Abstract:
A quick release pin has an elongated body having an axial bore therethrough and a shaft extending at least partially through the axial bore for rotational movement within the bore. A button is mounted on a first end of the shaft. At least one opening is formed in a second end of the shaft. A handle has a central passage through which the button extends. The handle is mounted to the elongated body. The button has a resilient member for engaging and disengaging an opening in the handle for locking and unlocking the pin. The knob can have a member which engages and slides along a groove formed in a surface of the handle.

Description:
CLAIM OF PRIORITY 
       [0001]    This application claims priority from Provisional Application Serial No. 60/841,623 filed on Aug. 31, 2006. 
     
     BACKGROUND OF THE INVENTION 
       [0002]    The invention of this application relates to release pins and, more particularly, to rotary release pins. 
         [0003]    Releasable securing devices, such as ball pins, are commonly used for joining two parts such as the parts of industrial fixtures together. Such ball pins have a hollow, hardened stem insertable through mating bores in the two parts to be joined. The device further includes an abutment surface on one side of the stem configured to be pressed against the one side of the stacked parts. The other side of the device includes depressible or retractable balls near the tip of the pin which are configured to engage the other side of the parts when they are in the extended position. 
         [0004]    Quick connect ball locking devices generally include a plurality of detents, such as balls, trapped within a tube but protruding out openings therein. A ball actuator is reciprocal within the tube and movable from a first position wherein the balls are retracted substantially within the tube or moved outwardly a sufficient distance to lock the balls within a mating receptacle. An example of such a ball locking device is shown in U.S. Pat. No. 5,394,594 which is incorporated by reference herein. U.S. Pat. No. 3,277,767 also shows such a releasable securing device and is also incorporated by reference herein for showing the same. 
         [0005]    More particularly, and with reference to  FIG. 1 , a prior art release pin RP is shown having a handle H, a knob K and a shank SH. Pin RP further includes a spindle SP that is configured to actuate balls B 1  and B 2 . Pin RP further includes a compression spring CS that is mounted within an enlarged bore EB between knob K and shank SH to urge knob K and spindle SP in axial direction A 1 . A knob shoulder KS on the knob engages abutment AB on handle H to limit this movement. In the position shown, pin RP is in the locked condition wherein land L of spindle SP holds balls B 1  and B 2  in a projected position. Knob K, extending from the shank, may be moved manually in axial direction A 2  to bring a groove G into registry with the balls and thereby permit radially inward movement of the balls to along ramp R to a release or unlocked condition. Spindle SP of pin RP further includes a spindle shaft SS that extends through a shank bore SB in Shank SH to interengage with knob K. Accordingly, the prior art device&#39;s spindle extends from its working end by land L to knob K. 
         [0006]    Thus, the prior art pins are biased in a locked position. The user has to depress the knob, thus compressing the spring and moving the shaft in an axial direction A 2  to allow the balls to move to a released or unlocked position. There is no indication on the existing release pins that the pin is in either a locked or unlocked position. Furthermore, the existing release pin requires axial movement of the shaft and button to actuate or release the balls. The user must continue to push on the button or knob to maintain the pin in an unlocked position. Thus, there is a need for a release pin with a knob which only needs to be rotated, can be locked into an unlock or lock position, and which indicates that the pin is in a locked or unlocked position. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention of this application relates to fastener devices and is particularly directed to quick release pin assemblies which have a knob rotatable between a locked and unlocked position. The release pin according to one aspect of the present invention includes a central shaft and an actuating knob or button attached thereto. The knob is rotated from a locked position to an unlocked position. A coiled spring is used to bias the knob to the locked position. When the knob is rotated 90 degrees, the central shaft also rotates within a longitudinal bore in the shank of a pin to translate the motion of the button. Rotation of the shaft acts to cause radial movement of balls outward beyond the outer surface of the pin shank to form a projecting abutment. One or more recessed portions on the movable shaft can be used to hold the balls in a recessed or unlocked position to permit the balls to be moved radially inwardly so that they do not project beyond the outer surface of the shank. 
         [0008]    The release pin of the present invention has a handle attached to the shank. The shaft is mounted within the bore of the shank and has the button mounted at one end of the shaft. 
         [0009]    In one embodiment, a spring can be mounted between the button and the handle which biases the knob or button to a locked position. 
         [0010]    In another embodiment, the knob has a locking pin which is biased within a locked recessed opening in the upper surface of the handle. The locking pin is manually pulled or moved out of engagement with the “lock” recessed opening and is flexed radially inwardly. The knob is rotated about 90 degrees to the “unlock” recessed opening in the handle. The pin is released, and the spring bias of the pin moves the pin into the “unlock” opening. 
         [0011]    In another embodiment, a quick release pin has an elongated body having an axial bore therethrough; a shaft extending at least partially through the axial bore for rotational movement within the bore; a button mounted on a first end of the shaft; at least one opening formed in a second end of the shaft; a handle having a central passage through which the button extends, wherein the handle is mounted to the elongated body; and wherein the button has a resilient member for engaging and disengaging an opening in the handle for locking and unlocking the pin. 
         [0012]    In yet another embodiment, a release pin has an elongated body having an axial bore therethrough; a shaft extending through the bore for rotational movement; a knob mounted to a first end of the shaft; at least one slot formed in a second end of the shaft; a handle mounted to the elongated body, the handle having a central passage therethrough; a biasing member interposed between the knob and the handle within the central passage for biasing the knob in a locked position; wherein the knob comprises a member which engages and slides along a groove formed in a surface of the handle. 
         [0013]    Other aspects of the present invention will become apparent to those of average skill in the art upon a reading and understanding of the following detailed description. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a side elevational view in cross-section of an existing release pin; 
           [0015]      FIG. 2A  is a top plan view of the handle of a rotary release pin in a locked position in accordance with an embodiment of the present invention; 
           [0016]      FIG. 2B  is a perspective view of the pin of  FIG. 2A ; 
           [0017]      FIG. 2C  is a side elevational view of the pin of  FIG. 2B ; 
           [0018]      FIG. 2D  is a cross-sectional view through lines  2 D- 2 D of  FIG. 2C ; 
           [0019]      FIG. 3A  is a top plan view of a handle of a rotary release pin in a locked position in accordance with a second embodiment of the present invention; 
           [0020]      FIG. 3B  is a perspective view of the pin of  FIG. 3A ; 
           [0021]      FIG. 3C  is a side elevational view of the pin of  FIG. 3B ; 
           [0022]      FIG. 3D  is a cross-sectional view through lines  3 D- 3 D of  FIG. 3C ; 
           [0023]      FIG. 4A  is a top plan view of a handle of a rotary release pin in a locked position in accordance with a third embodiment of the present invention; 
           [0024]      FIG. 4B  is a perspective view of the pin of  FIG. 4A ; 
           [0025]      FIG. 4C  is a side elevational view of the pin of  FIG. 4B ; 
           [0026]      FIG. 4D  is a cross-sectional view through lines  4 D- 4 D of  FIG. 4C ; 
           [0027]      FIG. 5A  is a top plan view of a handle of a rotary release pin in a locked position in accordance with a fourth embodiment of the present invention; 
           [0028]      FIG. 5B  is a perspective view of the pin of  FIG. 5A ; 
           [0029]      FIG. 5C  is a side elevational view of the pin of  FIG. 5B ; 
           [0030]      FIG. 5D  is a cross-sectional view through lines  5 D- 5 D of  FIG. 5C ; 
           [0031]      FIG. 6A  is a top plan view of a handle of a rotary release pin in a locked position in accordance with a fifth embodiment of the present invention; 
           [0032]      FIG. 6B  is a perspective view of the pin of  FIG. 6A ; 
           [0033]      FIG. 6C  is a side elevational view of the pin of  FIG. 6B ; 
           [0034]      FIG. 6D  is a cross-sectional view through lines  6 D- 6 D of  FIG. 6C ; 
           [0035]      FIG. 7A  is a top plan view of a handle of a rotary release pin in a locked position in accordance with a sixth embodiment of the present invention; 
           [0036]      FIG. 7B  is a perspective view of the pin of  FIG. 7A ; 
           [0037]      FIG. 7C  is a side elevational view of the pin of  FIG. 7B ; 
           [0038]      FIG. 7D  is a cross-sectional view through lines  7 D- 7 D of  FIG. 7C ; 
           [0039]      FIG. 8A  is a perspective view of a pin in accordance with a seventh embodiment of the present invention; and 
           [0040]      FIG. 8B  is a cross-sectional view through lines  8 B- 8 B of  FIG. 8A . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0041]    Referring now to the drawings, in particular referring to  FIGS. 2A-2D , a quick release pin assembly  10  in accordance with an embodiment of the invention is shown that includes a shank  12  and a handle  14  attached to an upper portion of the shank. The shank has a central axial bore  16  having a first and a second end  18  and  20 , respectively. Pin  10  further includes a shaft  22  that extends through bore  16  for rotational movement about axis A 3 . Shaft  22  has a first end and a second end  22   a  and  22   b , respectively. The shank and shaft are preferably made from metal in each of the embodiments described herein. 
         [0042]    Pin  10  further includes a knob  24  that can be configured in any one of a number of configurations, including any configuration known in the art, and/or other designs and configurations. Knob  24  has a thumb end  26 , which is configured to be pressed by the end user thereby rotating knob  24  in direction A 3 , and a shaft end  28  that can be opposite to thumb end as is shown in these figures. The knob and handle are preferably fabricated from plastic or metal in each of the embodiments discussed herein. 
         [0043]    Actuator button or knob  24  is fixed to the shaft  22  by any means known in the art. The handle  14  is secured to the shank  12  by any convenient means such as, for example by press fitting, brazing, swaging or screw threading. In the particular connection illustrated in the drawings, the shank and handle are connected by means of a threaded fit along inner surfaces of the shank and handle. 
         [0044]    Shaft end  28  of knob  24  is configured to interengage with shaft  22  at first end  22   a . First end  22   a  of the shaft has a smaller diameter than the second end  22   b . The shaft can be joined to knob  24  by any means known in the art including, but not limited to, press fitting, brazing, swaging, screw threading and/or crimping the knob to the shaft. As a result, rotational movement of the knob is translated to the shaft. 
         [0045]    Shaft end  22   b  has a pair of recessed openings or notches  28 ,  29  which serves to hold a pair of radially movable balls  30 ,  32  in their fully retracted position. The balls are preferably made of metal in each embodiment described herein. The recessed openings are shown as rectangular in shape, but they can be of other configurations as well without departing from the scope of the invention. In a fully projected position, the balls move radially outwardly into lateral bores or openings  34 ,  36 , respectively, in an outer wall  38  of shank  12 , as shown in  FIGS. 2B-2D . The outer ends of the bores can be “staked” to reduce the size of the openings which intersect outer cylindrical surface  38  of the shank, and this reduced size opening retains each ball from laterally escaping. Rotational movement of shaft  22  brings surface  40  of the shaft out of alignment with the balls, such that the balls move into recesses  28 ,  29  thereby allowing balls  30 ,  32  to move radially inwardly so that they fall into openings  34 ,  36  such that they no longer extend beyond the outer surface  38  of the shank  12 . Then, if the shaft is rotated  90  degrees (clockwise or counterclockwise), the balls are once again engaged by surface  40  which moves them radially outwardly such that they again move outwardly beyond surface  38  of shank  12 . 
         [0046]    In one embodiment, shown in  FIGS. 2A-2D , rotational movement in direction A 3  is by the force or thumb pressure exerted by the end user on knob  24 . The user presses or moves the resiliently biased arm  50  of knob  24  radially inwardly so that pin  52  on an end of arm  50  is released from locked engagement with LOCK notch or opening  54  of upper end  56  of handle  14 . Then, the knob is rotated  90  degrees either clockwise or counterclockwise until the pin  52  is aligned with one of the UNLOCK openings  58 ,  59 . Then, the user releases the arm, and the arm snaps into one of openings  58 ,  59  in the unlocked position. When the knob is being rotated  90  degrees, the balls move radially inwardly into recesses or slots  28 ,  29  of the shaft  22 . 
         [0047]    To place the pin back into a locked position, the user again moves pin  52  radially inwardly to release the pin from engaging UNLOCK opening  58  or  59 . Then, the knob is rotated clockwise or counterclockwise 90 degrees until the pin  52  is aligned with one of LOCK openings  54  or  60 . Then, the pin is released and snapped into engagement with one of openings  54  or  60 . The balls are pushed radially outwardly by outer surface  40  of shaft  22  until they move into openings  34 ,  36  of shank  12  and protrude beyond outer surface  38  of shank  12 . 
         [0048]    In accordance with another embodiment of the invention, referring to  FIGS. 3A-3D , rotational movement of knob  70  is by a force or thumb pressure exerted by the user on knob  70 . The user presses or moves the resiliently biased arm  72  of knob  70  radially inwardly so that pin  74  on an end of arm  72  is released from locked engagement with LOCK opening or slot  76 . The knob is then rotated  90  degrees clockwise to an UNLOCK opening or slot  78 . Then, the user releases the pin  74  to engage and lock into UNLOCK opening  78 . 
         [0049]    Shaft end  80  of knob  70  is configured to interengage with shaft  82  at first end  82   a . First end  82   a  of the shaft has a smaller diameter than a second end  82   b . The shaft can be joined to knob  70  by any means known in the art including, but not limited to, press fitting, brazing, swaging, screw threading and/or crimping the knob to the shaft. As a result, rotational movement of the knob is translated to the shaft. 
         [0050]    Shaft end  82   b  has a pair of recessed openings or notches  84 ,  86  which serves to hold a pair of radially movable balls  88 ,  89  in their fully retracted position. The recessed openings are shown as rectangular in shape, but they can be of other configurations as well without departing from the scope of the invention. In a fully projected position, the balls move radially outwardly into lateral bores or openings  90 ,  92 , respectively, in an outer wall  94  of shank  96 , as shown in  FIGS. 3B-3D . The outer ends of the bores can be “staked” to reduce the size of the openings which intersect outer cylindrical surface  94  of the shank, and this reduced size opening retains each ball from laterally escaping. Rotational movement of shaft  82  brings surface  98  of the shaft out of alignment with the balls, such that the balls move into recesses  84 ,  86  thereby allowing balls  88 ,  89  to move radially inwardly so that they fall into openings  90 ,  92  such that they no longer extend beyond the outer surface  94  of the shank  96 . Then, if the shaft is rotated 90 degrees, the balls are once again engaged by surface  98  which moves them radially outwardly such that they again move outwardly beyond surface  94 . 
         [0051]    Rotational movement in direction A 4  is by the force or thumb pressure exerted by the end user on knob  70 . The user presses or moves the resiliently biased arm  72  of knob  70  radially inwardly so that pin  74  on an end of arm  72  is released from locked engagement with LOCK opening  76  of upper end  100  of handle  102 . Then, the knob is rotated 90 degrees either clockwise or counterclockwise until the pin  74  is aligned with the UNLOCK opening  78 . Then, the user releases the arm, and the arm snaps into opening  78  in the unlocked position. When the knob is being rotated 90 degrees, the balls move radially inwardly into recesses or slots  84 ,  86  of the shaft  82 . 
         [0052]    To place the pin back into a locked position, the user again moves pin  74  radially inwardly to release the pin from engaging opening  78 . Then, the knob is rotated counterclockwise  90  degrees until the pin  74  is aligned with LOCK opening  76 . Then, the pin is released and snapped into engagement with opening  76 . The balls are pushed radially outwardly by outer surface  98  of shaft  82  until they move into openings  90 ,  92  of shank  96  and protrude beyond outer surface  94 . 
         [0053]    In accordance with another embodiment of the invention, referring to  FIGS. 4A-4D , rotational movement of knob  110  is by a thumb pressure or force exerted by a user on knob  110 . The user presses or moves the resiliently biased arm  112  of knob  110  radially inwardly and then a pin  114  on an end of arm  112  is released from locked engagement with LOCK opening  116 . The user then rotates the knob  90  degrees clockwise until the pin  110  is aligned with the end of groove  118  formed in upper surface  120  of handle  122  adjacent the label “UNLOCK”. A coiled spring  124  positioned underneath the knob between a surface  125  of the knob and an inner surface  127  of the handle biases the knob to the locked position. As the knob is rotated to the UNLOCK position, the spring is rotated and is pulled or extended. Then, when the user releases the knob, the spring is released and biases the knob back to the LOCK opening  116 . 
         [0054]    Shaft end  126  of knob  110  is configured to interengage with shaft  128  at first end  128   a . First end  128   a  of the shaft has a smaller diameter than a second end  128   b . The shaft can be joined to knob  110  by any means known in the art including, but not limited to, press fitting, brazing, swaging, screw threading and/or crimping the knob to the shaft. As a result, rotational movement of the knob is translated to the shaft. 
         [0055]    Shaft end  128   b  has a pair of recessed openings or notches  130 ,  132  which serves to hold a pair of radially movable balls  134 ,  136  in their fully retracted position. The recessed openings are shown as rectangular in shape, but they can be of other configurations as well without departing from the scope of the invention. In a fully projected position, the balls move radially outwardly into lateral bores or openings  138 ,  140 , respectively, in an outer wall  142  of shank  144 , as shown in  FIGS. 4B-4D . The outer ends of the bores can be “staked” to reduce the size of the openings which intersect outer cylindrical surface  142  of the shank, and this reduced size opening retains each ball from laterally escaping. Rotational movement of shaft  128  brings surface  131  of the shaft out of alignment with the balls, such that the balls move into recesses  130 , 132  thereby allowing balls  134 ,  136  to move radially inwardly so that they fall into openings  138 ,  140  such that they no longer extend beyond the outer surface  142  of the shank. Then, if the shaft is rotated 90 degrees, the balls are once again engaged by surface  131  which moves them radially outwardly such that they again move outwardly beyond surface  142 . 
         [0056]    Rotational movement in direction A 5  is by the force or thumb pressure exerted by the end user on knob  110 . The user presses or moves the resiliently biased arm  112  of knob  110  radially inwardly so that pin  114  on an end of arm  112  is released from locked engagement with LOCK opening  116  of upper end  120  of handle  122 . Then, the knob is rotated 90 degrees clockwise until the pin  114  is aligned with UNLOCK marking adjacent the end of groove  118 . Then, the user has to hold the arm in the unlocked position. When the knob is being rotated 90 degrees, the balls move radially inwardly into recesses or slots  130 ,  132  of the shaft  128 . 
         [0057]    To place the pin back into a locked position, the user releases pin  114 . Then, the knob rotates counterclockwise 90 degrees until the pin  114  is aligned with LOCK opening  116 . Then, the pin is released and snapped into engagement with opening  116 . The balls are pushed radially outwardly by outer surface  131  of shaft  128  until they move into openings  138 ,  140  of shank  144  and protrude beyond outer surface  142 . 
         [0058]    In accordance with another embodiment of the invention, referring to  FIGS. 5A-5D , rotational movement of knob  150  is by a force or thumb pressure exerted by a user on knob  150 . The user rotates the knob by holding pin  152  and rotating the knob 90 degrees either clockwise or counterclockwise. The user rotates the knob 90 degrees counterclockwise until a tab  154  of the knob is aligned with an end of groove  156  formed in upper surface  158  of handle  160  adjacent the labels “UNLOCK” and “LOCK”. A coiled spring  162  is located underneath the knob between a surface  165  of the knob and an inner surface  167  of the handle and biases the knob to the locked position. As the knob is rotated to the UNLOCK position, the spring is rotated and is pulled or extended. Then, when the user releases the knob, the spring becomes released and biases the knob back to the LOCK position. 
         [0059]    Shaft end  164  of knob  150  is configured to interengage with shaft  166  at first end  166   a . First end  166   a  of the shaft has a smaller diameter than a second end  166   b . The shaft can be joined to knob  150  by any means known in the art including, but not limited to, press fitting, brazing, swaging, screw threading and/or crimping the knob to the shaft. As a result, rotational movement of the knob is translated to the shaft. 
         [0060]    Shaft end  166   b  has a pair of recessed openings or notches  168 ,  169  which serves to hold a pair of radially movable balls  170 ,  172  in their fully retracted position. The recessed openings are shown as rectangular in shape, but they can be of other configurations as well without departing from the scope of the invention. In a fully projected position, the balls move radially outwardly into lateral bores or openings  174 ,  176 , respectively, in an outer wall  178  of shank  180 , as shown in  FIGS. 5B-5D . The outer ends of the bores can be “staked” to reduce the size of the openings which intersect outer cylindrical surface  178  of the shank, and this reduced size opening retains each ball from laterally escaping. Rotational movement of shaft  166  brings outer surface  182  of the shaft out of alignment with the balls, such that the balls move into recesses  168 ,  169  thereby allowing balls  170 ,  172  to move radially inwardly so that they fall into openings  174 ,  176  such that they no longer extend beyond the outer surface  178  of the shank. Then, if the shaft is rotated 90 degrees, the balls are once again engaged by surface  182  which moves them radially outwardly such that they again move outwardly beyond surface  178 . 
         [0061]    Rotational movement in direction A 6  is by the thumb pressure or force exerted by the end user on knob  150 . The user rotates the knob  150  by holding pin  152  and rotating the tab 90 degrees from the LOCK position to the UNLOCK position. The tab  154  is aligned with the UNLOCK marking at an edge of the groove  156 . The user must continue to hold pin  152  to maintain the tab in the UNLOCK position. When the knob is being rotated 90 degrees, the balls move radially inwardly into recesses or slots  168 ,  169  of the shaft  166 . 
         [0062]    To place the pin back into a locked position, the user releases pin  152  which releases the spring  162  which causes the knob to rotate counterclockwise  90  degrees until the tab  154  is aligned with the LOCK position. Spring  162  biases the knob in the LOCK position. The balls are pushed radially outwardly by outer surface  182  of shaft  166  until they move into openings  174 ,  176  of shank  180  and protrude beyond outer surface  178 . 
         [0063]    In accordance with another embodiment of the invention, referring to Figures  6 A- 6 D, rotational movement of knob  190  is by a force or thumb pressure exerted by a user on knob  190 . The user rotates the knob 90 degrees clockwise by holding a wedge shaped tab  192  between a LOCK position and one end of groove  194  formed in upper surface  196  of handle  198  and an UNLOCK position on an opposite edge of groove  194 . The user rotates the knob 90 degrees clockwise until the tab  192  is aligned with the end of groove  194  adjacent the label “UNLOCK”. A coiled spring  200  underneath the knob between a surface  202  of the knob and an inner surface  204  of the handle biases the knob to the locked position. As the knob is rotated to the UNLOCK position, the spring is pulled and is extended. The user must hold the tab in the UNLOCK position. Then, when the user releases the knob, the spring becomes released and biases the knob back to the LOCK position. 
         [0064]    Shaft end  206  of knob  190  is configured to interengage with shaft  208  at first end  208   a . First end  208   a  of the shaft has a smaller diameter than a second end  208   b . The shaft can be joined to knob  190  by any means known in the art including, but not limited to, press fitting, brazing, swaging, screw threading and/or crimping the knob to the shaft. As a result, rotational movement of the knob is translated to the shaft. 
         [0065]    Shaft end  208   b  has a pair of recessed openings or notches  210 ,  212  which serves to hold a pair of radially movable balls  214 ,  216  in their fully retracted position. The recessed openings are shown as rectangular in shape, but they can be of other configurations as well without departing from the scope of the invention. In a fully projected position, the balls move radially outwardly into lateral bores or openings  218 ,  220 , respectively, in an outer wall  222  of shank  224 , as shown in  FIGS. 6B-6D . The outer ends of the bores can be “staked” to reduce the size of the openings which intersect outer cylindrical surface  222  of the shank, and this reduced size opening retains each ball from laterally escaping. Rotational movement of shaft  208  brings outer surface  226  of the shaft out of alignment with the balls, such that the balls move into recesses  210 ,  212  thereby allowing balls  214 ,  216  to move radially inwardly so that they fall into openings  218 ,  220  such that they no longer extend beyond the outer surface  222  of the shank. Then, if the shaft is rotated 90 degrees, the balls are once again engaged by surface  226  which moves them radially outwardly such that they again move outwardly beyond surface  222 . 
         [0066]    Rotational movement in direction A 7  is by the force or thumb pressure exerted by the end user on knob  190 . The user rotates knob 90 degrees clockwise so that tab  192  is aligned with the UNLOCK position on groove  194 . When the knob is being rotated 90 degrees, the balls move radially inwardly into recesses or slots  210 ,  22  of the shaft. 
         [0067]    To place the tab back into a locked position, the user releases the tab  192 . Then, the spring  200  is released and the knob is rotated counterclockwise 90 degrees until the tab  192  is aligned with LOCK position of groove  194 . The balls are pushed radially outwardly by outer surface  226  of the shaft until they move into openings  218 ,  220  of the shank and protrude beyond outer surface  222 . 
         [0068]    In accordance with another embodiment of the invention, referring to  FIGS. 7A-7D , rotational movement of knob  240  is by a thumb pressure or force exerted by a user on knob  240 . The user uses a finger or thumb to press knob  240  within a thumb dimple or indentation  242  to rotate the knob  240  clockwise until the knob is aligned with an end of groove  244  formed in upper surface  246  of handle  248  adjacent the label “UNLOCK”. A coiled spring  250  is positioned underneath the knob between a surface  252  of the knob and an inner surface  254  of handle  248  and biases the knob to the locked position. As the knob is rotated to the UNLOCK position, the spring is pulled and extended. Then, when the user releases the knob, the spring becomes released and biases the knob back to the LOCK position. 
         [0069]    Shaft end  256  of knob  240  is configured to interengage with shaft  260  at first end  260   a.  First end  260   a  of the shaft has a smaller diameter than a second end  260   b.  The shaft can be joined to knob  240  by any means known in the art including, but not limited to, press fitting, brazing, swaging, screw threading and/or crimping the knob to the shaft. As a result, rotational movement of the knob is translated to the shaft. 
         [0070]    Shaft end  260   b  has a pair of recessed openings or notches  262 ,  264  which serves to hold a pair of radially movable balls  266 ,  268  in their fully retracted position. The recessed openings are shown as rectangular in shape, but they can be of other configurations as well without departing from the scope of the invention. In a fully projected position, the balls move radially outwardly into lateral bores or openings  270 ,  272 , respectively, in an outer wall  274  of shank  276 , as shown in  FIGS. 7B-7D . The outer ends of the bores can be “staked” to reduce the size of the openings which intersect outer cylindrical surface  274  of the shank, and this reduced size opening retains each ball from laterally escaping. Rotational movement of the shaft brings surface  278  of the shaft out of alignment with the balls, such that the balls move into recesses  262 ,  264  thereby allowing balls  266 ,  268  to move radially inwardly so that they fall into openings  270 ,  272  such that they no longer extend beyond the outer surface  274  of the shank. Then, if the shaft is rotated 90 degrees, the balls are once again engaged by surface  278  which moves them radially outwardly such that they again move outwardly beyond surface  274 . 
         [0071]    Rotational movement in direction A 8  is by the thumb pressure exerted by the end user on knob  240 . The user presses and rotates the knob 90 degrees clockwise until the knob is aligned with the UNLOCK position or groove  244 . The user continues to press on the indentation  242  to hold the knob in the UNLOCK position. When the knob is being rotated 90 degrees, the balls move radially inwardly into recesses or slots  262 ,  264  of the shaft. 
         [0072]    To place the pin back into a locked position, the user releases the knob which releases spring  250  which rotates the knob counterclockwise 90 degrees until knob  240  is aligned with LOCK position. The balls are pushed radially outwardly by outer surface  278  of the shaft until they move into openings  270 ,  272  of the shank and protrude beyond outer surface  274 . 
         [0073]    Referring to  FIGS. 8A and 8B , the pin of  FIGS. 7A-7D  is shown with a lower profile handle  300 . Knob  302  has a lower profile as well. Other features of the pin arrangement are essentially as described for  FIGS. 7A-7D . 
         [0074]    While considerable emphasis has been placed on the preferred embodiments of the invention illustrated and described herein, it will be appreciated that other embodiments and/or equivalents thereof can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the invention. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.