Abstract:
A multi-positional seat in one form accommodates a vehicle driver in a standup driving position, a seated driving position and a riding position. The seat back is shiftable relative to the seat base to expose a varying amount of seat base surface for supporting the buttocks of an individual seat user. The seat back and seat base may also be adjustable, for example in fore and aft directions as a unit, to shift the entire seat position. In addition, the elevation of the seat may be adjusted.

Description:
BACKGROUND  
         [0001]    The present invention relates to seats with multi-position backrests and one particularly desirable application involves vehicle seats usable in a driver standup mode. The present invention also relates to methods associated with such seats.  
           [0002]    Historically, standup seats have been designed for applications such as in the refuse market where the driver/worker makes frequent stops and exits from one side (e.g., in the United States, the right-hand side) of a vehicle to load handheld garbage cans into a main collection unit. These seats also are particularly suitable in other applications where a driver must exit and reenter a vehicle numerous times, with package delivery service use being another example.  
           [0003]    In the past, standup seats have been little more than a backrest which provides minimal relief to a driver in a standup position over extended periods of time. Drivers of these vehicles using this type of seat typically balance themselves on their left foot while controlling vehicle acceleration and braking with their right foot. This standing position causes static stresses in the legs and back of the driver and is made worse in cases where the driver strains to stand or sit in one position for extended periods of time.  
           [0004]    In addition, existing standup seats have paid little attention to accommodating drivers of widely varying sizes. Therefore, a need exists for an improved vehicle seat which in one form may be used in a standup vehicle seat application.  
         SUMMARY  
         [0005]    In one specific form, a multi-positional seat is provided and accommodates a driver in standup driving positions, seated driving positions and a riding position. In this form, the user has the ability to change the position of the seat to assist in avoiding undue stresses from the user having to stand or sit in one position for extended periods of time. These seats are also applicable to passenger use as well as vehicle driver use.  
           [0006]    The act of sitting involves a body balance between the back, buttocks and legs with the distribution of body weight through these body parts on a seat determining the comfort level of the individual. In a standup position, which is typically used most frequently in low entry cabs, it would often be desirable to balance the body weight in a leaning position with support provided under the buttocks and behind the back. In addition, it is typically desirable that the legs be slightly angled and bent to transfer weight off of the legs to the upper body. It is also desirable in accordance with one embodiment of a vehicle seat to provide multiple standup driving or seated positions for a seat to enhance the adjustability of the seat to maximize an individual user&#39;s comfort. For example, the seat may accommodate smaller users (e.g., the fifth percentile female driver in height on the anthropometric human scale) up to larger users (e.g., the ninety-ninth percentile male driver in height on the anthropometric human scale).  
           [0007]    In accordance with a specific embodiment, one form of standup seat is based on at least three orders of seat motion that cooperate to create personalized seat adjustments dependent on the user&#39;s work position which is desired for the moment. In one motion, a seat cushion and seat back may be moved, for example together as a unit, within limits of motion in respective opposed directions. For example, the seat back and cushion may be moved in fore and aft directions respectively toward and away from a steering wheel of the vehicle or the front of the vehicle. As a second desirable motion, the seat back may be moved in respective opposed directions, for example fore and aft directions, relative to the seat cushion. In this case, a varied amount of seat cushion surface is exposed forwardly of the seat back depending upon the seat back position. As a third desirable motion, particularly useful in standup seat applications, seat height adjustment may be provided. For example, the seat cushion may be raised and lowered relative to the floor of the vehicle, typically as a unit with the seat back. The embodiment is not limited to these specific motions as additional optional motions may be incorporated into the seat unit. For example, the seat back may also be pivoted for pivotal movement relative to the seat cushion to various angular positions, although this is less desirable because of added complexity to the seat. Also, various seat position adjustment mechanisms may be included as is common in vehicle seats, such as inflation mechanisms for shifting portions of the seat back relative to other portions of the seat back. Thus, a multiplicity of motions may be accommodated in seat embodiments in accordance with the present invention. The invention is not limited to the specific embodiments described in the detailed description below.  
           [0008]    In accordance with one embodiment of a vehicle seat, the seat comprises a seat support, a seat base and a seat back. The seat base and seat back are coupled to the seat support such that the seat base and seat back in this embodiment are selectively movable together as unit in respective first and second directions, such as fore and aft directions. Desirably, the seat back and seat base are movable together as a unit. The seat back may also be coupled to the seat support in this embodiment such that the seat back is selectively movable at least in the first and second directions relative to the seat base. The seat back may be directly coupled to the seat support or indirectly coupled to the seat support via the seat base.  
           [0009]    As another aspect of an embodiment, the seat support may comprise a seat elevation adjuster such that the seat support is selectively movable in upward and downward directions to thereby change the elevation of the seat base and seat back. The seat support may comprise a seat carrier coupled to the seat base and an upright post or pedestal coupled to the seat carrier. The post or pedestal may be adjustable in height. For example, the pedestal may comprise first and second members which slide relative to one another to respectively extend and retract the length of the pedestal to thereby raise the seat base with extension of the pedestal and lower the seat base with retraction of the pedestal. These first and second pedestal members may telescopingly interfit. A biasing mechanism, such as a gas shock absorber, may be coupled to the first and second telescoping members to bias these members to a desired position, such as to an extended position to thereby bias the seat carrier and carried seat base toward a raised position.  
           [0010]    As another aspect of an embodiment, the seat support may slidably support the seat base and seat back for sliding as a unit in first and second directions and may comprise a first slide coupler slidably coupling a seat base member and seat back member to a seat carrier for this purpose. In addition, the seat support may slidably support the seat back for sliding in the first and second directions relative to the seat base and may comprise a second slide coupler for this purpose. The second slide coupler may slidably couple the seat back member to the seat base member such that the seat back member is slidable relative to the seat base member in respective first and second opposed directions to at least three, and typically more, positions.  
           [0011]    As a further aspect, the seat base member may comprise a seat base frame with a seat base cushion carried by the seat base frame. Also, the seat back member may comprise a seat back frame together with a seat back cushion carried by the seat back frame. As the seat back member is slid in a first direction relative to the seat base member, a lesser area of the upper surface of the seat cushion is positioned forwardly of the seat back member. Conversely, as the seat back member is slid in a second direction, a greater area of the upper surface of the seat base cushion is located forwardly of the seat back member.  
           [0012]    As a more specific aspect of an embodiment, the first slide coupler may comprise a plurality of spaced apart elongated first tracks at least a portion of which extends in the first and second directions with the tracks being coupled to the seat carrier. A seat frame of the seat base member may comprise a plurality of first track engagers coupled to the seat frame and slidably engaging the respective first tracks to permit movement of the seat base member and seat back member together as a unit along the first tracks. A seat base latch may be provided and is operable to selectively prevent sliding of the first track engagers along the first tracks to thereby latch the seat base member and seat back member together as a unit relative to the seat carrier. In addition, the second slide coupler may comprise at least two elongated spaced apart seat back guide rails coupled to the seat frame with at least a portion of the guide rails extending in the first and second directions. At least two guide rail engagers, respectively coupled to the seat back member and slidably engaging the respective guide rails, may also be provided. In this case, the seat back member is slidable along the guide rails in the first and second directions and relative to the seat base member. A seat back latch may selectively prevent sliding of the guide rail engagers along the guide rails to thereby retain the seat back member in a desired position relative to the seat base member. The seat back latch may comprise a latch lever pivoted to the seat back member and a latch rod coupled to the latch lever and extending in a transverse direction relative to the first and second directions. The latch lever may pivot between a first seat back latched position and a second seat back unlatched position. In addition, the seat frame may comprise a plurality of latch rod receiving grooves which are spaced along the frame in the first direction. The latch rod receiving grooves are in respective positions to selectively receive the latch rod to latch the seat back member against movement relative to the seat base member when the latch lever is in the first seat back latched position. In addition, the latch rod is disengaged from the latch rod receiving grooves such that the seat back member is slidable relative to the seat base member when the lever is in the second seat back unlatched position.  
           [0013]    In one form, the vehicle seat support comprises a first elongated seat support member adapted to be mounted to the floor of the vehicle, the first seat support member defining a passageway. The seat support may also comprise a second seat support member slidably engaging the passageway and having respective upper and lower end portions. A seat carrier, for carrying the vehicle seat base, is coupled to the upper end portion of the second seat support member. Relative upward and downward movement of the first and second seat support members adjusts the elevation of the seat support and thereby of the carried seat. When the elevation latch is in a latched position, relative movement of the first and second seat support members is prevented, in this example, to establish the seat height. An elevation establishing latch selectively couples the first and second seat support members together to position the seat support at a desired elevation when the latch is in the latched position.  
           [0014]    A plurality of friction reducers may be interposed between the respective first and second seat support members. In one specific construction, the first and second seat support members define a plurality, such as at least three, elongated grooves positioned between these components. In addition, elongated friction reducers may be positioned within the elongated grooves and are engaged by the first and second seat support members as such seat support members slide relative to one another. These friction reducers may comprise plastic material.  
           [0015]    The friction reducer receiving grooves may have a generally circular cross-section with at least a portion of the circumference of each groove being defined by the first seat support member and at least a portion of the circumference of each groove being defined by the second seat support member. The first seat support member may define an interior channel which is generally rectangular in cross-section with four corners. A first groove defining portion may be respectively positioned at each of the corners of the interior channel. In addition, the second seat support member may have an exterior surface which is generally rectangular in cross-section with four corners and second groove defining portions being positioned at the respective corners thereof. The respective first and second groove defining portions at the corners between the interior of the first seat support member and the exterior of the second seat support member in this case together define the grooves at each respective corner. The first seat support member may comprise a plurality of elongated projections, with, for example, one being provided along at least a length of each corner of the first seat support member. The first groove defining portions may be located in the respective elongated projections.  
           [0016]    As another aspect of an embodiment, first and second flanges may project outwardly from respective two adjacent corners of the first seat support member. Such first and second flanges may extend rearwardly when the first seat support member is mounted to the vehicle. In addition, respective reinforcing braces may extend from each of the flanges to a portion of the vehicle at a location spaced above the floor of the vehicle.  
           [0017]    The vehicle seat support may also comprise an upper seat carrier member, together with a plurality of flange braces extending from the upper seat carrier member to the upper end portion of the second seat support member. At least three parallel spaced apart elongated seat supporting tracks may be mounted to a seat supporting surface of the upper seat carrier member in one specific embodiment.  
           [0018]    The seat elevation latch may comprise a lever actuated plunger or pin carried by the first seat support member and a plurality of spaced apart plunger receiving openings positioned along at least a portion of the length of the second seat support member. The plunger receiving openings are located so as to selectively receive the plunger and latch the first and second seat supporting members together when the plunger is inserted into at least one of the plunger receiving openings. In this specific example, a plunger actuating lever is shiftable from a first latching position in which the plunger is inserted into at least one of the plunger receiving openings to a second unlatched position wherein the plunger is retracted from the plunger receiving openings. When retracted, the first and second seat support members may move relative to one another to adjust the seat elevation. The lever may be pivotally carried by the first seat support member for pivoting about a lever pivot axis. A cam may be coupled to the lever A camming surface may be provided for engagement by the cam as the lever is shifted between the first and second positions. The lever and cam are coupled to the plunger such that pivoting of the lever in the respective first and second directions moves the cam along the camming surface to respectively insert and withdraw the plunger from the openings in the second support member. The latch structure may also comprise a collar coupled to the first support member which defines a plunger guide channel for guiding the movement of at least a portion of the plunger. A biasing mechanism may be positioned within the plunger receiving channel for biasing the plunger toward the plunger receiving openings. In addition, the camming surface may comprise a surface at the exterior of the collar.  
           [0019]    Methods of operating a vehicle seat are also illustrated by the described embodiments.  
           [0020]    The present invention is directed toward new and non-obvious features and method acts related to a vehicle seat disclosed herein both individually and in various combinations and sub-combinations with one another as set forth in the claims below. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    [0021]FIG. 1 is a front perspective view of one embodiment of a vehicle seat.  
         [0022]    [0022]FIG. 2 is a side elevational view, with some components shown in dashed lines, of a portion of the vehicle seat of FIG. 1.  
         [0023]    [0023]FIG. 3 is a back view of the portion of the vehicle seat of FIG. 2.  
         [0024]    [0024]FIG. 4 is a vertical sectional view of a portion of the seat of FIG. 2, taken along lines  4 - 4  of FIG. 2.  
         [0025]    [0025]FIG. 5 is a vertical sectional view of a portion of the seat of FIG. 2, taken along lines  5 - 5  of FIG. 2.  
         [0026]    [0026]FIG. 6 is a vertical sectional view of a portion of the seat of FIG. 2, taken along lines  6 - 6  of FIG. 2.  
         [0027]    [0027]FIG. 7 is a horizontal sectional view of a portion of the seat of FIG. 3, taken along lines  77  of FIG. 3.  
         [0028]    [0028]FIG. 8 is an exploded view of an embodiment of one form of seat support together with reinforcements or bracing which may be used in this construction.  
         [0029]    [0029]FIG. 9 is a bottom view of one form of a seat carrier portion of the seat support embodiment of FIG. 8, taken generally in the direction of lines  9 - 9  of FIG. 8.  
         [0030]    [0030]FIG. 10 is a front elevational view of the FIG. 8 seat support without the seat carrier of FIG. 9.  
         [0031]    [0031]FIG. 11 is a side elevational view of the seat support of FIG. 10.  
         [0032]    [0032]FIG. 12 is a vertical sectional view of the seat support of FIG. 11, taken along lines  12 - 12  of FIG. 11.  
         [0033]    [0033]FIG. 13 is a horizontal sectional view of the seat support of FIG. 10, taken along lines  13 - 13  of FIG. 10.  
         [0034]    [0034]FIG. 14 illustrates one form of a seat adjusted to accommodate the standup driving position of a relatively large driver.  
         [0035]    [0035]FIG. 15 illustrates the seat of FIG. 14 adjusted to a seated driving position for the driver of FIG. 14.  
         [0036]    [0036]FIG. 16 illustrates the seat of FIG. 14 adjusted to allow the driver of FIG. 14 to assume a full seated position on the seat, for example, when the driver in a passenger or riding position.  
         [0037]    [0037]FIG. 17 illustrates the seat of FIG. 14 adjusted to accommodate a relatively small driver in a standup driving position.  
         [0038]    [0038]FIG. 18 illustrates the seat of FIG. 18 adjusted to a riding position for the relatively small driver of FIG. 17. 
     
    
     DETAILED DESCRIPTION  
       [0039]    With reference to FIGS.  1 - 3 , one embodiment of a vehicle seat is shown. It is to be understood that the present invention is not limited to the specifically illustrated and described embodiments or to seats incorporating all of the features of a particular embodiment.  
         [0040]    The illustrated seat  10  comprises a seat support  12 , a seat base  14  and a seat back  16 . The seat base comprises a seat cushion  20  which is typically a padded cushion covered by vinyl, fabric, leather or other seat covering material. The seat cushion is mounted or otherwise coupled to a seat frame, one form of which is indicated generally at  22 . The seat back also comprises a seat back cushion  24  which again is typically padded with foam or other material and covered by a suitable covering, such as the covering used for the seat cushion. The seat back cushion is coupled to a seat back frame, and in FIG. 1 is carried by the seat back frame. A portion of one form of such seat back frame is indicated at  26  in FIG. 1.  
         [0041]    The seat base  20  is coupled to the seat support  12  such that the seat base is selectively movable at least in respective first and second directions. For example, in FIG. 1, arrows  30  indicate movement of the seat base in first and second directions which, in this example, correspond to fore and aft directions. In this case, for a seat positioned to face the dash of a vehicle, the forward direction is toward the dash of the vehicle and the rearward direction is away from the dash of the vehicle. The seat base  20  may be movable independently of the seat back  24  in these directions. However, desirably the seat back  24  and seat base  20  are coupled together such that they move together as a unit at least in first and second directions such as indicated by arrows  30 .  
         [0042]    Desirably, the seat back is coupled to the seat support such that the seat back is selectively movable relative to the seat base, for example, at least in the first and second directions. This motion is indicated by the arrows  32  in FIG. 1. As these components move relative to one another, the amount of seat base surface available for supporting a user of the seat is varied. For example, with reference to FIG. 1, movement of the seat back  24  forwardly in FIG. 1 relative to the seat base  20  reduces the available exposed upper seating surface of the seat base positioned forwardly of the seat back for sitting on by a user. Conversely, movement of the seat back relative to the seat base in the opposite direction exposes more of the upper seat base surface forwardly of the seat back for access by a user of the seat.  
         [0043]    A seat back adjustment release mechanism, one form being indicated at  40 , may be shifted between seat back released and seat back engaged positions. When in the seat back released position, the seat back is movable relative to the seat base. Conversely, when in the seat back engaged position, relative movement of the seat back and seat base in the first and second directions  32  is desirably blocked. A seat base release mechanism, one form being indicated generally at  42 , may be used and shifted between respective seat latched and seat released positions. When in the seat latched position, movement of the seat base  20  relative to the seat support is blocked. Conversely, when the seat base release mechanism is in the seat base released position, the seat base  20  may move in the direction of arrows  30  relative to the seat support and, in the FIG. 1 embodiment, the seat back  24  moves with the seat base.  
         [0044]    Although the seat base  20  may be supported by a seat support near the floor of the vehicle in a non-standup seat embodiment, the seat support desirably supports the vehicle at a location spaced sufficiently above the floor of the vehicle for standup use in at least some seat operating positions. An upright seat supporting member may be included in the seat support for this purpose. This seat supporting member may be adjustable in elevation to, for example, permit selective movement of the seat in upward and downward directions relative to the floor of the vehicle to change the elevation of the seat base and seat back. In one specific form, an upright post-like seat carrier, such as indicated in one form at  50 , is used to support the seat base and seat back above the floor  52  of the vehicle. Bracing, such as indicated at  54 , may couple the upright support to other vehicle components within the cab of the vehicle. Although not required, in the specific form shown, the upright support  50  comprises a telescoping pedestal having first and second telescoping members  60 , 62  which slide relative to one another to respectively extend and retract the telescoping pedestal. A seat carrier, one form of which is indicated generally at  64 , forms a part of the illustrated support  42 . The seat carrier  64  is coupled to the seat base  20  and to the seat back  24 . This coupling may of course be indirect through other components. In addition, the seat carrier  64  is also coupled to the upright seat support and in this case to an upper end portion of telescoping member  62 . A seat elevation latch, such as indicated in one form at  70  and described in greater detail below, selectively couples the first and second telescoping members  60 , 62  together to position the seat carrier at a desired elevation when the latch is in a latched position. When the latch is in an unlatched position, members  60 , 62  may move relative to one another to thereby permit adjustment of the elevation of the seat support. The seat may be biased, for example to an elevated position, by a biasing mechanism with one form of such mechanism being described below. It should be noted that, although desirable, components  60  and  62  need not telescopingly interfit but may simply be slidable or otherwise movable relative to one another to adjust the elevation of the seat cushion in those applications where seat elevation adjustments are desired. Arrows  72  indicate the direction of movement of the seat base  20  as its elevation is adjusted.  
         [0045]    Thus, in the form shown in FIG. 1, the vehicle seat is extremely versatile and is adjustable within limits of the mechanical constraints of the seat configuration in respective directions  30 ,  32  and  72 , it being understood that other seat movements may also be accommodated.  
         [0046]    In a desirable approach, a first slide coupler is utilized to slidably couple the seat base member  20  and the seat back member  24  to the seat support and more specifically to the seat carrier  64 , such that the seat base member and seat back member are slidable as a unit at least in the respective first and second opposed directions  30  relative to the seat carrier. Although other forms of slide couplers may be used, with reference to FIGS. 1, 3 and  7 , a plurality, in this case three, elongated first tracks  100 ,  102  and  104 , may be coupled to the seat carrier  42 . For example, tracks  100 ,  102  and  104  may be bolted or otherwise secured to the upper surface of a seat supporting member  106 , which may take the form of a planar plate-like member. In this example, at least a portion of these tracks extend in the respective first and second directions  30 . In the specific form shown, the tracks  100 ,  102  and  104  are generally of a U-shaped configuration. With reference to FIG. 3 and track  100 , a suitable track includes a base  110  and first and second legs  112 , 114  with outwardly flared locking flanges  116 , 118  at the upper ends of the respective legs  112 , 114 . The seat base frame  22  may include a track engager supporting member  124 , such as a plate (FIGS. 1 and 3), which extends under a majority of the seat base cushion. A plurality of first track engagers are coupled to the seat base frame and positioned to engage and slide along the respective tracks  100 , 102  and  104 . In the form shown, three elongated track engagers  130 ,  132  and  134  are provided and are mounted, such as by bolts or other fasteners, to the underside of support member  124 . The track engagers, such as shown in FIG. 3 for engager  132 , may be of a generally inverted U-shaped configuration. For example, each of the track engagers may have a base  140 , first and second leg portions  142 , 144 , and inwardly directing locking flange portions  146 , 148 . The illustrated respective flanges  118 , 148  and  116 , 146  in effect overlie one another and prevent the seat from being lifted off of the seat carrier in normal operating positions of the seat.  
         [0047]    The seat base latch  42  may be of a conventional construction. In a known form, a latch plate  170  (FIG. 7) is pivoted at  172  to the track engager  132 . An actuator lever  174  is rigidly secured to the plate  170  and extends forwardly where it may easily be grasped by a user of the seat. First and second gripping teeth  176  extend from plate  170  toward the track  102 . The track  102  is provided with a plurality of teeth receiving openings along its length. To latch the seat base in place, plate  170  is pivoted to a position where the teeth  176  engage respective latching apertures of track  102 . To unlatch the seat, the plate  170  is pivoted in the opposite direction so that teeth  176  clear the teeth engaging apertures and permit the seat to be slid to a different position. A biasing element such as a spring  180  biases the teeth  176  to a latched position.  
         [0048]    It should be noted that the above construction is simply one convenient way of slidably coupling the seat base and seat back to a seat support such that the seat base and seat back may slide as a unit at least in respective first and second directions relative to the seat support. Mechanisms of this type have been used before to couple a seat base directly to the floor of a vehicle but are not known by the inventor to have been used to couple a seat to an upper end portion of a post-like seat support. Other mechanisms may be used to interconnect these elements and permit the desired sliding or other relative motion of the seat back and seat base with respect to a seat supporting post or other seat carrier or support.  
         [0049]    With reference to FIGS. 2 and 3, the seat back frame, in the specific exemplary form shown, includes first and second side members  190 , 192 . A tubular seat back perimeter frame member has an upwardly extending first leg portion  194  coupled to side frame member  190 , an upwardly extending second frame portion  196  and a cross-piece portion  198  interconnecting portions  194  and  196 . A lower brace  200  extends between elements  194  and  196 . A plurality of back supporting springs  202 , 204  and  206  extend between spring coupling brackets mounted respectively to members  198  and  200 . The seat back frame  26 , in the form shown, also includes lower reinforcing elements  208 , 210  coupled respectively to frame members  190 , 192 . The lower portions of each of the members  208 , 210  extend below and provide support to a transversely extending rod  212  which forms one part of a specific form of an illustrated seat back latch.  
         [0050]    Although other mechanisms may be used, one form of slide coupler for slidably coupling the seat back for movement relative to the seat base is shown in FIGS.  2 - 7 . This specific form of slide coupling mechanism includes a plurality of elongated seat back guides coupled to the seat base member, such as to the seat base frame. Desirably, at least a portion of these guides may extend in the first and second directions. For example, two such seat back guides, such as indicated at  220  and  222 , may be provided. In the form shown (and described for guide  220 ), the guides include a base portion  224  secured to the seat base frame, such as to the underside of seat carrier member  124 , and downwardly projecting leg portions  226 , 228 . One of these leg portions, in this case leg portion  226 , includes an inwardly directed flange  230 . With this configuration, the seat back guides  220 , 222  define a guide channel which may be engaged by seat back guide engagers to support the seat back for sliding along the guide channels.  
         [0051]    The seat back guide engagers may be coupled to the side frame members  190 , 192 . In the form shown, side portion  190  includes an inwardly directed lower portion  240  with an upwardly directed portion  242  which extends between the sidewalls  226 , 228  of the guide  220 . A plurality of guide engagers, such as slide blocks or rollers are coupled to portion  242 . As best seen in FIG. 7, fore and aft slide blocks or rollers  260 , 262  are positioned at the outboard side of flange portion  242 . Blocks or rollers  260 , 262  (see FIG. 3) move along the upper surface of guide portion  230  and between portion  230  and the corresponding portion of base  224 . The slide blocks or rollers  260 , 262  are typically chamfered at their distal outer end. The outer end of such slide guide engagers may engage the inner surface of guide portion  226 . In addition, as best seen in FIG. 7, a slide block or roller  270  is positioned at the opposite side of portion  242  from engagers  260 , 262 . Slide guide  270 , if a roller, may pivot about a pivot axis which, like the pivot axes of rollers  260 , 262 , if engagers  260 , 262  comprise rollers, extend in a transverse direction normal to the elongated longitudinal axis of guide  220 . Engager  270  bears against the undersurface of guide portion  224  (see FIG. 3). A similar guide engager is located at the opposite side of the seat and supported by seat frame member  192 . The slide guide engagers may be formed of a friction reducing material such as ultrahigh molecular weight polyethylene or any other suitable material. Because of the three location support provided by guide engagers  260 ,  262  and  270  at one side of the seat back, and the corresponding three location support at the opposite side of the seat back, the seat back is stably supported and may slide relative to the seat base when the seat back is unlatched to permit such sliding movement. It should be specifically noted that the seat back may be coupled to the seat base and/or to the seat carrier utilizing other mechanisms which permit the desirable sliding movement of the seat back relative to the seat base.  
         [0052]    One form of seat back latch, as previously mentioned, is indicated generally by the number  40 . Mechanism  40  includes a lever  280  carried by an upwardly extending portion  282  of the rod  212 . It should be noted that a lever  280  may be positioned at either side, or both sides, of the seat. With reference to FIGS. 2 and 3, the illustrated rod  212  includes first and second inwardly extending sections  284 , 286  located at the respective sides of the seat. Portions  284 , 286  pass through the respective seat frame portions  190 , 192  above the supporting portion of the respective frame reinforcements  208 , 210 . The rod  212 , in this embodiment, includes rearwardly directed portions  288 , 290  (see FIGS. 2 and 3) and a major transverse portion  294  extending between the sections  288  and  290 . First and second rod engaging members project upwardly from the upper surface of support member  124  in this illustrated embodiment. The rod engaging members may take the form shown at  300  and  302  in FIGS. 2 and 3. A plurality of rod receiving slots, two of which are indicated by the number  304 , open upwardly and are positioned along the length of members  300 , 302 . With the construction shown, lever  280  may be tilted or pivoted forwardly in FIG. 2, from a latched position shown in FIG. 2, to an unlatched position. When pivoted in this manner, the transverse portion  294  of rod  212  is raised out of the slots  304  within which the rod is positioned. When rod portion  294  clears these slots, the seat back may be slid relative to the seat base in the respective directions  32  within the limits of the mechanical configuration of the seat. After the seat reaches a new desirable position, the rod  280  may be pivoted in the opposite direction (e.g., counterclockwise in FIG. 2) to again position rod section  294  in aligned slots  304  of the members  300  and  302 . This latches the seat back in the desired position relative to the seat base. Suitable stops may be provided to limit the extent to which the various seat components may be moved relative to one another. It should also be noted that other mechanisms which permit movement of the seat back relative to the seat base may be used. Clamps, stops and other mechanisms may also be used to retain the seat back in a desired position.  
         [0053]    One specific form of seat support is shown in FIGS.  8 - 12 . As previously mentioned, this form of seat support includes first and second member  60 , 62  which slide relative to one another to adjust the elevation of a seat carrier and thus of a supported seat. Element  60 , 62  may be telescopingly interconnected. In the embodiment shown, the lower element  60  is mounted, such as to the floor  52  of the vehicle, by brackets  310 , 320 . The illustrated member  60  is generally rectangular in cross-section with first, second, third and fourth corners  322 , 324 , 326  and  328 . Reinforcement attachment flanges or members may project outwardly from element  60 . In one specific form, these flanges are indicated at  330 , 332  and extend substantially from the top to the bottom of member  60 . In addition, flanges  330 , 332  project diagonally from the respective adjacent corners  328 , 326  of the illustrated form of member  60 . Reinforcements, two of which are indicated at  340 , 342  in FIG. 8, are fastened or otherwise secured, for example by welding or other connectors, to the respective flanges  330 , 332 . Reinforcements  340 , 342  in the form shown are spaced above the floor of the vehicle and are attached to other components of the vehicle, typically within the cab of the vehicle. For example, reinforcement  340  is shown in FIG. 14 attached to vehicle structure  56 . Reinforcements  340 , 342  in combination with brackets  310 , 320  provide a stable connection of the element  60  to the vehicle. Other alternative brackets and/or mounting mechanisms may be used.  
         [0054]    An upper end portion  344  of element  62  supports the seat carrier  64 . The seat carrier may include a plurality of flanges, some of which are indicated at  346 , 348  and  350 , which form a pocket for receiving the upper end portion  344  of member  62 . The seat carrier flanges may be fastened to end portion  344  to provide a stable support for the seat carrier and supported seat.  
         [0055]    A mechanism may be included to reduce the friction as members  60  and  62  slide relative to one another. In one specific form, a plurality, such as at least three, elongated grooves are defined and positioned between the respective first and second seat support members  60 , 62 . In addition, friction reducers may be positioned within the elongated grooves for engagement by the respective members to reduce sliding friction as they move. These friction reducers may be elongated and of a suitable material such as ultrahigh molecular weight polyethylene. More or fewer of such grooves and friction reducers may be provided. With reference to FIG. 13, an embodiment is illustrated with four such grooves indicated respectively at  400 ,  402 ,  404  and  406 . in the illustrated embodiment, at least a portion of the perimeter of each groove is defined by seat support member  60  and at least a portion of each groove is defined by seat support member  62 . In particular, the corners  322 , 324 , 326  and  328  of member  60  are enlarged with a portion of an associated groove being positioned in the respective enlarged corners. In FIG. 13, although the grooves may take other shapes, the grooves have a circular cross-section. Over 270 degrees of the perimeter of each of the grooves in this specific example is defined by the member  360 . In contrast, a minor portion of each groove is defined by a recessed arc at the respective corners of the member  62 . The grooves may extend along the full length of the respective element  60 , 62  or a lesser portion of such length. Respective friction reducers, in this case of circular cross-section, are shown in the respective grooves and indicated by the numbers  408 ,  410 ,  412  and  414 . Bearings or other types of friction reducers may be utilized although the construction shown in FIG. 13 is desirable and mechanically simple. Alternatively, elements  60 , 62  may simply slide or otherwise move relative to one another without friction reducing components.  
         [0056]    A biasing mechanism may be utilized to bias the seat toward a desired elevation. For example, the seat may be biased to a raised position. Although springs or other biasing mechanisms may be used, a particularly desirable mechanism is a gas-filled shock absorber indicated at  420  (see FIGS. 12 and 13). With reference to FIG. 12, the illustrated shock absorber is pivoted at a lower end  421  thereof- to a pin  422  which spans element  60 . The upper end portion  423  of shock absorber  420  is pivoted to a pin  424  which spans the member  62 .  
         [0057]    Clamps, simple pin inserts, or other mechanisms may be used to selectively prevent elements  60 , 62  from moving relative to one another. Alternatively, and less desirably, a seat post may be used which is not adjustable in elevation. One form of desirable seat elevation latch  70  is best seen in FIGS. 8, 11 and  13 . In this construction, a plurality of spaced apart plunger receiving openings are provided, some of which are indicated at  425 ,  426 ,  427 ,  428 ,  430  and  432  in FIG. 8. The plunger receiving openings extend through a side wall of member  62  and are spaced apart along the length of element  62 , or at least that portion of the length of element  62  which corresponds to the height through which the elevation of the seat is to be adjusted. The latch  70  is shown in the latched position in FIG. 13 with the head  434  of a plunger  436  inserted within an opening  430  to prevent relative sliding of member  60 , 62 . Plunger  436  in this form passes through a collar  438 , and more specifically through an interior passage of the collar. The collar  438  is typically threaded into or otherwise secured to a wall of member  60 . A biasing member, such as a spring  440 , is positioned between a shoulder  442  of plunger  438  and an interior shoulder  444  of the collar  438 . Spring  440  biases the plunger to a latched position. A lever  450  has a cam  452  mounted thereto which, in this case, comprises first and second spaced apart cam plates  454 , 456  each having an arcuate camming surface. One such camming surface is designated  458  in FIG. 11 for cam plate  456 . The lever  450  is pivoted by a pin  460  to cam plates  454 , 456 . Pin  460  extends through an end portion  462  of plunger  436  at a location which is spaced from the plunger receiving openings. When lever  450  is pivoted in a counterclockwise direction from the position shown in FIG. 11, the camming surfaces  458  bear against an outer surface of collar  438 , which may have a friction reducing washer or member  464  secured thereto. Continued pivoting of the lever  450  in this direction results in the withdrawal of the plunger from opening  430  to permit the relative movement of members  60 , 62  and adjustment of the seat elevation. After the seat is positioned at the desired elevation, lever  450  is pivoted in the opposite direction to again insert the plunger head  434  into a plunger receiving opening aligned with the plunger.  
         [0058]    The operation of the seat to accommodate drivers of various sizes and in various operating positions of the seat are illustrated with reference to FIGS.  14 - 18 .  
         [0059]    In the embodiment shown in these figures, although this may be varied, the elevation may be adjusted through about 6.75 inches of vertical travel, using six adjustment positions spaced about 1.3 inches apart. The seat in this case may be adjustable from a minimum seat height off the vehicle floor of about 31.7 inches (to accommodate a small driver, e.g., a fifth percentile female) to a maximum height of about 38.4 inches (to accommodate a large driver such as a male at the ninety-ninth percentile). In addition, the fore-aft seat back movement relative to the seat base may, for example, be about 9.5 inches, using ten adjustment positions of slightly less than about 1 inch each. Also, the seat back and seat base members may be moved together as a unit over a plurality of positions, such through about five inches of travel, using five position adjustments which are about 1 inch apart. These ranges and adjustment increments may be varied. Also, a continuous adjustment structure may be used rather than using incremental adjustments.  
         [0060]    [0060]FIG. 14 illustrates the seat of FIG. 1, with the seat support elevated to its uppermost position. In addition, the seat back  24  has been shifted forwardly relative to seat  20 . As one can see in this figure, when a driver is in the standup driving position, support is provided for the driver&#39;s buttocks as well as the back of the driver while still permitting the driver to reach the foot controls of the vehicle of the type shown in this figure. These adjustments accommodate a male in the ninety-ninth percentile for height on the anthropometric human scale, as represented by the human silhouette in FIG. 14.  
         [0061]    [0061]FIG. 15 illustrates a seated driver position of the seat. In this case, the elevation of the seat has been lowered in comparison to FIG. 14. In addition, the seat back has been shifted somewhat rearwardly relative to the seat base. In addition, the seat cushion and seat base have been shifted forwardly as a unit relative to the position shown in FIG. 14. In this example, the ninety-ninth percentile male silhouette is shown in a seated driving position.  
         [0062]    [0062]FIG. 16 illustrates the seat in one position to accommodate a seated individual who is in a passenger or non-driving position. In this case, the seat back and seat cushion have been shifted rearwardly as a unit relative to the position shown in FIG. 15. In addition, the seat has been raised relative to the position shown in FIG. 15. In addition, the seat back  24  has been shifted rearwardly to expose more of the upper surface of the cushion  20  for accommodating the buttocks of the seated individual.  
         [0063]    [0063]FIG. 17 is similar to FIG. 14, but shows a standup seated position for a small individual, such as a woman in the fifth percentile in height on the anthropometric human scale. In this case, the seat back and seat base have been shifted as a unit forwardly relative to the position shown in FIG. 14. In addition, the seat base  20  is lowered relative to the position shown in FIG. 14. In addition, the seat back  24  has been shifted relative to the seat base  20  to a position forwardly of that shown in FIG. 14 to expose less of the seat cushion forwardly of the seat back for access by the driver of the vehicle.  
         [0064]    [0064]FIG. 18 is similar to that shown in FIG. 16 except the seat has been adjusted for a smaller driver like that of FIG. 17. In comparison to FIG. 16, the seat back  24  and seat base  20  have been shifted forwardly, although the relative position of the seat cushion and seat base may be the same as shown in FIG. 16. In addition, the seat base  20  has been lowered in FIG. 18.  
         [0065]    Having illustrated and described the principles of my invention with reference to several embodiments, it should be apparent that these embodiments may be modified in arrangement and detail without departing from the principles of my invention. I claim all such modifications as fall within the spirit and scope of the following claims.