Abstract:
In a preferred embodiment, a shock-absorbing bicycle seat mount, including: a post fixedly attached to a bicycle seat at a proximal end of the post, a distal end of the post being inserted into a bicycle seat tube for axial movement therein; biasing apparatus disposed within the seat tube to support the post and provide a cushioning action for the post and the bicycle seat; and apparatus to prevent rotational movement of the post within the seat tube.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    The present application is a continuation-in-part of U.S. application Ser. No. 09/428,436, filed Oct. 21, 1999, and titled SHOCK-ABSORBING BICYCLE SEAT MOUNT, now U.S. Pat. No. ______, issued ______, which is a continuation-in-part of U.S. application Ser. No. 09/253,113, filed Feb. 19, 1999, and titled A SHOCK ABSORBING BICYCLE SEAT MOUNT, abandoned. The present invention was described, in part, in Disclosure Document No. 423458, date stamped Aug. 19, 1997. Benefit is claimed of the filing date of U.S. Provisional Application Serial No. 60/075,350, filed Feb. 20, 1998, and titled BICYCLE SLOTTED SEAT POST.  
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to bicycles generally and, more particularly, but not by way of limitation, to a novel shock-absorbing bicycle seat mount.  
           [0004]    2. Background Art  
           [0005]    Ordinarily, bicycle (bike) seats are supported on a post that is tightly clamped in a bike seat tube portion of a bike frame. This is true for movable bicycles and also for stationary, exercise, bikes. Seat height location is provided by a certain extension of the seat post upwardly and outwardly from the tube. At a post height extension for a particular rider&#39;s desired seat height, a clamp located at the top of the tube is tightened to prevent any dislocation movement of the seat post. Thus, the seat post becomes, in effect, integral with the rigid bike frame which ordinarily does not provide for any road mechanical shock absorption other than that absorbed by the bike&#39;s inflated rubber tires and front fork shock absorbers when the latter are provided.  
           [0006]    It would be desirable, therefore, to have the seat post supported on a compression coil spring inside the tube so that some of the imparted road shock would be absorbed by that spring. A seat post that would be enabled to move in a quasi-vertical motion along the longitudinal axis of and inside the seat tube unrestricted by a tightened clamp as described above but restricted as to it&#39;s rotational, “swivel”, motion is preferentially required for this desired shock absorbing effect.  
           [0007]    Accordingly, it is a principal objective of the present invention to provide a shock-absorbing bicycle seat mount that absorbs imparted road shock.  
           [0008]    It is a further objective of the invention to provide such a bicycle seat mount that prevents rotational motion of the bicycle seat mount.  
           [0009]    It is an additional objective of this invention to provide such a bicycle seat mount that can either be retrofitted to an existing bicycle or incorporated in the bicycle at the time of manufacture of the bicycle.  
           [0010]    It is another objective of this invention to provide such a bicycle seat mount that can be economically constructed.  
           [0011]    It is yet a further objective of this invention to provide such a bicycle seat mount that can be easily installed in a seat tube and attached thereto.  
           [0012]    Other objectives of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.  
         SUMMARY OF THE INVENTION  
         [0013]    The present invention achieves the above objectives, among others, by providing, in a preferred embodiment, a shock-absorbing bicycle seat mount, comprising: a post fixedly attached to a bicycle seat at a proximal end of said post, a distal end of said post being inserted into a bicycle seat tube for axial movement therein; biasing means disposed within said seat tube to support said post and provide a cushioning action for said post and said bicycle seat; and means to prevent rotational movement of said post within said seat tube.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0014]    Understanding of the present invention and the various aspects thereof will be facilitated by reference to the accompanying drawing figures, submitted for purposes of illustration only and not intended to define the scope of the invention, on which:  
         [0015]    [0015]FIGS. 1A, 1B, and  1 C are isometric, top plan, and bottom plan views, respectively of a seat post constructed according to one embodiment of the present invention.  
         [0016]    [0016]FIG. 2 is an isometric view of another embodiment of a seat post constructed according to the present invention.  
         [0017]    [0017]FIGS. 3A and 3B are isometric views of elements to prevent rotation of a seat post within a seat tube.  
         [0018]    [0018]FIG. 4 is a an exploded front elevational view, partially in cross-section, of a shock-absorbing bicycle seat mount according to the present invention.  
         [0019]    [0019]FIGS. 5A, 5B, and  5 C are side elevational, bottom plan, and top plan views, respectively, of a spacer block for use with the embodiment of FIG. 4.  
         [0020]    [0020]FIG. 6 is a top plan view of a ring clamp for use with the embodiment of FIG. 4.  
         [0021]    [0021]FIGS. 7A, 7B, and  7 C are side elevational, top plan, and bottom plan views, respectively, of a cylindrical insert for use with the embodiment of FIG. 4.  
         [0022]    [0022]FIG. 8 is a side elevational view of a cylindrical insert for use with the embodiment of FIG. 4.  
         [0023]    [0023]FIG. 9 is a side elevational view of a seat post for use with the embodiment of FIG. 4.  
         [0024]    [0024]FIG. 10 is an isometric view of a spacer sleeve for use with the embodiment of FIG. 4.  
         [0025]    [0025]FIGS. 11 and 12 are side elevational and front elevational views, respectively, of a support pillar for use with the embodiment of FIG. 4.  
         [0026]    [0026]FIG. 13 is an isometric view of a support pillar cover for use with the embodiment of FIG. 4.  
         [0027]    [0027]FIGS. 14 and 15 are side elevational and front elevational views, respectively, of an alternative embodiment of means for preventing rotational motion of a seat post.  
         [0028]    FIGS.  16 (A) and  16 (B) are side elevational and top plan views, respectively, of an alternative cylindrical insert.  
         [0029]    [0029]FIG. 17 is an end elevational view of a bicycle seat tube for use with the cylindrical insert of FIGS.  16 (A) and  16 (B).  
         [0030]    [0030]FIG. 18 is a side elevational view of a plug for supporting a shock-absorbing spring system.  
         [0031]    [0031]FIG. 19 is an end elevational view of reinforcement members disposed at a lower end of a bicycle seat tube.  
         [0032]    [0032]FIG. 20 is a side elevational view, partially cutaway, showing means to provide a minimum bicycle seat post elevation and means to prevent ejection of the bicycle seat post from a bicycle seat tube.  
         [0033]    FIGS.  21 (A) and  21 (B) are side elevational and end elevational views, respectively, of one embodiment of a tension spring arrangement for use in a bicycle seat mount shock-absorbing system.  
         [0034]    FIGS.  22 (A) and  22 (B) are top plan views of clamps that may be used to attach the tension spring system to a bicycle seat tube.  
         [0035]    [0035]FIG. 23 is a side elevational view of another embodiment of a tension spring arrangement for use in a bicycle seat mount shock-absorbing system.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]    Reference should now be made to the drawing figures, on which similar or identical elements are given consistent identifying numerals throughout the various figures thereof, and on which parenthetical references to figure numbers direct the reader to the view(s) on which the element(s) being described is (are) best seen, although the element(s) may be seen also on other views.  
         [0037]    [0037]FIGS. 1A, 1B, and  1 C illustrate a bicycle seat post  20  constructed according to one embodiment of the present invention. Bicycle seat post  20  is an elongated cylindrical member, preferably constructed of a suitable metallic or polymeric material, and having a vertically extending slot  30  defined therein. Slot  30  is open at the top end of bicycle seat post  20  and extends downwardly to nearly the bottom of the bicycle seat post. While not shown on the present figures, slot  30  is provided so that protrusion means (not shown) may extend therein and thus prevent rotational movement of the bicycle seat post, while permitting up and down motion of the bicycle seat post. It will be understood that lower end of bicycle seat post  20  is inserted in a bicycle seat tube and the upper end of the bicycle seat post is clamped to a bicycle saddle (neither shown). Slot  30  only approaches the bottom of bicycle seat post  20  such that the bottom of the slot serves as a stop to prevent the bicycle seat post from unintentionally being ejected from the bicycle seat tube.  
         [0038]    [0038]FIG. 2 illustrates a bicycle seat post  40  constructed according to another embodiment of the present invention. Bicycle seat post  40  is an elongated, hollow cylindrical member and has a vertical slot  50  defined through the wall thereof for the same purpose as slot  30  (FIG. 1). Although exact dimensions will depend on the application, bicycle seat post  40  is typically about 14 inches in length. Similar to slot  30  (FIG. 1A), slot  50  only approaches the bottom of bicycle seat post  40  for the same purpose as described above.  
         [0039]    [0039]FIG. 3A illustrates an elongated, hollow, cylindrical insert  60  for insertion between a bicycle seat post and a bicycle seat tube (neither shown), the cylindrical insert including a flange  62  formed around the upper end of the cylindrical insert to permit the cylindrical insert to rest on the upper end of the bicycle seat tube and a vertical protrusion  64  integral with an inner surface of the cylindrical insert. With protrusion  64  inserted, for example, in slot  50  of bicycle seat post (FIG. 2) and with cylindrical insert held immobile with respect to the bicycle seat tube, the bicycle seat post will be able to move vertically with respect to the bicycle seat tube, but will be restrained from rotational movement with respect thereto. Protrusion  64  may be molded in one piece with cylindrical insert  60  or it may be attached thereto by suitable means.  
         [0040]    [0040]FIG. 3B illustrates a solid bicycle seat post  80  having a vertical slot  82  defined therein. A vertical protrusion  84  is shown as being disposed in slot  82 . Protrusion  84  may be integrally molded with or otherwise be an integral aspect of a surrounding cylindrical insert (not shown) such as cylindrical insert  60  (FIG. 3A) or it may be attached thereto by suitable means. A plurality of ball or roller bearings, as at  90 , is disposed between and in contact with adjacent surfaces of slot  82  and protrusion  84  to reduce the friction therebetween. Of course, other anti-friction means may be provided as well.  
         [0041]    [0041]FIG. 4 illustrates a shock-absorbing bicycle seat mount, constructed according to the present invention, generally indicated by the reference numeral  200 , and inserted in a bicycle seat tube  202 .  
         [0042]    Seat mount  200  includes a bicycle seat post  210  having its upper end clamped to a bicycle saddle  212  with a variable thickness collar  214 . The lower end  220  of bicycle seat post  210  is rounded and engages the upper end of a rounded cylindrical spacer block  222 . Lower end  220  may instead be provided flat and the spacer block  222 , in that case, would also be flat. A series of such spacer blocks, which may be interfitting or in a simple “top-to-bottom” surface area contact, is provided so that one or more may be selected as needed to provide the necessary vertical spacing for a rider&#39;s preference in conjunction with the length of bicycle seat tube  202  of a particular bicycle. The bottom surface of the lowest spacer block  222  engages a compression spring  224 . The lower end of compression spring  224  rests on a resilient, circular, vibration eliminator support block  230  which is supported by a bolt  232  extending through the walls of bicycle seat tube  202 . In order to provide support for seat mount  200  in addition to that provided by bicycle seat tube  202 , bolt  232  extends through the upper ends of two support pillars  240  and  242  which have their lower ends engaging the upper surface of hub  204  to transfer the downward force generated by the seat mount to the stronger hub.  
         [0043]    A cylindrical insert  250  having a supporting flange  252  is disposed around bicycle seat post  210 . Depending from the lower side of flange  252  is an integral tab  260 . Cylindrical insert  250  also includes a lengthwise protrusion  262  for engagement with surface(s) of a lengthwise slot  264  on the inside surface of bicycle seat post  210 . If needed to retrofit a bicycle with the present invention, a spacer sleeve  270  having the required thickness is snugly disposed between the outer surface of cylindrical insert and the inner surface of bicycle seat tube  202 . When seat mount  200  is furnished for retrofitting, spacer sleeve  270  may be the tubular plastic packaging in which the elements of the seat mount are sold, with the sleeve cut to the proper length after removal therefrom of the other elements of seat mount  200 .  
         [0044]    A ring clamp  280  is provided for clamping around bicycle seat tube  202  and tab  260  is arranged such that, when a suitable fastener (not shown) is inserted through a pair of aligned holes  282  defined through the ends of the ring clamp, the fastener will also be inserted through a hole  284  defined through the tab, thus preventing swivel, lateral rotation of cylindrical insert  250  within bicycle seat tube  202  after its position therein has been fixed by tightening the fasteners. A self-tapping screw  286  is inserted through bicycle seat tube  202  into protrusion  262  to secure the elements together, as an optional or additional means to prevent swivel.  
         [0045]    As noted above, shock-absorbing bicycle seat mount  200  may be installed during manufacture of the bicycle or it may be retrofitted to an existing bicycle. In the former case, bolt  232  may be replaced with a disk (not shown) welded to the inner surface of bicycle seat tube  202 . In the latter case, the existing bicycle seat post is removed from bicycle seat tube  202 , holes are drilled through the bicycle seat tube for screw  286  and bolt  232 , bolt  232  is installed, the internal components of bicycle seat mount  200  are inserted in the bicycle seat tube, and screw  286  is inserted. Tab  260  is attached to ring clamp  280  previously slid over the outside surface of bicycle seat tube  202 . The thickness of spacer sleeve  270  and lengths and quantity of spacer blocks  222  are selected for the specific installation.  
         [0046]    The outside diameter of cylindrical insert  250  is selected such that it will fit into the bicycle seat tube of any standard bicycle and the inner diameter of the cylindrical insert is selected to closely fit bicycle seat post  210 . Spacer sleeve  270  then snugly fills in the annular space defined between the outer surface of cylindrical insert sleeve  250  and the inner surface of bicycle seat tube  202 , thus accommodating bicycle seat tubes having different inner diameters.  
         [0047]    [0047]FIGS. 5A, 5B, and  5 C illustrate a cylindrical spacer  222 . Spacer  222  includes a rounded depression  290  defined in the upper surface thereof into which lower end  220  of bicycle seat post  210  (FIG. 4) can be supportingly inserted. Rising upwardly from the upper surface of spacer block  222  are two pins  300  and  302  which are dimensioned to fit into complementarily dimension holes on another spacer block. Likewise, spacer block  222  has defined in the lower surface thereof two holes  310  and  312  to accept therein similar pins from another spacer block. Thereby, a chain of spacer blocks  222  is locked together.  
         [0048]    [0048]FIG. 6 illustrates ring clamp  280  and shows hole  282  defined therethrough. Also shown are one or more layers of double-sided adhesive tape  340  disposed on the inside of ring clamp  280  provided so that swivel prevention can be further provided and so that a single ring clamp can be used with bicycle tube seats of different diameters by proper selection of the number of layers of the double-sided adhesive tape used.  
         [0049]    [0049]FIGS. 7A, 7B, and  7 C illustrate the upper end of cylindrical insert  250  and the features thereof described above. In addition, there is shown a locator notch  350  that serves as a “target” and is used to locate self-tapping screw  286  to assure that it becomes accurately inserted in protrusion  262 .  
         [0050]    [0050]FIG. 8 illustrates an alternative embodiment of a cylindrical insert for use with bicycle seat mount  200  (FIG. 4), here, cylindrical insert  250 ′. Cylindrical insert  250 ′ includes a horizontal flange  252 ′ formed around the upper edge thereof and a tab  260 ′ depending from the flange. Tab  260 ′ includes three holes  284 ′ defined therethrough and vertically spaced apart. This arrangement is particularly advantageous when a system of bicycle seat mount  200  (FIG. 4) is to be retrofitted to an existing bicycle. The plurality of holes  284 ′ permits one to be chosen such that ring clamp  280  (FIG. 4) may be positioned away from any interfering structure on bicycle seat tube  202 .  
         [0051]    [0051]FIG. 9 illustrates bicycle seat post  210  and shows slot  264  and rounded bottom end  220 .  
         [0052]    [0052]FIG. 10 illustrates spacer sleeve  270  and shows that the spacer sleeve may have a vertical slot  400  defined through the wall thereof and extending fully from the top to the bottom of the spacer sleeve. This permits a single spacer sleeve  270  to accommodate varying diameters of cylindrical insert  250  that may be provided and also aids when it is necessary to employ more than one spacer sleeve.  
         [0053]    [0053]FIGS. 11 and 12 illustrate support pillar  240  with a hole  420  defined therethrough for bolt  232  (FIG. 4) and further show a resilient grommet  430  inserted in hole  420  and a resilient strip  440  disposed along a curved lower edge  450  of the support pillar. Grommet  430  and strip  440  are provided to ensure a snug fit of the components and the grommet also serves to exclude dirt and other foreign material from the interior of bicycle seat tube  202 . Support pillar  240  may also be arcuate such that it reinforces the lower end of bicycle seat tube  202  (FIG. 4).  
         [0054]    [0054]FIG. 13 illustrates a generally hollow support pillar cover  460 , having a hole  470  defined therethrough, that may be disposed over support pillar  240  (FIG. 11). When used, support pillar cover is provided for a more finished appearance and to protect the support pillar.  
         [0055]    [0055]FIGS. 14 and 15 illustrate an alternative arrangement for preventing rotating of a bicycle seat post, in this case bicycle seat post  500  inserted in a bicycle seat tube  502 . Here, one end of a linkage  520  is attached to the front end of a bicycle saddle  510 , while the other end of the linkage is attached by means of a clamp  522  to a frame member  524 . Linkage  520  is arranged such that saddle  510  is freely moveable up and down, but is restrained such that bicycle seat post  500  cannot rotate within bicycle seat tube  502 . Clamp  522  may be tightened and loosened with a manual crank handle  550  (FIG. 15) so that linkage  520  may be repositioned. Typically, the vertical movement of bicycle seat post  500  will be about two inches.  
         [0056]    Referring now to FIGS.  16 (A),  16 (B), and  17  together, there is illustrated an alternative arrangement to prevent swivel. Here, a vertical protrusion  600  in a cylindrical insert  602  extends outwardly of the wall of the cylindrical insert at the upper end thereof. This outward extension closely fits into a slot  606  defined in a bicycle seat tube  610  to prevent swiveling of the cylindrical insert. This arrangement is most applicable to those situations in which the manufacturer of the bicycle installs the shock-absorbing system, although retrofitting is not precluded.  
         [0057]    [0057]FIG. 18 illustrates a load support plug  620  welded into a bicycle seat tube  622  prior to attachment of the seat tube to a hub (not shown). This arrangement would be most suitable in those situations in which the manufacturer of the bicycle installs the shock-absorbing system.  
         [0058]    [0058]FIG. 19 illustrates bolt  232  and bicycle seat tube  202  described above with reference to FIG. 4 and support pillars  240  described above with reference to FIGS. 11 and 12 and also illustrates arcuate reinforcing members  630  disposed circumjacently against the bicycle seat tube inwardly of the support pillars. Reinforcement members  630  are attached to bicycle seat tube  202  by means of bolt  232  and suitable fasteners  640  and provide additional reinforcing of the lower end of bicycle seat tube  202 .  
         [0059]    [0059]FIG. 20 illustrates a slotted bicycle seat post  650  inserted in a bicycle seat tube  652 . A plurality of indents, as at  660 , is defined in the inner surface of vertical slot  662 . An annular collar  670  is disposed around bicycle seat post  650 , the collar having a threaded fastener  672  inserted therethrough and into a selected one of indents  660 , and the collar having dimensions such that it can rest on the top of bicycle seat tube  652 . Thus arranged, the minimum height of bicycle seat post  650  can be selectively fixed.  
         [0060]    [0060]FIG. 20 also illustrates vertical slot  662  extending the full length of bicycle seat post  650 . This is a more economical manufacturing arrangement than having vertical slot  662  terminate at some point short of the lower end of bicycle seat post  650 . To prevent ejection of bicycle seat post  650  from bicycle seat tube  652 , a plug  680  is inserted into the lower end of vertical slot  662  to engage the key protrusion (not shown on FIG. 20).  
         [0061]    [0061]FIG. 21(A) illustrates one embodiment of a tension spring arrangement for use in a bicycle seat mount shock-absorbing system, generally indicated by the reference numeral  700 , and attached to a bicycle seat tube  702 . Tension spring arrangement  700  includes a first vertical tube  710  having disposed therein a tension spring  712 . The upper end of tension spring  712  is attached to the lower end of a first rod  720  and the lower end of tension spring  712  is attached to the upper end of a second rod  722 . The lower end of second rod  722  and the upper end of a third rod  730  are threadedly attached to a turnbuckle  732 . The upper end of first rod  720  is attached to a collar  740  fixedly disposed around bicycle seat tube  702 , while the lower end of third rod  730  is attached to a yoke  742  which, in turn, is attached to the ends of a support rod  744  protruding through the wall of the bicycle seat tube through vertical slots  746  (only one shown on FIG. 21(A)) which may be provided with a flexible cover. A second vertical tube  750  telescoping inserted into the lower end of first vertical tube permits access to turnbuckle  732  for the adjustment thereof and provides for an adjustable total length of tension spring arrangement  700  that is suitable for emplacement along bicycle seat tube  702  of any originally manufactured bicycle. Upper and lower clamps  760  and  762 , respectively, may be provided for the attachment of tension spring arrangement  700  to bicycle seat tube  702  and/or the arrangement may be attached by means of a weld  764 . Support rod  744  supports internal compression spring components which may be similar to those described above with reference to FIG. 4 or the internal compression spring components may be of other types. In any case, tension spring arrangement  700  may be provided to assist the internal compression spring in its shock absorbing purpose. Upper and lower sliding means  770  and  772 , respectively, may be provided between bicycle seat tube  702  and first and third rods  720  and  730  and may consist of rollers, wheels, low-friction plastic blocks, or the like.  
         [0062]    [0062]FIG. 21(B) illustrates the same components of tension spring arrangement  700 , except weld  764  is not visible and upper and lower clamps  760  and  762  have been omitted.  
         [0063]    [0063]FIG. 22(A) illustrates in more detail the components of upper clamp  760  attaching first tube  710  to bicycle seat tube  702 , while FIG. 22(B) illustrates in more detail the components of lower clamp  762  attaching second tube  750  to the bicycle seat tube.  
         [0064]    [0064]FIG. 23 illustrates a more simplified tension spring arrangement, generally indicated by the reference numeral  800 , as compared with tension spring arrangement  700  (FIGS.  21 (A) and  21 (B)). Tension spring arrangement  800  includes a tension spring  810  disposed in a vertical tube  812 . The upper end of tension spring  810  is attached to the lower end of an upper rod  820 , while the lower end of the tension spring is attached to the upper end of a lower rod  822 . The upper end of upper rod  820  is attached to a collar  826  disposed around bicycle seat tube  802 , while the lower end of lower rod  822  is attached to a yoke  830  which, in turn, is attached to the ends of a support rod  832  protruding through a vertical slot formed in bicycle seat tube  802 . Upper and lower sliding means  840  and  842  may be provided, respectively, between bicycle seat tube  802  and upper rod  820  and lower rod  822 . Vertical tube  812  may be attached to bicycle seat tube  802  by means of weld  850 .  
         [0065]    Tension spring arrangement  800  is applicable in OEM bike manufacture where the length of bicycle seat tube  802  is known and no adjustment of the total length of tension spring arrangement is required, as would be required for retrofitting in a variety of bicycle seat tube lengths.  
         [0066]    In the embodiments of the present invention described above, it will be recognized that individual elements and/or features thereof are not necessarily limited to a particular embodiment but, where applicable, are interchangeable and can be used in any selected embodiment even though such may not be specifically shown.  
         [0067]    Terms such as “upper”, “lower”, “inner”, “outer”, “inwardly”, “outwardly”, “vertical”, “horizontal”, and the like, when used herein, refer to the positions of the respective elements shown on the accompanying drawing figures and the present invention is not necessarily limited to such positions.  
         [0068]    It will thus be seen that the objectives set forth above, among those elucidated in, or made apparent from, the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown on the accompanying drawing figures shall be interpreted as illustrative only and not in a limiting sense.  
         [0069]    It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.