Abstract:
A cam pin stop apparatus is provided which is resistant to a malicious pop-open condition. The cam pin stop apparatus includes a cam pin configured to be movable along a first axis, and a cam pin stop configured to be movable to a release location to prevent the cam pin from substantially moving along a second axis, wherein the second axis is substantially perpendicular to the first axis. A potential energy may be released by the cam pin stop when it moves to the release location.

Description:
CROSS REFERENCE TO PRIOR APPLICATIONS 
     This application claims priority and the benefit thereof from a U.S. Provisional Application No. 61/005,468, filed on Dec. 5, 2007, which is hereby incorporated by reference for all purposes as if fully set forth herein. 
    
    
     FIELD OF THE INVENTION 
     The invention generally relates to a locking system. More specifically, the invention relates to an apparatus for use with a barrel type lock system to prevent a pop-open condition, or the like. 
     BACKGROUND OF THE INVENTION 
     Locks have been in use for thousands of years, securing property from intrusion, tampering or theft. Some of the earliest locks used a pin-lock mechanism which included a wooden lock and key. The lock was strung on a rope hanging out of a hole in a door. A cylinder of wood with a hole drilled through its axis served as the key. The cylinder may be inserted into the hole to push a bolt in the door a predetermined distance to unlock the door. To lock the door, the rope may be pulled to extract the cylinder while simultaneously pulling the bolt closed. 
     Generally, barrel locks provide effective security against tampering or malicious unlocking. However, in certain instances, where a force is applied to the lock that is greater than the force provided by a compression spring, the lock may pop open. Thus, barrel locks may be vulnerable to a malicious pop open condition. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the invention, a cam pin stop apparatus is provided which is resistant to a malicious pop-open condition. The cam pin stop apparatus comprises an outer housing, a compression spring, and a push button housing. The push button housing comprises: a locking pin configured to receive a force from the compression spring along a first axis; a cam pin configured to engage the locking pin and to be movable along a second axis, the second axis being substantially perpendicular to the first axis; a cam pin spring configured to provide a force to the cam pin along the second axis; a cam pin stop configured to be selectively movable to a release location to prevent the cam pin from substantially moving along the second axis; and a cam attached to the cam pin, wherein the cam is configured to receive a tumbler. The cam pin stop may be further configured to rotate in a plane substantially perpendicular to the first axis. The cam pin stop may be further configured to move to the release location when the cam pin is moved along the second axis to engage a cam pin opening in the outer housing. The outer housing may be further configured to lockably receive the push button housing along the first axis against a force provided by the compression spring. 
     According to another aspect of the invention, a cam pin stop apparatus is provided which is resistant to a malicious pop-open condition. The cam pin stop apparatus comprises: a locking pin configured to be movable along a first axis; a cam pin configured to be movable along the first axis and a second axis, which substantially perpendicular to the first axis; and a cam pin stop configured to be movable to a release location to prevent the cam pin from substantially moving along the second axis. The cam pin stop may be further configured to rotate in a plane substantially perpendicular to the first axis. The cam pin stop may be further configured to move to the release location when the cam pin is moved along the second axis to engage a cam pin opening. The cam pin stop apparatus may further comprise a cam configured to be movable along the first axis. The cam pin may be configured to be situated between the locking pin and the cam along the first axis. The cam pin stop apparatus may further comprise a tumbler. The cam pin stop apparatus may further comprise: a cam pin spring configured to provide a force to the cam pin along the second axis. The cam pin stop apparatus may further comprise: an outer housing comprising a cam pin opening, wherein the outer housing is configured to receive a compression spring and a push button housing. The push button housing may comprise: a cam configured to be movable along the first axis; a cam spring; and a tumbler. The push button housing may further comprise a key hole for receiving a key. The push button housing may further comprise a cam pin opening configured to receive a locking portion of the cam pin. 
     According to yet another aspect of the invention, a cam pin stop apparatus is provided which is resistant to a malicious pop-open condition. The cam pin stop apparatus comprises: a cam pin configured to be movable along a first axis; and a cam pin stop configured to be movable to a release location to prevent the cam pin from substantially moving along a second axis, wherein the second axis is substantially perpendicular to the first axis. The cam pin stop may be further configured to rotate in a plane substantially perpendicular to the first axis. The cam pin stop may be further configured to move to the release location when the cam pin is moved along the second axis to engage a cam pin opening. The cam pin may be further configured to move substantially completely from a pathway of the cam pin stop, the pathway being along the first axis. A potential energy may be released by the cam pin stop when it moves to the release location. 
     Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the detailed description and drawings. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the disclosure, are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the detailed description serve to explain the principles of the disclosure. No attempt is made to show structural details of the disclosure in more detail than may be necessary for a fundamental understanding of the disclosure and the various ways in which it may be practiced. In the drawings: 
         FIG. 1  shows an exploded view of an example of a cam pin stop apparatus according to an aspect of the invention; 
         FIG. 2  shows an example of the cam pin stop apparatus of  FIG. 1  in a closed or locked configuration, according to an aspect of the invention; 
         FIGS. 3A-3G  show views of various operational stages of a cross-section of the cam pin stop apparatus shown in  FIG. 1 ; 
         FIGS. 4A-4G  show views of various operational stages of a longitudinal-section of the cam pin stop apparatus shown in  FIG. 1 ; and 
         FIG. 5  shows an example of a process for manufacturing and assembling the cam pin stop apparatus of  FIG. 1 , according to an aspect of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The embodiments of the invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following attached description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Descriptions of well-known components and operating techniques may be omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings. 
       FIG. 1  shows an exploded view of an example of a cam pin stop (CPS) apparatus  100  according to an aspect of the invention.  FIG. 2  shows an example of the cam pin stop apparatus of  FIG. 1  in a closed or locked configuration, according to an aspect of the invention. 
     Referring to  FIG. 1 , the CPS apparatus  100  includes an outer housing  110 , a compression spring  120 , a slotted locking pin  130 , a cam pin  140 , a cam pin spring  142 , a cam  150 , a cam pin stop  152 , a plurality of tumblers  160 , a push button housing  170  and a tumbler set pin  172 . 
     The outer housing  110  includes a housing body  102 , a pin opening  104  and an inner surface  101 . The outer housing  110  may include a cam pin opening  106 , or a recess within an inner wall of the housing body  102  configured to receive the cam pin head  144 . The outer housing  110  may be configured to receive the compression spring  120 , the slotted locking pin  130 , the cam pin  140 , the cam pin spring  142 , the cam  150 , the cam pin stop  152 , the plurality of tumblers  160 , the push button housing  170  and the tumbler set pin  172 , so that a button face  178  of the button housing  170  may be substantially flush with a surface edge  108  in a locked (or closed) position of the CPS apparatus  100 . It is noted that the CPS apparatus  100  may be configured so that the button face  178  may be substantially recessed within the outer housing  110  or substantially protruding from the outer housing  110  in the locked position. 
     As seen in  FIG. 1 , the compression spring  120  may be configured between an inner surface  101  of the outer housing  110  and a compression surface  134  of the slotted locking pin  130 . The compression spring  120  may provide a force against the inner surface  101  and the compression surface  134 , such that when the CPS apparatus  100  is in an unlock state, the slotted locking pin  130  may be forced to retract (or pop) from the outer housing  110  without any need for application of force by a user. The compression spring  120  may include a conical shape, a cylindrical shape, or the like. The compression spring  120  may be constructed from a bent or coiled metal, plastic, or other material that has elastic properties. Further, compression spring  120  may include plural springs configured to provide a unitary outward force on the slotted locking pin  130 . 
     For example, U.S. Pat. No. 6,619,078, titled “BARREL LOCK,” issued Sep. 16, 2003, and U.S. Pat. No. 6,813,918, titled “BARREL LOCK ASSEMBLY,” issued Nov. 9, 2004, both of which are expressly incorporated herein by reference, teach an example of a coil spring that may be used for the compression spring  120  herein. 
     The slotted locking pin  130  may include a slot (or opening)  136  for receiving the cam pin  140 . The cam pin  140  may include a spring head  146  on a side opposite the cam pin head  144 . The spring head  146  may be configured to be inserted into the cam spring  142 , with one end of the cam spring  142  pressing against a surface of the cam pin  140 . The cam spring  142  may include one or more springs having a conical shape, a cylindrical shape, or the like. The cam spring  142  may be constructed from a bent or coiled metal, plastic, or other material that has elastic properties. The cam pin  140  may be situated between the slotted locking pin  130  and the cam  150 , as shown in  FIG. 1 . 
     The cam  150  includes a body  156  which may include a cylindrical shape, an elongated elliptical shape, or the like. The cam  150  may have a substantially smaller eccentric cylindrical protrusion on one end. The cam  150  includes a cam pin stop  152 , a longitudinal recess  154  and an eccentric pin  158 . The cam pin stop  152  may include a spring having ends  152 A,  152 B, of which the end  152 A may be substantially longitudinal and attached to the cam  150  (or integrally formed with the body  156  of the cam  150 ) and the end  152 B may be curved and unattached. The cam pin stop end  152 A may include a rigid material (such as, e.g., metal, hard plastic, or the like) and the cam pin stop end  152 B may include an elastic material (such as, e.g., metal, plastic, or the like). Alternatively, the cam pin stop  152  may be constructed as a single unitary structure having substantially the same material consistency throughout, including both ends  152 A and  152 B. 
     The cam  150  may be configured to receive tumblers  160  and a tumbler set pin  172 . As seen in  FIG. 1 , the cam  150  may be situated axially adjacent the cam pin  140  and the slotted locking pin  130 . The cam  150  may be activated using, for example, a key that aligns the tumblers  160  and allows the cam  150  to be rotated radially about, for example, a one-quarter (¼) turn. When the cam  150  is turned, the eccentric pin  158  engages with the cam end of the cam pin  140 , overcoming the force of the cam pin spring  142  and moving the cam pin  140  to an inward or unlocked position, as shown, e.g., in  FIGS. 3A and 4A . The cam  150  may be situated within the push button housing  170 . 
     As seen in  FIG. 1 , the exemplary tumblers  160  may include twelve slotted rotating detainer discs. However, the number or type of tumblers  160  may not be limited to twelve tumblers or the slotted rotating detainer discs. Instead (or in addition), the tumblers  160  may include more or less than twelve tumblers and the tumblers may include, for example, tubular pins, rectangular pins, rods, or the like, as is known in the art. 
     The push button housing  170  may be configured to receive the tumbler set pin  172 , the tumblers  160 , the cam  150 , the cam pin stop  152 , the cam pin  140 , the slotted locking pin  130  and the cam pin spring  142 . Further, the push button housing  170  may be configured to be inserted into the outer housing  110 . The push button housing  170  may include a keyhole in the button face  178  (for receiving a key) and one or more cam pin openings  176 A,  176 B in a housing body  174 . Further, recesses (not shown) may be provided in the inner walls of the housing body  174 , in addition to the openings  176 A,  176 B, to receive the cam pin head  144 . The push button housing  170  may be configured as a single unit, except for the compression spring  120  and the outer housing  110 , which may be provided separately. 
       FIGS. 3A-3G  show views of various operational stages of a cross-section of the CPS apparatus  100  shown in  FIG. 1 ; and  FIGS. 4A-4G  show views of various operational stages of a longitudinal-section of the CPS apparatus  100  shown in  FIG. 1 . As seen in  FIGS. 3A-3G  and  4 A- 4 G, a cam pin stop end  152 A of the cam pin stop  152  may move away from the cam pin  140  as the cam  150  is rotated radially around the axis A. Simultaneously, the other end, i.e., the cam pin stop end  152 B, of the cam pin stop  152  may rotate around the axis A in the direction of the cam pin  140 , while being compressed between the cam  150  and the cam pin  140  as the cam  150  is turned. The radial rotation around the axis A may continue until the cam pin head  144  is fully retracted from the cam pin opening  106  in the outer housing  110 . At this point, the compression spring  120  may force the push button housing  170  (including, e.g., the slotted locking pin  130 , the cam pin  140 , the cam pin spring  142 , the cam  150 , the cam pin stop  152 , the tumblers  160 , the tumbler set pin  172 , etc.) axially out of the outer housing  110  along the axis A until a positive stop is reached (not shown). A key (not shown) may then be turned to a locked position and removed from the CPS apparatus  100 . As the key is turned around the axis A to the locked (or engaged) position, the cam  150  and the cam pin stop  152  also rotate around the axis A back to a locked (or engaged) position, with the cam pin stop  152  remaining compressed between the cam  150  and the cam pin  140  until the push button housing  170  is pushed back into the other housing  110  and the cam pin head  144  is aligned with the cam pin opening  106  in the outer housing  110 . At this point, the cam pin spring  142  may push the cam pin head  144  into the cam pin opening  106 , thereby allowing the cam pin stop end  152 B to spring into position behind the cam pin  140  (as seen, e.g., in  FIGS. 3A and 4A ). 
       FIGS. 3A and 4A  show an example of the CPS apparatus  100  in a pop-open-locked (or engaged) configuration, where the key (not shown) has been turned to the locked (or engaged) position while the push button housing  170  is in the pop open position. In this configuration, the cam pin head  144  is retracted from the cam pin opening  106  and the push button housing  170  may receive an outward force from the compression spring  120  along the axis A, forcing the push button housing  170  (including, e.g., the slotted locking pin  130 , the cam pin  140 , the cam pin spring  142 , the cam  150 , the cam pin stop  152 , the tumblers  160 , the tumbler set pin  172 , etc.) axially out of the outer housing  110  (along the axis A) against the positive stop (not shown). The positive stop may provide a force of substantially equal (or greater) magnitude, but opposite direction to the force exerted by the compression spring  120 . Further, the eccentric pin  158  may be in a locked (or engaged) position to provide minimal (or substantially zero) resistance against movement of the cam pin  140  along the axis B, allowing the cam pin head  144  to be inserted (e.g., by the force from the cam spring  142 ) into the cam pin opening  106  when properly aligned. 
     As seen in  FIGS. 3A and 4A , the elongated portion of the cam pin stop end  152 B is positioned against a portion of a surface of the cam pin  140  along an axis that is perpendicular to both the axis A and the axis B. In this position, the cam pin stop end  152 B receives a force from the surface portion of the cam pin  140  (as well as from the cam  150 ), thereby compressing the cam pin stop end  152 B and increasing the potential energy in the cam pin stop  152 . Thus, when the push button housing  170  is substantially completely pushed into the outer housing  110 , the cam pin head  144  may be aligned with the cam pin opening  106  and moved along the axis B into the opening  106  by the force of the cam pin spring  142 . In this regard, the movement of the cam pin  140  may release the cam pin stop end  152 B, releasing the potential energy in the cam pin stop  152  and positioning the cam pin stop end  152 B in a pop open prevention position (such as, for example, shown in  FIGS. 3B and 4B ), which prevents the cam pin  140  from maliciously caused retraction from the cam pin opening  106 . 
       FIGS. 3B and 4B  show an example of the CPS apparatus  100  in a closed-locked (or engaged) configuration, before the key (not shown) has been inserted and turned to the unlocked (or disengaged). In this configuration, the eccentric pin  158  is positioned (as shown, e.g., in  FIG. 3B ) to allow the cam pin spring  142  to force the cam pin head  144  to engage the cam pin hole  106  and lock the push button housing  170  in the outer housing  110 . The cam pin stop end  152 B is positioned along the axis B and perpendicular to the axis A, in a location (such as, e.g., shown in  FIGS. 3B ,  4 B) that prevents the cam pin  140  from being retracted from the cam pin opening  106 . It is noted that the cam pin stop end  152 B release location may include a recessed portion (not shown) within the cam  140  for receiving the cam pin stop end  152 B in addition to, or instead of the release location shown, e.g., in  FIGS. 3B ,  4 B. 
     Alternatively,  FIGS. 3B and 4B  may show an example of the CPS apparatus  100  substantially immediately after the push button  170  in the exemplary configuration shown in  FIGS. 3A and 4A  has been substantially completely pushed into the outer housing  110  and the cam pin head  144 , aligned and engaged with the cam pin opening  106 . 
     Referring to  FIGS. 3C-3F  and  4 C- 4 F, after the key is inserted and rotated to an unlocked (or disengaged) position, the eccentric pin  158  is also moved to the unlocked position, providing a force greater than the force provided by the cam spring  142 , thereby moving the cam pin  140  to the retracted position shown in  FIGS. 3F ,  4 F. Simultaneously, the cam pin stop end  152 A is also turned to the unlocked position, where the cam pin stop end  152 B is positioned along the axis B, but perpendicular to the axis A, as shown in  FIGS. 3F ,  4 F. As the cam pin stop end  152 A is turned and the cam pin  140  is retracted, a surface of the cam pin  140  which is substantially parallel to the axis B contacts and compresses the cam pin stop end  152 B, thereby increasing a potential energy in the cam pin stop  152 . When the cam pin head  144  has been substantially completely retracted from the cam pin opening  106  and the cam pin stop end  152 B is moved to the open position (where it is positioned along the axis B), the push button housing  170  may be popped open by a force of the compression spring  120 , as shown in  FIGS. 3F ,  4 F. In this position, the cam pin stop end  152 B may continue to receive a force from the surface of the cam pin  140  (as well as from the cam  150 ), maintaining the cam pin stop end  152 B in a compressed configuration and maintaining the potential energy in the cam pin stop  152 . 
       FIGS. 3F and 4F  show an example of the CPS apparatus  100  in a pop-open-unlocked (or disengaged) configuration, where the key (not shown) has been inserted and turned to the unlocked (or disengaged). 
     As the key is turned from the unlocked position shown in  FIGS. 3F ,  4 F to the locked position, the eccentric pin  158  and the cam pin stop  152  are both moved to the locked position shown in  FIGS. 3G ,  4 G, discussed above with reference to  FIGS. 3A ,  4 A. In this position, the cam pin stop end  152 B continues to receive a force from the surface of the cam pin  140  (as well as from the cam  150 ), maintaining the cam pin stop end  152 B in a compressed configuration and maintaining the potential energy in the cam pin stop  152 . Thus, when the push button housing  170  is substantially completely pushed into the outer housing  110  and the cam pin head  144  aligns with the cam pin opening  106 , the cam pin  140  may engage with the cam pin opening  106  and lock the push button housing  170  in the closed (or locked) configuration (such as, e.g., shown in  FIGS. 3B and 4B ). Simultaneously, the cam pin stop end  152 B may be released to the release location shown in  FIGS. 3B ,  4 B to securely keep the cam pin head  144  from being maliciously retracted from the cam pin opening  106 . As noted earlier, the cam pin stop end  152 B release location may include a recessed portion (not shown) within the cam  140  for receiving the cam pin stop end  152 B in addition to, or instead of the release location shown, e.g., in  FIGS. 3B ,  4 B. 
       FIG. 5  shows an example of a process for manufacturing and assembling the cam pin stop apparatus of  FIG. 1 , according to an aspect of the invention. 
     Referring to  FIGS. 1 and 5 , initially, a cam  150  may be manufactured or constructed with a cam pin stop  152  (Step  510 ). The cam pin stop  152  may be attached to the cam  150  by a screw, pin, or the like, or through a process such as, for example, but not limited to, welding, gluing, or the like. Alternatively, the cam pin stop  152  may be integrally manufactured with the cam  150 . 
     After the cam  150  has been manufactured with the cam pin stop  152 , one or more tumblers  160  may be inserted into the cam  150  (Step  520 ), as well as a tumbler set pin  172  (Step  530 ). The cam  150 , including the one or more tumblers  160  and cam pin stop  152 , may then be inserted into a push button housing  170  capable of wholly receiving the cam  150  (Step  540 ). A cam pin  140  may then be inserted into the push button housing  170  adjacent the cam  150  (Step  550 ). A slotted locking pin may then be inserted into the push button housing adjacent the cam pin  140  (Step  560 ) to create a push button housing assembly. A compression spring, such as, for example, a conical compression spring, or the like, may then be inserted into an outer housing (Step  570 ). The push button housing assembly may then be inserted into the outer housing, against the compression spring (Step  580 ). 
     It is noted that the sequence of Steps  510  to  580  in process  500  may be reconfigured without departing from the scope or spirit of the invention. For example, the tumbler set pin  172  may be inserted into the cam  150  (Step  530 ) before the tumblers  160  are inserted in the cam  150  (Step  520 ). 
     Further, a computer readable medium is provided that includes a computer program which when executed on a general purpose computer causes Steps  510  to  580  to be carried out. The computer program may include a code section or segment for the each of the Steps  510  to  580  of the process  500 . 
     While the invention has been described in terms of exemplary embodiments, those skilled in the art will recognize that the invention can be practiced with modifications in the spirit and scope of the appended claims. These examples are merely illustrative and are not meant to be an exhaustive list of all possible designs, embodiments, applications or modifications of the invention.