Ratcheted fuel cap
A fuel tank cap that is engageable with a neck of a fuel tank. The fuel tank cap includes a cap shell that has a cover portion and a substantially cylindrical wall extending from the cover portion to define a substantially cylindrical chamber. An arm extends from the cover portion toward the fuel tank. An inner shell is at least partially disposed within the cylindrical chamber. The inner shell includes an engagement portion that is engageable with the neck and a protrusion that is engageable with the arm to selectively couple the cap shell and the inner shell for rotation in unison.
The present invention relates to a fuel tank cap, and particularly to a fuel tank cap that inhibits overtightening and indicates proper tightening.
Internal combustion engines are often used to power small equipment such as lawnmowers, tillers, snow throwers, pressure washers, generators, and the like. Typically, these engines include a fuel system that supplies fuel for combustion. The fuel system includes a tank, in which fuel is stored for use and a cap that can be removed to add fuel to the tank. The fuel tank cap is typically threaded on the tank or on a fill spout attached to the tank.
Generally, small engines include a fuel tank cap that includes a gasket or resilient component that seals against the tank fill spout. The gasket is designed to provide a seal when tightened to a predetermined torque. However, some users tend to overtighten or undertighten the fuel tank cap. When the cap is overtightened, the gasket becomes crushed and can become damaged. The damage can reduce the effectiveness of the gasket, thus resulting in excess fuel vapor leakage, increased evaporative emissions, and spillage during operation. If the cap is undertightened, the gasket cannot provide a proper seal, thus resulting in excess fuel vapor leakage, increased evaporative emissions, and spillage during operation.
SUMMARYThe invention provides a fuel tank cap that is engageable with a neck of a fuel tank. The fuel tank includes a fuel chamber that is adapted to contain fuel. The fuel tank cap includes a cap shell that has a cover portion and a substantially cylindrical wall extending from the cover portion to define a substantially cylindrical chamber. An arm extends from the cover portion toward the fuel chamber of the fuel tank when the cap is installed on the fuel tank. The arm defines a longitudinal axis that is substantially orthogonal to the cover portion. An inner shell is at least partially disposed within the cylindrical chamber. The inner shell includes an engagement portion that is engageable with the neck and a protrusion that is engageable with the arm to selectively couple the cap shell and the inner shell for rotation in unison.
The invention also provides a fuel tank cap engageable with a neck that defines a neck axis. The fuel tank cap includes an inner shell that is rotatable relative to the neck to move between an engaged position and a disengaged position. A cap shell includes an arm that defines an arm axis. A protrusion extends from the inner shell. The protrusion cooperates with the arm to couple the inner shell and the cap shell for rotation in unison from the disengaged position to the engaged position. The protrusion displaces the arm such that the cap shell rotates independent of the inner shell when rotated beyond the engaged position. The protrusion is engaged with the arm to couple the inner shell and the cap shell for rotation in unison from the engaged position to the disengaged position.
The invention also provides a fuel cap that is engageable with a neck of a fuel tank that defines a neck axis. The fuel tank also includes a fuel chamber adapted to contain fuel. The fuel cap includes a cap shell that has a cover portion that is substantially normal to the neck axis and a substantially cylindrical wall that extends from the cover portion to define a substantially cylindrical chamber. An arm extends from the cover portion toward the fuel chamber of the fuel tank. An inner shell is at least partially disposed within the cylindrical chamber and is engageable with the neck. The inner shell is rotatable relative to the neck to move between a disengaged position and an engaged position. A protrusion has a first side and a second side. The first side is engageable with the arm to couple the cap shell and inner shell for rotation from the engaged position to the disengaged position. The second side is engageable with the arm to couple the cap shell and inner shell for rotation from the disengaged position to the engaged position when a rotational torque is below an engaged value. The second side is operable to displace the arm such that the cap shell rotates independent of the inner shell when the rotational torque exceeds the engaged value.
BRIEF DESCRIPTION OF THE DRAWINGSThe detailed description particularly refers to the accompanying figures in which:
With reference to
As shown in
With continued reference to
Each arm 75 is disposed near one of the lobe spaces 70 such that a radially outward force applied to the arm 75 will deflect the arm 75 into the lobe space 70. The cap shell 40 also includes a circumferential groove 85 and a clearance space 90 that extend around the interior of the cylindrical wall 50.
In addition to the cap shell 40, the fuel tank cap 20 includes an inner shell 95 and a gasket 100. The inner shell 95, best illustrated in
The outer surface 110 also includes a plurality of protrusions 125 that extend radially outward from the outer surface 110. In most constructions, there is one protrusion 125 for each arm 75. Thus, in the illustrated constructions, there are five protrusions 125 extending from the outer surface 110. Of course, other constructions may employ fewer protrusions 125 than arms 75, or more protrusions 125 than arms 75 if desired. For example, one construction may include two protrusions 125 for each arm 75.
The inner surface 115 of the inner shell 95 includes threads 35 that correspond with the threads 30 of the fill neck 25. Thus, when the cap 20 is installed on the fuel tank 15, the inner shell 95 engages the fill neck 25 and is rotated relative to the fill neck 25 to loosen or tighten the cap 20.
As shown in
The inner shell 95 includes a substantially planar flange 155 that extends around the end of the cylindrical portion 105 and cooperates with the cap shell 40 to trap a tether 160 as shown in
The gasket 100 (sometimes referred to as a liner or seal) fits within the inner shell 95 and cooperates with the fill neck 25 to form a seal. As illustrated in
In another construction, the gasket 100 cooperates with the inner surface of the inner shell 95 to define a tapered neck-receiving space. Because the neck-receiving space is tapered, the torque required to tighten the fuel tank cap 20 is not constant. Rather, the torque that must be applied to tighten the cap 20 continues to increase as the cap 20 is tightened and the fill neck 25 extends into the more narrow portions of the neck-receiving space. The fill neck 25 compresses the gasket 100 as it moves into the neck-receiving space to establish a seal between the cap 20 and the fill neck 25.
In another construction, the gasket 100 and inner shell 95 are formed together as a single component. This construction has the advantages of reducing the number of components and the complexity of the assembly. However, it is not possible to use different materials in this construction. As such, the seal achievable with this construction may not be suitable in all applications.
With reference to
The arm 75 includes a first angled surface 190 on the clockwise side (from the bottom view) and a second angled surface 195 on the counterclockwise side (from the bottom view). While both surfaces 190, 195 could be angled such that they are parallel, the second surface 195 is angled more acutely than the first surface 190. The protrusion 125 includes a planar surface 200 and an arcuate surface 205. The planar surface 200 is disposed on the counterclockwise side (from the bottom view) of the protrusion 125 and the arcuate surface 205 is disposed on the clockwise side (from the bottom view). The planar surface 200 is angled to substantially match the angle of the first angled surface 190.
With reference to
In operation, the fuel tank cap 20 is positioned on the fill neck 25 and rotated to begin tightening the cap 20. The cap shell 40 rotates about the neck axis 60 independent of the inner shell 95 until the arcuate surfaces 205 of the protrusions 125 engage the second angled surfaces 195, as illustrated in
As shown in
Thus, to remove the cap 20, the cap shell 40 is rotated in the clockwise direction 180 (as shown in
The cap arrangement described herein increases the likelihood that a proper seal between the cap 20 and the fill neck 25 is established each time the cap 20 is installed. In addition, the cap 20 provides both audible and tactile feedback to the user that indicates that the cap 20 has been properly tightened. Furthermore, the arrangement of the arms 75 within the cap 20 (and displaceable into the lobe spaces 75), allows for a cap 20 that has a reduced height when compared to other caps. The reduced height is particularly advantageous when the engine is used with equipment that includes an engine cover such as riding lawn mowers, snow throwers, and the like. The reduced height of the cap allows for a closer fit between the cover and the engine. In addition, tall caps can be unsightly and thus undesirable, while wide caps are generally more visually appealing and do not require additional space as they are typically disposed on top of a wide fuel tank.
Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.
Claims
1. A fuel tank cap engageable with a neck of a fuel tank, the fuel tank having a fuel chamber adapted to contain fuel, the fuel tank cap comprising:
- a cap shell including a cover portion and a substantially cylindrical wall extending from the cover portion to at least partially define a substantially cylindrical chamber;
- an arm extending from the cover portion toward the fuel chamber of the fuel tank when the fuel tank cap is installed on the fuel tank; and
- an inner shell at least partially disposed within the cylindrical chamber, the inner shell including an engagement portion that is engageable with the neck and a protrusion engageable with the arm to selectively couple the cap shell and the inner shell for rotation in unison.
2. The fuel tank cap of claim 1, wherein the cap shell includes a lobe that defines a lobe space, the lobe space disposed near the arm.
3. The fuel tank cap of claim 2, wherein the arm is substantially disposed outside of the lobe space when the cap shell and inner shell are coupled for rotation and the arm is deflected at least partially into the lobe space to decouple the cap shell and the inner shell.
4. The fuel tank cap of claim 2, wherein the arm is one of a plurality of arms and the lobe is one of a plurality of lobes, each lobe defining a lobe space and each arm disposed near one of the lobe spaces.
5. The fuel tank cap of claim 4, wherein each of the plurality of arms is deflectable into the lobe space to decouple the cap shell and the inner shell such that the cap shell is rotatable relative to the inner shell
6. The fuel tank cap of claim 1, wherein the engagement portion includes threads.
7. The fuel tank cap of claim 1, wherein the protrusion includes a first side engageable with the arm to couple the cap shell and the inner shell for rotation in unison.
8. The fuel tank cap of claim 7, wherein the first side is substantially planar.
9. The fuel tank cap of claim 7, wherein the protrusion includes a second side engageable with the arm to couple the cap shell and the inner shell for rotation in unison when a torque applied to the cap shell is at or below an engaged value.
10. The fuel tank cap of claim 9, wherein the second side of the protrusion engages and displaces the arm to allow the cap shell to rotate relative to the inner shell when the torque value exceeds the engaged value.
11. The fuel tank cap of claim 9, wherein the second side is not planar.
12. The fuel tank cap of claim 1, wherein the cap shell includes one of a bead and a recess that extends around the cylindrical wall, and the inner shell includes the other of the bead and recess, the bead engaged with the recess to rotationally couple the cap shell and the inner shell.
13. The fuel tank cap of claim 1, wherein the arm is connected to the cover portion such that the arm is supported in a cantilever fashion.
14. A fuel tank cap engageable with a neck that defines a neck axis, the fuel tank cap comprising:
- an inner shell rotatable relative to the neck to move between an engaged position and a disengaged position;
- a cap shell including an arm that defines an arm axis; and
- a protrusion extending from the inner shell, the protrusion cooperating with the arm to couple the inner shell and the cap shell for rotation in unison from the disengaged position to the engaged position, the protrusion displacing the arm such that the cap shell rotates independent of the inner shell when rotated beyond the engaged position, the protrusion engaged with the arm to couple the inner shell and the cap shell for rotation in unison from the engaged position to the disengaged position.
15. The fuel tank cap of claim 14, wherein the arm axis is substantially parallel to the neck axis.
16. The fuel tank cap of claim 14, wherein the inner shell includes a threaded portion and the neck includes a threaded portion, the inner shell threadably engageable with the neck.
17. The fuel tank cap of claim 14, wherein the cap shell includes a cover portion that is substantially normal to the neck axis and wherein the arm extends in a cantilever fashion from the cover portion.
18. The fuel tank cap of claim 14, wherein the cap shell includes a lobe defining a lobe space, and wherein a portion of the arm is movable into the lobe space.
19. The fuel tank cap of claim 18, wherein the arm is one of a plurality of arms, and the lobe is one of a plurality of lobes, each lobe defining a lobe space, at least a portion of each arm movable into one of the lobe spaces.
20. The fuel tank cap of claim 19, wherein the protrusion is one of a plurality of protrusions and wherein the number of protrusions is substantially equal to the number of arms.
21. The fuel tank cap of claim 14, wherein the arm Includes a first angled surface and the protrusion includes an angled surface engageable with the first angled surface to couple the cap shell and the inner shell for rotation.
22. The fuel tank cap of claim 21, wherein the first angled surface and the angled surface are angled such that when engaged, rotation of the cap shell produces a force that biases the arm toward the inner shell.
23. The fuel tank cap of claim 21, wherein the arm includes a second angled surface and the protrusion includes an arcuate surface engageable with the second angled surface to couple the cap shell and the inner shell for rotation.
24. The fuel tank cap of claim 23, wherein the second angled surface and the arcuate surface are such that when engaged, rotation of the cap shell produces a force that biases at least a portion of the arm away from the inner shell.
25. A fuel tank cap engageable with a neck of a fuel tank that defines a neck axis, the fuel tank also having a fuel chamber adapted to contain fuel, the fuel tank cap comprising:
- a cap shell including a cover portion that is substantially normal to the neck axis and a substantially cylindrical wall extending from the cover portion to at least partially define a substantially cylindrical chamber;
- an arm extending from the cover portion toward the fuel chamber of the fuel tank;
- an inner shell at least partially disposed within the cylindrical chamber and engageable with the neck, the inner shell rotatable relative to the neck to move between a disengaged position and an engaged position; and
- a protrusion having a first side and a second side, the first side engageable with the arm to couple the cap shell and inner shell for rotation from the engaged position to the disengaged position, the second side engageable with the arm to couple the cap shell and inner shell for rotation from the disengaged position to the engaged position when a rotational torque is below an engaged value, the second side operable to displace the arm such that the cap shell rotates independent of the inner shell when the rotational torque exceeds the engaged value.
26. The fuel tank cap of claim 25, wherein the inner shell includes a threaded portion and the neck includes a threaded portion, the inner shell threadably engageable with the neck.
27. The fuel tank cap of claim 25, wherein the cap shell includes a lobe defining a lobe space, and wherein a portion of the arm is movable into the lobe space.
28. The fuel tank cap of claim 27, wherein the arm is one of a plurality of arms, and the lobe is one of a plurality of lobes, each lobe defining a lobe space, at least a portion of each arm movable into one of the lobe spaces.
29. The fuel tank cap of claim 28, wherein the protrusion is one of a plurality of protrusions, the quantity of protrusions being substantially equal to the quantity of arms.
30. The fuel tank cap of claim 25, wherein the arm includes a first angled surface and the protrusion includes an angled surface engageable with the first angled surface to couple the cap shell and the inner shell for rotation.
31. The fuel tank cap of claim 30, wherein the first angled surface and the angled surface are angled such that when engaged, rotation of the cap shell produces a force that biases the arm toward the inner shell.
32. The fuel tank cap of claim 30, wherein the arm includes a second angled surface and the protrusion includes an arcuate surface engageable with the second angled surface to couple the cap shell and the inner shell for rotation.
33. The fuel tank cap of claim 32, wherein the second angled surface and the arcuate surface are arranged such that when engaged, rotation of the cap shell produces a force that biases the arm away from the inner shell.
Type: Application
Filed: Dec 13, 2004
Publication Date: Jun 15, 2006
Inventor: James Dehn (Brookfield, WI)
Application Number: 11/010,920
International Classification: B65D 43/18 (20060101); B65D 55/16 (20060101); B65D 55/02 (20060101);