this invention relates to body exercisers , and more particularly to a motorized unit for exercising legs and / or arms of a patient to enhance blood circulation , strengthen the muscles of the patient and provide a range of joint motion to prevent joint &# 34 ; freeze - up &# 34 ;. the unit is adaptable for use with the patient either in a chair or reclining in a bed . it is well recognized that exercise of bodily limbs greatly enhances the recovery process of individuals after surgery . similarly , such exercise has been found to be beneficial to various types of handicapped persons through increased blood circulation and muscle strengthening . it is for these reasons that a wide variety of devices have been developed to bring about the desired exercise . some of the devices are powered by the individual , these being considered &# 34 ; active &# 34 ; exercisers ; and others are driven by appropriate driving means to result in the needed motions , these being considered as &# 34 ; passive &# 34 ; exercisers . the following u . s . patents are typical of the devices that have been developed to be of assistance to patients : 3 , 730 , 174 issued to g . madison on may 1 , 1973 ; 3 , 911 , 908 issued to c . duke on oct . 14 , 1975 ; 4 , 478 , 213 issued to d . redding on oct . 23 , 1984 ; 4 , 587 , 960 issued to t . schotten on may 13 , 1986 ; 4 , 615 , 335 issued to c . searcy on oct . 7 , 1986 ; 4 , 637 , 379 issued to h . saringer on jan . 20 , 1987 ; 4 , 717 , 146 issued to h . nohara on jan . 5 , 1988 ; 4 , 844 , 454 issued to s . rogers on jul . 4 , 1989 ; 4 , 928 , 673 issued to f . heneger on may 29 , 1990 ; 4 , 953 , 541 issued to a . parker on sep . 4 , 1990 ; 4 , 973 , 046 issued to h . maxwell on nov . 27 , 1990 ; 5 , 020 , 795 issued to j . airy et al . on jun . 4 , 1991 ; and 5 , 027 , 794 issued to g . pyle on jul . 2 , 1991 . most of the above - listed patents are passive - type exercisers in that they are motor driven . most utilize some form of oppositely - disposed crank arms with foot pedals attached at the ends . as such , they are designed only for the exercise of the lower extremities of the patient and give no support for lower portion of the leg . at least one of the devices ( 4 , 717 , 146 ) can be used for either leg exercise or arm exercise , but not at the same time . accordingly , it is an object of the present invention to provide a motorized exercising device that permits individual exercise of the arms or the legs , or the arms and legs simultaneously , of a patient . it is another object of the present invention to provide a passive exerciser where individual or joint leg and arm exercise are accomplished by the same portion of the device . another object of the present invention is to provide a passive exerciser where the portion for leg exercise is separated from that for arm exercise , with either or both portions being used by a patient . a further object of the present invention is to provide a passive exerciser where the portion useful for arm exercising is adjustable in height relative to the shoulders of a patient to enhance certain muscle strengthening and provide a selected range of joint motion . still another object of the present invention is to provide a passive exerciser where there is support for the lower leg , with the support being sufficiently pivotable so as to prevent stress on the knee . these and other objects of the present invention will become apparent upon a consideration of the accompanying drawings and a complete description thereof . in accordance with the present invention , there is a passive exercising device that has a base for support on the floor or upon a bed , with an upstanding housing on the base to contain the drive system . the drive system causes rotation of a double ended shaft that projects on opposite sides of the housing substantially parallel with the surface of the base . attached to the opposite ends of the shaft are oppositely - directed crank arms that are caused to move in planes perpendicular to the shaft while pivoting around the shaft . an outwardly - directed axle on each crank arm pivotally supports a leg support cradle whereby the cradle will move in a motion similar to a bicycle , with the cradle pivotally supported so as to prevent stress on the knee joint . in one embodiment a hand grip is associated with each leg support cradle whereby arm exercise can be achieved during leg exercise . in another embodiment , hand grips are associated with auxiliary apparatus on an adjustable frame mounted to the housing , with this frame being adjustable with respect to a height of the shoulders of a patient . this adjustable arm exercising apparatus is manipulated by the drive system used to drive the crank arms . fig1 is a perspective elevational view , partially cut away , of one embodiment of the present invention . fig2 is a perspective elevational view , partially cut away , of another embodiment of the present invention in which a separate arm exercising frame is incorporated into the design of the embodiment of fig1 . fig3 is a drawing illustrating the use of the embodiment of fig2 by a patient reclining in a bed . fig4 is a perspective elevational view , partially cut away , of another embodiment of the present invention showing a further embodiment of a separate arm exercising frame . fig5 is a drawing illustrating another embodiment of a leg support cradle as attached to a drive system of either fig1 or fig2 . fig6 is a schematic circuit drawing of the electrical system of the embodiments of fig1 and 2 . fig7 a through 7e depict the use of a strap to be used to ensure grasp of a hand grip of the embodiments of fig1 - 3 by the hand of a patient , particularly where the patient has insufficient control of hand / finger muscles . shown generally at 10 in fig1 is one embodiment of the present invention . a base 12 , which is substantially planar , supports an upright housing 14 . the base 12 permits the unit to be supported on the floor or , in the case illustrated , on a bed mattress ( see fig3 ). in order to prevent movement of the base 12 on a bed , a restraining strap unit 16 with a strap 18 and clasp 20 are provided to encircle the mattress . when the base 12 rests on a floor in front of a chair ( or wheel chair ), an appropriate restraining element ( not shown ) may be desirable to prevent movement relative to the chair . positioned within the housing 14 , as mounted from a bracket 22 , is an electrical drive motor 24 coupled with a transmission 26 . it will be recognized that if a motor of proper speed is used , there will be no necessity for use of the transmission 26 . the transmission 26 is used to drive a pulley element 28 which through the effect of belt 30 , drives a second pulley 32 . this second pulley is affixed to a double - ended shaft 34 that is appropriately journalled in bearings ( not shown ) within the housing 14 . opposite ends of the shaft 34 project from sides 36 , 38 of the housing 14 where they receive oppositely - directed crank arms 40 , 42 . this orientation provides that the crank arms 40 , 42 move in planes substantially perpendicular to the axis of the shaft 34 as indicated with the arrow 43 . mounted to each of the crank arms 40 , 42 at a selected distance from the shaft 34 is a leg support cradle 44 , 46 . the double - ended arrow 48 is indicative that this distance is selectable . each of these leg support cradles 44 , 46 is substantially identical so that details of only one are given . the leg support cradle 44 is supported by chain members 52 , 54 each pivotally engaged with an axle 56 at 58 , 60 . the length of these chain members 52 , 54 is selectable as indicated by the double - ended arrow 62 ( at cradle 46 ). the opposite ends of the chain members 52 , 54 are joined at selectable positions along second chain members 64 , 66 as indicated by the double - ended arrow 68 . it will be understood that chain members 52 , 54 , 64 and 66 are examples of flexible supports , and that other supports that provide flexibility and adjustability can also be utilized in the present invention . as will be discussed herein after , these various adjustments control the degree of movement of the leg support cradles 44 , 46 and allow for leg movement without placing undue stress on the knee joint . the cradles 44 , 46 are typically fabricated with a rigid frame 70 , at least a semi - rigid external body 72 and a padded interior 74 . each are provided with a foot rest 76 and with a removable hand grip 78 . the foot rest 76 can be pivotally mounted from the frame 70 as indicated at 77 . the hand grip 78 can be positioned at selected distances from the body 72 as indicated by the double - ended arrow 80 . although not shown in this fig1 there is an electrical cable for powering the motor 24 ( see fig6 ). speed of the motor 24 can be controlled by a selector switch 82 , which can include on / off positions , and the duration of operation is controllable with a timer 84 . in a typical utilization of the embodiment of fig1 one or both legs of a patient are placed in their respective leg support cradles 44 , 46 with the feet placed proximate the foot rest 76 . the effective lengths of the crank arms 40 , 42 , as well as the length of the chains 52 , 54 , 64 and 66 , are adjusted for the desired degree of movement of the legs . if the hand grips 78 are to be used , their position is also selected . if the patient is reclining or semi - reclining on a bed , the base member 12 is placed on the mattress and the unit is secured by the strap unit 16 . however , if the patient is positioned in a chair , the base member 12 is placed on the floor . with the leg ( or legs ) in the cradles , the unit is energized at a selected speed and time duration using the controls 82 , 84 . the motion of the crank arms 40 , 42 in the direction of arrow 43 causes the lower limbs to be exercised to improve circulation , exercise muscles and generally be beneficial to the patient . when the hand grips 78 are held by the patient , arm movements occur that further are beneficial to the patient . it will be understood that one or both of the leg support cradles 44 , 46 and hand grips 78 can be used at one time . the motion and position of the components can provide for full extension of the limbs to give maximum exercise . there are applications for an exerciser where benefit is derived from having arm motion at a higher elevation than is possible with the embodiment of fig1 . accordingly , a modified embodiment is shown generally at 10 &# 39 ; in fig2 . elements of this embodiment that are substantially like their corresponding elements of fig1 carry the same numbers . elements that are only slightly different in configuration carry primed numbers . thus , there is a base member 12 and an upstanding housing 14 . if desired , the base member 12 can be provided with a strap unit 16 to attach the base member to a bed , etc ., or with some attaching element to the chair . a drive system in the form of a motor 24 &# 39 ; and transmission 26 &# 39 ; ( if required ) are mounted on a support 22 &# 39 ;. in this embodiment the double - ended shaft 34 &# 39 ; is directly driven by the transmission 26 &# 39 ; it will be recognized by persons skilled in the art that a double - ended shaft motor of proper speed can be used without use of a transmission ( and belt of fig1 ). the speed and time duration of operation is selectable with controls 82 , 84 . this embodiment illustrates the variation of placing these controls 82 , 84 in a removable unit 86 that can be placed near the patient . thus , there is provided an electrical umbilical cord 88 . the leg support cradles 44 and 46 in this embodiment are supported in a slightly different manner than the embodiment of fig1 . the chains 52 &# 39 ;, 54 &# 39 ; are joined at an upper end to a ring member 90 , with this ring member 90 engaged with the axle 56 as at 60 . the functioning , however , is similar to that of the embodiment of fig1 . the embodiment of fig2 provides for an alternate form of arm exercising . this provision is available using a frame member 92 that is pivotally joined to the housing 14 as at 94 . although not shown , there is a locking element to selectively fasten the frame member 92 at a selected pivotal position with regard to the housing 14 . further this frame member 92 , which is formed by legs 96 , 98 , and crossmembers 100 , 102 is adjustable in length as indicated by the double ended arrow 104 . during pivotal movement , the frame member 92 moves in the direction indicated by the double ended arrow 106 from a stored position proximate the housing 14 ( as illustrated in dashed lines ) to an extended position as illustrated in solid lines . a pair of arm exerciser units 108 , 110 are supported from this frame member 92 . each of these arm exerciser units 108 , 110 is identical , and each have a flexible but non - extendable cable member the cable member 112 passes through a pulley 114 proximate the cross member 100 , then through a second pulley 116 and returns to the frame member 92 again proximate the cross member 100 where it is attached as with a spring member 118 . the second pulley 116 is pivotally joined to the axle 56 on the crank arm 40 ,, as at 120 . the unattached end of the cable member 112 carries a hand grip 122 . this particular construction provides for generally axial movement , as indicated by the double ended arrow 124 , of the hand grip 122 that is twice the throw ( the distance between the axis of the shaft and the axis of the axle ) of the axle 56 . of course , other combinations of mechanical advantage can be utilized to give a desired movement of the hand grip 122 such that full extension of the arm can be achieved for maximum beneficial exercise . it will be understood that due to the flexibility of the cable units 110 and 112 , a user can move the hand grips 122 away from each other to get further shoulder exercise . it will be recognized that when the hand grip 122 is being used , the grip 78 on the leg cradle 46 can be removed if desired . a typical utilization of the embodiment 10 &# 39 ; of fig2 is illustrated in fig3 . a patient 126 is semi - reclining on a bed 128 with the base member 12 being secured to the bed with the strap unit 16 . the leg 130 of the patient 126 is supported in the leg support cradle 44 ( the other leg being in cradle 46 if both legs are to be exercised ). further , the patient 126 is grasping the hand grip 122 of the cable unit 112 with his hand 132 ( the other hand grasping the grip on the second cable unit 110 ). it will be recognized that only one of the leg cradle supports 44 , 46 and cable units 110 , 112 can be used , and those individually , for desired exercising . it will be recognized that this embodiment 10 &# 39 ; can also be used with a patient supported in a chair and the base member 12 supported on the floor . shown in fig4 is an alternate embodiment for giving full extension of arm movement as well as any leg movements . this differs in the frame 92 &# 39 ; and the arm exercising cables 110 &# 39 ;, and 112 &# 39 ;. with regard to the frame 92 &# 39 ;, rather than pivot with respect to a housing , this embodiment provides for storage of the frame 92 &# 39 ; within the housing 14 &# 39 ;. this is accomplished by providing a slideway 134 such that the frame 92 &# 39 ; can be raised from , or stored in , the housing &# 39 ;. a lock member 136 on the cross arm 102 &# 39 ; holds the frame 92 &# 39 ; in the extended position as shown . rotation of this lock member 136 so as to be aligned with the cross arm 102 &# 39 ; allows the frame 92 &# 39 ; to be lowered into the housing 14 &# 39 ;. the embodiment of fig4 eliminates the spring units 118 of fig2 . rather , elastic members 138 , 140 are incorporated at the ends of cables 110 &# 39 ;, 112 &# 39 ;. these elastic members pass over the cross member 100 &# 39 ; and ends engage one of a selected number of hook units 142 or corresponding attachment points . this permits adjustment of the total length of the cables 110 &# 39 ; and 112 &# 39 ; to achieve full extension of the arms of a patient using the machine . this embodiment further eliminates pulley 120 and , in its place , the cables 110 &# 39 ; and 112 &# 39 ; encircle the axles 56 as at 144 . a bin 146 is provided in housing 14 &# 39 ; for storage of ancillary equipment , such as a power cord for the unit . fig2 - 4 depict pulley units , e . g ., 112 , 114 , that permit axial movement of the two cable units 108 , 110 . it will be recognized , however , that other forms of rotatable members serving the same function can be utilized with the exercising device of the present invention . the embodiments of fig1 and 4 utilize chain elements 52 , 54 to adjust the leg cradles 44 , 46 in relationship to the crank arms 40 , 42 . an alternate construction is illustrated in fig5 which also shows a modified leg support cradle 46 &# 39 ;. this cradle 46 &# 39 ; pivots around axle 56 through the use of an arm 148 that is adjustable in length . typically this arm 148 is provided with a toothed edge 150 that receives a detent ( not shown ) operated by a lever 152 . thus , an unlocking of the detent by rotation of the lever 152 permits adjustment of the linkage length of the arm 148 and thus the position of the cradle 46 &# 39 ; with respect to the axle 56 . this length is designated by the double - ended arrow 62 &# 39 ;. the arm 148 extends beneath the cradle 46 &# 39 ; where its position can be adjusted to give the lengthwise adjustment indicated by the double - ended arrow 68 &# 39 ;. it will be recognized that other mechanical forms of adjustment can be substituted for that shown in this figure . thus , the leg cradle 46 &# 39 ; ( and a similar leg cradle 44 &# 39 ; on the opposite side ) can be adjusted for a given patient such that natural movement of the knee is effected to prevent undue strain . it will be understood that the operation of this embodiment will provide the same exercise for the legs as described with respect to fig1 - 3 . a schematic circuit diagram of the present invention is depicted in fig6 which is applicable to the embodiments of fig1 and 4 . a power cord 154 , which terminates in a plug 156 adapted for engagement with a conventional receptacle ( not shown ) provides power to components within the housing 12 ( see fig1 and 2 ). this power is fed to the motor 24 ( or 24 &# 39 ;) through the timer unit 84 and speed control 82 . an &# 34 ; on / off &# 34 ; switch is illustrated as being part of the timer unit 84 ; however , a separate switch can be inserted in the circuit if desired . preferably there is a fuse 158 or other overload protective device in the system . some patients , due to their disabilities , will not be able to securely grasp a hand grip ( 78 or 122 of fig1 - 4 ). in order that such patients can utilize the present invention , a gripping glove 160 is illustrated in fig7 . referring first to fig7 a and b , this glove 160 is generally i - shaped having a generally rectangular body portion 162 that defines a pocket 164 for receipt of the hand 166 of a patient . a distal end of the body portion 162 carries a pair of oppositely - directed flaps 168a , 168b . one of these flaps ( e . g ., 168a ) is provided with the loop portion 170a of a hook - and - loop fastener ( e . g ., velcro ), with the other flap being provided with the cooperating hook portion 170b . the opposite end of the body portion 162 is also provided with a pair of oppositely - directed flaps 172a , 172b : one being provided with the loop portion 174a of a hook - and - loop fastener , with the other flap of the pair being provided with the hook portion 174b . of course , other fastening means can be used , such as straps with buckles , for example . in fig7 c is illustrated how the flaps 172a , 172b are wrapped around the patient &# 39 ; s wrist 166 after the hand has been inserted in the pocket 164 . in fig7 d it can be seen that the remainder of the glove 160 is threaded through the hand grip 122 with the fingers bent , and in fig7 e the flaps 168a and 168b are overlapped so as to secure the patient &# 39 ; s hand on the hand grip 122 . it will be understood that this glove unit 160 can also be used to assist in the grasp of the hand grip 78 of fig1 - 3 . further , the glove unit 160 can be used wherever a hand is to be similarly secured . from the foregoing it will be recognized by persons skilled in the art that a universal exerciser for the limbs of a patient has been developed . the degree of motion of both the legs and arms of a patient are adjustable so as to get up to full extension of either . such a device provides this extension , and the exercise useful for improving circulation and developing muscles . even persons who cannot normally hold a hand grip can use the device through the use of the glove unit . the device permits use of either or both of the leg support cradles and / or use of either or both of the arm exercising portions . although certain specific recitations of components are used for illustration of the present invention , these are not for limiting the invention . rather , the invention is to be limited only by the appended claims and their equivalents .