46 provided between rings 45 
and 47. The rubber ring 46 serves as a damping means for absorbing bending 
and twisting of the crankshaft 2. In addition to the output gear 23, 
fitted onto the endmost web 20 of the crankshaft 2 and located on the 
inner side of an endmost journal 48 of the crankshaft 2, the crankshaft 2 
is provided with a flywheel 30 secured to a rear end mount 29 thereof 
adjacent the endmost journal 48. Because the output gear 23, acting as a 
damping means, is provided on the crankshaft 2 in a position at which the 
crankshaft 2 is subjected to the most serious bending, bending vibrations 
of the crankshaft 2 are effectively dissipated. 
The output gear 23, fixed to the crankshaft 2, transmits rotation of the 
crankshaft 2 to the supplemental apparatus drive shaft 10 through the idle 
gear 17, integral with the drive sprocket 21, and the driven sprocket 16, 
fixed to the drive shaft 10, which is operationally connected to the drive 
sprocket 21 by the chain 22. As a result, the drive shaft 10 drives the 
automatic transmission oil pump 11, the power steering pump 12, the water 
pump 13, and the lubricant oil pump 14 all together. In transmitting drive 
power, the idle gear shaft 18 is subjected, on its one end, to a force 
applied to the idle gear 17 from the output gear 23, in mesh with the idle 
gear 17, and on the other end to a force equal to a tension of the chain 
22. However, because the supporting member 19 is located at a position at 
which the forces act on the opposite ends of the shaft 18 in the same 
direction, namely, vertically downward as viewed in FIG. 2, no force 
couple, which applies pressure locally to a bearing surface of the 
supporting member 19, arises on the shaft 18. 
Oil pan 4 is provided with an oil filter 24 attached to the outer surface 
of the front wall of the oil pan 4 so that an inlet 25 of the oil filter 
24 is in communication with an outlet 26 of the lubrication oil pump 14. 
Due to the arrangement of the oil filter 24 and the lubrication oil pump 
14, a "sub-gallery" 27, between the outlet 26 of the lubrication oil pump 
14 and the inlet 25 of the oil filter 24, is short in length, so as to 
decrease pressure loss. Lubricant oil, introduced into the oil filter 24 
via the sub-gallery 27, is supplied, via a main gallery 28, to various 
portions of the engine 1, for example, journals of the crankshaft 2, etc. 
Referring to FIGS. 2 and 6, the crankshaft 2 is provided at its front end 
with a crankshaft pulley 32, which is coupled to an air conditioner 
compressor 31 by a belt (not shown). The crankshaft pulley 32 is formed as 
a pulley ring 34, with a belt groove 34a formed on its outer periphery, 
fitted onto a pulley mount 33 integrally formed with the crankshaft 2 
through a rubber ring 35 filled therebetween. The rubber ring 35 functions 
as a damper for twisting vibrations of the crankshaft 2. Consequently, 
twisting vibrations of the crankshaft 2 are effectively absorbed by both 
of the crankshaft pulley 32 and the output gear 23 fixed at the opposite 
ends of the crankshaft 2. Since the pulley gear 49 serves as a vibration 
damper, a change in angular velocity and twisting vibrations, transmitted 
to the supplemental apparatuses via the idle gear 17, are reduced, so as 
to prevent the output gear 23 and the idle gear 17 from producing noises. 
Connecting the oil pump 14 directly to the drive shaft 10 enables more 
effective reduction of changes in angular velocity and associated twisting 
vibrations of the crankshaft 2, transmitted to the supplemental 
apparatuses via the idle gear 17, with the use of pulsations of oil 
discharged by the oil pump 14. That is, the ratio of rotation speed of the 
supplemental apparatus drive shaft 10 relative to rotation speed of the 
crankshaft 2 is properly determined so as to properly adjust the phase and 
order of discharge pulsations of the oil pump 14. More specifically, the 
oil pump 14 inherently produces variations in the quantity of oil 
discharged therefrom. Variations in the quantity of oil discharged by the 
oil pump 14 produce periodic changes in a torsional force applied to the 
drive shaft 10. On the other hand, the angular velocity and twisting 
vibrations of the crankshaft 2 also periodically change. To cancel the 
effects of the periodic changes in angular velocity and twisting 
vibrations on the crankshaft 2, the ratio of rotation speeds referred to 
above is determined so that these effects are cancelled by a reaction 
force produced by the torsional force applied to the drive shaft. 
An alternator 43 is disposed on the front side of the engine 1. The 
alternator 43 is attached to an upper portion of the engine 1. The 
alternator pulley 40 is almost symmetrically disposed with respect to the 
crankshaft pulley 32 relative to the compressor pulley 44. However, the 
alternator pulley 40 is offset forward with respect to a vertical 
diametric line passing through a center of the crankshaft pulley 32 
relative tot eh compressor 31. All of the pulleys 32, 40 and 44 are 
operationally connected or coupled by a drive belt 36. There are provided 
a tensioning means 37, disposed between the crankshaft pulley 32 and the 
compressor pulley 44, and an idler roller 39, disposed between the 
crankshaft pulley 32 and the alternator pulley 40. The tensioning means 37 
comprises a pair of tension rollers 38A connected by a connection arm 38B 
so as to apply a proper tension to the belt 36 between the crankshaft 
pulley 32 and the compressor pulley 44. The tensioning roller 38A and the 
idler roller 39, thus arranged, allow angles, through which the drive belt 
36 contacts outer peripheries of the crankshaft pulley 32, the compressor 
pulley 44 and the alternator pulley 40, to large, as shown in FIG. 6. 
Various kinds of belt driven supplemental apparatus drive mechanisms or 
apparatuses, in which more than two supplemental apparatuses disposed on 
either the front or the rear side of an engine are driven by a single 
drive belt, have been realized. In such a belt driven supplemental 
apparatus drive mechanism, it is typical to operationally couple a 
crankshaft pulley and supplemental apparatus pulleys, disposed in a 
generally triangular formation, by a drive belt. In this case, the 
supplemental apparatuses have a large drive load requirement, and the 
drive belt is subjected to an imbalance in tension between a tightened 
side and a loosened side. Consequently, when the engine increases its 
speed rapidly, slippage between the drive belt and the pulleys may occur 
on the tightened side of the drive belt, due to a rapid increase in 
tension. 
In order to eliminate such slippage effectively, it was thought that a 
tensioning device should be located so as to provide a large angle through 
which the belt surrounds the pulley of the supplemental apparatus or 
apparatuses having a large drive load requirement and to have the belt be 
in contact with the crankshaft pulley at two circumferential sections. 
However, because there may be a relatively large number of supplemental 
apparatuses driven by a single drive belt and laying of the drive belt is 
complex, it is difficult to arrange the necessary number tensioning means, 
since only a limited space is available. 
In contrast with conventional belt driven supplemental apparatus drive 
mechanisms or apparatuses, the belt driven supplemental apparatus drive 
apparatus according to the preferred embodiment of the present invention 
described above drives supplemental apparatuses having a relatively small 
drive load requirement and a relatively large drive load requirement 
differently. Supplemental apparatuses having a small drive load 
requirement include the water pump 13 and the oil pump 14, disposed around 
the oil pan 4. The water pump 13 and the oil pump 14 are driven by the 
drive shaft 10 supported by the oil pan 4. Specific supplemental 
apparatuses having relatively large drive load requirements, such as the 
air conditioner compressor 31 and the alternator 43 disposed on the front 
side of the engine, are driven by the drive belt 36, which is moved by 
crankshaft 2. This divided arrangement of the plurality of supplemental 
apparatuses enables a plurality of tensioning means and idler rollers to 
be arranged so as to apply a proper tension to the drive belt. 
Although the idle shaft supporting member is disclosed as being provided as 
a part to be fixed to the oil pan, it may be formed integrally with the 
oil pan. Also, various combinations of supplemental apparatuses, which are 
mounted on opposite end portions of the supplemental apparatus drive 
shaft, are possible. The supplemental apparatus drive mechanism according 
to the preferred embodiment of the present invention is installed in an 
engine with a transmission coupled to the engine in series. 
The damper means installed in the front end of the crankshaft 2 can be 
omitted. Also, the damper means incorporated in the output gear 23 of the 
rear end of the crankshaft 2 may function to dissipate either bending 
vibrations or twisting vibrations. In addition, although the output gear 
23 is designed to perform a damping function, the idle gear 17 may 
alternatively perform the damping function if reduction of the sound or 
noise of grinding gears only is desired. 
It is finally to be understood that although preferred embodiments of the 
present invention have been described, various other embodiments and 
variations may occur to those skilled in the art which fall within the 
scope and spirit of the invention, and such other embodiments and 
variations are intended to be covered by the following claims.