Patent Publication Number: US-6212700-B1

Title: Portable toilet unit

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based upon U.S. provisional application Ser. No. 60/126,655 filed Mar. 29, 1999, the disclosure of which is incorporated by reference herein. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Toilets that are provided in vehicles, or used for camping purposes or are otherwise portable, are typically made primarily of plastic. Constructing such toilet units of plastic not only is relatively inexpensive and allows simple construction thereof, but also the use of plastic saves weight, which is important in any type of vehicle, or for portability in general. Therefore conventional portable and mobile toilet units include a plastic toilet bowl, a plastic body positioned exteriorly of the toilet bowl, and a plastic toilet seat. 
     The toilet environment is extremely harsh and plastic components—plastic toilet bowls in particular—have a tendency to degrade more quickly than desired as a result of attack by chemicals and light. While it is thus highly desirable to provide toilet bowls having improved characteristics, so as to extend the life thereof, that desirable goal cannot be achieved by compromising the cost and low weight criteria that are very important for portable and mobile toilets. For example it is not possible—in a manner consistent with low weight and low cost—to replace the plastic toilet bowl with a toilet bowl material, like porcelain, that has outstanding resistance to degradation but relatively high cost and weight. 
     According to the present invention, a portable or mobile toilet unit is provided which is able to achieve a significantly longer life for the toilet bowl, and increase the hygiene associated therewith, while at the same time only minimally increasing the weight and cost of the toilet unit. This is accomplished according to the present invention by providing a non-polymeric, substantially poreless, material that is substantially not degraded as a result of contact with excrement, light, and toilet bowl cleaning agents, disposed interiorly of the plastic toilet bowl and for contacting liquid and materials passing through the toilet bowl open top. The material has an outlet adjacent the bottom thereof for leading sewage away from the toilet bowl. In appropriate cases the material may be provided as a layer or coating of, for example, porcelain or glazed ceramic (each about 0.3125 inches thick, for example); glass; or corrosion resistant sheet metal, or sheet metal with a corrosion resistant substantially poreless interior coating, (e.g. each about 0.05 inches thick). In the preferred embodiment, however, the material comprises a thin-walled (that is having the minimum thickness necessary for structural integrity considering the material utilized) insert liner which is disposed within and is at least partially supported by (typically almost completely supported by) the interior of the plastic toilet bowl. Using such an insert liner, the plastic toilet bowl itself can be made thinner than in conventional toilet units since it primarily only provides a supporting function; and since the insert liner is at least partially supported by the plastic toilet bowl, it can be thinner than it otherwise would have to be to have the sufficient structural integrity if it served as the only toilet bowl structure. 
     The insert liner may be attached by adhesive directly to the toilet bowl interior surface, or may be attached thereto by mounting foam. The toilet unit also preferably comprises a liquid flush mechanism which flushes liquid (such as water, or a deodorant liquid as commonly used in conventional vehicle toilets) into and through the insert liner. The insert liner outlet is typically sealed by a lip seal to other components. The plastic body may include an annular plastic cover adjacent the toilet seat and an upper rim of the insert liner may be received by the annular plastic cover. The annular plastic cover may mount a plurality of nozzles for introducing flushing liquid into the toilet bowl, directed against the insert liner, and the plastic toilet bowl may have a substantially radially extending portion which supports the annular plastic cover. 
     The plastic body may be rotatably supported by a socket, which in turn is rotatable about a substantially vertical axis and is mounted below the toilet bowl and insert liner. Within the socket may be a funnel-shaped conduit, communicating with a connection which passes through a wall of the socket, to lead sewage away from the toilet bowl outlet, e.g. to a holding tank either integral with the toilet unit or—in the case of most vehicles—distinct from the toilet unit. The toilet unit according to the invention is particularly suitable for use with vacuum flush toilets, such as sold by Sealand Technology, Inc. of Big Prairie, Ohio, such as under the “VACU-FLUSH” trademark. A common foot pedal actuator may be provided for operating a valve to supply flushing liquid to the nozzles, and to substantially simultaneously open a spherical segment valve to allow sewage to pass out of the insert liner through the outlet. 
     It is the primary object of the present invention to provide a toilet unit having necessary lightweight and low cost characteristics, but having enhanced hygiene and longevity of the toilet bowl thereof. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view, partly in elevation and partly in cross-section, of an exemplary portable or mobile toilet unit according to the present invention; 
     FIG. 2 is an end view, partly in cross-section and partly in elevation, and partly in outline, of the toilet unit of FIG. 1; 
     FIG. 3 is a schematic top view showing the common pedal actuator for the liquid flush valve, and the spherical segment valve for opening or closing the toilet bowl outlet, in the toilet unit of FIGS. 1 and 2; 
     FIG. 4 is a side primarily cross-sectional view of an alternative construction of the base for the portable toilet according to the present invention; and 
     FIG. 5 is a side view of the base of FIG. 4 with a minor modification thereof. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     In the drawings the reference numerals refer to the following components: 
       1 ,  101  toilet unit 
       2  plastic basic body 
       3  plastic toilet seat 
       4  toilet seat cover 
       5  toilet bowl 
       6 ,  106  socket 
       7  support 
       8  outlet, exit 
       9 ,  109  spherical segment valve 
       10  water level 
       11 ,  111  plastic toilet bowl 
       12 ,  112  insert liner for plastic toilet bowl 
       12 ′ insert liner upper edge 
       13 ,  113  flange 
       14  seal 
       15 ,  115  cylinder section 
       16  insert liner bottom cylindrical section 
       17 ,  117  lip seal 
       18 ,  118  polyurethane mounting foam 
       19  annular plastic cover 
       20  radially extending upper edge 
       21  flush liquid introducing nozzles 
       22  locking mechanism 
       24 ,  124  pedal actuator 
       25 ,  125  flush valve unit 
       26 ,  126  funnel-shaped outlet 
       27  connecting piece 
       28 ,  28 ′ connecting channel 
       29  vacuum source 
       30  holding tank 
       31  fresh water source 
       33  flange base for cylindrical section 
       34  bolts for holding flanges  113 ,  133  together 
       35  nuts for bolts  34   
       36  elastomeric seal for flanges  113 ,  133  and valve  109   
       37  pivot pins for valve  109   
       38  outlet opening in bottom of funnel  126   
       39  outlet conduit from toilet unit 
       40  discharge outlet opening from outlet conduit 
     The toilet unit according to the present invention, in one exemplary form, is shown generally by reference numeral  1  in FIGS. 1 and 2. The basic generally conventional components include a plastic toilet bowl  11  having an interior surface, an open top, and an exterior surface, a plastic body  2  positioned exteriorly of the toilet bowl  11  exterior surface, a plastic toilet seat  3  for partially closing the open top of a plastic toilet bowl  11 , and a plastic cover  4  for covering the toilet seat  3 . While these components are conventional, the plastic toilet bowl  11  according to the present invention may be made thinner than in conventional constructions of portable or mobile toilet units. 
     According to the present invention in order to enhance the longevity and hygiene of the portable or mobile toilet unit  1 , a non-polymeric, substantially poreless, material that is substantially not degraded as a result of contact with excrement, light, and toilet bowl cleaning agents, is disposed interiorly of the plastic toilet bowl  11  and for contacting liquid and materials passing through the toilet bowl  11  open top. The material may be in the form of a layer or coating on the plastic toilet bowl  11  interior surface if the plastic of the toilet bowl  11  and the non-polymeric material are compatible. However in the preferred embodiment illustrated in the drawings, the material comprises a thin-walled insert liner  12  which is disposed within and is at least partially supported by the interior surface of the plastic toilet bowl  11  (preferably all or the majority of the support for the insert liner  12  is provided by the plastic bowl  11 ). The insert liner  12  also defines the outlet  8  adjacent the bottom thereof for leading sewage away from the toilet bowl  5  (collectively the plastic toilet bowl  11  with the insert liner  12 ). Normally the outlet  8  is closed by a suitable valve  9 , preferably a conventional spherical segment valve. A water level  10  is typically established within the bowl  5 . Establishing the water level  10  so that it is substantially permanently maintained in the toilet bowl  5  indicates the tightness of the seal provided by the valve  9 , and assists in providing an odor free environment. 
     The non-polymeric material, forming a layer, coating, or the preferred insert liner  12 , may comprise or consist essentially of porcelain, glazed ceramic, glass, corrosion resistant sheet metal, or sheet metal with a corrosion resistant substantially poreless interior coating (e.g. enamel). The insert  12  is thin-walled, meaning that it has only the thickness necessary to provide sufficient structural integrity so that it does not crack or become easily damaged, considering that it is at least partially (if not substantially wholly) supported by the plastic toilet bowl  11 . The thickness of the insert  12  will depend upon the particular material used therefor; for example if the insert liner  12  is of corrosion resistant sheet metal, such as aluminum or stainless steel, it will typically have a thinner wall than if of porcelain or glazed ceramic. A typical nominal thickness of a sheet metal liner  12  is about 0.05 inches, a typical nominal thickness of a vitreous china (or other porcelain or glazed ceramic) insert  12  is about 0.3125 inches, and a typical nominal thickness of the plastic toilet bowl  11  when the insert  12  is used is about 0.125 inches. 
     The insert  12  may be adhesively secured directly to the interior surface of the plastic toilet bowl  11 , or it may be attached to the plastic toilet bowl  11  interior surface by mounting foam, such as the polyurethane mounting foam  18  illustrated in FIGS. 1 and 2. Polyurethane mounting foam  18  is preferred since when used the tolerances need not be as tight when manufacturing the toilet bowl  5  components  11 ,  12 , and because the foam  18  provides improved breaking strength as well as noise dampening. 
     The plastic toilet seat  11  is supported at the bottom end thereof by a flange  13  of a socket  6 . The flange  13  includes a seal  14  which comprises a cylindrical section  15  for receipt of a concentric cylindrical section  16  of the insert liner  12 , and a lip seal  17  is also provided at the interface between the cylindrical section  15  and the concentric section  16  at the top of the cylindrical section  15 . The socket  6  mounts the valve  9  for rotation about a substantially horizontal axis. 
     During manufacture of the toilet unit  1 , the insert liner  12  is placed within the plastic toilet bowl  11 , and then preferably the polyurethane mounting foam  18  is injected into a space between the bodies  11 ,  12 —as illustrated in FIGS.  1  and  2 —and allowed to cure. Where the tolerances are sufficient, the exterior surface of the insert liner  12  may be adhesively secured substantially directly to the interior surface of the plastic toilet bowl  11 . 
     Preferably the plastic toilet bowl  11  includes a substantially radially extending upper edge  20  which provides a circumferential seat for an annular plastic cover  19 , i.e. supports the substantially annular plastic cover  19 . Cover  19  supplies vertical play for the plastic body  2 . When a user sits on the toilet seat  3 , a downward force is transmitted to the cover  19 , which prevents the compression force from being transmitted to the insert liner  12  because the force is instead exerted on the plastic toilet bowl  11  and the plastic body  2  primarily via the substantially radially extending upper edge  20 . The plastic cover  19  receives the upper edge  12 ′ of the insert liner therein. 
     Preferably the toilet unit  1  has a liquid flush mechanism which flushes liquid into and through the insert liner  12 . While any suitable conventional type of flush mechanism may be utilized, in the embodiment illustrated in the drawings the flush mechanism is provided by: a plurality of nozzles  21  mounted adjacent the bottom interior of the plastic cover  19 , as seen in FIGS. 1 and 2, and for spraying liquid directly on to the insert liner  12  interior surface; and a conventional valve assembly  25  for selectively applying water, or other flushing liquid, from a flush liquid source (e.g. a toilet tank, or a separate tank, or the surrounding environment if on a boat)  31  (see FIG.  3 ). The nozzles  21  spray flush liquid on substantially all portions of the interior surface of the insert liner  12  below the plastic cover  19  and above the bottom section  16  thereof. 
     The socket  6  preferably mounts bowl  5  and body  2  so that they are rotatable about a substantially vertical axis for ease of installation, to allow proper positioning of the components thereof in areas where space is at a premium, such as in conventional vehicles in which the toilet unit  1  might be used (such as RVs, boats, caravans, trailers, and the like). Also rotation of the components  5 ,  2  with respect to the socket  6  may be maintained even after installation in situations where it is desirable—again because of space considerations—to rotate the bowl  5  forwardly during use, and then to the side when not in use. 
     The relative rotation between the socket  6  and the bowl  5  can be prevented or retarded, however, by the utilization of a locking mechanism, shown schematically at  22  in FIGS. 1 and 2. The locking mechanism  22  may comprise any conventional mechanism, such as a spring-biased clamp, which provides a clamping action between the seal  14  and the flange  13  which precludes relative movement. The spring force, or like force, provided by the biasing clamp of the locking mechanism  22  may be sufficient to preclude rotational movement between the parts  5 ,  6 , completely, or merely be great enough to prevent any leakage and to hold the components  5 ,  6  into a relative position to which they have been moved, yet allow at least 90° of relative rotation between them. To accommodate this rotation, seals  23  may be mounted on the support surface  7  for the toilet unit  1  so as to allow rotation of the plastic body  2  with respect to the mounting surface  7 . It is then necessary to provide a recess—shown only schematically at  2 ′ in FIG.  2 —for the pedal  24  to accommodate the relative rotation between the part  2  and the support  7  while allowing the pedal  24  to be in a relatively fixed position with respect to the vertical axis rotation of the body  2 . 
     The pedal actuator  24  preferably substantially simultaneously actuates both the conventional flush liquid valve  25  and the spherical segment valve  9  for closing the outlet  8 . That is upon pressing down on the pedal  24 , the valve  25  is caused to be open causing flushing liquid to pass from the source  31  through the nozzles  21  into contact with the interior surface of the insert liner  12 , while at the same time the valve segment  9  is rotated about a substantially horizontal axis to move to an open position allowing liquid and other materials within the toilet  5  to flow through the outlet  8  into a funnel-shaped outlet unit  26  mounted within the socket  6 . The funnel-shaped outlet  26  is connected via a connecting piece  27  to one or more connecting channels  28 ,  28 ′. A number of different channels  28 ,  28 ′, which pass through the wall of the socket  6 , may be provided to facilitate easy mounting of the unit  1  in cramped locations, such as on vehicles. Any connecting channel  28 ,  28 ′ not used is plugged. 
     The connecting channel  28  is illustrated in FIG. 1 connected up to a conventional vacuum source  29 , and a conventional holding tank  30 , such as used in the vacuum toilets sold by Sealand Technology Inc. of Big Prairie, Ohio, including under the “VACU-FLUSH” trademark, and/or such as illustrated in U.S. Pat. Nos. 3,663,970, 4,672,690, 5,408,704, 5,621,924, and/or 5,681,148. The vacuum source  29  and the holding tank  30  are mounted where convenient in the vehicle in which the toilet unit  1  is positioned. When a vacuum source  29  is used, the actuator pedal  24  also automatically connects the interior of the toilet bowl  5  to a vacuum tank or the like. 
     In the FIGS. 4 and 5 embodiment, the base of the toilet unit is revised, providing a simplified pedestal arrangement. In the FIGS. 4 and 5 embodiment components functionally comparable to those in FIGS. 1-3 are shown by the same reference numeral plus  100 . In FIG. 4 one version of part of the plastic toilet bowl  111  is shown on the left, but omitted on the right for clarity of illustration, and in FIG. 5 the elements  11 ,  12  have been removed completely. The upper portion of the toilet unit  101  is preferably substantially the same as that of the toilet unit  1 . Other versions of the element  111  may also be provided, such as having a flange that is held in place by the bolts  34  with nuts  35 . 
     In the FIGS. 4 and 5 embodiment the clamps  22  of FIGS. 1 and 2 have been replaced by the conventional plurality (e.g. four) of fasteners  34 ,  35 , which compress the elastomeric seal  36  between the flanges  33 ,  113 . The seal  36  also cooperates with the valve  109 , which is mounted for pivotal movement about a substantially horizontal axis by the pivot pins  37 . 
     The funnel shaped interior  126  of the socket  106  ends in an outlet opening  38  that extends completely into the larger diameter conduit  39 . The discharge opening  40  of the conduit  39  is larger in cross-sectional area (e.g. has a larger diameter) than opening  38 . The pedal actuator  124  is simpler than the actuator  24 . 
     The FIG. 5 embodiment differs from that of FIG. 4 only in the position of the discharge outlet  40 , the rear position of FIG. 5 being preferred to that of FIG.  4 . 
     While the invention has been herein shown and described in what is presently conceived to be the most practical and preferred embodiment thereof, it will be apparent to those of ordinary skill in the art that many modifications may be made thereof within the scope of the invention. For example the material which provides enhanced longevity and hygiene that is disposed in association with the interior surface of the plastic toilet bowl  11  may be provided by a metal coating (e.g. galvanized) on plastic material, or by producing a compound material such as by casting plastic around a porcelain insert, or pressing an insert into a prefabricated carrier body. Also, in addition to adhesively connecting the insert  12  or like material to the interior surface of the plastic toilet bowl  11 , or using the mounting foam  18 , the insert  12  may simply be slipped into the toilet bowl  11  without a connection between them, or by providing spaced pressure and tension release components. Thus the invention is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and devices.