in the embodiment illustrated in the drawings , there is shown a vacuum cleaner 10 comprising a suction producing unit 11 which contains a motor - blower suction producing unit and a filter bag to separate dirt particles from the suction air stream , both of which are not illustrated here , a connecting suction hose 12 from the unit 11 to a suction nozzle 13 that is movable over a surface 14 on supporting wheels 15 and a manipulating wand 16 connecting the flexible hose 12 with the nozzle 13 . the surface 14 to be cleaned is illustrated at fig3 as of a carpet having a short pile and therefore the supporting wheels 15 are in retracted position . a different type surface 17 illustrated in fig4 is of a carpet having a long pile and the supporting wheels 15 are in raised or extended position . the nozzle 13 has at the front end 18 thereof a nozzle opening 21 through which extends the bottom 22 of a customarily rotatable brush 23 that is rotatable by means not shown and that is provided with helically arranged brush elements 24 . as is illustrated in fig2 the supporting wheels 15 which are in the form of rollers are mounted on the opposite coaxial ends 25 of a yoke 26 interconnected by a bight 27 and is spaced from and parallel to the coaxial ends 25 . the yoke 26 is rotatable with the bight 27 so as to adjust the position of the supporting wheels 15 between the extreme positions of fig3 and 4 and thus the height of the nozzle 13 and brush 22 relative to the surfaces being cleaned as illustrated by the carpets 14 and 17 . the adjusting mechanism is illustrated in fig5 - 8 with a portion being illustrated at the broken away section of fig2 . in this illustrating embodiment , for positioning the supporting wheels 15 relative to the nozzle 13 , the yoke 26 comprises the hinged support for the wheels that extends rearwardly thereof . this support is hingedly mounted on the housing 28 at the bight 27 of the yoke 26 for arcuate movement of the wheels 15 relative to the housing 28 comprising the nozzle 13 . the improved front wheel height adjuster as illustrated comprises a unitary adjusting member 31 that can be inexpensively molded from a synthetic resin and comprises an integral assembly of a thumb wheel 32 that is rotatable about an axis of rotation 33 , the wheel having a solid internal web 34 and an outer circumference provided with spaced knurls 35 for secure manual engagement . this outer surface of the thumb wheel 32 is also provided with marked indicia 36 such as the two sets of 1 , 2 and 3 illustrated for indicating the relative position of the supporting wheels 15 . on one side of the web 34 there is located the cam 37 coaxial with the axis of rotation 33 and having two diametrically opposite cam surfaces 38 of gradually increasing surfaces from a low point 41 to its greatest distance from the axis of rotation 33 which thereby comprises a high point 42 . as can be seen in fig6 there are provided two of these cam surfaces 38 located diametrically opposite to each other and extending for about 180 ° each around the axis 33 . with this construction , each complete revolution of the thumb wheel 32 causes two complete cycles of operation of the cam . that is , each time the cam is rotated full circle , the cam follower will be operated twice . the cam follower illustrated at 43 is rotatably mounted on a support bracket 44 at one side of the adjusting member 31 . this cam follower 43 has a cam engaging intermediate portion 45 and an end portion 46 that engages a forwardly extending intermediate leg 48 of the yoke 26 on which the supporting wheels 15 are located at the coaxial ends 25 . on the other side of the web 34 of the unitary adjusting member 31 there is located a circular locking ratchet 51 provided with spaced cross grooves 52 that are parallel to the axis of rotation 33 . these grooves comprise the ratchet means that are engaged by the resilient and thereby springy pawl 53 . the ratchet 51 and pawl 53 arrangement permits rotation of the thumb wheel 32 and associated parts only in a clockwise direction as indicated by the arrow 54 in fig8 ( this direction is , of course , counterclockwise as viewed in fig5 - 7 ). the rotatable unit 31 is held against rotation by the ratchet 51 and pawl 53 engagement and is held against counter - rotation by the positioning of the spring pawl 53 to coincide with a chord of the circular ratchet 51 . the parts of the device of this invention are most inexpensive of molded or otherwise shaped plastic materials . thus the member 31 includes the integral wheel , cam , ratchet and aligned axle projections 55 and 56 and are of one - piece molded construction as well as the radiating strengthening webs 57 and 58 . the supporting housing 61 with its supporting brackets 62 , 63 , 43 and 44 are also of molded plastic material . in addition , the nozzle 13 itself comprises a molded plastic and contains a top opening 64 through which the top of the thumb wheel 32 extends for manual adjustment . this nozzle 13 as is customary is provided with a top 65 and bottom 66 and an exterior resilient bumper strip 67 . operation with the parts arranged such that the parallel legs 48 are in raised position with the supporting wheels 15 retracted as shown in fig3 and 6 , the front of the nozzle and the brush 24 are in position for contacting and cleaning short pile 14 carpets or even bare surfaces as illustrated in fig3 . when the parts are in their opposite location , the supporting wheels 15 are at their most extended position so as to maintain the nozzle opening 21 and brush 24 in proper position for cleaning deep pile carpeting , for example , as illustrated at 17 in fig4 . in changing the position of the supporting wheels 15 relative to the nozzle 13 , the operator manually engages the top of the thumb wheel 32 as it extends through the nozzle opening 64 . the operator can only rotate the wheel 32 in one direction 54 because of the provision of ratchet 51 and pawl 53 construction . furthermore , because of the springy nature of the pawl 53 there is a loud click when the wheel 32 has been moved to the next adjusted position . with the parts in the position shown in fig6 the wheels 15 are in their retracted position as shown in fig3 and 6 . with rotation of the wheel 32 in the direction 54 ( the only direction it can rotate ), the cam follower 45 is pushed away from the axis 33 by the cam follower 43 bearing against the first cam surface 38 which are here shown as two , but may be one or a further plurality . they are shown as two each with its own set of numerals or indicia because this provides ratchet adjustment of position on rotation 54 of the unit and permits rapid change from the most extended position of the wheels 15 of fig7 back to the most retracted position of these wheels of fig6 . the foregoing disclosure of specific embodiments is illustrative of the broad inventive concepts comprehended by the invention .
a vacuum cleaner nozzle adjuster for adjustably positioning a nozzle opening relative to the surface being cleaned so as to accommodate surfaces of all textures in which an integral manually accessible thumb wheel , lifting cam and locking ratchet unitary member is provided that is rotatable by manual engagement to cause the lifting cam operating against a movable front wheel support for the housing to properly position the nozzle opening and a pawl engages the locking ratchet to hold the wheel and nozzle in adjusted position .