BACKGROUND OF THE INVENTION
The present invention relates to a valve device for a pump and, more particularly, to a valve device that is mounted between a piston and an air output tube of a vertical pump and that prevents reverse flow of air during inflation.
FIGS. 1 and 2 show a vertical pump for bicycles. Vertical pumps generally include miniature, portable type and floor type. A floor type pump is placed on a floor when in use. Both types of vertical pumps have common features. Taking the vertical pump P shown in FIGS. 1 and 2 as an example, the vertical pump P includes a barrel 10 having a bore 101. A valve device 60 is mounted to a lower end of the barrel 10 and includes a one-way valve structure. A base 30 having a larger area is mounted below the valve device 60. A hose 50 has an end connected to a side of the valve device 60. The other end of the hose 50 has a nozzle 51 for engaging with a valve of a tire. High pressure air currents flow from the valve device 60 and through the hose 50 to the tire for inflating purposes. A top cap 11 is mounted on a top end of the barrel 10 and includes a central opening through which a piston rod 42 of an inflating device 40 extends. A hooked portion 111 is provided on a side of the top cap 11 for retaining the hose 50. A handle 41 is provided on an upper end of the piston rod 42 for manual operation. A piston 43 is mounted to an inner end of the piston rod 42 in the barrel 10. In use, a user engages the nozzle 51 with the valve of the tire and grips and moves the handle 41 to inflate air into the tire. A leg of the user can step on the base 30 to retain the vertical pump P on the floor. Then, the user can move the piston rod 42 up and down for inflating operation. Air is driven into the tire under vertical movement of the piston 43 after passing through the valve device 60, the hose 50, and the nozzle 51.
An example of the valve device 60 of FIG. 2 is disclosed in Taiwan Utility Model No. M364772. Specifically, the valve device 60 includes a valve body 61, a plug valve 62, a plug 63, and a pressure spring 64. The plug valve 62 is mounted in the valve body 61. The valve body 61 includes a port 611 located below the plug valve 62. The port 611 is coupled with the hose 50. The barrel 10 is threadedly engaged with the valve body 61 at a location above the plug valve 62. Thus, the top end of the plug valve 62 can be inserted into the bore 101 and in airtight contact with the barrel 10.
With reference to FIG. 3, the plug valve 62 includes an opening 621 in the top end thereof and a chamber 622 below and larger than the opening 621. The plug valve 62 further includes an annular groove in an outer periphery thereof for receiving an O-ring 623 in airtight contact with an inner periphery of the bore 10. The plug 63 includes a plug body 632 and a smaller tip 631 on a top end of the plug body 632. The tip 631 is movably received in the opening 621. After the inflation stroke, the air pressure from the tire flowing back into the chamber 622 via the hose 50 pushes the plug 63 upward, causing the plug body 632 to press against a conic joint area between the opening 621 and the chamber 622, forming an airtight state to prevent reverse flow of air. A lower end of the plug body 632 includes a reduced section 633 forming a shoulder. A portion of the pressure spring 64 is mounted around the reduced section 633 and abuts the shoulder, biasing the plug 63 upward to press against the joint area between the opening 621 and the chamber 622. During the inflation stroke, air currents flow through the opening 621, and the plug body 632 is moved downward by the air pressure, revealing the opening 621. Thus, air can be outputted through the port 611 and the hose 50. In a balanced state, the air pressure F1 outputted from the bore 101 is equal to the reverse pressure F2 that is the sum of the spring force and the tire pressure. The larger the ratio of the cross-sectional area A2 of the plug body 632 to the cross-sectional area A1′ of the opening 621, the smaller the pressure F1 outputted from the bore 101 is required.
However, the plug 63 is in the form of a cylinder having a considerable length and, hence, a smaller, limited cross-sectional area A2. Furthermore, the plug 63 must include a conic section to press against the conic joint area between the opening 621 and the chamber 622 for airtight purposes. Furthermore, the air pressure acting on the plug 63 has an active vertical component that moves the plug 63 downward and an inactive horizontal component that may cause undesired movement of the top 631 in a transverse direction (FIG. 3). The user has to apply larger force to overcome the reverse pressure F2. In another approach, the plug is in the form of a ball and has the same disadvantages. If the diameter of the ball is increased to increase the cross-sectional area A2, the ball would be too large while still having the disadvantage of reduced active force during the inflation stroke.
FIG. 4A shows another conventional valve device using a disk 65 for sealing the opening 621. However, the disk 65 is made of soft material such as rubber and, thus, apt to deform under pressure. Thus, a protrusion 651 is likely to appear on the disk 65 under the action of the large air pressure of the tire, as shown in FIG. 4B. As a result, the disk 65 can not seal the opening 621 after the inflation stroke. The larger the curvature of the protrusion 651, the more the air leaks.
Thus, a need exists for a novel valve device for a vertical pump.
BRIEF SUMMARY OF THE INVENTION
In an aspect, the present invention provides a pump including a base having an engagement section. A nozzle is adapted to be coupled to the base. A barrel is engaged with the engagement section of the base and has a bore. A piston rod includes an upper end outside of the barrel and a lower end received in the bore of the barrel. A handle is mounted to the upper end of the piston rod. A piston is mounted to the lower end of the piston rod. A valve device includes a valve seat and a cap. The valve seat is mounted between the barrel and the engagement section of the base. The valve seat includes a compartment and a passageway in communication with a lower end of the compartment. The cap is mounted in the compartment and includes an opening in communication with the bore of the barrel. The cap further includes a chamber located intermediate and in communication with the opening of the cap and the passageway of the valve seat. A disc is mounted in the chamber and has a thickness smaller than a height of the chamber. A spring is mounted in the passageway of the valve seat and located between the base and a bottom end of the disc, biasing the disc towards the opening of the cap. The disc includes a top portion, at least one channel, and at least one abutting portion. A gasket is mounted to the top portion of the disc. The gasket has an upper edge located above the top portion of the disc. The gasket has a sealing diameter that is a spacing between two centers respectively of two circles on a cross-sectional plane including a central line of the gasket. The sealing diameter is larger than a diameter of the opening of the cap and larger than the thickness of the disc.
Preferably, with the engagement section of the base includes a fixing portion at a lower end thereof. The fixing portion includes a port adapted to be in communication with the nozzle. The fixing portion includes a plurality of holes.
Preferably, a hose is mounted between the port and the nozzle.
Preferably, the valve seat includes an annular groove in an outer periphery thereof. An O-ring is received in the annular groove and in sealing contact with an inner periphery of the bore.
Preferably, the valve seat includes an outer threading. The barrel includes a lower end having an inner threading threadedly engaged with the outer threading of the valve seat. The valve seat includes a plurality of screw holes aligned with the plurality of holes of the fixing portion. A plurality of screws extends through the plurality of holes of the fixing portion into the plurality of screw holes, fixing the valve seat in the engagement section of the base.
Preferably, the cap includes an outer threading. The compartment of the valve seat includes an inner threading. The outer threading of the cap is threadedly engaged with the inner threading of the compartment.
Preferably, an O-ring is mounted to an upper end of an outer periphery of the cap, providing airtight contact between the outer periphery of the cap and an upper end of an inner periphery of the compartment of the valve seat.
Preferably, the at least one channel is formed in an outer periphery of the disc for guiding air currents from the opening to the passageway. The at least one abutting portion includes at least one protrusion formed on the bottom side of the disc and defines at least one air passageway. The spring abuts said at least one protrusion. The air currents from the opening flow through the at least one channel and the at least one air passageway into the passageway of the valve seat during an inflation stroke of the pump.
Preferably, the disc includes a maximum diameter larger than the sealing diameter of the gasket.
The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a vertical pump having a conventional valve device.
FIG. 2 shows a partial, enlarged, cross sectional view of the vertical pump of FIG. 1.
FIG. 3 shows an enlarged view of a circled portion of FIG. 2.
FIG. 4A shows an enlarged view of another conventional valve device for a pump.
FIG. 4B shows deformation of a disk of the conventional valve device of FIG. 4A during operation.
FIG. 5 shows a partial, cross sectional view of a pump according to the present invention.
FIG. 6 shows an exploded, perspective view of a valve device of the pump of FIG. 5.
FIG. 7 shows an enlarged view of a circled portion of FIG. 5, with a disc in an open position during an inflating stroke of the pump.
FIG. 8 is a view similar to FIG. 7, with the disc in a blocking position.
FIG. 9A is a view similar to FIG. 7, illustrating a modified embodiment of the valve device according to the present invention.
FIG. 9B is a view similar to FIG. 7, illustrating another modified embodiment of the valve device according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 5 and 6, a pump according to the present invention includes a barrel 10, a valve device 20, and a base 30. The barrel 10 has a bore 101 in which a piston rod 42 is slideably received. A handle is mounted to an upper end of the piston rod 42 that extends beyond the barrel 10. A piston 43 is mounted to a lower end of the piston rod 42 received in the barrel 10. An O-ring 431 is mounted around the piston 43 and in airtight contact with an inner periphery of the barrel 10. The upper and lower ends of the piston rod 42 are spaced in a longitudinal direction.
The base 30 includes an engagement section 33 in which the valve device 20 is mounted. The engagement section 33 includes a fixing portion 31 at a lower end thereof. The fixing portion 31 includes a port 311 in communication with an air output tube, such as a hose. The fixing portion 31 further includes a plurality of holes 32.
The valve device 20 is mounted in a space defined by the engagement section 33 of the base 30 and the barrel 10. The valve device 20 includes a valve seat 21 and a cap 22. The valve seat 21 includes a compartment 213 having an upper end facing the bore 101 and a passageway 215 in communication with a lower end of the compartment 213. An O-ring 212 is mounted in an annular groove formed in an outer periphery of the valve seat 21 to provide airtight contact with the inner periphery of the barrel 10. The compartment 213 of the valve seat 21 includes an inner threading. The valve seat 21 further includes an outer threading 214 threadedly engaged with an inner threading formed in the lower end of the barrel 10. The valve seat 21 further includes a plurality of screw holes 211 aligned with the holes 32 of the fixing portion 31. Screws 25 are extended through the holes 32 into the screw holes 211, fixing the valve seat 21 in the engagement section 33 of the base 30.
The cap 22 includes an outer threading 223 threadedly engaged with the inner threading of the compartment 213 of the valve seat 21, removably fixing the cap 22 in the compartment 213. The cap 22 further includes an opening 221 in communication with the bore 101 of the barrel 10. The cap 22 further includes a chamber 222 located intermediate and in communication with the opening 221 of the cap 22 and the passageway 215 of the valve seat 21. A disk 23 is mounted in the chamber 222. The chamber 222 has a height in the longitudinal direction larger than an overall height of the disk 23 in the longitudinal direction, allowing movement of the disk 23 in the longitudinal direction between an open position (FIG. 7) and a blocking position (FIG. 8). A spring 24 is mounted in the passageway 215 of the valve seat 21 and located between the fixing portion 31 and the disk 23, biasing the disk 23 from the open position to the blocking position. An O-ring 224 is mounted to an upper end of an outer periphery of the cap 22, providing an airtight effect between the outer periphery of the cap 22 and an upper end of an inner periphery of the compartment 213 after the cap 22 is threadedly engaged with the valve seat 21. The cap 22 can be disengaged from the valve seat 21 for easy maintenance and repair.
With reference to FIGS. 6, 7, and 8, the disk 23 includes a top portion 231. A maximum diameter A3 of the disk 23 (the diameter of a lower portion in this embodiment) perpendicular to the longitudinal direction is larger than an outer diameter of the top portion 231 perpendicular to the longitudinal direction. A gasket 234 in the form of a ring is mounted the top portion 231. An outer diameter of the gasket 234 perpendicular to the longitudinal direction is smaller than the diameter of the lower portion of the disk 23. At least one channel 232 is defined in an outer periphery of the disc 23 for guiding air currents. At least one abutting portion 233 is provided on a bottom side of the disk 23. In the form shown, the disk 23 includes four channels 232 and four abutting portions 233 in the form of protrusions. An upper end of the spring 24 abuts the abutting portions 233, leaving a gap between the bottom side of the disk 23 and the top side of the valve seat 21. The abutting portions 233 also form air passageways between the channels 232 and the passageway 215. Thus, air from the bore 101 can flow through the opening 221, the channels 232, and the air passageways into the passageway 215 of the valve seat 21 when the disk 23 is in the open position. After the gasket 234 is mounted around the top portion 231 of the disk 23, an upper edge of the gasket 234 is located above the top portion 231 of the disc 23 (i.e., located intermediate an upper end wall of the chamber 222 of the cap 22 and the top portion 231 of the disk 23). The gasket 234 has a sealing diameter Ac perpendicular to the longitudinal direction. The sealing diameter Ac is the spacing between two centers respectively of two circles on a cross-sectional plane including a central line of the gasket 234 and perpendicular to the longitudinal direction. The sealing diameter Ac is larger than the diameter A1 of the opening 221 of the cap 22 and larger than a thickness h of the disc 23 in the longitudinal direction. By such an arrangement, an airtight state is obtained by pressing the gasket 234 against the upper end wall of the chamber 222 when the disk 23 is in the blocking position under the bias of the spring 24 while the pump is not in the inflation operation.
Specifically, the upper end wall of the chamber 222 lies in a plane parallel to the sealing diameter Ac of the disc 23. The force acting on the disc 23 has no inactive horizontal component and, thus, actively pushes the disc 23 and overcomes the spring 24 during the inflation stroke. Furthermore, the airtight effect between the gasket 234 and the upper end wall of the chamber 222 is excellent, eliminating the need of processing precision required in conventional surface-to-surface contact design. Further, deformation of the gasket 234 is less likely to occur due to support from the disk 23. Further, the sealing diameter Ac of the disk 23 perpendicular to the longitudinal direction is larger than the height h of the disc 23 in the longitudinal direction, such that the overall volume of the disk 23 can be reduced while providing the largest cross sectional area. In a balanced state, the larger the ratio of the cross-sectional area of the disc 23 to the cross-sectional area of the opening 221, the smaller the pressure outputted from the bore 101 is required. The user can apply smaller force to push the disk 23 downward and to overcome the spring 24 during the inflation stroke. Furthermore, the maximum diameter A3 of the disk 23 provides an increased contact area between the air currents leaving the opening 221 and the disk 23, such that the air currents can continuously maintain the disk 23 in the open position, achieving enhanced inflating effect.
FIG. 9A shows a modified embodiment of the valve device 20. Specifically, the disk 26 includes a recessed portion 261 in a top end thereof, forming an annular wall 262. A gasket 264 in the form of a ring is received in the recessed portion 261. On or more abutting portions 263 are provided on a bottom side of the disk 26. One or more channels 266 are formed in an outer periphery of the disk 26. The channels 266 and abutting portions 263 are similar to the channels 232 and abutting portions 233 of the disk 23. An upper edge of the gasket 264 is located above the top portion 231 of the disc 23. The gasket 264 has a sealing diameter Ac perpendicular to the longitudinal direction. The sealing diameter Ac is larger than the diameter A1 of the opening 221 of the cap 22 and larger than a thickness h of the disc 23 in the longitudinal direction.
In another modified embodiment shown in FIG. 9B, the gasket 26 includes a solid, cylindrical portion and an annular protrusion 2651 formed on an upper side of the solid, cylindrical portion. The annular protrusion 2651 is located above the top portion 231 of the disc 23. The gasket 264 has a sealing diameter Ac perpendicular to the longitudinal direction. The sealing diameter Ac is larger than the diameter A1 of the opening 221 of the cap 22 and larger than a thickness h of the disc 23 in the longitudinal direction. The gasket 264 shown in FIG. 9B includes channels 266 and abutting portions 263 similar to those of the gasket 264 shown in FIG. 9A.
In view of the foregoing, the valve device 20 according to the present invention allows the user to apply less force to achieve the same inflating effect while providing airtight effect in the air intake stroke. Furthermore, the valve device 20 can be assembled or detached easily, allowing easy maintenance.
Although specific embodiments have been illustrated and described, numerous modifications and variations are still possible without departing from the essence of the invention. The scope of the invention is limited by the accompanying claims.
Patent Application
20110280756
