Patent Publication Number: US-6216313-B1

Title: Handle with integral cord wrap

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an improved hollow, tubular handle for a steam cleaning machine with an integral cord wrap, which design improves the flexural strength of the handle. 
     2. Brief Description of the Prior Art 
     The design of tubular plastic handles for steam cleaning machines, particularly those used by consumers, are motivated by a desire to make the machine as light as possible. Tubular plastic handles for such machines, however, may be lacking in flexural rigidity. 
     Light weight shell structures may be strengthened with metal parts. Metal clips can also be attached to the handle to provide a cord wrap but such metal parts add expense to the fabrication of a handle because the parts themselves cost money and because additional labor is required for the assembly of the handle. Second, metal parts may become loose over time, decreasing the dependability and strength of the handle. And third, set screws or the like that attach the metal parts and protrude inside the handle may cause an electrical hazard because the fasteners could damage the electrical wires inside the handle. 
     BRIEF SUMMARY OF THE INVENTION 
     In view of the above, it is an object of the present invention to provide a light weight tubular plastic handle for a steam cleaner with an integral cord wrap that improves the flexural strength of the handle without the addition of metal parts other than bushings. It is another object to provide such a handle wherein the bushings may be rotationally molded with the handle. Other objects and features of the invention will be in part apparent and in part pointed out hereinafter. 
     In accordance with the present invention, a handle for a steam cleaner having a support housing has a hollow tubular member with a flat front and rear face. The tubular member has a longitudinal axis and is T-shaped in longitudinal cross-section with a stem and a cross bar. The cross bar is attached to a first end of the stem and has a pair of grips on opposite sides of the stem. The stem widens towards a second end and is bifurcated into a pair of branches which are adapted to be journaled to the main support housing of the cleaner. 
     The hollow tubular member has an integrally formed tubular outrigger connected by a pair of hollow posts, lying in the same plane as the hollow tubular member and forming a closed loop with the hollow tubular member. The outrigger provides an integral cord wrap while the closed loop that the outrigger and posts make with the hollow tubular member increases the flexural rigidity of the handle along the longitudinal axis of the hollow tubular member. 
     A linkage is provided for controlling the angle of the handle with respect to the support housing. Preferably hollow tubular member has an aperture adjacent its bifurcated end providing a second loop increasing the flexural rigidity of the handle. The aperture in the hollow tubular member also permits access to a pin threaded on a rod, under the control of a lever within fingertip reach of the crossbar, forming the linkage for controlling the angle of the handle. Preferably the pin is reciprocated in a bushing integrally molded with the handle. Integrally molded bushings may also be provided in the branches of the tubular member, about which the handle is journaled. 
     The invention summarized above comprises the constructions hereinafter described, the scope of the invention being indicated by the subjoined claims. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated, corresponding reference characters refer to corresponding parts throughout the several views of the drawings in which: 
     FIG. 1 is a perspective view of a steam cleaning machine with a handle in accordance with the present invention; 
     FIG. 2 is an exploded rear elevation of the handle and a main support housing of the steam cleaning machine; 
     FIG. 3 is a fragmentary side elevation of the handle in three of various possible positions; 
     FIG. 4 is a left side elevation of the handle; 
     FIG. 5 is a right side elevation of the handle; 
     FIG. 6 is a section taken along line  6 — 6  in FIG. 5; and, FIG. 7 is a detail taken along line  7 — 7  in FIG.  6 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings more particularly by reference character, starting with FIG. 1, reference numeral  10  refers to a portable self-contained carpet steam cleaning machine. Steam cleaner  10  includes, vertically stacked, a vacuum head  12  mounted on a main support housing  14 , a removable waste recovery tank  16  slidable in and out of the main support housing and a bottom clean water tank  18  upon which the main support housing and waste recovery tank are mounted. A handle  20  in accordance with the present invention is pivotally attached to main support housing  14  at the rear of the machine for moving the machine on a pair of wheels  22  attached to the underside of clean water tank  18 , which in addition to serving as a reservoir for premixed cleaning solution, serves as a chassis for the machine. 
     As shown in FIGS. 2 and 3, main support housing  14  has a cylinder  24  along its top rear edge. A groove  26  is formed in cylinder  24  midway the length thereof, about which is wrapped a plate  28  with a plurality of spaced apart apertures  30 . Plate  28  serves as a ferrule protecting the cylinder from wear. 
     Referring now to FIGS. 4-6, it is seen that handle  20  is a hollow tubular member  32  with generally flat front and rear faces  34 ,  36 , respectively. Tubular member  32  is T-shaped in longitudinal cross-section with a crossbar  38  mounted at one end of a stem  40  with the crossbar forming a pair of grips on opposite sides of the stem. The grips are ergonomic and preferably taper toward the ends because of the foreshortening of an operator&#39;s fingers and the cross-section of the grip perpendicular to a longitudinal axis of crossbar  38  is preferably oval to accommodate a variety of hand sizes. A switch  42  for activating a water pump/brush motor (not shown) is provided at the center of crossbar  38  for right and left handed reach. An internal wiring harness (not shown) provides electrical connections between switch  42  and the water pump/brush motor. Stem  40  widens and is bifurcated at its opposite end forming branches  44  with bushings  46  journaled about a pair of bolts  48  attached to the ends of cylinder  24 . 
     Handle  20 , thus far described, is similar to the handle described in U.S. Pat. No. 5,513,415 except as to the location of switch  42  and as to bushings  46  which may be integrally molded with hollow tubular member  32  as more particularly described below or may be inserted post molding. Handle  20  differs, however, in the provision of an outrigger  50  and an aperture  52  at its widened end. Outrigger  50  is a hollow tube, generally parallel to a longitudinal axis  56  of hollow tubular member  32  and is connected to the hollow tubular member by a pair of spaced apart hollow posts  58 . Posts  58  are spaced adjacent the ends of outrigger  50 , with the free ends of the tube forming horns  60  for use as a cord. Outrigger  50  and posts  58  are integrally molded in the same plane with hollow tubular member  32  and with member  32  form a first loop  62 . Aperture  52  has sidewalls normal to front and rear faces  34 ,  36  of tubular member  32  and forms a second loop  64  in handle  20 . 
     Flexural rigidity is a measure of an object&#39;s resistance to bending and is proportional to the object&#39;s (1) moment of inertia about an axis and (2) material stiffness. Applied to handle  20 , the moment of inertia about longitudinal axis  56  is increased by wall components parallel to the normal direction of bending, such as the walls around first and second closed loops  62 ,  64  and vertical walls  66  around a boot  68  provided on rear face  36 . The rigidity of the handle is increased by these wall components with height “h” because of their effect on deflection, as illustrated by the formula for deflection in a rectangular beam, supported at both ends, with a single load in the middle: 3lW/2fh 2 , where l=length, W=load and f=stress. 
     Handle  20  has a rod  70  attached near crossbar  38  to a lever  72 , one end of which is within fingertip reach of the right grip and the other end of which is pivoted in stem  40  about an axis normal to front and rear faces  34 ,  36 . An access door  74  is provided in rear face  36  through which lever  72  and the upper end of rod  70  may be accessed for connection to the pivot. An opposite end of rod  70  ends with a pin  76  which is received in one of apertures  30  in plate  28 . Rod  70  is biased with a spring  78 , the details of which are shown in FIGS. 6 and 7, such that pin  76  is extended except when lever  72  is pulled up. Depending on the arrangement of apertures  30 , handle  20  can be adjusted between a vertically up and a vertically down position, and at selected angles ergonomic to the operator therebetween as shown in FIG.  3 . 
     Pin  76  as shown in FIGS. 6 and 7, is received in a bushing  80  which is preferably molded in handle  20 . An upper end of pin  76  is threaded for attachment to rod  70 . Within limits, the effective length of pin  76  with respect to plate  28  may be adjusted by threading pin  76  more or less on rod  70 , for which purpose pin  76  may have flats  82  such that it can be gripped with a wrench. This feature is advantageous during assembly of the machine and for maintenance. Once pin  76  has been threaded on the rod to a desired extent, it may be fixed with a locking nut  84 . In the embodiment shown in the drawings, pin  76  increases in diameter below its upper end providing an abutment shoulder  86  between which and a bottom of bushing  80 , spring  78  is compressed. As shown in FIG. 7, pin  76  is received in a selected aperture  30  in plate  28 , with the enlarged bottom of the pin providing a second abutment shoulder  88  in contact with plate  28 , locking handle  20  in a selected position. In other embodiments, pin  76  may terminate in a blade which is wedged into aperture  30  in plate  28  or the like. 
     Hollow handle  20  with bushings  46  and  80  may be rotationally molded as an integral unit from plastic. This feature improves structural integrity and manufacturing efficiency. A preferred material for handle  20  is high density polyethylene (HDPE) but other thermoplastics, including copolymers, may be used. Boot  68  provides a space in the mold for granulated HDPE at the beginning of the molding process, in addition to increasing the flexural rigidity of the finished handle. Boot  68  is advantageous since handle  20  contains many narrow passageways. After hollow tubular member  32  with outrigger  50  is molded, lever  72 , rod  70  and pin  76  are assembled through access door  74  and aperture  52 , respectively. Handle  20  can then be journaled on main support housing  14  with bolts  48 . The power cord (not shown) for steam cleaning machine  10  may be wrapped around posts  58 , under horns  60 . Since outrigger  50  is integrally molded with tubular member  32 , the cord wrap does not loosen with use. 
     In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.