text: fig1 shows a partially exploded , side elevational view of a wheelchair 10 generally constructed according to the teachings of this patent disclosure . the wheelchair 10 has an overall frame 12 comprised of various tubular elements 12 a , 12 b , 12 c , 12 d , 12 e , 12 f , 12 g , 12 h , 12 i , etc . this overall frame 12 includes a plurality of load - bearing , substantially vertical , support elements such as 12 b , 12 b ′, 12 i , 12 e , 12 e ′, etc . the frame 12 also includes certain substantially horizontal members , e . g ., horizontal member 14 a , that serves to help support a seat 16 upon which a load such as a portion of the weight of an incapacitated human being ( not shown ) is placed . ultimately , the overall frame 12 is supported by its load - bearing wheels &# 39 ; contact with a ground or floor surface 17 . fig1 shows the wheelchair 10 provided with a relatively large , rear wheel 18 a and a relatively small , front wheel 20 a . as can be better seen in fig8 a corresponding rear wheel 18 b and a corresponding front wheel 20 b are mounted on the opposite side of the wheelchair 12 depicted in fig1 . thus , observing this mobile weighing apparatus 10 from the rear ( e . g ., in the manner shown in fig8 ), rear wheels 18 a and 18 b might be termed , respectively , the right rear wheel and the left rear wheel . this same “ right / left ” terminology can be applied to the front wheels 20 a ( right ) and 20 b ( left ) as well . a “ left ” horizontal member 14 b for supporting seat 16 also can be seen in fig8 . the wheelchair 10 shown in fig1 is shown provided with a footrest 22 , an elbow rest 24 and a back rest 26 . the footrest 22 is shown mounted on a rotatable collar 28 that is mounted on front vertical support element 12 b in ways known to those skilled in the wheelchair manufacturing arts . so mounted , the footrest 22 constitutes another element of the overall frame 12 . fig1 also generally indicates that the wheelchair 10 is provided with a microprocessor 34 that resides in a housing 36 having a weight display 38 . a representative wire 31 a ( 15 ) leading from a load cell ( e . g ., leading from load cell 31 a as shown in fig2 ) is depicted leading to the microprocessor 34 shown in fig1 . load - bearing , substantially vertical , support elements 12 e , 12 e ′, 12 b and 12 b ′ of frame 12 are each shown mechanically connected to a respective load cell . for example , the top surface of load cell 30 a is shown mechanically connected to an upper , right rear , load - bearing , substantially vertical , support element 12 e . an opposing , lower , right rear , substantially vertical , support element 12 e ′ is shown connected to the bottom surface of load cell 30 a . via the structure of the overall frame 12 , support element 12 e ′ is ultimately supported by wheel contact with the floor surface 17 . thus , regardless of the magnitude of a downward force 32 a placed upon it , the lower , right rear , substantially vertical , support element 12 e ′ will provide an , opposing , upward , force 32 a to any downward force 32 a ′ placed on the load cell 30 a by the upper support element 12 e . consequently , load cell 30 a will be compressed between downward force 32 a and upward force 32 a ′. the resulting mechanical compression placed on the load cell 30 a by opposing forces 32 a and 32 a ′ is detected and transduced by the load cell 30 a , in ways hereinafter more fully described , into an electrical signal ( e . g ., a voltage signal ) that is sent to microprocessor unit 34 . similarly , a downward force placed on load cell 31 a by certain components of the weight of the wheelchair — and a person in it — is generally depicted by downward force direction arrow 32 b on the upper , right front vertical support element 12 b . in the general manner just discussed with respect to the downward force 32 a on load cell 30 a , the downward force 32 b on lead cell 31 a may be thought of as being opposed by an opposing or upward force 32 b ′ placed on the bottom of load cell 31 a by a lower , right front , load - bearing , substantially vertical support element 12 b ′ ( here again , this upward force 32 b ′ is ultimately provided by wheel contact with the ground 17 ). thus , load cell 31 a likewise experiences a compression action when it is pressured between opposing forces 32 b and 32 b ′. a strain on load cell 31 a resulting from these opposing compressive forces is likewise detected and transduced into an electrical signal which is sent to the microprocessor 34 . it also should be noted that the downward force 32 b placed on load cell 31 a need not necessarily be of the same magnitude as the downward force 32 a placed on load cell 30 a . such differences are taken into account by a computer program that constitutes a part of the microprocessor 34 . it might also be noted here that those forces placed on the overall frame 12 by various cantilevered force components , ( e . g ., for example , the cantilevered force component depicted by downward direction arrow 32 c ( e . g ., such as those resulting from the cantilevered weight of the wheelchair occupant &# 39 ; s legs and feet ) will , to some degree , become a component of the loads placed on the load cells of this mobile weighing apparatus 10 . this is especially true of those load cells , e . g ., load cell 31 a , that are connected to a vertical support , e . g ., vertical element 12 b , to which a cantilevered load such as that depicted by direction arrow 32 c is transferred . be these cantilevered forces as they may , the microprocessor unit 34 can be programmed in ways known to those skilled in this art to deal with cantilevered force components , such as the one generally depicted in fig1 by force direction arrow 32 c . methods of connecting load cells with load bearing , vertical support elements such as members 12 b and 12 b ′ of applicant &# 39 ; s overall frame 12 are well known to those skilled in making , mounting and using such load cells . however , for purposes of illustration , a variety of detailed representative vertical support element / load cell connections are given in fig2 , 5 and 6 . for example , fig2 depicts , in exploded , cut - away detail , the load cell 31 a shown in fig1 . this load cell 31 a has a top surface 31 a ( 1 ), a bottom surface 31 a ( 2 ), a left side surface 31 a ( 3 ), a right side surface 31 a ( 4 ), an outside face piece 31 a ( 5 ) and an inside face piece 31 a ( 6 ). the upper , load - bearing , vertical support element 12 b is shown in abutting mechanical connection with the top surface 31 a ( 1 ) of load cell 31 a . for example the vertical support element 12 b can be welded , screwed or glued to the top surface 31 a ( 1 ) of the load cell 31 a . a downward force or load placed on vertical support element 12 b is again depicted by downward force direction arrow 32 b . this downward force 32 b also is depicted as being transmitted as a continuum of downward vertical force components 32 b ( 1 ), 32 b ( 2 ), etc . over the outside face piece 31 a ( 5 ) of the load cell 31 a . such forces create a strain in the load cell which are detected and transduced into electrical signals . fig2 also illustrates that vertical support element 12 b is preferably tubular in nature . hence , it is shown provided with a hollow core region 12 b ( 1 ) through which electrical connection wires , such as wire 31 a ( 15 ), may be conveniently passed in order to electrically connect the load cell 31 a with the microprocessor 34 in the manner generally suggested in fig1 . similarly , fig2 depicts a lower , opposing , vertical support element 12 b ′ in abutting contact with the bottom surface 31 a ( 2 ) of load cell 31 a . vertical support element 12 b ′ is also shown provided with a hollow center region 12 b ′ ( 1 ). the upward force carried by lower vertical support element 12 b ′ is depicted by upward force direction arrow 32 b ′. this force 32 b ′ also is , in turn , depicted as being transmitted as a continuum of upward vertical force components 32 b ′ ( 1 ), 32 b ′ ( 2 ), etc . over the outside face piece 31 a ( 5 ) of the load cell 31 a . thus , the right face piece 31 a ( 5 ) is subjected to a compression force between these downward forces and upward forces . fig2 also shows various strain gauge element attached ( typically by gluing a flat face side of the strain gauge to a rear side 31 a ( 5 )′ of the outside face piece 31 a ( 5 ), of the load cell 31 a ). a strain placed on the load cell — and particularly on its right rear side 31 a ( 5 )— is detected by such strain gauge elements which , under compression , undergo strain and an accompanying change in the electrical resistivity of their strain gauge element ( s ). again , it is this change in electrical resistivity that is detected and transduced into an electrical signal that is sent to the microprocessor 34 . those skilled in the arts of making and using load cells will appreciate that such load cells are generally comprised of an array of strain gauge elements , resistor elements and voltage detection elements . these elements are usually electrically connected in a wheatstone bridge type circuit such as the one depicted in fig7 . the representative circuit described in fig7 also is shown , by way of example , as part of the load cell 31 a detailed in fig2 . this representative circuit includes a series of strain gauges 31 a ( 7 ), 31 a ( 8 ), 31 a ( 9 ) and 31 a ( 10 ). each of these strain gauges respectively has at least one strain detector element , e . g ., 31 a ( 7 )′, 31 a ( 8 )′, 31 a ( 9 )′ and 31 a ( 10 )′ whose function is to transduce the mechanical strain that it experiences into electrical signals . preferably , all of these strain gauge elements are attached to the same vertical surface . for example , fig2 depicts all of these strain gauge elements attached to the rear surface 31 a ( 5 )′ of outside face piece 31 a ( 5 ). in any case , these electrical signals are then further processed through use of resistor pattern elements such as those indicated by item numbers 31 a ( 11 ) and 31 a ( 12 ) in fig2 . such load cell circuits also typically include compensation resistor elements such as those depicted by item numbers 31 ( a ) 14 and 31 a ( 17 ) . the electromotive force e o produced by such a load cell circuit is also generally depicted by a voltage detection device 31 a ( 16 ). the connector wires needed to create this load cell circuit are generally indicated by item number 31 a ( 13 ) throughout the load cell circuit indicated in fig2 . once created and detected by such a load cell circuit , a resulting voltage can be transmitted , e . g ., via line 31 a ( 15 ), to the microprocessor 34 . fig3 depicts , in exploded , cut - away detail , a load cell 31 a that is very similar to the load cell 31 a shown in fig2 . the only difference is the fact that the load cell 31 a shown in fig3 is shown being supported by two support elements 12 b ′ ( 1 ) and 12 b ′ ( 2 ) rather than the single , lower , vertical support element 12 b ′ shown in fig2 . thus , a vertical component 32 b ′ ( 1 ) of the force carried by support element 12 ′ ( 1 ) and a vertical component 32 b ′ ( 2 ) of the force carried by support element 12 b ′ ( 2 ) each serve to support the load cell 31 a against any downward force ( e . g ., downward force 32 b ) placed on the load cell via upper vertical support element 12 b . fig3 also shows that vertical support elements 12 b ′ ( 1 ) and 12 b ′ ( 2 ) each contact the bottom surface 31 a ( 2 ) of the load cell 31 a at an angle θ , i . e ., an angle θ relative to vertical line 12 b ′ ( 3 ) or relative to vertical support line 12 b ′ ( 4 ). thus , support elements 12 b ′ ( 1 ) and 12 b ′ ( 2 ) are not truly “ vertical ”. nonetheless , such elements can be used to mechanically support the load cells ( e . g ., load cell 31 a ) of this invention and thereby create strain forces upon a load cell &# 39 ; s strain gauge elements . hence , for the purposes of this patent disclosure , the term “ vertical ” ( e . g ., as in the terms “ vertical support element ”, “ substantially vertical support elements ”, etc .) can be taken to mean a support element that is connected to a load cell at an angle from the vertical of 45 ° or less . in this regard , applicant also would note that use of truly vertical support elements ( e . g ., those whose angle θ of element connection to the load cell from a true vertical line such as vertical lines 12 b ′ ( 3 ) and 12 b ′ ( 4 ) in fig3 is substantially zero degrees ) are preferred ; but that support elements ( e . g ., 12 b ′ ( 1 ) and 12 b ′ ( 2 ) that address a bottom or top surface of the load cell at an angle of 45 ° or less can also be employed . fig4 is a side elevational view of a wheelchair made according to another teaching of this patent disclosure wherein said wheelchair includes a front load cell that is attached to each two , upper load - bearing , substantially vertical , support elements and two , opposing , lower , vertical support elements . fig5 is an enlarged , cut - away view of a load cell connected to two , upper , load - bearing , substantially vertical , support elements and to two , opposing , lower , vertical support elements in the manner shown in fig4 . in fig5 the load cell 31 a is shown compressed from above by two , upper , load - bearing , substantially vertical support elements 12 b and 12 b ( 1 ). the load carried by vertical support element 12 b is depicted by force direction arrow 32 b . vertical support element 12 b is shown provided with a core 12 b ( 1 )′ through which a wire 31 a ( 15 ) passes . the other , upper , vertical support element 12 b ( l ) carries a downward force 32 b and also is tubular in nature as indicated by its core 12 b ( 1 )″. the lower , vertical support element that generally opposes the upper support element 12 b is designated 12 b ′. it carries an opposing , upward , vertical force 32 b ′ and is depicted with a core 12 b ′ ( 1 )′. similarly , lower , vertical support element 12 b ′ ( 1 ) carries an upward force 32 b ′ and has a core 12 b ′ ( 1 )″. fig6 is an enlarged , cut - away view of a load cell whose underside is supported by a load - bearing , substantially vertical support element that is bent in a manner such that an extended portion of the tubular element abuts against , and hence supports , the bottom 31 a ( 2 ) of load cell 31 a . in other words the lower support element 12 x is a bent tubular element having a left end 12 b ′ ( 1 ) that approaches the bottom 31 a ( 2 ) of the load cell 31 a at an angle θ and a right end 12 b ′ ( 2 ) that approaches the bottom of the load cell at an angle θ ′. fig7 shows a load cell circuit employing an array of strain gauges and resistor elements . for example , the strain gauges 31 a ( 7 ), 31 a ( 8 ), 31 a ( 9 ) and 31 a ( 10 ) shown in this circuit diagram are shown forming a part of a wheatstone bridge circuit . such wheatstone bridge circuits serve to produce an electromotive force that is generally depicted as e o in fig2 . that is to say that a mechanical strain experienced by a load cell surface and detected by one or more strain gauge elements 31 a ( 7 )′, 31 a ( 8 )′, etc . are transduced into a voltage e o that is detected and sent to the microprocessor unit 34 . the more specific character and design criteria of such load cells are well known to those skilled in this art and are described in the appropriate literature . for example , they are described in a booklet entitled “ strain gages , bondable resistors , installation accessories ”, published by micro - measurement division , measurement group , inc ., raleigh , n . c . 27611 . this booklet is incorporated herein by reference . those skilled in the load cell manufacturing and application arts also will appreciate that these load cell circuits can be programmed to make various refinement computations , e . g ., ( 1 ) zero balance calculations , ( 2 ) zero temperature shift calculations , ( 3 ) zero creep compensation calculations , etc . for example , a zero balance computation can be programmed into the microprocessor 34 to “ subtract out ” the weight of the wheelchair and display only the weight of the person in it . fig8 shows a rear view of a wheelchair 10 such as the one shown in fig1 . fig8 particularly illustrates that rear wheel 18 a can be mounted on its own axle 22 a and rear wheel 18 b can be mounted on its own axle 22 b . fig8 also illustrates that axles 22 a and 22 b can be respectively mounted in a journal element of such load cells 30 a and 30 b . similarly , front wheel 20 a is shown mounted to its own axle 24 a while front wheel 20 b is mounted to its own axle 24 b . fig8 also illustrates that the frame 12 of such a wheelchair can be laterally folded through use of pivotally mounted cross support elements 12 f and 12 g by applying lateral forces f , f ′, g and g ′ in the manner generally suggested in fig8 . fig9 shows a microprocessor housing 36 having a weight display window 38 . the housing 36 contains a microprocessor 34 ( which is not actually shown ) that is connected via lead wires 31 a ( 15 ), 31 a ( 15 ) ( 1 ), 31 a ( 15 ) ( 2 ) and 31 a ( 15 ) ( 3 ) to the microprocessor 34 . thus , the microprocessor 34 can receive electrical voltage signals from each of the load cells 30 a , 30 b , 31 a , 31 b , etc . via these lead wires . the housing 36 is preferably rotatably mounted on a tubular vertical frame element ( e . g ., vertical frame element 12 e ) so that the weight display 38 can be rotated and , hence , seen by the person in the wheelchair as well as by those attending to that person . to this end , the housing 36 can further comprise an arm element 40 whose wheelchair frame contacting end 42 is tubular in nature so that it can be rotatably mounted on a tubular vertical element 12 e of the frame 12 . preferably this vertical element 12 e will end in a horizontal portion 44 to which a hand grip 46 a can be attached for the convenience of the person pushing the wheelchair 10 . fig1 depicts a mobile weighing device 10 ′ mounted on three wheels . in effect the wheelchair 10 shown in fig1 has been modified such that the front of said wheelchair 10 ′ is supported on a single front wheel 48 mounted on a vertical support element 50 having prongs soa and sob which serve as a mounting for an axle 52 for the front wheel 48 . fig1 also suggests that this front wheel 48 may be guided by a guide bar 54 which is operated by the wheelchair &# 39 ; s occupant . indeed , fig1 further illustrates the case where a mobile weighing apparatus 10 ′ of this patent disclosure may be a motor vehicle such as one powered by an electric motor . that is to say that the mobile weighing apparatus of this patent disclosure may be provided with a power source such as a battery powered electrical motor 56 or a gasoline powered engine . those skilled in this art also will appreciate that while this invention generally has been described in terms of the general discussions , specific examples , drawings and preferred embodiments , none of these should be taken individually as a limitation upon the overall inventive concepts which are set forth in the following claims .