Abstract:
A ride height adjustable oil damped air shock boat seat pedestal with selectively lockable swivel capability is shown, which includes a locking pin extending below the seat and moving up and down with the seat as permitted and controlled by the air shock. The locking pin being received by a structure, which limits rotation of the seat.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date of the provisional patent application with the same title and filed by the same inventors on Mar. 24, 2015, and having Ser. No. 62/137,352, which application is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to improved systems and methods for supporting a boat seat. 
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a ride-height and/or passenger weight adjustable shock absorbing boat seat pedestal, and methods of constructing and utilizing same. 
     More particularly, the present invention relates to a shock absorbing boat seat pedestal which uses an air filled portion, and liquid and gaseous matter combination filled portion, and methods of constructing and utilizing same. 
     The prior art includes at least the following U.S. patents: 
     U.S. Pat. No. 5,465,679 issued on Nov. 14, 1995 to Albert Mardikian entitled “PERSONAL WATERCRAFT AND BOAT WITH SHOCK ABSORBING FLOORBOARDS;” 
     U.S. Pat. No. 6,182,590 issued on Feb. 6, 2001 to John M. Patera entitled “PERSONAL WATERCRAFT SUSPENSION SYSTEM;” 
     U.S. Pat. No. 6,880,483 issued on Apr. 19, 2005 to Brandon J. Fedders entitled “ACTIVE SEAT SUSPENSION FOR WATERCRAFT;” 
     U.S. Pat. No. 7,549,387 B2 issued on Jun. 23, 2009 to James Joseph Funk entitled “SHOCK ABSORBING SEAT PEDESTAL;” 
     U.S. Pat. No. 7,703,585 B2 issued on Apr. 27, 2010 to Robert C. Fox entitled “INTEGRATED AND SELF-CONTAINED SUSPENSION ASSEMBLY HAVING AN ON-THE-FLY ADJUSTABLE AIR SPRING;” 
     U.S. Pat. No. 5,911,191 issued on Jun. 15, 1999 to Peter J. Surer entitled “SHOCK ABSORBING SEAT PEDESTAL;” and 
     U.S. Pat. No. 8,511,655 B2 issued on Aug. 20, 2013 to Yan-Ting Wu entitled “BICYCLE SEAT POST.” 
     While these prior art methods have been known in the past and may have provided some utility to persons sitting in boat seats, they do have several problems, some of which are overcome by the present invention. One challenge not fully addressed by the prior art is the fact that, as the boat&#39;s speed across the water increases, both the frequency of impacts with waves increases as well as the magnitude of the force on the seat pedestal (or pilot&#39;s vertebrae) from each individual wave impact increases. This increases the need for a highly durable shock and for a durable swivel lock. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a comfortable ride to persons sitting in a boat seat. 
     It is a feature of the present invention to include a ride-height adjustable pneumatic boat seat pedestal with a locking swivel. 
     It is an advantage of the present invention to provide for simultaneous and independent ride-height adjustment and rebound speed-damping adjustment of a selectively swivelable boat seat. 
     The present invention is designed to achieve the above-mentioned objectives, include the previously stated features, and provide the aforementioned advantages. 
     An embodiment of the present invention comprises a selectively lockable swivel seating system for supporting a person in an elevated position above a lower portion of a boat, where the seating system comprises: 
     a boat seat having a bottom portion; 
     a boat seat base portion configured to couple with said bottom portion of said boat seat; 
     a base member portion configured to couple with a portion of a boat, which is generally lower than a boat seat height; 
     a non-fixed length pedestal disposed between said boat seat base portion and said base member portion, said non-fixed length pedestal comprising:
         a first tube;   a second tube; said second tube at least partially nested within said first tube; said second tube being sized and configured to permit rotation of said second tube inside said first tube;   an air chamber disposed within one of said first tube and said second tube;   a liquid chamber disposed within another of said first tube and said second tube; said liquid chamber being variably disposed within said one of said first tube and said second tube;   a piston disposed within said liquid chamber and coupled to a portion of said one of said first tube and said second tube;   means for introducing pressurized air into said air chamber where an increase in air pressure in said air chamber results in an adjustment of support provided for said boat seat;   means for adjustably restricting a liquid flow rate from one side of said piston to another side of said piston and thereby adjustably limiting a rebound rate of said piston after a temporary force applied to said boat seat pedestal is reduced; and   a selective swivel locking mechanism, which comprises:   a lock pin; and   a lock pin receiver configured to receive therein the lock pin at variable penetration depths.       

     Another embodiment of the present invention comprises a system for supporting a seated person in a boat comprising:
         a support structure, configured to support a seated person;   a floor plate mount configured to be rigidly fixed to floor in a boat;   a first tube, having a first tube central longitudinal axis;   a second tube, having a second tube central longitudinal axis which is co-linear with respect to said first tube central longitudinal axis;   said first tube and said second tube being arranged with respect to each other in a nested arrangement where relative translational movement therebetween is possible along said first tube longitudinal axis and said second tube longitudinal axis; and said nested arrangement extending along said first tube central longitudinal axis between said support structure and said floor plane mount;   said first tube and said second tube forming a portion of an oil damped shock having a shock central longitudinal axis which is co-linear with said first tube central longitudinal axis;   one of said first tube and said second tube being configured to allow rotation around said shock central longitudinal axis; and   a rotational lock system comprising:
           a lock pin having a lock pin central longitudinal axis;   a lock pin receiver having a lock pin receiver central longitudinal axis which is co-linear with respect to said lock pin central longitudinal axis;   a release pin configured to release one of said lock pin and said lock pin receiver from a coupled relationship with respect to said support structure when said release pin is removed from a release pin receiving orifice; and   said lock pin and said lock pin receiver being configured to prohibit rotation of said support structure about said shock central longitudinal axis when said release pin is disposed in said release pin receiving orifice.   
               

     Other objectives, advantages and features of the invention will become apparent to those persons skilled in this particular area of technology, and to other persons, after having been exposed to the following detailed description, when read in conjunction with the accompanying patent drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of a shock absorber boat seat pedestal in accordance with the invention. 
         FIG. 2  is a cross-sectional view of a first embodiment of the invention including the optional external reservoir. 
         FIG. 3  is a cut-away elevation view of a boat of the present invention, exposing a variant of the pedestal of  FIG. 1  and  FIG. 2 . 
         FIG. 4  is a first perspective view of a swivel locking seat embodiment of the present invention. 
         FIG. 5  is a second perspective view of the swivel locking seat embodiment of  FIG. 4 . 
         FIG. 6  is an exploded perspective view of the swivel lock assembly of  FIG. 4 . 
         FIG. 7  is an elevation view of the embodiment of  FIG. 4 , wherein the line from A to A defines the view of  FIG. 8  and the line from B to B defines the view of  FIG. 9 . 
         FIG. 8  is a cross-sectional view of the embodiment of  FIG. 4  taken on line A-A of  FIG. 7 . 
         FIG. 9  is a cross-sectional view of the embodiment of  FIG. 4  taken on line B-B of  FIG. 7 . 
         FIG. 10  is a perspective view of partially dismantled portions of the present invention, exposing to view exterior surface features of tube  24 . 
         FIG. 11  is a perspective view of a collection of pieces of the present invention arranged to shown a configuration of internal components. 
         FIG. 12  is a first side elevation view of an alternate embodiment of the present invention. 
         FIG. 13  is a backside elevation view of the embodiment of  FIG. 12 . 
         FIG. 14  is a second side elevation view of the embodiment of  FIG. 12 . 
         FIG. 15  is an exploded perspective view of the embodiment of  FIG. 12 . 
         FIG. 16  is a first side elevation view of an alternate embodiment of the present invention. 
         FIG. 17  is a backside elevation view of the embodiment of  FIG. 16 . 
         FIG. 18  is a second side elevation view of the embodiment of  FIG. 16 . 
         FIG. 19  is an exploded perspective view of the embodiment of  FIG. 16 . 
         FIG. 20  is a first side elevation view of an alternate embodiment of the present invention. 
         FIG. 21  is a backside elevation view of the embodiment of  FIG. 20 . 
         FIG. 22  is a second side elevation view of the embodiment of  FIG. 20 . 
         FIG. 23  is an exploded perspective view of the embodiment of  FIG. 20 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Now referring to the drawings wherein like numerals refer to like structure shown in the drawings and text included in the application throughout. With reference to  FIG. 1 , there is shown a boat seat pedestal of the present invention generally designated  100  which includes a seat base, or boat seat mating plate  1 , a Schrader valve  3  with an adjacent o-ring  2 . Schrader valve  3  is provided as an input location for air into the air compartment of the upper tube  24 . A high pressure air source  33  ( FIG. 3 ) could be a manual air pump, an electric air pump, a reserve air tank or other source of pressurized air, which could be coupled to the Schrader valve  3 , or it could replace the Schrader valve  3  in some applications. Inside of upper tube  24 , running from an upper location to a lower location, is a hollow shaft  15  with a rebound-metering rod  4  disposed therein. In some embodiments, the hollow shaft  15  could be replaced with a solid shaft, and rebound adjustment would be omitted from involvement with the shaft coupled to the piston  17 . 
     A lower tube or body  19  is disposed near a base, or floor plate mount  20 , which is attached to the boat  300  of  FIG. 3 . Disposed within body  19  is a piston  17 , which is coupled to and moves up and down with shaft  15 . Metering rod  4  forms, or controls, a portion of a valve which regulates the rate at which fluid can flow from one side of the piston to another side. This regulation of flow rate is a rebound adjustment, which is adjusted by rebound adjuster  13 , which manipulates a top portion of the rebound-metering rod  4 . Additionally, variable sized holes may be located through the piston so that flow rate corresponds to hole size. Hole size may be changed by inserting sleeves, shims, partial plugs, etc. Placed atop the body  19  and inside the upper tube  24  is bearing assembly  16 , which is affixed to the body  19  and separates the upper (inside upper tube  24 ) and lower (inside body  19 ) fluid chambers. Bearing assembly allows the upper tube to pass by and allows the shaft  15  to pass therethrough. Bearings  5  and  162 , seal  6  and o-rings  161  and  163  are shown. A bumper  7  is also shown which performs the function of preventing metal on metal collisions. 
     Piston  17  has a piston bearing  8  and a nut  18 . At the lower end of the upper tube  24 , there is a bearing  241 , a wiper seal  9  and an end seal  242 . 
     The body  19  is designed to retain oil and nitrogen, and an O-ring  11  is shown as a seal, also there is a retainer  10 , which holds a rubber pill  21 , through which nitrogen can be added when necessary. 
     Now referring to  FIG. 2 , there is shown the pedestal  100  of  FIG. 1  with oil and nitrogen in the oil chamber  23 , body  19  and air in the air chamber  22  in upper tube  24 . The oil chamber  23  may be filled with just oil and a reservoir can be provided to allow oil to escape as more of the shaft  15  moves downward into the body  19 . The oil chamber is divided into upper variably sized oil chamber  232  and a lower variably sized oil chamber  231 . As the piston goes down, such as in response to a person sitting down on the seat or the boat hitting a wave, the volume in upper variably sized oil chamber  232  is increasing and therefore has decreasing pressure, therefore the oil passes through the holes in piston  17  and/or through the valve opening variably created by the bottom end of metering rod  4  ( FIG. 1 ). If the jolt from the wave is particularly large, the speed at which the piston travels downward will be limited by how quickly the oil can pass through the holes in the piston and the valve. Similarly, the maximum rate of flow of oil will restrict the speed at which the piston  17 , and therefore the seat base  1  and boat seat, rebound to being fully extended. The adjustment of rebound adjuster  13  therefore sets the amount of damping of the air shock which is formed by air chamber  22 . 
     Now referring to  FIG. 3 , there is shown a boat  300  with a variation of the pedestal  100 , which has an air pressure input source  33  at the site of the Schrader valve  3  of  FIGS. 1 and 2 , and a rebound-adjusting nob  130  at the site of the rebound adjuster  13 . A seat  310  is disposed atop the upper tube  24 . 
     Now referring to  FIGS. 1 through 3 , and in operation, the air pressure within air chamber  22  is increased and thereby the ride height is increased for a given passenger or the ride height is maintained for a heavier passenger, and when a person sits on the seat, the seat base goes down, the other tube  24  passes over more of the inner tube  19 , the size of the air chamber  22 , which is defined by the space inside the outer tube  24 , which is above the bearing assembly  16 , decreases. The lower variably sized oil chamber is caused to decrease in volume proportional with a decrease in the air chamber volume. 
     Now referring to  FIGS. 4 and 5 , there is shown a selectively lockable swivel boat seat pedestal of the present invention, generally designated  400 , which includes a boat seat mating plate  401 , which is configured to mate with a portion of a seat (not shown), and a boat floor mating plate  402 , which is configured to mate with structure on a boat floor. The boat seat mating plate  401  and boat floor mating plate  402  are coupled to each other by an assembly such as is described and shown in  FIGS. 1-3 . It should be noted that the embodiment of  FIG. 4  may be nearly identical to that of  FIGS. 1-3  except that the shock has been inverted so that tube  19  is disposed above tube  24 . There may be some advantages relating to oil containment as well as other factors. It is believed that a person skilled in the art who understands the system described in  FIGS. 1-3  could readily understand how to invert the assembly of  FIGS. 1-3  and have tube  19  above tube  24 . This embodiment of the present invention includes additional structure to permit simultaneous shock absorption and swiveling of the seat while it is attached to a boat and further permit selectively locking the swivel capability, while the vessel is under way, so as to better correspond to standards of the American Boat and Yacht Council, of Annapolis, Md., which develops consensus safety standards for small craft. 
     A lock pin assembly  410  is coupled to boat seat mating plate  401  by a pair of lock pin retaining bolts  780 . An elongated portion of lock pin assembly  410  extends downward from boat seat mating plate  401  and is used to selectively restrict swiveling of the boat seat mating plate  401 . The elongated portion of lock pin assembly  410  could be a distinct piece from the portion which is bolted to boat seat mating plate  401  and, in some embodiments, it may be configured to rotate in a way that could benefit in reduction of binding forces during certain scenarios of operation. Lock pin assembly  410  can be aluminum, steel, brass or other suitable material. 
     Bearing head assembly  420  can be aluminum, steel, brass or other suitable material and is shown disposed around and at a top portion of tube  24 . Tube  24  is configured to retain a bearing therein to facilitate the rotation of tube  19  within tube  24 . Bearing head assembly  420  comprises a bearing head-lock lever portion  421  and mating therewith and bolted thereto a bearing head-lock pin engaging portion  422 . Both bearing head-lock lever portion  421  and bearing head-lock pin engaging portion  422  have internal surface relief features thereon and therein which are configured to mate with surface relief features of the exterior of the bearing retaining portion at the top of tube  24 . See  FIGS. 10 and 11  for additional details regarding such surface features. 
     Locking lever assembly  440  can be aluminum, steel, brass or other suitable material and is shown disposed only partially within bearing head-lock lever portion  421 . Locking lever assembly  440  could include a handle  441  and a threaded connector  442 . Bearing head assembly  420  is designed to selectively couple to the surface features of tube  24  so as to eliminate relative movement between bearing head assembly  420  and tube  24  when locking lever assembly  440  is in a locked configuration. Bearing head-lock pin engaging portion  422  is shown with a bearing head-lock pin engaging portion closed end portion  424  which could be omitted so long as enough of bearing head-lock pin engaging portion  422  is disposed about lock pin assembly  410  that rotation of lock pin assembly  410  about tube  24  is not possible when the locking lever assembly  440  is in a locked configuration. Also shown is pin guard  411 , which can be aluminum, plastic or other suitable material and is a safety shroud to protect clothing, items, or body parts from being damaged if pinched between the bottom of lock pin assembly  410  and boat floor mating plate  402  or other structure. The minimum length of pin guard  411  is determined by the maximum travel of the boat seat pedestal when absorbing shock. Also, the bottom of pin guard  411  is configured to be above any potentially interfering structures, such as valve  3 . 
     During times when the boat operating is not underway, the locking lever assembly  440  can be in an unlocked configuration and when the boat seat mating plate  401  is rotated (along with the attached seat—not shown) the bearing head assembly  420  is free to rotate about tube  24 , thereby enabling swiveling of the seat. However, when the pilot or passenger desires to have the seat fixed (without the ability to rotate), the locking lever assembly  440  is locked and the bearing head assembly  420  becomes coupled to the tube  24 . However, an important distinction between the present invention and certain prior art devices is that the shock absorbing capability of the invention is not eliminated because tube  19  is free to translate in and out of tube  24 . Another key aspect of the present invention is that when the locking lever assembly  440  is locked, it does not cause a deformation of the shape of tube  24  so much as to prevent rotation of or translation of the tube  19  within tube  24  by substantially increasing contact between tube  19  and tube  24 . Such deformation is also undesirable for oil retention purposes. 
     Now referring to  FIG. 6 , there is shown an exploded view of the portions of the present invention, which selectively prohibits rotations of tube  19  in tube  24 . Bearing head assembly  420  is selectively coupled to tube  24  via manipulation of locking lever assembly  440 , which includes wear washer  450  and brake shoe  430  and another brake shoe  430 , lever lock nut flat washer  460  and lever lock nut  470 , all of which can be aluminum, steel, brass or other suitable material. Bearing head-lock lever portion  421  and bearing head-lock pin engaging portion  422 , when bolted together, generally create a circular void therein to receive a top portion of tube  24 . When the handle  441  of locking lever assembly  440  is put in a locked or tightened orientation, then brake shoes  430  are forced to engage the surface features at the top of tube  24  and thereby limit the ability of bearing head assembly  420  to rotate about tube  24 . When lock pin assembly  410  is coupled to boat seat mating plate  401  ( FIG. 4 ) and is inserted through lock pin receiving void  423  in bearing head-lock pin engaging portion  422  this causes bearing head assembly  420  to rotate with tube  19 . However, when locking lever assembly  440  is locked, then bearing head assembly  420  is coupled to tube  24 , which is substantially fixed with respect to the boat floor mating plate  402 . As the boat encounters waves, the bottom end of lock pin assembly  410  safely moves up and down within pin guard  411 . 
     Now referring to  FIG. 7 , there is shown an elevation view of the apparatus of  FIG. 4 . Lock pin retaining bolt  780  is shown disposed through boat seat mating plate  401  and held in place with the assistance of lock pin retaining washer  790  and lock pin retaining lock nut  710 . Also shown is an optional handle retention means which could include a first magnet  702  coupled to the handle  441  and a second magnet coupled to the brake shoe  430 , so that when the handle  441  is unlocked and the tubes  19  and  24  are permitted to rotate with respect to each other, then the handle  441  may be held in an orientation which eliminates engagement and entanglement with clothing, etc. Note that optional items  702  and  704  are not shown in any other figure. 
     Now referring to  FIG. 8  there is shown a cross-sectional view of an embodiment of the present invention taken on line A-A of  FIG. 7 . The nearly perfect alignment of top bearing groove mating brake shoe protuberance  1102  and top bearing groove mating protuberance  1002  would suggest that the lever of locking lever assembly  440  is not in a fully locked orientation. When locking lever assembly  440  is fully locked, the top bearing groove mating brake shoe protuberance  1102  would be expected to be slightly protruding into the central void for receiving tube  24 . This slight protrusion would be expected to engage the surface features at the top of tube  24  and thereby prohibit rotation of bearing head assembly  420  about tube  24 . 
     Now referring to  FIG. 9 , there is shown a cross-sectional view of an embodiment of the present invention taken on line B-B of  FIG. 7 . The lever of locking lever assembly  440  is shown in a not fully locked orientation. 
     Now referring to  FIG. 10 , there are shown partially disassembled portions of the present invention to reveal surface features of the exterior of the top portion of tube  24 . The top portion of tube  24  is shown having a pair of spaced apart indentations. These indentations may correspond to protruding rings inside tube  24 , which aid in retention of a bearing used to facilitate rotation of tube  19  within tube  24 . Bearing head-lock pin engaging portion  422  is shown have top bearing groove mating protuberance  1002  and bottom bearing groove mating protuberance  1004  disposed within top groove  1001  and bottom groove  1003 , respectively. 
     Now referring to  FIG. 11 , there is shown an assembly of parts of the present invention, which displays an orientation of the locking lever assembly  440  in an unlocked configuration. Top bearing groove mating brake shoe protuberance  1102  is shown recessed from top bearing groove mating protuberance  1002 . Similarly, bottom bearing groove mating brake shoe protuberance  1104  is recessed from bottom bearing groove mating protuberance  1004 . If the locking lever assembly  440  were fully locked, the top bearing groove mating brake shoe protuberance  1102  and bottom bearing groove mating brake shoe protuberance  1104  would extend inwardly past the adjacent edges of top bearing groove mating protuberance  1002  and bottom bearing groove mating protuberance  1004 , respectively. 
     Now referring to  FIGS. 12-15 , there is shown a selectively lockable swivel shock absorbing boat seat pedestal of the present invention comprising a lock base member  1200 , which is coupled to a lock pin receiver  4111 , which receives the lock pin assembly  4101 , which is coupled to the boat seat mating plate  401 .  FIG. 12  shows a side view of where the right side of the drawing would likely be below the back side of the boat seat bottom, not shown. The left side of  FIG. 12  would be nearer the front of the boat seat bottom.  FIG. 13  shows the same structure where the boat seat mating plate  401  has been rotated 90 degrees from  FIG. 12 .  FIG. 14  shows the same structure rotated another 90 degrees. This embodiment differs in several ways from the embodiment of  FIGS. 4-9 , including that the clamping to the tube  24  is down toward the bottom and not toward the top. It should be noted that the tube top free end surface  4112 , located near the top of tube  24 , does not have any structure which is configured to restrict rotation of the tube  19  within tube  24 . Similarly, tube top surface features exposed surfaces  4113 , which are fully exposed and perform no function of restricting such rotation. It should be understood that it may be preferred to eliminate tube top surface features exposed surfaces  4113  from some embodiments as they are not needed in some embodiments. Rotation of the lock rotary head tension adjuster  1202  pulls together two portions of the lock base member  1200  and increases the friction between lock base member  1200  and tube  24 . When boat seat mating plate  401  rotates by the pilot turning the pilot&#39;s seat, the lock base member  1200 , (which is coupled via lock pin assembly  4101 ) will rotate around the tube  24 . When the lock rotary head tension adjuster  1202  is tightened sufficiently, the lock base member  1200  is clamped to the tube  24  and the pilot seat will not rotate and is effectively rotationally locked, while still permitting vertical motion of the shock absorber (tube  19  into tube  24  and via lock pin assembly  4101  into lock pin receiver  4111 ). 
     Now referring to  FIGS. 16-19 , there is shown an alternate embodiment of the present invention where lower pivot lock assembly  1600  is coupled to a lower end of tube  24 . There is clearance between a bottom portion of lower pivot lock assembly  1600  and a top side of floor plate mount  1900 . A functional difference between the embodiment of  FIGS. 12-15  and  FIGS. 16-19  is that the clamping force applied on the tube  24  by the lower pivot lock assembly  1600  is not provided by turning a rotary knob but by pivoting a lower pivot lock handle  1602 . Lock pin assembly  1610  and lock pin receiver  1611  are similar to lock pin assembly  4101  and lock pin receiver  4111  of  FIG. 15 . The line marked  1901  is the first tube central longitudinal axis and the second tube central longitudinal axis and is also the shock central longitudinal axis  1901 . Line  1902  is parallel to line  1901  and is the lock pin central longitudinal axis and the lock pin receiver central longitudinal axis. 
     Now referring to  FIGS. 20-23 , there is shown an alternate embodiment of the present invention which has no clamping force applied to the tube  24  to restrict rotations of tube  19 . There is shown a lock pin  2010  and a lock pin receiver  2011 , which allows for telescopic movement as similar structure in the other above discussed embodiments. However, the bottom portion of lock pin  2010  and the lock pin receiver  2011  do not rotate around tube  24  as do the lock pin and the lock pin receivers in other embodiments. Instead, the lower end of lock pin receiver  2011  is bolted to floor plate mount  2300  through mounting holes  2302 . There is shown a lock pin  2010  top receiving mount with a lock pin release pin outer receiving orifice  2005  therein. This mount is bolted to the boat seat mating plate  401 . Lock pin release pin inner receiving orifice  2006  is shown disposed in the top end of lock pin  2010 , and when lock pin release pin  2003  is inserted through both lock pin release pin outer receiving orifice  2005  and then through lock pin release pin inner receiving orifice  2006 , the seat is rotationally locked while still permitting vertical motion for shock absorption. When the pilot wishes to rotate the pilot&#39;s seat, a quick removal of the lock pin release pin  2003 , by pulling on the lock pin release pin ring  2004  in a single direction, results in the lock pin  2010  falling down into the lock pin receiver  2011 . In this configuration, the boat seat mating plate  401  is coupled to the floor plate mount  2300  only through the tubes  19  and  24  (which permit relative rotary movement therebetween). The mount with the lock pin release pin outer receiving orifice  2005  therein remains bolted to the boat seat mating plate  401  and rotates around the central axis of the tube  24  when the pilot&#39;s seat is rotated. To relock the seat, the mount with lock pin release pin outer receiving orifice  2005  therein must be located directly above the top of lock pin  2010  and it is pulled up and moved into so that lock pin release pin  2003  can be inserted through both lock pin release pin outer receiving orifice  2005  and lock pin release pin inner receiving orifice  2006 , effectively locking rotation of the seat. 
     Although the invention has been described in detail in the foregoing only for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those of ordinary skill in the art without departing from the spirit and scope of the invention as defined by the following claims, including all equivalents thereof. 
     For example, in the embodiment of  FIGS. 4-11 , the locking lever assembly  440  could be replaced with a bolt with a stationary head and a nut on the opposing end. The nut could be tightened further to achieve the same result as locking the lever of locking lever assembly  440 . In such an arrangement, the stationary bolt and nut could be an effective means for selectively engaging a structure to an outer tube, without interfering with translation of tube through the outer tube. This nut could also have graduated markings thereon to show how far to turn the nut. The nut could be coupled to a cap or handle to assist in wrench free manipulations. 
     Similarly, the lock pin receiving void  423  could be a slot instead of a hole (i.e. bearing head-lock pin engaging portion closed end portion  424  is omitted) and the lateral portions of bearing head-lock pin engaging portion  422 , which would contact the sides of the lock pin assembly  410  could be configured to be able to be pivoted up or down so as to allow the lock pin assembly  410  to escape from the slot and thereby allow the lock pin assembly  410  to be selectively engaged with tube  24 . In such a configuration, if the portion of bearing head-lock pin engaging portion  422 , which is pivoting out of engagement with lock pin assembly  410 , is permanently attached to the tube  24 , there would be no need for the remainder of bearing head assembly  420 , brake shoe  430 , locking lever assembly  440 , etc. The locking could be accomplished by merely pivotally deploying a stop or latch on either side of lock pin assembly  410  so as to prevent rotation in either direction. The latches or stops could pivot, slide from the tube  24  or be detachably coupled to the tube  24 . These arrangements and others could be effective means for selectively stopping the rotation of a lock member around a support tube. 
     It is thought that the method and apparatus of the present invention will be understood from the foregoing description, and that it will be apparent that various changes may be made in the form, construct steps, and arrangement of the parts and steps thereof, without departing from the spirit and scope of the invention, or sacrificing all of their material advantages. The form herein described is merely a preferred exemplary embodiment thereof.