Patent Publication Number: US-11649094-B1

Title: Slide-lock lid

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to liquid containers, and more particularly to lids for portable beverage containers. 
     BACKGROUND 
     Portable beverage containers are ubiquitous, with users carrying their beverages in water bottles, canteens, travel mugs, and the like. These portable beverage containers often have lids of various types to limit or prevent spillage when the containers are not in use. For example, many portable coffee mugs utilize lids that allow users to drink coffee and other beverages with relative ease while they are on the go. Simpler lids can merely have small drinking openings, while others can include a mechanism that allows the drinking opening to be closed off. 
     Unfortunately, many such closing mechanisms can be cumbersome to operate, often requiring full attention of the user and the use of both hands. Simpler closing mechanisms may also allow some leakage while closed and/or provide inadequate venting when the mechanism is open and the beverage container is in use. Further, many such closing mechanisms have designs that are not aesthetically pleasing. For example, some simpler travel mug lids have a sliding closing mechanism that can be operated with one hand while the other hand holds the travel mug. While these sliding closing mechanisms can be slid into a closed position, they sometimes allow leakage while closed. They can also provide poor venting while in an open position. 
     Although traditional portable beverage lids have worked in the past, improvements are always helpful. In particular, what is desired are portable beverage container lids that fully prevent leakage, provide good venting, are easy to operate, and are aesthetically pleasing. 
     SUMMARY 
     It is an advantage of the present disclosure to provide improved lids for fluid containers, which can include portable beverage containers such as coffee travel mugs, among other possible fluid containers. The disclosed lids fully prevent leakage, provide good venting, are easy to operate, and are aesthetically pleasing, among other improvements. These advantages can be accomplished at least in part by utilizing a slide-lock lid arrangement that is leak proof, has multiple fluid passages and seals, requires only one hand to operate, and has a sleek and attractive appearance. A cooling well built into the slide-lock lid also minimize burning from coffee and other hot beverages during use. 
     In various embodiments of the present disclosure, an apparatus can include a main outer housing, a slider top assembly, a carrier, a first fluid seal, and a second fluid seal. The main outer housing can have a first fluid opening for a first fluid to pass therethrough and a second fluid opening for a second fluid to pass therethrough. The slider top assembly can be coupled to the main outer housing and can be configured to slide laterally between an open position and a closed position with respect to the main outer housing. The carrier can be disposed within the main outer housing and can be configured to move when the slider top assembly slides laterally with respect to the main outer housing. The first fluid seal can be coupled to the carrier and can be configured to close the first fluid opening when the slider top assembly is in the closed position and allow the first fluid to pass through the first fluid opening when the slider top assembly is in the closed position. The second fluid seal can be coupled to the carrier and can be configured to close the second fluid opening when the slider top assembly is in the closed position and allow the second fluid to pass through the second fluid opening when the slider top assembly is in the closed position. 
     In various detailed embodiments, the apparatus can be configured to be a lid for a portable beverage container. In such instances, the first fluid can be a beverage, the first opening can be a beverage opening, the second fluid can be air, and the second opening can be an air vent. In some arrangements, the slider top opening can be configured to be operated by a user with one hand while the one hand also holds a fluid container associated with the apparatus. The apparatus can also include a piston disposed within the main outer housing and coupled to the carrier, wherein the piston causes the carrier to move when the slider top assembly slides laterally with respect to the main outer housing. The piston and carrier can move vertically as a combined assembly when the slider top assembly slides laterally. Also, the piston can be spring-loaded to force the first fluid seal and the second fluid seal to close when the slider top assembly is in the closed position. The slider top assembly can define a bottom surface having a feature that contacts and slides along the top of the piston when the slider top assembly slides laterally between the open position and the closed position. This feature can include a curved portion that pushes the piston downward as the slider top assembly slides from the closed position to the open position. 
     In further detailed embodiments, the slider top assembly can define an upper surface that is disposed at a first angle with respect to the main outer housing when the slider top assembly is in the closed position. The upper surface can also be disposed at a second angle with respect to the main outer housing when the slider top assembly is in the open position. The difference between the first angle and the second angle can be about ten degrees. In some arrangements, the main outer housing can include a cooling well integrally formed therein, with the cooling well being configured to allow the first fluid to cool after the first fluid passes through the first opening and is still within the main outer housing. The slider top assembly can include integrally formed rails and the main outer housing can include integrally formed tracks, and the rails can slide along the tracks when the slider top assembly slides laterally between the open position and the closed position with respect to the main outer housing. 
     In various further embodiments of the present disclosure, a portable beverage container lid can include a main outer housing, a slider top assembly, a carrier, a beverage seal, and a vent seal. The main outer housing can have a beverage opening for a beverage to pass therethrough and a vent opening for air to pass therethrough. The slider top assembly can be coupled to the main outer housing and can be configured to slide laterally between an open position and a closed position with respect to the main outer housing. The carrier can be disposed within the main outer housing and can be configured to move when the slider top assembly slides laterally with respect to the main outer housing. The beverage seal can be coupled to the carrier and can be configured to close the beverage opening when the slider top assembly is in the closed position and allow the beverage to pass through the beverage opening when the slider top assembly is in the closed position. The vent seal can be coupled to the carrier and can be configured to close the vent opening when the slider top assembly is in the closed position and allow air to pass through the vent opening when the slider top assembly is in the closed position. The portable beverage container lid can be configured so that sliding the slider top assembly to the open position can open both the beverage seal and vent seal simultaneously. 
     In various detailed embodiments, the portable beverage container lid can also include a spring-loaded piston disposed within the main outer housing and coupled to the carrier. The piston and carrier can move vertically as a combined assembly when the slider top assembly slides laterally with respect to the main outer housing. Also, the slider top assembly can define a bottom surface having a curved portion that contacts and slides along the top of the piston and pushes the piston downward when the slider top assembly slides laterally between the open position and the closed position. The slider top assembly can also define an upper surface that is disposed at a first angle with respect to the main outer housing when the slider top assembly is in the closed position and is disposed at a second angle with respect to the main outer housing when the slider top assembly is in the open position. The difference between the first angle and the second angle can be about ten degrees. The main outer housing can include a cooling well integrally formed therein, with the cooling well being configured to allow the beverage to cool after the beverage passes through the beverage opening and is still within the main outer housing. 
     In still further embodiments of the present disclosure, a portable beverage container can include a main reservoir configured to hold a beverage therein and a lid removably coupled to the main reservoir. The lid can include a main outer housing, a slider top assembly, a carrier, a beverage seal, and a vent seal. These components can have some or all of the foregoing features from the previous embodiments in any combination. 
     Other apparatuses, methods, features, and advantages of the disclosure will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional apparatuses, methods, features and advantages be included within this description, be within the scope of the disclosure, and be protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The included drawings are for illustrative purposes and serve only to provide examples of possible structures and arrangements for the disclosed systems, apparatuses, features, and methods for beverage container lids. These drawings in no way limit any changes in form and detail that may be made to the disclosure by one skilled in the art without departing from the spirit and scope of the disclosure. 
         FIG.  1    illustrates in front perspective view an example beverage container according to one embodiment of the present disclosure. 
         FIG.  2    illustrates in side perspective view the beverage container of  FIG.  1    according to one embodiment of the present disclosure. 
         FIG.  3 A  illustrates in side elevation view the beverage container of  FIG.  1    in a closed position according to one embodiment of the present disclosure. 
         FIG.  3 B  illustrates in side elevation view the beverage container of  FIG.  1    in an open position according to one embodiment of the present disclosure. 
         FIG.  4    illustrates in obverse perspective view the beverage container of  FIG.  1    in an open position according to one embodiment of the present disclosure. 
         FIG.  5    illustrates in front perspective view an example slide-lock lid according to one embodiment of the present disclosure. 
         FIG.  6    illustrates in exploded view the slide-lock lid of  FIG.  5    according to one embodiment of the present disclosure. 
         FIG.  7 A  illustrates in top perspective view an example main outer housing for a slide-lock lid according to one embodiment of the present disclosure. 
         FIG.  7 B  illustrates in bottom perspective view the main outer housing of  FIG.  7 A  according to one embodiment of the present disclosure. 
         FIG.  8 A  illustrates in top plan view an example slider top assembly for a slide-lock lid according to one embodiment of the present disclosure. 
         FIG.  8 B  illustrates in bottom plan view the slider top assembly of  FIG.  8 A  according to one embodiment of the present disclosure. 
         FIG.  9    illustrates in side cross-section view the slide-lock lid of  FIG.  5    according to one embodiment of the present disclosure. 
         FIG.  10 A  illustrates in side cross-section view an example piston and carrier assembly for a slide-lock lid according to one embodiment of the present disclosure. 
         FIG.  10 B  illustrates in side cross-section view an alternative example piston and carrier assembly for a slide-lock lid according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary applications of apparatuses, systems, and methods according to the present disclosure are described in this section. These examples are being provided solely to add context and aid in the understanding of the disclosure. It will thus be apparent to one skilled in the art that the present disclosure may be practiced without some or all of these specific details provided herein. In some instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the present disclosure. Other applications are possible, such that the following examples should not be taken as limiting. In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments of the present disclosure. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the disclosure, it is understood that these examples are not limiting, such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the disclosure. 
     The present disclosure relates in various embodiments to systems, apparatuses, and features for high-quality fluid container lids. In particular, the disclosed systems, apparatuses, and features provide portable beverage container lids that fully prevent leakage, provide good venting, are easy to operate, and are aesthetically pleasing, among other benefits. In various embodiments, slide-lock lids can include 
     Although the various embodiments disclosed herein focus on lids for beverage containers, such as portable coffee mugs, for purposes of simplicity in illustration, it will be readily appreciated that the disclosed systems, apparatuses, and features can similarly be used for any other kind of fluid container. For example, the disclosed systems, apparatuses and features can be used for watering cans, fuel dispensers, and any other form of fluid holding device. 
     Referring first to  FIG.  1   , an example beverage container  10  is shown in front perspective view. Beverage container  10  can include a lid  100  and a main reservoir  200  configured to hold a beverage such as coffee therein. In various embodiments, lid  100  can be removable from main reservoir  200 , such as by way of a threaded arrangement. Both lid  100  and main reservoir  200  can be reusable and can be easily cleaned when separated from each other. In a particular example, beverage container  10  can be a travel coffee mug. 
     Lid  100  can be referred to as a “slide-lock” lid and can have various components to facilitate sleek and smooth opening and closing operations. For example, a slider top assembly  110  at the top of the slide-lock lid  100  can slide between open and closed positions. As shown in  FIG.  1   , slider top assembly  110  is slid to an open position with respect to a main outer housing  120  of the slide-lock lid  100 . 
     Continuing with  FIG.  2   , the beverage container of  FIG.  1    is alternatively shown in side perspective view. Again, beverage container  10  can include a main reservoir  200  and a lid  100 , which in turn can include a slider top assembly  110  and a main outer housing  120 , among other various components, as detailed below. As shown in  FIG.  2   , slider top assembly  110  is slid to a closed position with respect to a main outer housing  120  of the slide-lock lid  100 . Slider top assembly  110  can define an upper surface  111  that resides at a first angle (i.e., closed angle) with respect to main outer housing  120  when it is in this closed position. In various arrangements, upper surface  111  can reside slightly above an outer circumference lip of main outer housing  120  as shown, so as to present a more aesthetically pleasing appearance. 
       FIGS.  3 A and  3 B  illustrate in side elevation views the beverage container of  FIG.  1    in closed and open positions respectively. As shown in  FIG.  3 A , slider top assembly  110  is not visible from a side elevation perspective when it is slid into a closed position. Conversely, slider top assembly slides  110  from left to right and in so doing pivots upward when it is moved from a closed to an open position, as shown in  FIG.  3 B . Upper surface  111  then resides at a second angle with respect to main outer housing  120  when it is in this open position. In various embodiments, the first angle can be different than the second angle of the upper surface  111 . For example, the difference between the first and second angles can be about 10 degrees. Other differences in angle are also possible, as may be desired. 
     Continuing with  FIG.  4   , beverage container  10  is shown in obverse perspective view in an open position. As can be seen in comparison with  FIG.  2   , which depicts a closed position, slider top assembly  110  has slid to an open position and in so doing has changed the angle of upper surface  111  with respect to main outer housing  120 . An indentation  112  integrally formed on upper surface  111  can help to readily facilitate the sliding action of slider top assembly  110  between open and closed positions. For example, a user can place a thumb within indentation  112  to push forward or backward on slider top assembly  110  to move it as desired. In some arrangements, the thumb on the same hand holding beverage container  10  can be used for this purpose. Accordingly, a single hand can be used to hold the beverage container  10  and also manually operate the slider top assembly  110  between open and closed positions. 
     When in the open position, a beverage opening (i.e., first fluid opening)  121  can be exposed. This beverage opening  121  can be integrally formed in main outer housing  120  of slide-top lid  100 . A user can then drink a beverage contained within beverage container  10  through this beverage opening  121  when beverage container  10  is in this open position. In some arrangements, a cooling well  122  can be integrally formed in main outer housing  120 . Such a cooling well  122  can facilitate a slight cooling of coffee or any other hot beverage after the beverage has passed through beverage opening  121  and is still within main outer housing  120 . 
     Transitioning now to  FIG.  5   , an example slide-lock lid is shown in front perspective view. Slide-lock lid  100  has been removed from an associated liquid container, such as a portable beverage container. This can be the beverage reservoir  200  of  FIG.  1   , for example. Removal from the associated liquid container can be facilitated by way of any suitable coupling arrangement, such as a threaded arrangement  101 , for example. Again, slide-lock lid  100  can include a slider top assembly  110  that slides back and forth between open and closed positions with respect to a main outer housing  120 . An indentation  112  can facilitate such a manual sliding action by the user. As shown in  FIG.  5   , slide-lock lid  100  is in a closed position. 
       FIG.  6    illustrates in exploded view the slide-lock lid of  FIG.  5    according to one embodiment of the present disclosure. As will be readily appreciated, slide-lock lid  100  can include a variety of components to facilitate its functions as a portable beverage container lid that fully prevents leakage, provides good venting, is easy to operate, and is aesthetically pleasing. In order, slide-lock lid  100  can include a slider top assembly  110 , a piston  130 , a biasing spring  131 , a main outer housing  120 , an O-ring  102 , a vent seal  141 , a beverage seal  142 , a carrier  140 , a threaded arrangement  101 , and a bottom gasket  103 . Beverage seal  142  can be considered a first fluid seal, while vent seal  141  can be considered a second fluid seal. O-ring  102 , vent seal  141 , beverage seal  142 , and bottom gasket  103  can all be considered gaskets or seals. 
     Piston  130  can be coupled to carrier  140 , which in turn is coupled to both vent seal  141  and beverage seal  142  to form a combined assembly of these components. Slider top assembly  110  can be arranged to provide a downward force to piston  130  when slider top assembly  110  slides from a closed position to an open position. This can result in piston  130  moving downward, which also moves carrier  140 , vent seal  141 , and beverage seal  142  downward as a combined assembly with piston  130 . Downward motion of the piston, carrier, beverage seal and vent seal assembly correspondingly moves beverage seal  142  and vent seal  141  away from beverage and vent openings respectively to open the overall slide-lock lid  100 . Biasing spring  131  can be configured to bias piston  130  in an upward direction such that the combined assembly of piston  130 , carrier  140 , vent seal  141 , and beverage seal  142  is forced in an upward position to close the vent and beverage seals against their respective openings when slide-lock lid  100  is in the closed position. These relationships and details thereof can be seen with respect to the figures below, such as the cross-section view shown in  FIG.  9   . 
     Turning next to  FIGS.  7 A and  7 B , an example main outer housing for a slide-lock lid is illustrated in top perspective and bottom perspective views respectively. Main outer housing  120  can include a beverage opening  121 , a cooling well  122 , a vent opening  123 , and tracks  124 , among other possible features. Beverage opening  121 , which can also be referred to as a mouth opening or first fluid opening, can allow beverage to pass therethrough from an associated beverage or fluid reservoir to a user. Cooling well  122  can allow a hot beverage to cool after it has passed through beverage opening  121  and is still within main outer housing  120 . Vent opening  123 , which can also be referred to as a second fluid opening, can allow air to pass therethrough so as to facilitate a smooth flow of beverage through the beverage opening  121 , as will be readily appreciated. Tracks  124  can mate with associated rails (as noted below) on an associated slider track assembly so as to facilitate a smooth and directed sliding motion of the slider track assembly. 
     Each of features  121 ,  122 ,  123 ,  124  can be integrally formed within main outer housing  120 . For example, main outer housing  120  can be a singularly formed molded plastic material. Alternatively, one or more of features  121 ,  122 ,  123 ,  124  can be formed from a separate component coupled to main outer housing  120 . Main outer housing  120  can also be formed of any other suitable material besides a molded plastic material. For example, a suitable metal material may also be used. 
     Continuing with  FIGS.  8 A and  8 B , an example slider top assembly for a slide-lock lid is shown in top plan and bottom plan views respectively. Slider top assembly  110  can include an upper surface  111 , an indentation  112 , a bottom surface  113 , a curved portion (i.e. feature)  114 , rails  115 , and a detent  116 , among other possible features. Upper surface  111  can present as the top of slider top assembly  110  and can include indentation  112  to facilitate ease of use. Bottom surface  113  can include each of curved portion  114 , rails  115 , and detent  116 . Curved portion  114  can be a feature that contacts the top of an associated piston (not shown) and pushes the piston downward. In particular, curved portion  114  slides along the top of the piston and pushes it downward as slider top assembly  110  slides from a closed position to an open position. Rails  115  mate with associated tracks on an associated slider track assembly to facilitate a smooth and directed sliding motion of the slider top assembly  110  between open and closed positions, as noted above. Detent  116  provides a mechanical stop against the associated piston when the slider top assembly  110  reaches a fully open position so as to prevent the slider top assembly from sliding off the associated main outer housing during regular use. 
     Each of features  111 ,  112 ,  113 ,  114 ,  115 ,  116  can be integrally formed within slider top assembly  110 . For example, slider top assembly  110  can also be a singularly formed molded plastic material. Alternatively, one or more of features  111 ,  112 ,  113 ,  114 ,  115 ,  116  can be formed from a separate component coupled to slider top assembly  110 . Slider top assembly  110  can also be formed of any other suitable material besides a molded plastic material. For example, a suitable metal material may also be used. 
     Moving next to  FIG.  9    the slide-lock lid of  FIG.  5    is depicted is side cross-section view. As noted above, slide-lock lid  100  can include a slider top assembly  110  that is removably coupled to and slidable with respect to a main outer housing  120 . As shown in  FIG.  9   , slide-lock lid  100  is in a closed position, such that slider top assembly  110  slides toward the right with respect to the view shown when the slider top assembly slides to an open position. As noted above, the angle of slider top assembly  110  changes as it slides from a closed to an open position, such that the end having indentation  112  is lowered while the opposite end of the slider top assembly is raised. Main outer housing  120  does not move during such a sliding operation. A threaded arrangement  101  at the bottom of main outer housing  120  can be used to removably couple the entire slide-lock lid  100  to an associated beverage container or other fluid reservoir. 
     While slide-lock lid  100  is in the closed position, coffee or another beverage or fluid may enter a hollow region  125  within main outer housing  120  since the bottom of main outer housing  120  is open and hollow where it couples to an associated beverage container. The coffee or other fluid cannot exit or leak from the slide-lock lid, however, due to the presence of beverage seal  142  sealing off beverage opening  121  and vent seal  141  sealing off vent opening  123  when the entire arrangement is in the closed position. 
     When slider top assembly  110  is slid into an open position (not shown in  FIG.  9   ), a curved portion  114  along the bottom surface of the slider top assembly  110  slides along and pushes downward against the top of piston  130  in a cam action. This causes the piston  130  to be pushed downward vertically as the slider top assembly  110  slides from left to right with respect to the view shown in  FIG.  9   . Piston  130  can be removably coupled to carrier  140 , such that downward movement of the piston also moves the carrier downward. Beverage seal  142  and vent seal  141  can be coupled to carrier  140 , such that downward movement of the carrier also moves the beverage and vent seals downward, thus opening beverage opening  121  and vent opening  123 . A detent  116  located on the bottom surface of slider top assembly  110  can prevent the slider top assembly from sliding past a fully open position and coming completely detached from the main outer housing  120  during ordinary use. 
     When slider top assembly  110  is slid into an open position, coffee, beverage, or other fluid contained within hollow region  125  can flow through open beverage opening  121  with adequate venting provided through open vent opening  123 , such as when the entire arrangement is tilted to allow fluid flow. Notably, a single sliding operation of the slider top assembly  110  actuates both beverage and vent seals  142 ,  141  simultaneously. After the coffee or other beverage or fluid has passed through the beverage opening  121 , it can be slightly cooled within a cooling well  122  prior to being consumed or otherwise expelled from the slide-lock lid  100 . 
     When the slider top assembly  110  of slide-lock lid  100  is slid from an open position to a closed position, a biasing spring  131  situated about piston  130  can push the piston upward against the bottom surface of the slider top assembly  110 . This can then cause the carrier  140  coupled to the piston  130  to be pushed upward, which also causes the beverage seal  142  and vent seal  141  to seal off their respective openings. In some arrangements, an additional protrusion on the bottom surface of the slider top assembly  110  can snap into a hollow region atop piston  130 , such that a snapping or locking effect is achieved as the slider top assembly reaches a fully closed position. A slight static force can be provided by this protrusion and hollow region arrangement, which can prevent the entire device from slipping open but which can also be overcome with a slight manual force by a user. 
     In various embodiments, various components of slide-lock lid  100  can be disassembled to allow for easier cleaning, maintenance, and interchangeability of parts. For example, slider top assembly  110  can be completely removed from main outer housing  120  in some arrangements. This can be accomplished by allowing a user to manually override the function provided by detent  116 . When slide-lock lid  100  is unscrewed or otherwise removed from an associated beverage container or other fluid reservoir, a user can reach into hollow region  125  and pull down on the bottom of carrier  140 . This can override the force of biasing spring  131  and serve to pull the entire carrier, seal and piston assembly downward such that detent  116  will no longer cause slider top assembly  110  to stop at a fully open position, and the slider top assembly can continue to be slid completely off of the main outer housing  120 . 
     Lastly,  FIGS.  10 A and  10 B  illustrate in side cross-section view two examples of a possible piston and carrier assembly for a slide-lock lid.  FIG.  10 A  shows one version of such an assembly, while  FIG.  10 B  shows an alternative version for this assembly. It will be appreciated that either version can be used, and that other arrangements and designs of piston and carrier assemblies can also be used as desired. 
     As noted above, piston  130  and carrier  140  can be coupled together to form a combined assembly that moves as a single unit, which assembly can also include a beverage seal, a vent seal, or both. In various arrangements, piston  130  can be readily removably coupled from carrier  140 . Again, separation of various slide-lock lid components can advantageously facilitate cleaning, maintenance and part maintenance or replacement. In some arrangements, beverage and vent seals can be affixed to the carrier  140  and can be formed of different materials from the carrier, which materials may be more suitable for forming seals against their respective openings. 
       FIG.  10 A  shows one possible arrangement where piston  130  is rotatably locked within carrier  140 . In this arrangement, protrusions  133  located toward the shaft bottom of piston  130  can insert into a slotted feature  143  that can be integrally formed within a recess in carrier  140 . After protrusions  133  have been inserted slotted feature  143 , the piston  130  can be rotated to lock the piston within the carrier  140 . This can be arranged such that a rotation of one-quarter turn in one direction is sufficient to lock the piston  130  within the carrier  140 , and a rotation of one-quarter turn in the opposite direction is sufficient to unlock the piston such that it can be removed from the carrier. Other rotational amounts and arrangements are also possible. 
     In some arrangements, a coin slot  132  or other similar feature can be located atop the piston  130  to facilitate such a rotation of the piston. Of course, a user can also simply rotate the piston without such an additional coin slot  132  or other similar helpful feature. In addition, a knob  144  or other similar feature can be integrally formed at the bottom of carrier  140  to facilitate gripping and downward pulling by a user when the user wants to override the detent function and remove the slider top assembly from the main outer housing, as noted above. 
       FIG.  10 B  shows an alternative possible arrangement for a piston and carrier. Rather than have protrusions and slots, piston can have a threaded region  134  at its bottom end. This bottom end can be placed completely through an opening in the carrier  140  and a locking cap  145  with internal threading can be screwed onto this threaded region  134  to hold the piston and carrier together as a combined assembly. Such a locking cap  145  can be suitably shaped so that a user can then pull on the locking cap to release the function of the detent, as noted above. 
     Although the foregoing disclosure has been described in detail by way of illustration and example for purposes of clarity and understanding, it will be recognized that the above described disclosure may be embodied in numerous other specific variations and embodiments without departing from the spirit or essential characteristics of the disclosure. Certain changes and modifications may be practiced, and it is understood that the disclosure is not to be limited by the foregoing details, but rather is to be defined by the scope of the appended claims.