Combination pump head with slotted camming device

A pump head includes a main body defining a chamber and having a top end and a bottom end, a first force transmitting member slidably positioned in the chamber adjacent the top end of the main body, and a second force transmitting member slidably positioned in the chamber adjacent the first force transmitting member and the top end of the main body. A camming device is pivotally mounted at the top end of the main body, the camming device having first, second third and fourth engagement surfaces, the first, second, and third engagement surfaces in selective engagement with the first force transmitting member, and the first, second and fourth engagement surfaces in selective engagement with the second force transmitting member. A resilient collar stationarily positioned in the chamber between the bottom end and the first force-transmitting member, and defining an axial cavity having an inner wall and an inside diameter. The inside diameter is at a maximum dimension when the first engagement surface en cages the first force transmitting member, the inside diameter is at a intermediate dimension when the second engagement surface engages the first force transmitting member, and the inside diameter is at a minimum dimension when the third engagement surface engages the first force transmitting member. The second force transmitting member is displaced downwardly a first distance when the first engagement surface engages the second force transmitting member, and is displaced downwardly a second distance when the second engagement surface engages the second force transmitting member, and is displaced relatively upwardly when the fourth engagement surface engages the second force transmitting member.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a pump head for use in connection with pumps for 
inflating bicycle tires or other inflatable objects, and more particularly 
to a dual purpose pump head able to be used with both Schraeder and Presta 
valve stem types. 
2. Description of the Prior Art 
Virtually every bicycle tube has a valve stem which allows the tube to be 
inflated and deflated. The two most popular types of valve stems are the 
Schraeder valve seem and the Presta valve stem, both well known in the 
art. The Schraeder valve stem generally comprises a hollow cylinder 
including a depressible valve having an upper or sealed position and a 
lower or unsealed position. The valve is spring biased into the upper or 
sealed position to keep air from escaping from the inner tube through the 
valve. When an inner tube is filled through a Schraeder valve, the pump 
head is required to have a nipple which depresses the valve against the 
spring bias to allow air to flow past the valve and into the tube. When 
the pump head is removed, the spring bias, as well as the internal air 
pressure, move the valve to the upper or sealed position. The Schraeder 
valve is very popular on most styles of bicycle inner tubes. 
The Presta valve stem is also a very popular valve for use on bicycle inner 
tubes. The Presta valve stem generally comprises a hollow cylinder 
(smaller in diameter than the Schraeder valve stem) having a valve at the 
top end thereof. The valve includes an externally threaded post movably 
positioned in the hollow cylinder and protruding away from an upper end 
thereof. An internally threaded nut mates with the external threads on the 
post, whereby advancement of the nut along the post causes the nut to 
engage the top of the cylinder, pulling a sealing head on the bottom of 
the post into a sealing relationship with a seat inside the cylinder. In 
this position, the post keeps air from leaking out of the inner tube 
through the valve. When the nut is backed-off or unscrewed along the 
length of the post, the post is free to slide downwardly into the cylinder 
until the nut again engages the top of the cylinder, in which position air 
is free to flow into or out of the inner tube. The post is not spring 
biased into the sealed position as in the Schraeder valve. When the nut is 
unscrewed, the air pressure inside the inner tube biases the valve to 
maintain the sealed position. The nut has notches formed in its sidewalls 
to allow air to flow through the nut past the post and into the valve, and 
ultimately into the inner tube. 
Application of air pressure to inflate the tube overcomes the tube 
pressure, and forces the post down into the cylinder until the nut engages 
the top of the cylinder, allowing, air to flow into the tube through the 
Presta valve stem. 
Currently available pump heads for use in inflating inner tubes having 
either the Schraeder, Presta, or Italian style valve stems have required 
either an adapter, or the manipulation of the pump head mechanism to 
convert it to a suitable configuration for use with the different style 
valve stems. The prior art pump head version requiring an adapter utilizes 
the adapter to increase the smaller diameter Presta valve stem to a larger 
diameter to replicate the size of a Schraeder valve stem. The adapter is a 
separate piece that is releasably attachable to the upper end of the 
Presta valve and can be easily lost or damaged, thus affecting, the 
ability of the user to inflate an inner tube having a Presta valve stem. 
Pump heads having convertible mechanisms generally have an inner mechanism 
which must be removed and reinserted in a different orientation to allow 
the conversion of the pump head for use with both Schraeder and Presta 
valve stems. During conversion, the mechanism can be lost or damaged, 
causing the pump head to be useless in inflating inner tubes having, 
either the Schraeder or Presta valve stems. Such convertible pump heads 
are manufactured by A-PLUS Manufacturing of Taiwan, and are available 
under the brand names TREK or Blackburn, among others. 
It is to overcome the shortcomings in the prior art that the present 
invention was developed. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a pump head capable of 
sealingly engaging different sized valve stems without modification in a 
single chamber. 
It is another object of the present invention to provide a pump head 
capable of sealingly receiving a Schraeder style valve stem for inflating 
an inner tube, and that can also sealingly receive a Presta style valve 
stem for inflating an inner tube. 
The pump head of the present invention allows a user to engage valve stems 
of varying, diameters for inflating inner tubes without having to modify 
either the valve stem or the pump head. The pump head has a single chamber 
which sealingly engages a relatively broad valve stem such as a Schraeder 
valve stem and actuates the spring loaded valve required to inflate the 
inner tube. The pump head also sealingly engages in the same chamber a 
relatively small diameter valve stem such as a Presta valve stem to 
inflate the inner tube. The pump head is designed to be applied to a floor 
pump or a frame pump, as well as other types of pumps. 
Accordingly, the pump head of the present invention comprises a main body 
defining a chamber and having, a top end and a bottom end, a force 
transmitting member slidably positioned in the chamber adjacent to the top 
end of the main body, a resilient deformable collar positioned in the 
chamber adjacent to the bottom end of the main body in engagement with the 
force transmitting member, and a camming device pivotally mounted at the 
top end of the main body. The collar defines an axial cavity having an 
inner wall. 
The camming device has first, second and third cam surfaces in selective 
engagement with the force transmitting member. The second and third cam 
surfaces act to displace the force-transmitting member into the chamber to 
different extents to compress the collar. Compression of the collar 
deforms the collar radially inwardly to decrease the inner diameter of the 
collar thus causing the collar to sealingly engage the valve stem 
positioned in the axial cavity. 
The inside diameter of the deformable collar is at a maximum dimension when 
the first cam surface engages the plunger, the inside diameter is at an 
intermediate dimension when the second cam surface engages the plunger, 
and the inside diameter is at a minimum dimension when the third cam 
surface engages the plunger. Accordingly, a larger diameter valve stem is 
sealingly engaged when the second cam surface is in contact with the 
plunger, and a smaller diameter valve stem is scalingly engaged when the 
third cam surface is in contact with the plunger. 
In an alternative embodiment of the present invention, the pump head 
includes a main body defining a chamber and having a top end and a bottom 
end, a first force transmitting member slidably positioned in the chamber 
adjacent the top end of the main body, a second force transmitting member 
slidably positioned in the chamber adjacent the first force transmitting 
member and the top end of the main body, a camming, device pivotally 
mounted at the top end of the main body, the camming, device having first, 
second third and fourth engagement surfaces, the first, second, and third 
engagement surfaces in selective engagement with the first force 
transmitting member, and the first, second and fourth engagement surfaces 
in selective engagement with the second force transmitting member, and a 
resilient collar stationarily positioned in the chamber between the bottom 
end and the first force-transmitting member, and defining, an axial cavity 
having an inner wall and an inside diameter, wherein the inside diameter 
is at a maximum dimension when the first engagement surface engages the 
first force transmitting, member, the inside diameter is at a intermediate 
dimension when the second engagement surface engages the first force 
transmitting member, and the inside diameter is at a minimum dimension 
when the third engagement surface engages the first force transmitting 
member, and wherein the second force transmitting member is displaced 
downwardly a first distance when the first engagement surface engages the 
second force transmitting member, and is displaced downwardly a second 
distance when the second engagement surface engages the second force 
transmitting member, and is displaced downwardly a third distance when the 
fourth engagement surface engages the second force transmitting member. 
More specifically, the alternative embodiment includes a pump head for 
alternate use with a relatively larger diameter valve stem having a valve 
biased in a sealing position and a relatively smaller diameter valve stem, 
the pump head including a main body having, a chamber, a top end and a 
bottom end, and an air inlet port communicating with said chamber; a 
plunger forming, a bore sealingly and slidably positioned in the chamber 
adjacent the top end of the main body having a top end with an engagement 
surface and a bottom surface, a ram follower sealingly and slidingly 
positioned in the bore, and defining a centrally located bottom end; a 
spacer slidably positioned in the chamber and defining a center bore and 
having a top end with a plurality of circumferentially spaced fingers 
defining a plurality of notches therebetween, the fingers each having, 
defining a top engagement surface, a bottom end, each of the top 
engagement surfaces being in engagement with the bottom surface of the 
plunger; a camming device pivotally mounted at the top end of the main 
body, the camming device having, a first, second, third and fourth cam 
surfaces, the fourth cam surface being formed in and offset from the third 
cam surface, the first, second and third cam surfaces in selective 
engagement with the top engagement surface of the plunger, and the first, 
second and fourth cam surfaces in selective engagement with said ram 
follower; a resilient collar stationarily positioned in the chamber 
adjacent the bottom end and defining an axial center bore, the collar 
having an inner wall and an inner diameter, the collar engaging the bottom 
end of the spacer; and wherein when the large diameter valve stem is 
positioned in the axial cavity and the second cam surface engages the top 
engagement surface of the plunger and the top of the ram follower, the 
bottom end of the ram follower engages the biased valve to release the 
sealing engagement, and the inner wall of the collar engages the larger 
diameter valve stem to form an airtight seal, and upon positioning the 
smaller diameter valve stem in the axial cavity and the third cam surface 
engages the top engagement surface of the plunger, and the fourth cam 
surface engages the ram follower simultaneously, the inner wall of the 
collar engages the smaller diameter valve stem to form an airtight seal. 
Other aspects, features and details of the present invention can be more 
completely understood by reference to the following detail description of 
a preferred embodiment, taken in conjunction with the drawings and from 
the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring first to FIG. 1, a pump head 20 incorporating the present 
invention is illustrated and includes a Generally cylindrical main body 22 
defining, a slot 24 through its top end 26 for receiving a camming device 
28, an interior chamber 29 (not shown) extending from the base of the slot 
24 to the open bottom end 30 of the main body 22, and lateral hollow arm 
32 defining a port extending from and in fluid communication with the 
interior chamber of the main body 22. An air hose 34 of any normal design 
is attached to the lateral arm 32 for transmitting air under pressure to 
the chamber. A Schraeder valve 36, being mounted by any normal means to an 
inner tube 38 and in fluid communication therewith for use in inflating 
and deflating the inner tube, is also shown in FIG. 1, for receiving the 
pump head 20 to inflate the inner tube. The camming device 28 is pivotally 
attached between the flanges 40 formed by the slot 24 to be moved from an 
open, or first, far right position as shown, to a second, or vertical, 
position (FIG. 5), and to a third, or far left, position (see FIG. 8), 
depending on the type of valve to which the pump head 20 is applied. 
Referring next to FIG. 2, the components of the pump head 20 of the present 
invention are shown in exploded relationship. The chamber (See FIG. 3) of 
the main body 22 or housing contains a plunger 42 in sliding sealed 
engagement with the cylindrical wall 44 of the interior chamber 29. The 
plunger 42 rests upon a spacer 46, which in turn rests upon a cylindrical 
collar 48, or seal gasket, made of a resilient material having an internal 
surface 50 and an external surface 52. The internal surface of the collar 
48 defines an inside diameter, and the external surface of the collar 
defines 48 an outside diameter. The plunger 42, spacer 46, and collar 48 
are held in the main body by a base cap 54 having an end 56 defining an 
aperture 58 formed there through in communication with the interior 
chamber 29 of the main body 22. The base cap 54 is threadedly received on 
the bottom end 30 of the main body 22 to allow releasable attachment of 
the base cap 54 to the main body 22 for access to and replacement of the 
various parts contained within the main body 22. 
The camming device 28 is pivotally mounted between the pair of flanges 40 
defined on either side of the slot 24 by a pin 60 inserted through the 
flanges 40 with the camming device 28 positioned between the flanges 40. 
The camming device 28 generally includes a substantially square shaped cam 
head 62 and a handle 64, the cam head 62 defining first 66, second 68 and 
third 70 engagement surfaces which are in selective contact with a top 
surface 104 of the plunger 42 when in first, second, and third positions, 
respectively. 
In general, actuation of the camming device 28 to the second and third 
positions allows the pump head 22 to grip and sealingly engage different 
sized valve stems, alleviating the need for extra parts or pump head 
modification. Actuation of the camming device 28 causes the plunger 42 to 
be pressed downwardly against the spacer 46, which in turn presses 
downwardly or axially against the collar 48. The collar 48 is restrained 
by the base cap 54 on the bottom and the interior walls 44 of the chamber 
29 along its external surface 52, such that when it is axially compressed 
by the spacer 46 as a result of actuation of the camming device 28, the 
inner wall 44 of the collar 48 bulges inwardly and thus decreases the 
inside diameter of the collar. The further the collar 48 is compressed, 
the smaller the inside diameter of the collar 48 becomes. 
When the camming device 28 is in the first or open position the first 
engagement surface 66 is in contact with the top 72 surface of the plunger 
42, but little or no force is placed on the collar 48 to alter the inner 
diameter of the collar. When the camming device 28 is moved to the second 
position, the second engagement surface 68 contacts the plunger 42 and the 
plunger is pressed or moved downwardly a first predetermined distance to 
compress the collar 48 a predetermined amount, and in turn reduce the 
inside diameter of the collar 48. When the camming device 28 is moved to 
its third position, the third engagement surface 70 is in contact with the 
top surface 104 of the plunger 42, displacing the plunger 42 even further 
downwardly, resulting in the collar 48 being compressed to a greater 
extent, and further reducing the inner diameter of the collar. 
The changing inner diameter of the collar 48 allows the pump head 22 to 
sealingly engage valve stems of different outer diameters, such as the 
Schraeder and the Presta valve stems. 
The pump head 20 of the present invention is shown in the first or open 
position in FIGS. 3 and 6. The chamber 29 formed in the main body 22 is 
cylindrical in shape, and extends along the length of the main body from 
the bottom end 30 to the base 74 of the slot 24. The outer diameter of the 
bottom end 30 is threaded to receive the base cap 54. 
The port 76 is defined by the lateral arm 32 which extends radially from 
the main body to receive an end of the air hose 34 of a floor pump (not 
shown) or a pump body of a frame pump (not shown). The port 76 is in fluid 
communication with the internal chamber 29 of the main body 22. 
The center bore of the collar and the center bore of the spacer together 
form a single chamber for receiving the desired valve stem. 
The aperture 58 formed in the end 56 of the base cap 54 is centrally 
located to be positioned in alignment with the internal chamber 29 of the 
main body 29 when the base cap is threadedly received on the bottom end 30 
of the main body 22 and is dimensioned to slidably receive Schraeder or 
Presta valve stems. The end surface 56 of the base cap 54 exposed to the 
internal chamber 29 when the base cap 54 is attached to the main body 22 
forms a raised annular support surface 78 surrounding the aperture 58 
formed therein for supporting the collar 48. When the base cap 54 is 
releasably attached to the main body 22 the raised annular support surface 
78 fits into the cavity 29 in the main body. The end of the main body 30 
engages the well 80 formed between the raised annular support surface 78 
and the outer flange 82 of the base cap 54 to provide an indication that 
the base cap is received onto the main body to its fullest extent, and 
does not compress the collar 48. The main body 22 and the base cap 54 are 
formed of metal or high impact plastic, but could be formed of other 
materials having suitable strength. 
The cap is for fine adjustment which may be required due to inaccuracies in 
the manufacturing or because of wear on the parts, but is not required for 
the invention to operate properly. If desired, the cap can cause a preload 
to be placed on the collar with the camming device is in the first 
position. 
The collar 48 is made of a resilient material, such as Ethylene Propylene 
elastomer, or EPDM, which is compression moldable and has good weather 
resistance and sealing properties. The hardness characteristic of the 
rubber is preferably between approximately 40 shore A and 50 shore A on 
the ASTM standard, with a hardness of 42A on the ASTM standard having been 
shown to be highly desirable. The collar 48 is cylindrical in shape 
defining a center bore, and having an outer wall 52 defining the outside 
diameter and the inner wall 50 defining the inside diameter. The outer 
diameter of the collar is substantially the same as the inside diameter of 
the chamber in the main body. Since the collar is made of a resilient 
material, axial compression of the collar 48 causes the height of the 
collar 48 to decrease, and the thickness of the wall 49 of the collar 48 
to increase in a central location, which in turn decreases the inner 
diameter of the collar 48 (see FIG. 7). 
Generally, the outside diameter of the collar is approximately 13.77 mm. 
the inside diameter (uncompressed) is approximately 8.25 mm. the wall 49 
thickness is approximately 2.76 mm, and the height is approximately 12.95 
mm. 
The spacer 46 as mentioned previously is axially aligned with and rests 
against the top surface 84 of the collar 48 inside the chamber 29 of the 
main body 22. The spacer 46 is made of a hard plastic, such as ABS, and 
defines a generally cylindrical body 86 having an outside wall 88 and an 
inner wall 90, the inner wall defining a center bore having an inside 
diameter. The outside wall 88 of the spacer has an outside diameter which 
is substantially equal to the inside diameter of the chamber 29 of the 
main body 22. The spacer 46 is slidably disposed within the chamber 29 
inside the main body 22. An annular base surface 92 of the spacer 46 is in 
continuous engagement with the top surface 84 of the collar 84. A series 
of notches 94 are formed in the upper end of the spacer 46 with the 
notches 94 oriented radially through the wall of the spacer 46. The 
notches 94 define circumferentially spaced fingers 96 at the top of the 
spacer 46 and each finger 96 has a top engagement surface 98. The top 
portion 100 of the spacer 46 has a slightly smaller outer diameter than 
the bottom portion 102, such that an annular tap 103 is formed between the 
top portion 100 of the spacer 46 and the wall 44 of the chamber 29 in the 
main body 22. 
Generally, the outside diameter of the top portion 100 of the spacer 46 is 
approximately 11.77 mm, the outside diameter of the bottom portion 102 is 
approximately 13.77 mm, the inside diameter of the center bore is 
approximately 8.00 mm, and the height is approximately 12.1 mm. 
The plunger 42 is slidably positioned inside the chamber 29 in the main 
body 22, and rests upon the top engagement surfaces 98 of the spacer 46. 
The plunger 42 is made of metal, high impact plastic, or other material 
having suitable strength. The plunger 42 is solid and cylindrical in 
shape, and defines a top cam engagement surface 104 and a bottom 
engagement surface 106 for contact with the top engagement surfaces 98 of 
the spacer. The plunger 42 has an outer diameter substantially the same as 
the inner diameter of the chamber 29 in the main body 22 and is maintained 
in a sealed sliding engagement with the inner wall 44 of the chamber 29 by 
an O-ring 108 positioned in an annular groove 110 formed continuously 
around the plunger 42. The O-ring 106 engages the wall 44 of the chamber 
29 in the main body 22 to maintain a sealed engagement yet allows the 
plunger 42 to move axially alone the chamber 29. The bottom engagement 
surface 106 of the plunger 42 defines a centrally located nipple 112 or 
pin extending downwardly therefrom. The plunger 42 in combination with the 
spacer 46 form a force-transmitting device 114. 
Generally, the outside diameter of the plunger is approximately 13.77 mm, 
and the height is approximately 11.73 mm. The pin 112, or nipple, extends 
approximately 5.18 mm from the bottom surface 106 of the plunger 42. 
The camming device 28 pivots about the pivot pin 60 at a location off 
center of the cam head 62. There are three active cam surfaces 66, 68 and 
70, each corresponding to a different handle position. In any given 
position, one cam surface engages the top engagement surface of the 
plunger. In the open, or first, position, the handle 64 extends 
horizontally to the right, as viewed in FIGS. 3, 4 and 6. In the open or 
first position, the first cam surface 66 engages the top engagement 
surface 104 of the plunger 47. The first engagement surface 66 is aligned 
parallel to the extension of the handle 64, and is spaced from the center 
of the pivot pin 60 by approximately 5 mm. 
In the second position, the second cam surface 68 is in engagement with the 
top engagement surface 104 of the plunger 42, and the handle 64 extends 
vertically with respect to the pump head 20, as shown in FIGS. 5 and 7. 
The second cam surface 68 is oriented perpendicularly to the extension of 
the handle 64. The second cam surface 68 is approximately 7 mm from the 
center of the pivot pin. 
In the third position, the third cam surface 70 is in engagement with the 
top encasement surface 104 of the plunger 42, with the handle 64 extending 
to the left of the pump head 20, as shown in FIG. 8. The third cam surface 
70 is opposite the first cam surface 66, also extends parallel to the 
handle 64, and is approximately 9.3 mm from the center of the pivot pin 
60. The cam head 62 has rounded corners 116 between the cam surfaces to 
allow the cam head 62 to be pivoted about the pivot pin 60 by use of the 
handle 64. Each of the distances mentioned above between the center of the 
pivot pin and the different cam surfaces is the minimum distance as 
measured along a line perpendicular to the cam surface that extends 
through the center of the pivot pin 60. Each cam surface is planar. 
The pump head 20 of the present invention can be used on either a Schraeder 
style valve stem 36 or a Presta style valve stem 118 without the use of 
any conversion piece and without requiring the disassembly of the internal 
components of the pump head. The operation of the pump head 20 of the 
present invention with a Schraeder valve stem 36 is described below with 
reference to FIGS. 3 through 5, and with the Presta valve stem 118 in 
FIGS. 6 through 8. 
Referring first to FIG. 3, the pump head 20 is shown positioned above a 
Schraeder valve 36. The camming device 28 is positioned in the open, or 
first position, where the first cam surface 66 is in engagement with the 
top engagement surface 104 of the plunger 42. In the first or open 
position, preferably no force is applied to the collar 48, so that the 
wall 49 of the collar 48 are not significantly bulged inwardly to reduce 
the dimension of the inside diameter of the collar 48. In the first or 
open position, the plunger 42 is in engagement with the spacer 46, the 
spacer is in engagement with the collar 48, and the collar is constrained 
between the spacer 46 and the base cap 54. 
Referring next to FIG. 4, the pump head 20 is shown positioned over the 
Schraeder valve stem 36, but prior to the movement of the camming, device 
28 to the second position. The pump head 20 is positioned on the Schraeder 
valve stem 36 preferably until the nipple 112 engages the valve 120 on the 
Schraeder valve stem 36 and depresses the spring-biased valve 120 to 
release the seal engagement of the valve. The Schraeder valve stem 36 in 
this position fits closely within the inner diameter of the collar 48. At 
this point, air can escape from the inner tube through the valve 120 and 
out through the bottom 30 of the main body 22 of the pump head 20. 
Referring to FIG. 5, the camming, device 28 is shown having been moved to 
the second position so that the second cam surface 68 is in engagement 
with the top engagement surface 104 of the plunger 42. Since the second 
camming surface is approximately 2 mm further away from the pivot pin 60 
than the first cam engagement surface 66, the plunger 42 has been 
displaced into the chamber 29 in the main body 22 by approximately 2 mm. 
The downward movement of the plunder 42 causes the spacer 46 to move 
downwardly approximately 2 mm, acting to compress the collar 48 against 
the base cap 54. The inner wall 50 of the collar 48 then bulges radially 
inwardly reducing the inside diameter, and form an air tight seal around 
the outside of the Schraeder valve stem 36. Preferably, the collar 48 at 
least partially engages the Schraeder valve stem on the threaded upper 
portion to provide enhanced gripping strength. 
The movement of the plunger 42 also causes the nipple 112 to push the valve 
120 downwardly by approximately 2 mm, thus further opening the air passage 
way for inflation of the inner tube. The plunger 42 maintains a sealed 
engagement with the inner wall 44 of the chamber 29 in the main body 22, 
because of the O-ring 108, thus keeping any air from escaping through the 
top of the main body 22. The inner tube is inflated by pumping air through 
the air tube 34, through the aperture 76 formed in the pump head 20, into 
the annular gap 103 between the upper portion of the spacer 46 and the 
inner wall 44 of the chamber 29, through the notches 94 formed in the top 
of the spacer 46, down around the nipple 112 and through the Schraeder 
valve stem 36 and finally into the inner tube. This air flow path is shown 
by arrows in FIG. 5. 
To remove the pump head from the Schraeder valve 6, the camming device 28 
is moved from the second position to the first position, which thus allows 
the valve 120 to move back into sealed engagement under the spring bias 
mentioned above. The collar 48 also is unloaded, and the inside diameter 
increases to disengage the wall 50 from the valve stem 36. The pump head 
20 is then simply pulled off of the Schraeder valve stem 36. It will be 
appreciated that the third position of the camming device 28 is not used 
with Schraeder valve stems 36. 
In the event the Schraeder valve stem 36 is not inserted entirely into the 
pump head 20 to cause the engagement of the nipple 112 with the valve 120 
to result in the release of air from the inner tube, the slight downward 
movement of the plunger 42 in moving the camming device 28 from the first 
to the second position may still be sufficient to displace the nipple 112 
sufficiently to depress the valve 120 and release the air tight seal of 
the valve. 
Use of the pump head 20 with a Presta valve stem 118 is shown in FIGS. 6-8. 
Referring to FIG. 6, the Presta valve stem 118 is shown with the pump head 
20 positioned over the Presta valve stem 118 and the camming device 28 in 
its first or open position. The top nut 122 on the Presta valve has been 
unscrewed a small amount to allow the center post 124 to move axially into 
the Presta valve stem, as will be described further below. The Presta 
valve stem 118 fits easily within the collar 48 when the camming device 28 
is in the first position. To form an airtight seal around the Presta valve 
stem 118 prior to inflation, the camming device 28 is moved from the first 
or open position, through the second position and into the third position. 
In the third position, the third cam surface 70 is in engagement with the 
top engagement surface 104 of the plunger 42. FIG. 7 shows the camming 
device 28 in the second position with the second cam surface 68 in contact 
with the top engagement surface 104 of the plunger 42, and shows the inner 
wall 50 of the collar 48 bulging under the compression force, but not a 
sufficient amount to create an airtight seal with the Presta valve stem 
118. 
Referring to FIG. 8, the camming device 28 has been moved to the third 
position where the third cam surface 70 is in contact with the top 
engagement surface 104 of the plunger 42, resulting in a net downward 
movement of the plunger 42 of approximately 4.3 mm from its position when 
in contact with the first cam surface 66. The nipple 112 or pin is not in 
contact with the top of the Presta valve stem 118 at this point, but a 
tight seal between the collar 48 and the valve stem 118 has been 
established. As the user begins to inflate the inner tube by pumping air 
through the hose 34 to the pump head 20, the differential pressure between 
the inner tube pressure and the pressure from the pump causes the post 124 
of the Presta valve stem 118 to move axially downwardly into the Presta 
valve stem 118, thus disengaging the seal, and letting air flow into the 
inner tube through the Presta valve stem 118 to inflate the inner tube. 
The air flow, shown by arrows in FIG. 8, moves from the pump (not shown) 
through the air hose 34, through the port 76, through the notches 94 
formed on the top of the spacer 46, and into the Presta valve stem 118 
similar to the air flow in the Schraeder valve stem 36 as described above, 
to inflate the inner tube. 
In the event the Presta valve stem 118 is inserted to the point where the 
nipple 112 contacts the post 124 of the Presta valve stem 118 and slightly 
depresses it, air will escape from the inner tube and pass the collar 48 
until the camming device 28 is moved to the third position. At that time 
the nipple 112 will have pressed the post 124 of the Presta valve stem 118 
even further down to disengage the seal, and allow the air from the pump 
to pass through the Presta valve stem 118 and into the inner tube. 
To remove the pump head 20 from the Presta valve stem 118, the camming 
device 28 is moved from the third position through the second position and 
into the first or open position to disengage the collar 48 and allow the 
internal wall 50 of the collar to reform into its original shape to break 
the sealing engagement of the collar 48 with the Presta valve stem 118. 
The post 124 is then biased upwardly by the inner tube air pressure into a 
sealing position to keep air from escaping through the Presta valve stem 
118. The user then tightens the nut 122 on the post 124 until it is in 
engagement with the top of the Presta valve stem 118 to maintain an 
airtight seal. 
As has been described above, the pump head 20 of the present invention can 
be used on valve stems having different diameters, such as the Schraeder 
36 and Presta 118 valves used in the examples above, without any 
modification of the pump head 20 or the valve stem to facilitate use. The 
movement of the camming device 28 from the first to the second position 
causes the plunger 42 to be pushed downwardly a certain distance which has 
two effects. With the Schraeder valve, the first effect is that it 
compresses the collar 48 to form a seal around the Schraeder valve stem 
36, and the second effect is that it depresses the valve 120 in the 
Schraeder valve stem 36 to allow air to flow through the Schraeder valve 
stem 36 and into the inner tube. 
When used on a Presta valve stem 118, the movement of the camming device 28 
from the first or open position to the third position displaces the 
plunger 42 downwardly even further than when the camming device 28 is in 
the second position, to cause the collar 48 to bulge an even greater 
amount to decrease the inside diameter of the collar 48 to form an 
airtight seal around the relatively smaller diameter Presta valve stem 
118. The nipple 112 or pin has no necessary function in use with the 
Presta valve, although if the nipple does engage the center pest 124 of 
the Presta valve, it only facilitates opening the seal to allow air into 
the Presta valve and thus into the inner tube. 
The seal on the various valve stems formed by the compression of the collar 
48 also generates a substantial gripping force on the valve stem to keep 
the pump head 20 from disengaging from the valve stem during use. The key 
elements of the utility of the pump head 20 of the present invention 
include the amount of any pre-compression loading of the compressible 
collar, the length (height) of the compressible collar, the Durometer 
values associated with the material used in the compressible collar 48, 
the inside diameter of the collar 48, and the wall 50 thickness of the 
compressible collar 48. 
The pump head 20 of the present invention is able to be used, but is not 
limited to use on, both floor pumps and frame pumps. 
An alternative embodiment of the present invention is shown in FIGS. 9 
through 13. In this alternative embodiment, the pump head 150 functions 
fundamentally in the same manner, however some of the components have been 
modified to more easily accept Schraeder and Presta valves. 
Referring first to FIG. 9, an exploded view of the components of this 
embodiment of the present invention is shown. The main housing body, 152 
end cap 154 and camming device 156 enclose the internal working components 
of the present invention in the interior cavity 158 of the main body 152. 
The internal components include a modified plunger 160 defining an axially 
oriented bore 162 having three portions. The first bore portion 164 is 
positioned at the top of the plunger and defines a cylindrical cavity. The 
second bore portion 166 is formed by an annular inwardly extending flange 
168 defining a reduced-diameter bore, and top 170 and bottom 172 
engagement surfaces. The third bore portion 174 is positioned at the 
bottom of the plunger, has a larger diameter than the other two bore 
portions, and is relatively shallow. An annular groove 176 is formed about 
the outside surface of the plunger to receive an o-ring 178. When the 
plunger 160 is positioned in the main body 152, the o-ring 178 forms an 
air-tight seal between the outer surface of the plunger 160 and the inside 
surface of the cavity 158 in the main body 152. The plunger 160 also has 
an annular top surface 180 which engages the camming device 156, as 
defined below. 
A ram-follower 182 is positioned in the bore 162 of the plunger 160, and 
defines a top key 184, a middle cylinder 186, and a bottom ram rod 188. 
The transition between the key 184 and the middle cylinder 186 defines an 
upwardly facing upper annular shoulder 180, and the transition between the 
middle cylinder 186 and the ram rod 188 defines a downwardly facing lower 
annular shoulder 192. An o-ring 194 is received in an annular groove 196 
formed on the outer surface of the middle cylinder 186 to form an air 
tight seal with the wall of the bore 162 when the ram-follower 182 is 
positioned in the bore 162 of the plunger 160, as defined below. 
The ram follower 182 is positioned in the bore 162 formed in the plunger 
160. The ram rod 188 is slidably received through the middle bore portion 
166 and the middle cylinder 186 is sealingly and slidably received in the 
first bore portion 164. The o-ring 194 on the middle cylinder 186 forms 
the air-tight connection between the ram follower 182 and the plunger 160. 
The ram follower 182 is restricted in its downward movement with respect to 
the plunger 160 by the engagement of the lower facing shoulder 192 of the 
middle cylinder 186 and the top engagement surface 170 of the annular 
flange 168, termed the "bottom position". A compression spring 198 is 
preferably positioned between the lower facing shoulder 192 and the top 
engagement surface 170 to bias the ram follower 182 upwardly. The spring 
198 overcomes the frictional engagement of o-ring 194 with the plunger 160 
to push the ram follower upwardly to the length of the spring 198. The 
upward movement of the ram follower 182 in the plunger 160 is limited by 
the sealing engagement between the middle cylinder 186 and the top edge 
200 of the plunger 160. This top-most position of the ram follower 182 in 
the plunger 160 is termed the "top position". 
The spacer 202 used in this alternative embodiment is structurally and 
functionally the same as previously described, with the only change being 
its length dimension. This feature is described in more detail below. The 
top end 204 of the spacer, defining spaced fingers 206, is positioned, or 
seated, in the third bore portion 174 of the plunger 160 in engagement 
with the bottom engagement surface 172 to center the position of the 
spacer under the plunger. The spaces between the fingers 206 allow air to 
flow into the center bore and into the particular valve stem when in use. 
The cylindrical collar 208, or seal gasket, defining an continuous side 
wall 210 having an internal surface 212 and an external surface 214 is 
also structurally and functionally the same as previously described. 
The end cap 154 releasably mounted on the bottom of the main body 152 is 
functionally and structurally the same as previously described. 
The camming device 56 is generally had the same structure and function as 
defined with respect to the first described embodiments. The camming 
device is pivotally attached between the flanges 216 formed by the slot 
218 to be moved from an open, or first, far right position as shown in 
FIG. 10, to a second, or vertical, position (FIG. 11), and to a third, or 
far left, position (see FIG. 12), depending on the type of valve to which 
the pump head 150 is applied. The camming device 156 generally includes a 
substantially square shaped cam head 220 and a handle 222, the cam head 
220 defining first 224, second 226 and third 228 engagement (cam) surfaces 
which are in selective contact with a top surface 180 of the plunger 160 
when in first, second, and third positions, respectively. The first 224, 
second 226 and third 228 engagement surfaces are each at an increasing 
distance, respectively, from the pivot point of the camming device 156, as 
previously described. 
A groove 230 or slot is formed in the third engagement surface 228 on the 
cam head 220. The groove forms a fourth engagement surface formed in and 
displaced away from the third engagement surface. The groove 230 is 
positioned substantially down the middle of the third engagement surface, 
in the same direction the camming device 156 pivots. The groove smoothly 
transitions around the comer of the cam head 220 between the second 226 
and third 228 engagement surfaces. The groove 230 defines side walls 232 
and a base wall 234 (fourth engagement surface). The side walls 232 are 
spaced apart sufficiently to easily receive the key 184 on the top of the 
ram follower 182. The base wall 234 is offset from the third engagement 
surface 228 to be at a substantially shorter distance from the pivot point 
than the third engagement surface. Preferably, the base wall is spaced 
from the pivot point approximately the same as the first engagement 
surface 224. 
The corners of the cam head are rounded to facilitate easy transition from 
one engagement surface to the other. The distance between the pivot point 
223(the point about which the cammed device pivots) and the first corner 
225 between the first 224 and second 226 engagement surfaces is greater 
than the distance between the pivot point 223 and the second engagement 
surface 226. However, this distance can be modified such that it is less 
than the distance between the second engagement surface 226 and the pivot 
point 223. To do this the first corner 225 can be smoothed out. Similarly, 
the distance between the pivot point 299 and the second corner 227 between 
the second 226 and third 228 engagement surfaces is greater than the 
distance between the pivot point 223 and the third engagement surface 228. 
However, this distance can be modified such that it is less than the 
distance between the third engagement surface 228 and the pivot point 223. 
To do this the second corner 227 can be smoothed out. Smoothing the first 
225 and second 227 corners out may facilitate even easier transition 
between engagement surfaces. 
The combination of the plunger and the spacer forms a first 
force-transmitting member 171 which the camming device 156 acts upon. The 
ram follower 182 forms the second force-transmitting member 173 which the 
camming device acts upon. The first 224, second 226 and third 228 cam 
surfaces selectively engage the top of the first force-transmitting member 
171. The first 224, second 226 and fourth 234 cam surfaces selectively 
engage the top of the second force-transmitting member 173. The third cam 
surface 228 engages the top of the first force-transmitting member 171 
simultaneously with the engagement of the fourth cam surface 234 with the 
top of the second force-transmitting member 173. 
In general, actuation of the camming device 156 to the second and third 
positions allows the pump head 150 to grip and sealingly engage different 
sized valve stems, alleviating the need for extra parts or pump head 
modification. More specifically, actuation of the camming device 156 
causes the plunger 160 and the ram follower to be pressed downwardly 
against the spacer 202, which in turn presses downwardly or axially 
against the collar 208. 
The collar 208 is restrained by the base cap 154 on the bottom and the 
interior walls of the chamber 158 along its external surface 214, such 
that when it is axially compressed by the spacer 202 as a result of 
actuation of the camming device 156, the inner wall 212 of the collar 208 
bulges inwardly and thus decreases the inside diameter of the collar 208. 
The further the collar 208 is compressed, the smaller the inside diameter 
of the collar 208 becomes, as fully described above. 
When the camming device 156 is in the first or open position, the first 
engagement surface 224 is in contact with the top surface 180 of the 
plunger 160 and the top of the key 184 of the ram follower 182, but little 
or no force is placed on the collar 208 to alter the inner diameter of the 
collar 208. When the camming device 156 is moved to the second position, 
the second engagement surface 226 contacts the plunger 160 and the top of 
the key 184, and the plunger 160 and the key 184 are pressed or moved 
downwardly a first predetermined distance (substantially equal to the 
difference between the distances of the second engagement surface and the 
first engagement surface from the pivot point) to compress the collar 208 
the same predetermined amount, and in turn reduce the inside diameter of 
the collar 208. When the camming device 156 is moved to its third 
position, the third engagement surface 228 is in contact with the top 
surface 180 of the plunger 160 displacing the plunger 160 even further 
downwardly, resulting in the collar 208 being compressed to a greater 
extent, and further reducing the inner diameter of the collar 208. At the 
transition between the second 226 and third 228 engagement surfaces, the 
key 184 enters the slot 230 to not be offset downwardly as far as the 
plunger 160. Preferably, the plunger is not offset any further downwardly 
than when the key 184 is in engagement with the first engagement surface 
224. The compression spring 198 biases the ram follower 182 upwardly to 
keep the key 184 in engagement with the base wall 234 of the slot 230. 
The changing inner diameter of the collar 208 allows the pump head 150 to 
sealingly engage valve stems of different outer diameters, such as the 
Schraeder and the Presta valve stems. 
The action of the plunger 160, the spacer 202, and the collar 208, being in 
force transmitting contact with one another has been described above. It 
is essentially the same interaction in this alternative embodiment as in 
the first disclosed embodiment. The action of the ram follower 182 upon 
the engagement with the different cam surfaces is somewhat different 
because the ram follower 182 can move relative to the plunder 160 since it 
is sealingly and slidably received within the bore 162 of the plunger 160. 
The movement of tile ram follower 182 is being limited to between the top 
and bottom positions. 
As shown in FIGS. 10 and 11, when a Schraeder valve is inserted into the 
pump head 150 and the camming device 156 is pivoted from the first 224 to 
the second engagement surface 226, the plunger 160 and the ram follower 
182 move downwardly the same amount. The bottom end 236 of the ram rod 188 
engages the valve of the Schraeder valve stem to compress the valve and 
allow air to pass through the valve stem into the inner tube. 
As shown in FIG. 12, when a Presta valve stem is positioned in the pump 
head 150, the plunger 160 and the ram follower 182 are again displaced 
downwardly the same amount. However, when the camming device 156 is 
pivoted to the third position, the third engagement surface 228 displaces 
the plunger 160 downwardly even further. However, because the key 184 is 
received in the slot 230 on the third engagement surface 228, the ram 
follower 182 is not displaced further downwardly. This keeps the bottom 
236 of the ram rod 188 from engaging the valve of the Presta valve stem to 
displace it any further downwardly, which could damage the valve of the 
Presta valve stem, or interfere with air flowing, through the Presta valve 
stem. 
The thickness of the walls of the plunger, spacer, and collar are increased 
in this alternative embodiment. The thickness of the plunger wall defines 
the surface area which the cam surfaces of the camming device engage. The 
more surface area on the top of the plunger 160 that the camming device 
engages, the more distributed the force, which is less likely to damage 
the top surface of the plunger after repeated uses. A metal washer can be 
used on top of the plunger to help further distribute the force of the 
camming device when it engages the plunger 160. The walls of the plunger, 
spacer and collar are made thicker by enlarging the outer diameter of the 
parts, since the inner diameter of the parts must be a certain size to 
receive the particular valve stem. 
One of the problems addressed by the alternative embodiment is that the 
Schraeder valve can be difficult to insert sufficiently into a pump head 
152 because of the Schraeder valve it typically has a slightly conical 
shape. Thus, if the length of the pump head 150 is shortened (for instance 
by shortening the length of the spacer from approximately 0.5 inches to 
approximately 0.34 inches), the Schraeder valve stem does not have to be 
inserted as far into the pump head 150 to work properly. However, the 
Presta valve has to be inserted a specific distance to insure the proper 
fit of the collar 208 around the threads for a good seal. Thus, if the 
Presta valve is inserted into the same pump head 150 with a shortened 
length (because of the shortened spacer 202), then the plunger 160 (first 
embodiment described above), or the ram follower 182, can be pushed too 
far downwardly to engage the valve of the Presta valve stem, which could 
displace it too far downwardly also and damage could result. 
The slot 230 in the third engagement surface 228 of the camming device 156 
allows the ram follower 182 to move independently from the plunder 160 and 
not move any further downwardly. 
The effectiveness of tile pump head 150 of the present invention with 
respect to the Presta valve stem does not rely on the actuation of the 
camming device 156 to depress the valve to allow air into the inner tube. 
This fact means that keeping the bottom 236 of the ram rod 188 from 
depressing, or even touching the valve of the Presta valve stem, is 
satisfactory to allow sufficient flow of air into the inner tube. 
Although the present invention has been described with a certain degree of 
particularity, it is understood that the present disclosure has been made 
by way of example, and changes in detail or structure may be made without 
departing from the spirit of the invention, as defined in the appended 
claims.