GB2066222A - A locking cap for a threaded filler neck - Google Patents

Abstract

A locking cap for a threaded filler neck includes a closure member (12) for engaging and closing the neck, a shell (50) providing a hand grip and including a key-operated lock (54), and a race (42) disposed for rotation between the shell and closure. The race (42) includes axially inwardly opening pockets (44), and the closure includes flexible pawl fingers (34) for engaging the pockets to provide a driving connection between the closure and race which is positive in the cap-removal direction and torque- limited in the cap-advancing direction. The race also includes a set of peripherally spaced, radially inwardly projecting teeth (47). A lock-controlled bolt mechanism (62) is mounted in a hub which is connected for rotation with the shell (50) and is removable by the lock to a cap-removal position. The bolt (74), Figure 7, of the bolt mechanism engages driving teeth (31) provided within the closure member. The driving teeth (31) are formed such that rotation of the shell in the cap-advancing direction, after the lock has been returned to the cap-locking position, cams the bolt out of engagement with the driving teeth. The hub also provides a pair of flexible drive fingers (92), Figure 8, for engaging the peripherally spaced and radially inwardly projecting teeth (47) to provide a driving connection between the shell (50) and race (42) which is positive in the cap-advancing direction and torque- limited in the cap-removal direction for free ratcheting of the cap when it is in position on the filler neck and locked. <IMAGE>

Description

SPECIFICATION A locking cap for a threaded filler neck This invention relates to a locking closure cap for a vehicle fuel tank threaded filler neck, and particularly to a cap of substantially all-plastics construction and having a low axial profile.

It is an object of the invention to provide a locking cap for a threaded filler neck which is simple and easy to manufacture.

According to this invention there is provided a locking cap for a threaded filler neck, the cap comprising:- a threaded closure adapted to engage and close the neck; a key-openable lock; a shell including means for retaining the lock; an annular race disposed for rotation between the shell and closure, the race including first engaging means and the closure including second engaging means for engaging the first engaging means to provide a driving connection between the closure and race which is positive in the cap-removal direction and torque-limited in the cap-advancing direction, the race further including third engaging means, the shell including a hub mounted for rotation with the shell and providing fourth engaging means for engaging the third engaging means to provide a driving connection between the third and fourth engaging means which is positive in the capadvancing direction and torque-limited in the capremoval direction; and bolt means mounted for rotation with the shell, and fifth engaging means on the closure, the bolt means being openable by key actuation of the lock for movement into engagement with the fifth engaging means to couple the bolt means and shell directly to the closure to permit removal of the cap from the filler neck.

The cap of the invention permits a low axial profile for the threaded fuel tank filler neck cap. Such a cap requires less space for the apparatus required to operate the unlocking and cap-removal mechanism.

The shell may include a portion which is integrally moulded with flexible fingers forming a part of the unlocking mechanism. Much of the cap can be constructed of moulded plastics material. An advan tageofthisconstruction is that such parts can be made quite inexpensively in two-part moulds.

The invention will now be described by way of example with reference to the drawings, in which: Figure 1 is an axial section partly in side elevation of a threaded locking petrol tank cap in accordance with the invention; the section is taken on the line 1 1 of Figure 2; Figure 2 is a section on plane 2 - 2 of Figure 1, showing the lock in an unlocking, or cap removal, position; Figure 3 is an underneath plan, partly in section, as viewed on the plane 3-3 of Figure 1; Figure 4 is a fragmentary section of a detail on plane 4-4 of Figure 3; Figure 5 is a fragmentary section on plane 2-2 of Figure 1, with the lock mechanism in a locking position; Figure 6 is an exploded perspective view of a portion of the cap; Figure 7 is an axial section of another embodiment; Figure 8 is a section on the plane 8-8 of Figure 7; and Figure 9 is an exploded perspective view of a portion of the cap of Figures 7 and 8.

Referring to Figure 1, a locking cap 10 includes a moulded plastics closure 12 having an axially inwardly extending shank portion 14 which is threaded at 16 to engage a threaded filler neck 17. Closure 12 includes a gasket 18 which sealingly engages the conventional peripherally and radially outwardly extending lip of the filler neck 17. Closure 12 further includes a pressure-vacuum vent valve housing 19 into which is assembled a pressure-vacuum vent valve assembly 20. Assembly 20 controls venting of pressure and vacuum which develop within the fuel tank in a manner which is well-known. The valve assembly 20 is retained within housing 19 by a cover plate 22 which is press fitted into the axially outer end 24 of housing 19. Closure 12 further includes an annular supporting wall 26 axially outwardly from housing 19.A generally cylindrical wall region 28 is defined within the axially outer end 30 of closure 12.

Wall region 28 has a plurality of radially inwardly extending engaging teeth 31 (see Figure 2). Each tooth 31 includes a radially and axially extending locking surface 33 and a chordally and axially extending camming surface 35. Closure 12 also includes a flange 32 at its axially outer end. Flange 32 extends radially outwardly and includes four peripherally extending resilient fingers 34 (Figure 2) attached at their proximal ends to flange 32 and provided at their distal ends with pawl teeth 36. Each tooth 36 has an inclined camming surface 38 and a radially and axially extending locking surface 40.

Cap 10 further includes an annular race 42 (Figures 1 and 3) which is disposed for rotation within the cap. As can be seen from Figure 1, race 42 lies directly axially outwardly from flange 32. Race 42 includes a set of peripheraliy spaced, axially inwardly opening pockets 44 (Figure 3). Each pocket 44 includes an inclined camming surface 46, and a radially and axially extending, abrupt locking surface 48. Surface 38,46 of teeth 36 and pockets 44, respectively, cooperate to provide a torqueoverriding connection of race 42 to closure 12 in the direction (counterclockwise in Figure 3) which adv ances closure 12 into the fuel tankfiller neck.

Surfaces 40,48 of teeth 36 and pockets 44, respectively, cooperate to provide the direct connection of race 42 to closure 12 in the direction (clockwise in Figure 3) which removes closure 12 from the filler neck.

Race 42 also includes a radially inwardly facing, peripherally extending surface 45 with four radially inwardly extending projections 47. Each projection 47 includes an abrupt radially and axially extending driving face 49, and an inclined camming surface 51.

Cap 10 further includes a moulded plastic shell 50 (see Figure 1) secured to closure 12 for rotation with respect to the closure about the axis of cap 10. Race 42 is captured in an annular space between shell 50 and closure 12. Shell 50 has a central axial opening 52 to accommodate a cylinder lock assembly 54 which is retained within shell 50 by a locking lug 56 which projects radially outwardly from assembly 54 near its axially inner end to engage a radially inwardly extending cylindrical wall portion 58 of shell 50.Lock assembly 54 includes an axially extending drive pin 60 which projects from the axially inner end of the assembly 54, and-which is actuated by turning the key 61 (Figure 1) in the assembly 54 to move drive pin 60 counterclockwise as viewed in Figure 2 (from the position illustrated in broken lines to the position illustrated in solid lines) to condition the cap 10 for removal from the filler neck.

Cap 10 further includes a locking bolt mechanism 62, see Figures 2,5, and 6. Bolt mechanism 62 includes a cup-shaped portion 63 and axially outwardly extending projections 64 diametrically disposed about the upper annular edge 66 of cupshaped portion 63 (Figures 1,3 and 6). Projections 64 extend into the moulded plastics shell 50. The bottom 68 of mechanism 62 is provided with a pair of chordaliy extending guides 70 defining a bolt slideway 72. A bolt 74 having an enlarged, rectangular prism-shaped head 75 is slidably guided in the slideway 72 and is held in the slideway by the bottom 68 of portion 63 and the closely spaced axially inner end 76 of the lock assembly 54. Head 75 includes a notch 77 having dimensions such that rotation of key 61 to the cap-removal position moves the bolt 74 to the position illustrated in Figure 2.The bolt head 75 further includes a resilient spring-like projection 78 which extends generally longitudinally of the slideway 72 across portion 63. The generally cylindrical interior wall 79 of portion 63 is provided with an axially extending blocking ridge 81 which cooperates with the head 83 of projection 78 on bolt 74, to hold the bolt yieldably in either of two positions which will be described.

Referring to Figure 3, it will be seen that the outer end 80 of shell 50 has a pair of windows 82 which extend axially through end 80. A pair of axially inwardly extending projections 84 (Figures 3-4) are moulded on the axially inner surface 86 of end 80.

Axially extending surfaces 88 of projections 84 are co-terminous with end edges 90 of windows 82.

Resilient moulded drive fingers 92 project from surfaces 88 within windows 82. Fingers 92 extend generally along chords of a circle defined by shell 50.

Windows 82 enable fingers 92 to be moulded in a simple, two-part mould. Fingers 92 include radially and axially extending engaging surfaces 94 and camming surfaces 95 at their distal ends. The outer end 80 also includes a pair of diametrically opposed windows 100. Projections 64 extend through windows 100 (see Figures 1 and 3) to lock bolt mechanism 62 for rotation with shell 50.

Closure 12, race 42 and shell 50 are held in relatively rotatable engagement by a retainer ring 110 (Figure 1) and shell cover 112. Ring 110 and shell cover 112 are both constructed from stamped sheet metal, with a depending skirt portion 114 of shell cover 112 being crimped as at 116 to hold ring 110 axially outwardly against the axially inner surface 118 of flange 32. A plurality of radial and axial indentations 120 are stamped into shell cover 112.

These indentations 120 correspond in their peripherallocations with a plurality of similar indentations 122 which are moulded into shell 50. Engagement of indentations 120,122 prevents rotation of shell cover 112with respectto shell 50. The axially outer face 124 of shell cover 112 has a central circular aperture 126 for access to the lock assembly 54.

Turning now to Figures 2, 3, 5, and 6, operation of cap 10 will be explained. Assuming that the cap 10 is to be removed from the filler neck 17, the key 61 is first inserted into the slot in the lock assembly 54 and turned to move pin 60 from its cap-locking position, illustrated in broken lines in Figure 2, to it capremoval position, illustrated in solid lines in Figure 2.

This action slides bolt 74 in the slideway 72 from its position illustrated in solid lines in Figure 5 to its position illustrated in solid lines in Figure 2. The head 83 of spring-like projection 78 is thereby cammed overthe blocking ridge 81. Bolt 74 is thereby held yieldably in the position illustrated in solid lines in Figure 2, with the locking surface 128 of its end 130 projecting through an opening 132 in side wall 79 of cup-shaped portion 63 to engage the locking surface 33 of one of the engaging teeth 31 on the cylindrical wall region 28 of closure 12. With the bolt in this position, shell 50 can be rotated in the cap-removal direction (counterclockwise in Figure 2, clockwise in Figure 3).Since the bolt assembly 62 is locked for rotation with the shell 50 by the engagement of projections 64 in windows 100, such rotation of shell 50 backs the threads 16 out of engagement with the filler neck 17 and permits the cap 10 to be removed.

Once the key 61 has been rotated to rotate the pin 60 to move the bolt 74 into the position illustrated in solid lines in Figure 2, the key 61 may be rotated back to move the pin 60 to the position illustrated in broken lines in Figure 2, so that the key 61 may be removed from the lock assembly 54. The notch 77 on the bolt head 75 is sufficiently large that pin 60 may be in either of the positions illustrated in broken or solid lines in Figure 2, without moving the bolt 74 from the cap-removal position illustrated in solid lines in Figure 2 to the cap-locking position illustrated in solid lines in Figure 5. The bolt 74 is held in the cap-removal position by the cooperation of the head 83 of projection 78 with the blocking ridge 81.

Assuming now that the cap 10 is to be replaced on the filler neck 17 and locked, threads 16 are engaged in neck 17, and the shell 50 is rotated in the direction which advances cap 10 onto the filler neck 17 (ciockwise in Figure 2 and counterclockwise in Figure 3). As the shell 50 is turned, the camming surface 134 atthe end 130 of bolt74 and the camming surface 35 of one of the engaging teeth 31, engage, causing a thrust on the bolt 74. As this thrust increases, resilient projection 78 flexes to permit the head 83 of projection 78 to cam over the blocking ridge 81 to the position illustrated in solid lines in - Figure 5. The bolt assembly 62 no longer directly engages the closure 12. However, continued rotation of shell 50 in the cap-advancing or cap-replacement direction brings engaging surfaces 94 of fingers 92 (Figure 3) into engagement with driving faces 49 on the race 42 projections 47. Flexing of fingers 92 is blocked by wall 45 of race 42. This establishes the necessary driving connection between shell 50 and race 42 to drive the race in the cap-advancing, or cap-replacement, direction (clockwise in Figure 2 and counterclockwise in Figure 3). This rotation of race 42 is coupled through camming surfaces 46 of pockets 44 in race 42 and the cooperating camming surfaces 38 of fingers 34 on the flange 32 of closure 12 to advance the threads 16 of closure 12 into the filler neck 17.When the threads 16 have been sufficiently advanced into the closure 17, the gasket 18 seals against the lip at the axially outer end of filler neck 17, a break-away torque is reached between camming surfaces 38 on fingers 34 of the closure 12 and camming surfaces 46 of the pockets 44 on the race 42. At this torque, continued rotation of the shell 50 does not result in further rotation of the closure 12, as the race 42 continues to ratchet on the teeth 36 due to the flexibility of the fingers 34.

Anyattemptto remove the cap 10 by rotating shell portions 50, 112 when bolt 74 is in the position illustrated in Figure 5 causes surfaces 51 of teeth 47 to be engaged by surfaces 95 of fingers 92. As torque is applied to shell 50, fingers 92 flex and surfaces 51, 95 ratchet, preventing removal of the cap.

Referring now to Figures 7-9, in which another embodiment of the invention is illustrated, those elements having the same reference numerals as in Figures 1 to 6 perform the same or similar functions.

Although the caps of the two embodiments are similar, the second embodiment (see particularly Figures 8 and 9) differ from those of the first embodiment. Bolt mechanism 62 includes a cupshaped portion or hub 63 and axially outwardly extending projections 64 diametrically disposed about the upper annular edge 66 of cup-shaped portion 63.

As seen in Figures 7 and 9, slideway 72 includes an axially inward, chordally extending slot 200 formed in one of the chordally extending guides 70 and bolt 74 includes an axially inward projection 202 which slidably engages in slot 200 to keep bolt 74 from being projected axially outwardly in slideway 72 and to improve the assembly of the various components in, for example, an upside-down position.

Projections 64 extend into diametrically opposed pockets 100 moulded into the underside of the hand grip portion 150 of plastics shell 50. The axially extending projections 64 also provide resilient moulded drive fingers 92. Fingers 92 extend along chords of a circle defined by shell 50. Fingers 92 include radially and axially extending engaging surfaces 94 and camming surfaces 95 at their distal ends. The engagement of projections 64 in pockets 100 locks bolt mechanism 62 for rotation with shell 50.

Further, the cylinder lock assembly 54 is held in place in shell 50 by a freeze-resistant assembly including a retainer ring 270 and O-ring 272 (Figure 7).

Closure 12, race 42, and shell 50 are held in relatively rotatable engagement by a retainer ring 110 and shell skirt portion 214. Ring 110 and skirt portion 214 are joined by the system described in United States Patent Number 4,091,955, that is, skirt portion 214 includes a radially outwardly extending flange 220 adjacent its axially inner edge 222. Flange 220 provides a peripherally extending, axially outwardly facing surface 224.

Retainer ring 110 includes a radially outer, axially outwardly extending portion 226 and a radially inner, axially outwardly extending portion 228 joined by an axially inner, radially and peripherally extending web portion 230. The flange 32 of closure 12 rests upon surface 131 of portion 228. Portion 226 is provided at its axially outer extend with a surface 232 for supporting closure 12 and race 42 with pawl teeth 36 in engagement in pockets 44 on race 42. The retainer ring 110 and shell 50 of this embodiment resiliently snap together during final assembly of the cap 10 to capture all the cap components in working engagement.

The operation of the second embodiment is basically the same as that of the first embodiment, but a difference exists in the function of cap 10 during cap replacement.

Assuming that the cap 10 of Figures 7 to 9 is to be replaced on the filler neck 17 and locked, these threads 16 are engaged in neck 17, and the shell 50 is rotated in the direction which advances cap 10 onto the filler neck 17 (counterclockwise in Figure 8). With reference to Figure 9, as the shell 50 is turned, the camming surface 134 at the end 130 of bolt 74 and the camming surface 35 of one of the engaging teeth 31 on the cylindrical wall region 28 of closure 12 engage, causing a thrust on the bolt 74. As this thrust increases, resilient projection 78 flexes to permit its head 83 to cam over the blocking ridge 81 to the position illustrated in solid lines in Figures. The bolt assembly 62 no longer directly engages the closure 12.However, continued rotation of shell 50 in the cap-replacement directions brings engaging surfaces 94 of fingers 92 (Figure 8) into engagement with driving faces 49 on the projections 47. Flexing of fingers 92 is blocked by wall 45 of race 42. This establishes the necessary driving connection between shell 50 and race 42 to drive the race in the cap-replacement direction (counter-clockwise in Figure 8). This rotation of race 42 is coupled through camming surfaces 46 of pockets 44 in race 42 and the co-operating camming surfaces 38 of fingers 34 on the flange 32 of closure 12, to advance the threads 16 into the filler neck 17. When the threads 16 have been sufficiently advanced, the gasket 18 seals against the lip at the outer end of neck 17, break away torque is reached between camming surfaces 38 on fingers 34 of the closure 12 and camming surfaces 46 of the pockets 44 on the race 42. At this torque, continued rotation of the shell 50 does not result in further rotation of the closure 12, as the race 42 continues to ratchet on the teeth 36 due to the flexibility of the fingers 34.

Any attempt to remove the cap 10 by rotating shell portions 50, 112 when bolt 74 is in the cap-locking position causes surfaces 51 of teeth 47 to be engaged by surfaces 95 of fingers 92. As torque is applied to shell 50, fingers 92 flex and surfaces 51,95 ratchet, preventing removal of the cap.

Claims (13)

1. A locking cap for a threaded filler neck, the cap comprising:- a threaded closure adapted to engage and close the neck; a key-openable lock; a shell including means for retaining the lock; an annular race disposed for rotation between the shell and closure, the race including first engaging means and the closure including second engaging means for engaging the first engaging means to provide a driving connection between the closure and race which is positive in the cap-removal direction and torque-limited in the cap-advancing direction, the race further including third engaging means, the shell including a hub mounted for rotation with the shell and providing fourth engaging means for engaging the third engaging means to provide a driving between the third and fourth engaging means which is positive in the cap-advancing direction and torque-limited in the cap-removal direction; and bolt means mounted for rotation with the shell, and fifth engaging means on the closure, the bolt means being openable by key actuation of the lock for movement into engagement with the fifth engaging means to couple the bolt means and shell directly to the closure to permit removal of the cap from the filler neck.

2. A cap according to claim 1 wherein the third engaging means comprises at least one radially inwardly projecting engaging tooth on a radially inwardly facing surface of the race, the tooth including an inclined camming surface and a locking surface, the fourth engaging means includes at least one flexible finger integrally moulded to the shell for projecting into engagement with thetooth,the finger including a camming surface and a locking surface, the camming surfaces of the tooth and finger and the flexibility of the finger co-operating to provide the torque-limited connection between the race and shell in the cap-removal direction, and the locking surfaces of the tooth and finger co-operating to provide the positive connection between the race and shell in the cap-advancing direction.

3. A cap according to claim 1 and claim 2 wherein the hub includes a cup-shaped member extending axially inwardly from the shell into the closure, and the bolt means includes means in the cup-shaped member providing a slidewaywhich extends substantially chordally across the cupshaped member, a bolt slidable in the slideway between a position in engagement with the fifth engaging means to permit cap removal and a position out of engagement with the fifth engaging means to prevent cap removal, the cup-shaped member having a cylindrical side wall including an opening through which the bolt projects when in position to engage the fifth engaging means, the bolt means further including a yieldable spring extending from the bolt, and stop means on the cylindrical wall of the cup-shaped member, the spring including a head co-operating with the stop means yieldably to hold the bolt in either of the said two positions.

4. A cap according to claim 3 wherein the bolt includes a bolt end having a locking surface and a camming surface, and the fifth engaging means includes an engaging tooth on the closure, the engaging tooth having a locking surface and a camming surface, the locking surfaces of the bolt and fifth engaging means tooth co-operating when the bolt is in the cap-removal position and the shell is rotated in a cap-removal direction to permit removal of the cap, and the camming surfaces of the bolt and fifth engaging means tooth co-operating when the bolt is in the cap-removal position and the shell is rotated in a cap-advancing direction to overcome the spring force and drive the spring head over the stop means and move the bolt to the cap-locking position.

5. A cap according to claim 4 wherein the lock includes a drive pin and the bolt includes a head defining a slot for receiving the drive pin, rotation of the key in the lock in one direction moving the pin in the slot to move the bolt to the cap-removal position, the slot being of a size to permit rotation of the key in the opposite direction without moving the bolt back to the cap-locking position to permit removal of the key from the lock while the bolt remains in the cap-removal position.

6. A cap according to claim 2 having a pair of the said flexible drive fingers, and the hub is concentric with the race and positioned within it, the fingers being mounted at diametrically opposed points on the hub and extending along chords of a circle defined by the race and terminating at diametrically opposed points within the race.

7. A locking cap for a fuel tank threaded filler neck, the cap comprising:- a gasket capable of being damaged by overtightening of the cap on the neck; a lock for controlling cap-removal; a shell providing a hand grip; a threaded closure for engaging the filler neck to close it; first and second engaging means providing a torque-limited connection between the shell and the closure in a direction to advance the cap into the filler neck to protect the gasket; third engaging means positively drivingly connected to the closure in the cap-removal direction; and a hub providing fourth engaging means, the hub including means for coupling it for rotation with the shell, the third and fourth engaging means positively engaging one another in the cap-advancing direction and co-operating to provide a torque-iimited connection in the cap-removal direction, the hub supporting lock-actuated bolt means, and the closure including co-operating fifth engaging means for selectively coupling the hub to the closure for cap removal

8.A cap according to claim 7 wherein the third engaging means comprises at least one radially inwardly projecting engaging tooth formed on a radially inwardly facing surface of an annular race axially positioned between the shell and closure, the tooth including an inclined camming surface and a locking surface, the hub including a moulded plastics portion, and the fourth engaging means includ- - ing at least one flexible finger integrally formed on the plastics portion, the finger projecting into engagement with the tooth, the finger including a camming surface and a locking surface, the camming surfaces of the tooth and finger and the flexibility of the finger co-operating to provide the torque-limited connection between the race and shell in the cap-removal direction and the locking surfaces thereof co-operating to provide the positive connection between the race and shell in the capadvancing direction.

9. A cap according to claim 8 wherein the plastics portion comprises a cup-shaped member extending axially inwardly from the shell into the closure, and the bolt means includes a slideway provided in the cup-shaped member to extend substantially chordally across the cup-shaped member, a bolt slidable in the slideway between a position in engagement with the fifth engaging means to permit cap removal and a position out of engagement with the fifth engaging means to prevent removal of the cap, the cupshaped member having a cylindrical side wall including an opening through which the bolt projects when in position to engage the fifth engaging means, the bolt means further including a yieldable spring extending from the bolt, and stop means on the cylindrical wall of the cup-shaped member, the spring including a head co-operating with the stop means yieldably to hold the bolt in either of the said two positions.

10. A cap according to claim 9 wherein the bolt includes a bolt end having a locking surface and a camming surface, and the fifth engaging means includes an engaging tooth on the closure, the engaging tooth having a locking surface and a camming surface, the locking surfaces of the bolt and fifth engaging means tooth co-operating when the bolt is in the cap-removal position and the shell is rotated in a cap-removal direction to permit removal of the cap, and the camming surfaces of the bolt and fifth engaging means tooth co-operating when the bolt is in the cap-removal position and the shell is rotated in a cap-advancing direction to overcome the spring force and drive the spring head over the stop means and move the bolt to the cap-locking position.

11. A cap according to claim 10 wherein the lock includes a drive pin and the bolt includes a head defining a slot for receiving the drive pin, rotation of the key in the lock in one direction moving the pin in the slot to move the bolt to the cap-removal position, the slot being of a size to permit rotation of the key in the opposite direction without moving the bolt back to the cap-locking position to permit removal of the key from the lock while the bolt remains in the cap-removal position.

12. A cap according to claim 8 having a pair of the said flexible drive fingers, mounted at diametrically opposed points on the plastics portions, the fingers extending along chords of a circle defined by the race and terminating at diametrically opposed points within the race.

13. A locking cap constructed and arranged substantially as herein described and shown in Figures 7 to 9 of the drawings.