FIG. 1 shows an example of a traditional 2-stroke motor reed valve. The reed valve 10 includes a v-shaped base 12, pliable reed petals 14, and stoppers 16. The base is substantially hollow with a plurality of openings covered by the reed petals 14. In operation, air flows into the center of the base 12 and through the openings in the base 12, pushing the reed petals 14 back towards the stoppers 16. When the air reverses flow, the reed petals 14 press firmly against the base 12, covering the openings and substantially impeding airflow.
One problem with the traditional 2-stroke motor reed valve is wear on the reed petals. A reed petal opens and closes 133 times per second if the motor is running at 8,000 rpm. The resulting fatigue on the reed petals requires regular replacement of the reed petals. Therefore, a reed valve design was needed that reduced wear on the reed petals.
FIG. 2 shows a more recent example of a traditional 2-stroke motor reed valve. The reed valve 20 includes a w-shaped base 22, pliable reed petals 24, guards 26, and an inner stopper 28. The design of this reed valve 20 creates a broader opening for passage of air and improved engine performance. Also the reed petals 24 against the guards 26 are not required to bend as far for the reed valve 20 to allow more airflow than the traditional reed valve 10 because of the volume of airflow allowed past the reed petals 24 against the inner stopper 28. The reduced movement radius of the reed petals 24 reduces wear on the reed petals 24. The reed petals 24 against the guards 26 are held between the guards 26 and the base 22 by screws 30. The reed petals 24 against the inside stopper 28 are held in place by the reed cage in the base 22 and the inside stopper 28. Finally, the reed valve 20 is held in place within the motor by a flange 32, which is attached to the base 22 by screws 5.
This more recent reed valve 20 has several problems. One problem is the screws 50 attaching the base 22 to the flange 32 and the screws 30 attaching the base 22 to the guards 26. The screws required are special order screws increasing the cost of assembly. Also, with regular use and repair, the screws need to be repeatedly removed and reinserted, causing the screws and screw holes to become stripped. This can, in turn, result in the screws falling into the motor, significantly damaging the motor. Therefore a reed valve is needed that does not contain screws.
Another problem with the reed valve 20 is assembly time. The number of parts and screws to be assembled with assorted tools increases the assembly time used to make the reed valve. Labor costs cause the reed valve to be unduly expensive.
In response to these problems, the most recent example of a traditional 2-stroke motor reed valve, described in U.S. patent application Ser. No. 10/142,509, was invented.
One embodiment of this reed valve assembly 40, as shown in FIG. 3, includes a reed cage 42, a retainer 44, and reed petals 46. The retainer 44 is independently interlockable with the reed cage 42. Independently interlockable is understood to mean that no separate parts are required to connect the retainer 44 to the reed cage 42. As implied by the term interlockable, the retainer 44 and reed cage 42 are separable. The reed petals 46 are removably secured to the reed cage 42 by the retainer 44.
In that embodiment, the reed petals 46 are secured to the reed cage 42 with the retainer 44. The retainer 44 is a flange 44a, one of several possible embodiments for the retainer 44. Tabs 48 are formed in the reed cage 42. The reed petals 46, with holes 50 formed therein, fit over the tabs 48. The flange 44a is slotted 52 to accept the tabs 48, thereby interlocking the retainer 44 to the reed cage 42 and securing the reed petals 46 in place.
In another embodiment, as shown in FIG. 4, the reed valve assembly 40 has a w-shaped reed cage 42 as is designed such that the reed petals 46 pivot on the base 54 of the reed cage 42 to open at the tip 56 of the reed cage 42, allowing airflow moving from the base 54 to the tip 56. The reed petals 46 include inner reed petals 62 removably secured to the reed cage 42 by an insert 64 and outer reed petals 66 removably secured to the reed cage 42 with the flange 44a. This embodiment requires the reed cage 42 to be in a w-shape or some other multiple v-shapes (wherein the w-shape is the equivalent of abutting v-shapes). The insert 64 independently interlocks with the reed cage 42 to hold the reed petals 46 in place. The only difference between the inner reed petals 62 and outer reed petals 66 in this embodiment is the means of securing. This embodiment is further narrowed wherein the top of the inner reed petals 62 is located above the top of the outer reed petals 66.
While this most recent example of a traditional reed valve assembly, described in U.S. patent application Ser. No. 10/142,509, is an improvement over other traditional reed valves, it, nevertheless, has the problem of still requiring significant assembly time to align the reed cage, petals and retainer and to interlock them.