TORQUE-LIMITING DEVICE

• US 3,820,680 A
• Filed: 11/20/1972
• Issued: 06/28/1974
• Est. Priority Date: 11/20/1972
• Status: Expired due to Term

• Current Assignee: Friend D
• Original Assignee: Friend D
• Inventors: FRIEND D
• Application Number:
  US05/307,820
• Time in Patent Office: 585 Days
• US Class Current: 220/288
• CPC Class Codes: B60K 15/0406 Filler caps for fuel tanks
• CPC Class Codes: B65D 55/00 Accessories for container closures not otherwise provided for

Abstract

A valved cap for closing a chamber having a filler neck formed to provide an internal thread and a peripherally extending lip at its mount, the cap comprising a housing formed to provide, at its outer end portion, an outwardly extending flange and, extending axially inwardly from the flange, a shank with a mating external thread. A concentric sealing ring is disposed adjacent the flange for sealing engagement with the lip, and a shell covers at least the outer portion of the housing and is rotatable relative to the housing about the axis of the shank. The flange provides at least one resilient finger having a lug at its distal end, and the shell provides at least one pocket for receiving the lug and providing a driving connection between the shell and the housing. This pocket is formed with a camming surface at its trailing end as the shell is turned to advance the shank inwardly and an abrupt surface at its leading end. The camming surface is effective to cam the lug out of the pocket to break the driving connection when the torque resistance to rotation of the housing in the said one direction exceeds a predetermined level.

Claims

1. A valved cap for closing a chamber having a filler neck formed to provide an internal thread and a peripherally extending lip at its mouth, said valve cap comprising a housing formed to provide, at its outer end portion, an outwardly and peripherally extending flange and, extending axially inwardly from said flange, a shank with a mating external thread on the outer periphery thereof, said flange providing at least one resilient finger having a lug at its distal end, a concentric sealing ring disposed adjacent said flange for sealing engagement with such a lip, a shell covering at least said outer portion of said housing, said shell being rotatable relative to said housing about the axis of said shank, said shell providing at least one pocket for receiving said lug and providing a driving connection between said shell and said housing, said pocket being formed with a camming surface at its trailing end when said shell is turned in one direction to advance the shank into engagement with such a filler neck and an abrupt surface at its leading end, said camming surface being effective to cam said lug out of said pocket to break the driving connection between said shell and said housing when the torque resistance to rotation of said housing in said one direction exceeds a predetermineD level.

2. The invention of claim 1 in which said finger extends peripherally about a portion of said flange, said lug extending axially outwardly from the distal end of said finger.

3. The invention of claim 1 in which said shell provides a plurality of said pockets equally peripherally spaced about said axis, whereby, when said lug is cammed out of one of said pockets, said shell rotates in said one direction relative to said housing until said lug engages the next adjacent pocket.

4. The invention of claim 3 in which there are four of said pockets spaced 90* apart and two of said fingers diametrically opposed with said lugs spaced 180* apart.

5. The invention of claim 2 in which said pocket opens axially inwardly, said pocket being disposed at the outer peripheral edge portion of said shell.

6. The invention of claim 5 in which said shell includes means engaging the axially inner side of said flange to connect said shell to said housing for said relative rotation.

7. The invention of claim 6 in which the axially inner side of said finger inclines axially outwardly from its proximal end to its distal end, the combined axial thickness of said lug and the distal end of said finger being not substantially greater than the axial thickness of said flange such that said lug and distal end can be cammed axially inwardly from said pocket to move relative to said shell and said means engaging the axially inner side of said flange.

8. The invention of claim 2 in which said housing is integrally molded of plastic to provide said flange, shank, finger and lug at the distal end of said finger, and a valved venting passageway extending axially therethrough.

9. The invention of claim 2 in which said lug is generally rectangularly shaped having axially extending leading and trailing edges, the distal end of said finger and said lug being resiliently movable axially inwardly relative to said flange to disengage said pocket.

10. The invention of claim 2 in which said finger is proportioned and designed such that said lug normally extends axially outwardly from the outer side of said flange into engagement with said pocket, the distal end portion of said finger being resiliently movable axially inwardly so that said lug does not protrude axially beyond the outer surface of said flange.

11. A cap for closing a chamber having a filler neck formed to provide a thread and a peripherally extending lip at its mouth, said valve cap comprising a housing member formed with a mating thread, said housing member having an outer end portion and an inner end portion, a concentric sealing ring disposed adjacent said outer end portion for sealing engagement with such a lip, said housing providing at least one resilient finger having an engaging portion at its distal end, and a shell covering at least said outer portion of said housing, said shell being rotatable relative to said housing about the axis of said shank, said shell providing a cooperating engaging portion in the peripheral path of said first-mentioned engaging portion, said engaging portions being proportioned and designed to provide a torque-limited driving connection between said housing and said shell when said shell is turned in the direction which advances said sealing ring toward such a lip and a firm driving connection between said housing and shell when said shell is turned in the opposite direction which moves said sealing ring away from such a lip.