Portable toilet unit

A lightweight toilet unit is provided particularly for use with vehicles such as boats, RVs, and trailers. The toilet unit includes a plastic toilet bowl having an interior surface, open top, and exterior surface, a plastic body positioned exteriorly of the toilet bowl exterior surface, and a plastic toilet seat for partially closing the open top of the toilet bowl. To enhance the longevity and effectiveness of the toilet bowl without significantly increasing the cost and weight of the toilet unit, a layer, coating, or thin walled insert liner made of a non-polymeric substantially poreless material that is not degraded by contact with excrement, light, or toilet bowl cleaning agents, is disposed interiorly of the plastic toilet bowl and is at least partially supported by the plastic toilet bowl and may comprise porcelain, glazed ceramic, glass, corrosion resistant sheet metal, or sheet metal with a corrosion resistant poreless interior coating. The toilet bowl may be rotatably supported by a socket which mounts a common valve actuator (e.g. pedal) for supplying flushing liquid to the interior of the insert liner and substantially simultaneously opening a spherical segment valve at the outlet at the bottom of the toilet bowl.

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.

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.degree. 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.