Patent Publication Number: US-11383901-B2

Title: Pressure relief cap

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 62/775,564, filed Dec. 5, 2018, the entirety of which is hereby incorporated by reference. 
    
    
     FIELD 
     The present invention relates to caps for containers and, more particularly, to pressure relief caps. 
     BACKGROUND 
     When containers are sealed with a cap, a pressure difference may develop between the interior of the container and the surrounding atmosphere. For example, pressure within the container may increase or decrease in response to changes in temperature and/or changes in phase of the contents of the container. When the pressure within the container differs from the pressure of the surrounding atmosphere, it may become difficult to remove the cap. In addition, if the cap is removed, rapid pressure equalization may cause contents of the container to be expelled out of the container. 
     SUMMARY 
     The present disclosure may provide, in one independent aspect, a pressure relief cap configured to be coupled to a container. The pressure relief cap may include a body engageable with the container and rotatable about an axis to couple or decouple the body from the container, a handle coupled to the body and rotatable about the axis in a loosening direction and an opposite, tightening direction, and a ring member coupled for co-rotation with the handle in the loosening direction. The pressure relief cap may also include relief valve assembly coupled to the body. The ring member and the body may be configured with a lost motion region in which the ring member may be rotatable relative to the body in the loosening direction. Rotation of the ring member relative to the body in the loosening direction in the lost motion region may open the relief valve assembly, and rotation of the ring member in the loosening direction beyond the lost motion region may cause the body to co-rotate with the ring member in the loosening direction. 
     The pressure relief cap may also include a first biasing member coupled between the body and the ring member and configured to bias the ring member relative to the body in the tightening direction. The ring member may include a first rib, the body may include a second rib, and a first biasing member may be configured to bias the first rib into engagement with the second rib. Engagement of the first rib with the second rib may cause the body to co-rotate with the ring member in the tightening direction. 
     The ring member may include a third rib offset in a circumferential direction from the first rib, and the body may include a fourth rib offset in a circumferential direction from the second rib. Rotation of the handle in the loosening direction disengages the first rib and the second rib to allow the ring member to enter the lost motion region. When the ring member reaches the end of the lost motion region the third rib on the ring member engages with the fourth rib on the body to allow the body to co-rotate with the ring member and the handle. 
     A spacing between the first rib and the third rib may be less than a spacing between the second rib and the fourth rib. A difference between the spacing between the first rib and the third rib and the spacing between the second rib and the fourth rib may be about 45 degrees. 
     The relief valve assembly may include a plunger and a second biasing member operable to bias the plunger toward a sealed position. The ring member may include a cam-shaped actuator configured to move the plunger toward an unsealed position when the ring member rotates relative to the body in the loosening direction through the lost motion region. 
     The pressure relief cap may further include a ratchet assembly operable to permit the handle to rotate relative to the ring member in the tightening direction when torque applied to the handle in the tightening direction exceeds a predetermined torque threshold. 
     The present disclosure may provide, in another independent aspect, a pressure relief cap configured to be coupled to a container. The pressure relief cap may include a body engageable with the container and rotatable about an axis, a handle coupled to the body and rotatable about the axis in a loosening direction and a tightening direction, a ring member coupled for co-rotation with the handle in the loosening direction, and a relief valve assembly coupled to the body. The handle and the ring member may be rotatable relative to the body in the loosening direction from a first position to a second position. The relief valve assembly may be configured to open to vent the container in response to rotation of the handle and the ring member from the first position to the second position. The body may be configured to rotate in the loosening direction in response to further rotation of the handle and the ring member from the second position in the loosening direction. 
     Other independent aspects of the invention may become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating a pressure relief cap. 
         FIG. 2  is a cross-sectional view of the cap of  FIG. 1 , with a pressure relief valve assembly of the cap illustrated in a sealed state. 
         FIG. 3  is a cross-sectional view of the cap of  FIG. 1 , with the pressure relief valve assembly illustrated in an unsealed state. 
         FIG. 4  is a perspective view illustrating a portion of the pressure relief cap of  FIG. 1 . 
         FIG. 5  is an exploded view of the portion of the pressure relief cap of  FIG. 4 . 
         FIG. 6A  is a perspective view of a portion of the pressure relief cap of  FIG. 1 , illustrating the pressure relief valve assembly in the sealed state. 
         FIG. 6B  is a perspective view of a portion of the pressure relief cap of  FIG. 1 , illustrating the pressure relief valve assembly in the unsealed state. 
         FIG. 7  is a perspective view of the pressure relief cap of  FIG. 1  including a tether. 
         FIG. 8  is a cross-sectional view of an alternative construction of a pressure relief cap with a pressure relief valve assembly of the cap illustrated in a sealed state. 
         FIG. 9  is a cross-sectional view of the pressure relief cap of  FIG. 8 , with the pressure relief valve assembly illustrated in an unsealed state. 
     
    
    
     Before any independent embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other independent embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     Use of “including” and “comprising” and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of “consisting of” and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof. 
     Also, the functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way but may also be configured in ways that are not listed. 
     Relative terminology, such as, for example, “about”, “approximately”, “substantially”, etc., used in connection with a quantity or condition would be understood by those of ordinary skill to be inclusive of the stated value and has the meaning dictated by the context (for example, the term includes at least the degree of error associated with the measurement of, tolerances (e.g., manufacturing, assembly, use) associated with the particular value, etc.). Such terminology should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4”. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a pressure relief cap  10  that is removably couplable to an opening or inlet  14  of a container  18 . When positioned on the inlet  14 , the illustrated cap  10  blocks the inlet  14  to enclose the contents of the container  18 . In some embodiments, the container  18  includes a fuel tank  22 , such as a standalone fuel tank or a fuel tank incorporated into a vehicle or other powered machine. In other embodiments, the cap  10  can be used with any other container  18  storing any other contents. 
     The illustrated cap  10  includes a body  26  ( FIG. 2 ) and a handle  30  coupled to the body  26 . The body  26  has an annular wall  34  with internal threads  38  engageable with external threads  42  on the inlet  14  of the container  18  ( FIG. 1 ) to couple the body  26  to the container  18 . In an alternative construction (not shown), the body  26  may include external threads engageable with internal threads on the inlet  14 . The body  26  is rotatable about an axis  46  in a tightening direction  50  and a loosening direction  54  to respectively couple and decouple the body  26  from the inlet  14 . 
     Referring to  FIG. 2 , the body  26  carries a gasket  56  that is surrounded by the annular wall  34 . The gasket  56  is engageable with an outer edge of the inlet  14  to create a substantially liquid and/or gas-tight seal between the body  26  and the inlet  14  when the body  26  is coupled to the inlet  14 . In some embodiments, a tether  58  ( FIG. 7 ) may be provided to retain the cap  10  with the container  18  even when the body  26  is decoupled from the inlet  14 . In such embodiments, the tether  58  may be coupled to the body  26  or the handle  30  of the cap  10 . 
     In the illustrated embodiment, the handle  30  has a top side  62  and a circumferential side  66  extending downward from the top side  62 . The illustrated circumferential side  66  has a plurality of ridges or undulations  70  ( FIG. 1 ), which enhance a user&#39;s ability to grip and rotate the handle  30  (e.g., when tightening or loosening the cap). 
     The handle  30  is coupled to the body  26  via a ratchet  78  and a ring member  74  ( FIGS. 4 and 5 ). As described in greater detail below, the ratchet  78  and the ring member  74  are configured to selectively couple the handle  30  and the body  26  for co-rotation and to selectively permit the handle  30  to rotate relative to the body  26 . 
     The ratchet  78  is fixed inside of the handle  30  (e.g., via a snap fit), such that the ratchet  78  co-rotates with the handle  30  ( FIGS. 2-3 ). The illustrated ratchet  78  includes an annular central hub  82  and a plurality of flexible arms  86  extending outward from the hub  82  ( FIG. 5 ). Each of the flexible arms  86  terminates with a pawl  90 . The ratchet  78  is received in an annular recess  94  on top of the ring member  74 . The flexible arms  86  press the pawls  90  into engagement with ratchet teeth  98  that extend radially inwardly from an outer annular wall  102  of the ring member  74 . 
     The ratchet  78  and the ring member  74  thus define a ratchet assembly  106  ( FIG. 5 ) operable to limit the amount of torque that may be transferred from the ratchet  78  (and, therefore, from the handle  30 ) to the ring member  74 . Once a predetermined torque threshold is reached (based at least in part on the constructions of the pawls  90 , the ratchet teeth  98 , the flexible arms  86 , etc.), the pawls  90  slide away from the ratchet teeth  98  while the arms  86  bend inwardly. 
     In the illustrated embodiment, the ratchet assembly  106  only limits torque transfer in one rotational direction (e.g., the tightening direction  50 ). In some embodiments (not shown), the ratchet assembly  106  may be omitted, such that the handle  30  may be directly coupled to the ring member  74 . 
     Referring to  FIGS. 4-5 , the ring member  74  is coupled to the body  26  for limited rotation relative to the body  26  about the axis  46 . A first rib  110  is located on an outer periphery of the ring member  74 , and a second rib  118  is located on an outer periphery of the body  26 . The first rib  110  is engageable with the second rib  118  to cause the body  26  to co-rotate with the ring member  74  in the tightening direction  50 . 
     The ring member  74  also includes a third rib  126  on the outer periphery of the ring member  74 , offset in a circumferential direction from the first rib  110 , and the body  26  includes a fourth rib  130  on the outer periphery of the body  26 , offset in a circumferential direction from the second rib  118 . The third rib  126  is engageable with the fourth rib  130  to cause the body  26  to co-rotate with the ring member  74  in the loosening direction  54 . 
     In the illustrated embodiment, the spacing between the first and third ribs  110 ,  126  is less than the spacing between the second and fourth ribs  118 ,  130 . Thus, a lost motion region is defined in the region between the second and fourth ribs  118 ,  130 . That is, the ring member  74  is rotatable relative to the body  26  in either direction (e.g.,  FIG. 6B ), until either the first rib  110  comes into engagement with the second rib  118  ( FIGS. 4 and 6A ) or the third rib  126  comes into engagement with the fourth rib  130 , at which point the ring member  74  (and, thus, the handle  30 ) rotates the body  26 . 
     In the illustrated embodiment, the lost motion region spans an angular distance of about 45 degrees. In other embodiments, the extent of the lost motion region may be varied based on the relative positions of the ribs  110 ,  118 ,  126 ,  130 . Although only one set of ribs  110 ,  118 ,  126 ,  130  is described herein, the cap  10  may include multiple sets of ribs that engage and disengage simultaneously (e.g., to improve the strength of the torque-transmitting connection between the ring member  74  and the body  26 ). 
     With reference to  FIG. 5 , the cap  10  further includes a first biasing member  134  coupled between the ring member  74  and the body  26  to bias the ring member  74  relative to the body  26  (e.g., in the tightening direction  50 ) to define an initial position of the body  26  relative to the ring member  74 . As such, the first rib  110  is biased into engagement with the second rib  118 . 
     In the illustrated embodiment, the first biasing member  134  is a coil spring bent into an arc shape and accommodated within a toroidal pocket  136  in the body  26 . In other embodiments (not shown), the first biasing member  134  may be a torsion spring or any other suitable means for biasing the ring member  74  relative to the body  26  in the tightening direction  50 . 
     With continued reference to  FIG. 5 , the cap  10  further includes a relief valve assembly  138  coupled, in the illustrated construction, to the body  26 . The illustrated valve assembly  138  includes a plunger  142  with an upper retaining portion  146  and a lower retaining portion  150 . The plunger  142  is slidably received within a valve bore  154  extending through the body  26  along a valve axis  158  ( FIGS. 2 and 3 ) parallel to the rotational axis  46  of the body  26 . A peripheral seal  162  (e.g., an O-ring) is coupled to the upper retaining portion  146  of the plunger  142 . 
     An arm  166  extends from the upper retaining portion  146  of the plunger  142  for engagement with a cam shaped actuator  170  disposed adjacent an inner periphery of the ring member  26 . The arm  166  extends from the top of the plunger  142  in an L-shape. The actuator  170  is slidable underneath the arm  166  when the ring member  74  is rotated relative to the body  26  in the loosening direction  54 , and this movement actuates the valve assembly  138 , as described in greater detail below. 
     The valve assembly  138  includes a second biasing member  182  disposed between an underside of the body  26  surrounding the valve bore  154  and the lower retaining portion  150 . The second biasing member  182  acts on the plunger  142  to bias the plunger  142  downwardly, in the direction of arrow  186 , such that the peripheral seal  162  is biased into engagement with a seat  190  surrounding the valve bore  154  in the body  26  ( FIGS. 2 and 3 ). When engaged with the seat  190 , the peripheral seal  162  and the seat  190  create a substantially gas-tight seal. 
     In the illustrated embodiment, the second biasing member  182  is a coil spring, in other constructions (not shown), the second biasing member  182  may alternatively or additionally include, for example, magnets, a disc spring, or any other means for biasing the plunger  142 . 
     The plunger  142  is axially movable along the valve axis  158  between a first position ( FIG. 2 ), in which the peripheral seal  162  is engaged with the seat  190  to define a closed or sealed state of the valve assembly  138 , and a second position ( FIG. 3 ), in which the peripheral seal  162  is disengaged from the seat  190  to define an open or unsealed state of the valve assembly  138 . The actuator  170  is engageable with the arm  166  to move the plunger  142  upwardly, in direction of arrow  194 , towards the second position to open the valve assembly  138 . That is, when the handle  30  is rotated in the loosening direction  54 , the ring member  74  rotates relative to the body  26  through the lost motion region, and the actuator  170  to engages with the arm  166  to raise the plunger  142  and thereby open the valve assembly  138 . As such, the illustrated valve assembly  138  is configured to relieve a pressure imbalance between the interior of the container  18  and the surrounding atmosphere before a user can loosen the cap  10  from the container  18 . 
     In operation, to close the container  18 , the user inserts the body  26  of the cap  10  into the inlet  14  and grasps and rotates the handle  30  in the tightening direction  50  ( FIGS. 1-2 ). Torque is transferred from the handle  30 , through the ratchet assembly  106  and to the body  26  via the engaged first rib  110  and the second rib  118  ( FIGS. 4 and 6A ). The body  26  can thus be threaded onto the threads of the inlet  14 . 
     If torque applied to the handle  30  in the tightening direction  50  exceeds the torque threshold of the ratchet assembly  106 , the arms  86  flex inwardly, and the pawls  90  ride over the associated ratchet teeth  98 . As such, the handle  30  and the ratchet  78  rotate relative to the ring member  74  and the body  26 , and the torque-transmitting connection between the handle  30  and the body  26  is at least momentarily disengaged. The ratchet assembly  106  may thus prevent over-tightening of the cap  10 . In addition, when the pawls  90  ride over the ratchet teeth  98 , the ratchet assembly  106  may provide audible and/or tactile feedback to the user that a sufficient level of torque (e.g., at or greater than a minimum retention torque) has been achieved. 
     To remove the cap  10  and open the container  18 , the user grasps and rotates the handle  30  in the loosening direction  54 . Torque is transferred from the handle  30 , through the ratchet  78 , and to the ring member  74 . The torque required to compress the first biasing member  134  is less than the torque required to overcome the friction between the gasket  56  on the body  26  and the inlet  14  of the container  18 , along with the friction between the threads  38 ,  42 . As such, initial rotation of the handle  30  in the loosening direction  54  disengages the first rib  110  and the second rib  118  to allow the ring member  74  to enter the lost motion region ( FIG. 6B ). 
     In the lost motion region, the ring member  74  rotates against the first biasing member  134  ( FIG. 5 ), while the body  26  remains stationary. As the ring member  74  rotates, the actuator  170  slides underneath and bears upwardly against the arm  166  on the plunger  142 . The actuator  170  thus moves the plunger  142  from the first position ( FIG. 2 ), in which the peripheral seal  162  is engaged with the seat  190 , toward the second position ( FIG. 3 ) to open the valve assembly  138 . Pressure can then be vented into or out of the container  18  through the valve bore  154  to equalize any imbalance between the interior of the container  18  and the surrounding atmosphere. 
     As the user continues to apply torque in the loosening direction  54 , the ring member  74  reaches the end of the lost motion region, and the third rib  126  on the ring member  74  engages with the fourth rib  130  on the body  26  (e.g., a second position of the ring member relative to the body  26 ). Continued rotation of the handle  30  is then transferred to the body  26  to allow the body  26  to be unscrewed from the threads  42  of the inlet  14 . 
     Thus, the handle  30  and the ring member  74  may be rotated together relative to the body  26  in the loosening direction  54  from a first or initial position (e.g.,  FIGS. 4 and 6A ) to a second position (e.g.,  FIGS. 3 and 6B ) to open the valve assembly  138 , and the handle  30  and the ring member  74  may be further rotated in the loosening direction  54  from the second position to cause the body  26  to co-rotate with the handle  30  and the ring member  74  in the loosening direction. 
     Once the torque required to unscrew the body  26  from the inlet  14  reduces below the torque applied by the first biasing member  134  (e.g., when the gasket  56  is unseated from the inlet  14 ), the first biasing member  134  recovers and rotates the body  26  of the cap  10  relative to the handle  30  to the initial position of the body  26  in which the first rib  110  is engaged with the second rib  118 . The relief valve assembly  138  closes under the influence of the second biasing member  182 . 
     Because the gasket  56  is unseated, any pressure imbalance that may remain after initial venting through the relief valve assembly  138  can be equalized via flow between the threads  38 ,  42 . The first biasing member  134  is stiff enough to cause the body  26  to co-rotate with the handle  30  as the user continues to rotate the handle  30  in the loosening direction  54 , until the cap  10  is fully removed from the container  18 . 
       FIGS. 8-9  illustrate an alternative construction of a pressure relief cap  310 . The cap  310  is similar to the pressure relief cap  10  described above with reference to  FIGS. 1-7 , and the following description focuses primarily on differences between the cap  310  and the cap  10 . In addition, common features and elements of the pressure relief cap  310  corresponding with features and elements of the pressure relief cap  10  are given common reference numbers plus  300 . 
     The cap  310  includes a body  326 , a handle  330  ( FIG. 8 ) coupled to the body  326  via a ring member  374 , and a pressure relief valve assembly  438 . The valve assembly  438  includes a plunger  442  that, instead of being biased downwardly like the plunger  142 , is biased upwardly (i.e. in the direction of arrow  494  by the second biasing member  482 ). 
     The upper portion  446  of the plunger  442  is formed with a rounded engagement surface, and the peripheral seal  462  surrounds the lower portion  450 . When rotated, the cam shaped actuator  470  on the ring member  374  is configured to press down in the direction of arrow  486  against the rounded engagement surface on the upper portion  446  of the plunger  442  ( FIG. 9 ). This moves the plunger  442  downwardly to unseat the peripheral seal  462  from the valve seat  490  and thereby open the valve assembly  438 . 
     Thus, the present disclosure may provide a pressure relief cap  10 ,  310  with a relief valve assembly  138 ,  438  configured to relieve pressure from a container  18  when rotated in a loosening direction  54 ,  354 . The cap  10 ,  310  may also include a body  26 ,  326  and a ring member  74 ,  374  that allows for the valve assembly  138 ,  438  to be actuated before a driving connection to remove the cap  10 ,  310  is established between the handle  36 ,  336  and the body  26 ,  326 . 
     Although the disclosure has been described in detail with reference to certain independent embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the disclosure as described. 
     One or more independent features and/or advantages may be set forth in the following claims.