Dispensing tool assembly for evacuating and charging a fluid system

A generally oval upper body supports a generally cylindrical lower body comprising an outlet tube on which is mounted an inner piston containing an annular resilient sealing member adapted to be connected to the tubular inlet fitting of a liquid coolant system. The lower body supports a set of arcuate collar sections which are cammed inwardly for gripping external threads on the inlet fitting in response to axial movement of an outer air actuated annular piston surrounding the outlet tube. The sealing member is compressed axially into the upper face of the inlet fitting in response to axial movement of the inner air actuated annular piston confined between the outlet tube and the outer piston. A tubular valve member comprising an integral air actuated annular piston is supported for axial movement within the upper body in alignment with the outlet tube for selectively connecting the passage within the outlet tube to a suction passage for evacuating the coolant system and then to a fluid supply passage for filling the system. A streamlined obturator mounted in the upper body is aligned axially with the outlet tube and comprises arcuate passageways for flow of the fluid following connection of the valve member to the outlet tube.

FIELD OF THE INVENTION 
The present invention relates to a tool used to evacuate and charge a fluid 
system. 
BACKGROUND OF THE INVENTION 
The present invention relates to a tool assembly constructed for evacuating 
and charging a fluid receiving system such as a liquid coolant system for 
an internal combustion engine. This tool assembly is adapted to be 
connected to an inlet fitting for a radiator of an engine coolant system 
in place of the radiator cap for first evacuating air and moisture from 
the system and then charging the system with a predetermined volume of 
liquid coolant. This invention is an improvement of the dispensing tool 
assembly disclosed in U.S. Pat. No. 5,560,407 invented by the applicant of 
the present invention. The improvement of the present invention pertains 
to an increase in fluid charging flow rate, elimination of sealing member 
to inlet fitting sticking, and protection of the tool outlet tube during 
handling. 
SUMMARY OF THE INVENTION 
The present invention is directed to a further improved dispensing tool 
assembly which is ideally suited for evacuating and charging a liquid 
receiving system such as a coolant system having a tubular inlet fitting 
with external threads for receiving an internally threaded closure or cap. 
The dispensing tool offers a reduction in the number of essential 
components and features a new valving method to control evacuation and 
charging. Positive gripping of the tubular inlet is accomplished via a set 
of arcuate collar sections, which grip the threaded exterior of the inlet 
fitting in response to axial movement of the air operated outer piston. 
Sealing of the inlet fitting is accomplished by a resilient seal forming a 
face seal with the top end of the inlet fitting. 
In accordance with one embodiment of the invention, a dispensing tool 
assembly is formed in three primary sections; a separable manifold for 
connecting hose fittings to the tool assembly having a generally oval 
shape, an upper body containing the valving means used to switch between 
evacuation and charging modes also having a generally oval shape, and a 
lower body containing the gripping and sealing means and having a 
generally cylindrical shape. 
A primary consideration of the present invention is to increase the 
charging rate of the fluid over the previous invention ('407 patent). The 
fluid charging rate of the previous invention can be improved by 
streamlining the fluid passageway and aligning it with the outlet tube. 
This is accomplished by the introduction of a streamlined obturator to 
which the valve in the upper body contacts. This obturator alternately 
blocks the flow of fluid and allows the fluid to flow in a generally axial 
direction through the tool. Flow turning of the fluid, which would 
otherwise create a large pressure drop, is minimized by directing the flow 
in a nearly axial direction around the obturator. In one embodiment the 
obturator contains four arcuate passageways at its periphery with a 
combined cross-sectional area slightly greater than that for the inner 
diameter of the tubular valve. The increase in cross-sectional area at the 
obturator passageways offsets the pressure drop imposed by the slight 
turning of the fluid flow. Whereas in the '407 patent the tubular valve 
moved away from the lower body (upward) to allow fluid to flow through the 
tool, the present invention forces the tubular valve to move toward the 
lower body (downward) and away from the obturator, thereby permitting the 
fluid to flow through the passageways and around the obturator. 
The invention also differs form the '407 patent in that the jaws do not 
surround the resilient annular sealing member, as this seal member is now 
contained within the bottom end of the inner air actuated piston. The 
benefit of relocating the seal from the outlet tube of the tool to the 
inner piston is two-fold; first it allows the inner wall of the outlet 
tube to grow in diameter which promotes an increased fluid charging rate 
due to the increase in cross-sectional area, and second, it prevents the 
inadvertent sticking of the seal to the inner wall of the inlet fitting 
following release of the clamping collars. In the '407 patent the seal 
expands radially outward to contact the inner surface of the inlet 
fitting. This seal may stick to the inlet wall when the clamping pressure 
is relieved, due to the time required to evacuate and charge the coolant 
system and the resulting set of the seal. In the present invention this 
possibility is eliminated as the resilient seal is compressed axially 
forming a face seal. This improvement has particular benefit for automatic 
retraction of the tool in an assembly line mode. 
The outlet tube of the tool disclosed in the '407 patent can be bent by 
rough handling, which degrades the smooth movement of the inner and outer 
clamping pistons. The risk of damage to the tool is due to the fact that 
the outlet tube extends from beyond the protective confine of the lower 
body. The tool of the present invention has an outlet tube of decreased 
length and one which is fully protected by the lower body. The shorter 
length of the present invention's outlet tube increases the range of 
angulation of the tool about the inlet fitting, which has importance 
during automatic removal of the tool. This outlet tube may also be 
constructed of more lightweight materials, such as aluminum, since the 
importance of strength is lessened.

DETAILED DESCRIPTION OF THE INVENTION 
All black dots shown in the cross-section views represent resilient o-ring 
used to form fluid-tight seals between adjacent components. In describing 
components or features of components, the terms "upper" and "lower" mean 
most distant from the inlet fitting and most near to the inlet fitting 
respectively. 
FIGS. 1-2 depict a dispensing tool assembly 10 comprising a generally oval 
upper body 12 having a top end closed by a manifold 14 secured to the body 
by a series of four irregularly spaced manifold screws 16. The bottom end 
of the upper body 12 is covered or closed by a closure member 18 by four 
symmetrically spaced closure member screws 21. 
Referring to FIGS. 3-4, the tool assembly 10 has an obturator 11 having a 
common axis with an outlet tube 24 defining a cylindrical outlet passage 
26. The obturator 11 has four arcuate passageways 13 and four spokes 15. 
Referring to FIGS. 5-6, the body 12 has a stepped cylindrical bore 29 which 
contains a stepped cylindrical valve member 32 sharing a common axis with 
the cylindrical bore 29. The valve member 32 is permitted to move axially 
between an evacuated position (FIG. 5) and a charging position (FIG. 6). 
The valve member 32 has an axially extending fluid passage 34 which aligns 
with the outlet passage 26 of the outlet tube 24 and the obturator 11. The 
valve member 32 has a top end 35 and a bottom end 36 which alternately 
seal against o-rings in the obturator 11 and closure member 18. A suction 
passage 39 extends upwardly to an internally threaded suction port 42 
within the manifold 14, and the port 42 is adapted to receive a flexible 
vacuum or suction line (not shown) from a vacuum pump (not shown). 
The valve member 32 contains an integral annular piston 33 constrained for 
axial movement within a cylindrical chamber 53 for the purpose of 
shuttling the valve member 32 between the vacuum state (FIG. 5) and the 
fluid charge state (FIG. 6). A compression spring 56 is located below the 
piston 33 portion of the valve member 32 and within the stepped 
cylindrical bore 29, and acts to force the valve member 32 toward the 
manifold 14. An air passage 63 (FIG. 5) extends from the upper end of the 
chamber 53 (FIG. 6) to a threaded air port 64 of the manifold 14 for the 
purpose of moving the valve member 32 in a downwardly direction. The air 
port 64 connects with a flexible pressurized air supply line (not shown). 
A plug 67 or "Lee Plug" closes the outer end of a radially extending 
portion of the air passage 63. 
Referring to FIGS. 5 and 6, an axially aligned fluid supply passage 72 is 
also formed within the body 12 and has an upper end connected to a 
threaded fluid port 74 formed within the manifold 14. The port 74 connects 
with a flexible fluid supply line (not shown) extending from a fluid or 
liquid supply source such as a pressurized source of a glycol-water 
coolant mixture (not shown). The manifold 14 has a tapered or 
frusto-conical surface 83 in the vicinity of the obturator 11. The body 12 
has a tapered surface 85 also in the vicinity of the obturator 11. The 
obturator 11 is concentrically aligned with the supply passage 72 and has 
upper and lower tapered surfaces 75. These surfaces (75, 83, and 85) 
smooth the flow path of the fluid during the charge state. 
FIG. 3 depicts one embodiment of the present invention in which the 
passageways 13 of the obturator 11 have a combined cross-sectional area 
greater than the cross-sectional area of the fluid passage 34 of the valve 
member 32. The spokes 15 connect the island-like conical center of the 
obturator 11 to an integral annular clamping ring 17, which restrains the 
obturator 11 between the manifold 14 and the body 12. The lower side of 
the obturator 11 contains an internal groove for retaining a resilient 
o-ring. This o-ring contacts the top end 35 (FIG. 6) of the valve member 
32 when the valve member moves upwardly to a fluid closed position (FIG. 
5) in response to the force exerted by the compression spring 56, thus 
preventing the flow of fluid through the arcuate passageways 13 of the 
obturator 11. 
When the valve member 32 is in the closed, or vacuum position (FIG. 5), the 
suction passage 39 (FIG. 6) is connected to the outlet passage 26 and the 
fluid supply passage 72 is closed by the interface of the valve member 32 
and the obturator 11. When the valve member 32 is shifted to its retracted 
or lower position (FIG. 6) in response to pressurized air on the top of 
the piston 33 of the valve member 32, the suction passage 39 is closed by 
the interface of the bottom end 36 (FIG. 5) of the valve member 32 and the 
top end of the closure member 18, and the fluid supply passage 72 is 
connected with the outlet passage 26. Fluid tight sealing between the 
valve 32 and the closure member 18 is accomplished by a resilient o-ring 
installed in an annular groove in the closure member 18. 
Referring to FIGS. 5 and 6, a generally cylindrical lower body 92 forms an 
extension of the body 12 and includes an outwardly projecting upper flange 
94 which is secured to the body 12 by the four screws 21 which also secure 
the closure member 18 to the body. The lower body 92 surrounds the outlet 
tube 24 and includes an inwardly projecting bottom or lower flange 97. A 
cylindrical or tubular inner piston 106 is mounted on the outlet tube 24 
for axial movement, and contains a resilient annular sealing tube or 
member 102 in an annular cavity 107 at the lower end of the piston 106. 
This sealing member 102 has a lower end 105 (FIG. 5) which is aligned to 
contact an upper surface 143 of an inlet fitting 140. An annular outer 
piston 110 is supported for axial movement within an annular outer chamber 
111 defined between the lower body 92 and the outlet tube 24 and 
cooperates with the outlet tube 24 to define an annular inner chamber 112 
for receiving the inner piston 106. Two axially extending bleed air ports 
114 (FIG. 5) connect the inner chamber 112 to the outer chamber 111 which 
receives the outer piston 110. An annular lock ring 27 is secured to the 
lower end of the outlet tube 24 by three screw 28 and retains the inner 
piston 106 from over-travel in the event the chambers 111 and 112 are 
pressurized when the tool assembly 10 is not connected to the inlet 
fitting 140. 
A set of four arcuate gripping jaws or collar sections 120 are supported by 
the lower flange 97 of the lower body 92 for movement in corresponding 
radial directions. Each of the collar sections 120 has internal threads 
122 (FIG. 5), and the threads on each section mate with the threads on the 
adjacent sections so that the four sections form one continuous helical 
thread when the sections are moved inwardly to a gripping position as 
shown in FIG. 6. 
Each of the arcuate collar sections 120 has a tapered outer surface 124 
which mates with a tapered annular surface 127 (FIG. 5) on a lower annular 
portion of the outer piston 110. A spring wire expansion spring 132 urges 
the collar sections 120 radially outward against the lower body 92. A 
compression spring 135 is confined within a spring chamber 129 defined 
between the outer piston 110 and the inner piston 106. The lower end of 
the spring 135 seats upon a flat annular washer 136 (FIG. 5) which engages 
the top surfaces of the collar sections 120. As shown in FIGS. 5 and 6, a 
series of resilient o-rings form fluid-tight seals between the inner 
piston 106, the outer piston 110, the inner surface of the lower body 92, 
the closure member 18 and the outer surface of the outlet tube 24. 
Referring to FIG. 6, operation of the tool 10 is controlled by a start 
button 150 and reset button 152 located within a rectangular chamber 154 
of the upper body 12. The buttons 150 and 152 are secured to the body 12 
by a plate 156 and two attach screws 158. Signals are sent from the 
buttons 150 and 152 via an electrical cable 160 which attaches to an 
electrical connector 162. Wiring (not shown) from the buttons 150, 152 
attaches to the connector 162. The electrical cable 160 can be 
disconnected from the connector 162 to allow quick change of the tool 10 
by removing the manifold attach screws 16 (FIG. 2). These components are 
non-essential to the tool assembly 10, and may not be installed in some 
embodiments of the invention. 
When it is desired to use the dispensing tool assembly 10 to evacuate a 
fluid system, such as an engine cooling system (not shown) comprising an 
inlet fitting 140 (FIGS. 5 and 6) having external threads 142, the tool 
assembly 10 is centered over the inlet fitting 140 and lowered until the 
lower flange 97 of the lower body 92 rests on the inlet fitting 140. The 
lower end 105 of the sealing member 102 is aligned for engagement with the 
upper surface 143 of the inlet fitting 140 by the close fit of the lock 
ring 27 to the inner surface of the fitting 140. In this position, the 
arcuate clamping jaws or collar sections 120 are retracted outwardly by 
the expansion spring 132, as shown in FIG. 5. 
Pressurized air is then supplied to the outer chamber 111 through an air 
passage 147 (FIG. 5) extending through the body 12 from an internally 
threaded air port 148 (FIG. 2) formed within the manifold 14 and connected 
to a source of pressurized air. The pressurized air within the outer 
chamber 111 on top of the outer piston 110 moves the piston downwardly so 
that the collar sections 120 are cammed inwardly until the internal 
threads 122 on the collar sections 120 engage the external threads 142 on 
the inlet fitting 140. This forms a positive coupling of the tool assembly 
10 to the inlet fitting 140. 
The pressurized air within the outer chamber 111 also passes through the 
bleed ports 114 and into the inner chamber 112, thus forcing the inner 
piston 106 downwardly to compress the lower end 105 of the resilient 
sealing member 102 contained within the inner piston 106 axially against 
the upper surface 143 of the inlet fitting 140. The cooling system is then 
evacuated by partial vacuum or suction within the passages 26 and 39. 
After the evacuation, pressurized air is introduced into the top of the 
chamber 53 through the passage 63 in order to pressurize the top surface 
of the annular piston 33. This moves the valve member 32 downwardly 
against the compression spring 56 so that the suction passage 39 is closed 
and the fluid supply passage 72 is open to the outlet passage 26 (FIG. 6). 
After a predetermined volume of the liquid coolant is suppied to the fluid 
receiving or cooling system, the chamber 53 is exhausted and the valve 
member 32 returns to the normal evacuation position shown in FIG. 5, 
thereby closing the fluid supply passage 72 to the outlet passage 26. The 
pressurized air passage 147 and outer chamber 111 are exhausted so that 
the air pressure on the inner piston 106 and the outer piston 110 is 
released. The pistons then return to their upper retracted positions with 
the aid of the compression spring 135. The tool assembly 10 is thereby 
uncoupled from the inlet fitting 140, and may be automatically or manually 
removed from the fitting 140. 
From the drawings and the above description, it is apparent that a 
dispensing tool assembly constructed in accordance with the invention 
provides features and advances more desirable than the previous invention 
disclosed in the '407 patent. For example, the obturator 11 incorporating 
the arcuate passageways 13 minimize flow turning of the fluid during 
charging, thus increasing flow rate and decreasing charge time. Containing 
the sealing member 102 within the lower end of the piston 106 allows for 
an increase in the diameter of the outlet passage 26, and thus promotes an 
increase in flow rate over the '407. In addition, sticking of the sealing 
member to the inlet fitting 140 during clamp release is eliminated. The 
decreased length of the outlet tube 24 allows it to be fully protected by 
the lower body 92 during handling and allows for greater angulation of the 
tool assembly 10 about the fitting 140, which is critical for automatic 
retraction. The tool assembly 10 offers a reduction in the number of 
essential components due to the use of a single compression spring 135 and 
the consolidation of the piston 33 into the valve member 32. 
The invention is not limited to the above preferred embodiments and various 
modifications thereof may be made without departing from the spirit and 
scope of the invention. Rather, the scope of the invention is defined by 
the appended claims.