CA1157207A

CA1157207A - Portable toilet

Info

Publication number: CA1157207A
Application number: CA000385667A
Authority: CA
Inventors: John M. Stewart
Original assignee: Sanitation Equipment Ltd
Current assignee: Sanitation Equipment Ltd
Priority date: 1981-09-11
Filing date: 1981-09-11
Publication date: 1983-11-22

Abstract

ROGERS, BERESKIN & PARR C A N A D A
INVENTION: PORTABLF TOILET
INVENTOR: JOHN M. STEWART
ABSTRACT OF THE DISCLOSURE
A two-piece portable toilet is constructed with a bowl unit supported on a holding tank. In a preferred embodiment of the invention, a friction fit is used to secure the bowl unit to the holding tank at the front of the toilet. The friction fit is provided by roughened vertical surfaces which are pressed horizontally against one another as the bowl unit is seated vertically on the holding tank.
In the preferred embodiment the roughened surfaces are provided on an inner wall of a recess at the bottom of the bowl unit, and corresponding roughened surfaces are provided on the sidewall of a projection which extends upwardly from the holding tank to be received in the recess during seating of the bowl unit. Elastic deformation of portions of the bowl unit and holding tank ensure that the roughened surfaces are biased against one another to resist removal of the bowl unit.

Description

- 2 - l~S72V7 The invention relates to portable toilets of the two-piece variety in which ~ bowl unit is detachably secured to and supported by a holding tank. More particularly, the in~en-tion relates to imprOvements in the manner in which a bowl unit is secured to a holding tank.
Portable toilets of a two-piece const~uction consistin~ of a bowl unit supported by a holding tank are well known. The bowl unit generally includes a toilet bowl having an outlet which communicates with an inlet provided in the top the holding tank. A valve mechanism in the holding tank regulates movement of waste into the holding tank, the valve mechanism serving normally to close the inlet but being selectively openable to allow waste to enter the holding tank, The holding tank must be readily separable from the bowl unit so that it can be transported to a convenient location for emptyingO
Various proposals have previously been made for securing the holding tank and bowl unit together. For example, in the toilet disclosed in our United States Patent No. 4,091~475 over-centre clips are used for securing the bowl unit to the holding tank. A clasp mechanism located bet~een the ~owl unit and the holding tank is disclosed in United States Patent No, 3,94~,430 (Miller et al). United States Patent No. 4,180,876 (Sargent et at~ discloses a releasa~le clamping axrangement for securing the bowl unit to the holding tnak, In this case, the bowl unit is hinged to the holding tank at the front and a clasp mechanism is provided adiacent to the rear o~ the toilet, This mechanism includes a strap secured to the underside of the bo~l unit for tr~nsverse sliding movement and adapted to engage a retention "

;

- 3 - 1~z07 member which protrudes upwardly from the holdin~ tank~ The retention mem~er has an enlarged head which co~operates with the strap as it moves transversely, to hold the two parts of the toilet together, The opening of the strap is keyhole-shaped so that the retention member can be disengaged from the strap. Movement of the strap is effected by a small handle ~hich protrudes from the rear of the toilet. In practice, this ~echan~sm is somewhat inconvenient in that the user must reach down to the back of the toilet, locate the strap handle, and move the handle laterally in order to disengage the two parts of the toilet~ Also, the mechanism may be somewhat bulky in that the strap may not always move easily. Also, there may be a problem in locating the retention member in the keyhole-shaped opening in the strap because these components will be located between the respective upper and lower surfaces o~ the holdin~ tank and bowl unit and will not be visible to t~e user, An object of the present invention is to provIde a two-piece portable toilet having an improved coupling arrangement between the bowl unit and the holding tank.
Accordingly, the invention provides a bowl unit including a toilet bowl havin~ an outlet at the bottom of the unit.
The bowl unit is supportable on a holding tank, which has an inlet that can be placed in communication with the outlet of the toilet bowl when the bowl unit is seated on the holding tank. A valve mechanism regulates the movement of waste between the bowl unit an~ the holding tank. Securing `:

- 4 - 1~72~

means releasably secure the bowl unit ~o the holding tank, and include a bowl unit portion having first gen-erally vertical friction surface and a holding tank portion having a second yenerally vertical friction sur-face. The bowl unit and holding tank portions are so positioned at the bottom of the bowl unit and the top of the holding tank respectively that the friction surfaces are pressed horizontally against one another into over lapping frictional engagement as the bowl unit is seated.
The frictional forces created by this pressing of the friction surfaces against one another tend to resist vertical removal of the bowl unit from the holding tank.
The coupling means provided by the invention will generally be located to one side of a portable toilet. Rel-easable securin~ means such as a latch and keeper will then be provided at an opposite side to complete securement of the bo~l unit to the holding tank, In such an arrangement the coupling means eliminate more complicated clasp or hinge mechanisms, Various advantages of the invention will be better understood with reference to the accompanying drawings which illustrate a preferred embodiment of the invention. In the drawings, Fig. 1 is a perspective view from the front of a t~oepiece portable toilet according to a preferred embodiment of the invention~ in which the bowl unit is shown in an exploded position above the holding tank;
~ 2 is an exploded rear perspective view correspondin~ to F~g. l; ~nd, Fig, 3 is a side elevation, partl~ in section, ho~;ng the ~owl unit and holding tank coupled together as in

- 5 ~ 1~57~7 the assem,bled toilet, In the draw~ngs, the toilet is generally indicated by reference 20 and includes a bowl unit 22 and a holding tank 24, The bowl uni~t includes a toilet bowl 26 having an outlet at the lower end of the bowl unit, indicated i.n dotted outline at 28, The hold~ng tank 24 is assembled although the bowl unit is shown in an exploded position in Figs. 1 and 2, The holding tank has an upper wall generally indicated ~y reference 30 which includes an inlet 32 co-operable with bowl outlet 28 (see Fig, 3) when the bowl unit is supported on the holding tank, Reference numeral 34 generally indicates valve means disposed inside the holding tank and arranged to normally close the holding tank inlet but operable to permit wastes to enter the holding tank at appropriate times.
The bowl unit and holding tank are normally coupled together as shown in Fig, 3. Alignment means are provided to ensure that the bowl unit 22 is properly seated on the holding tank 24, These alignment means comprise a pair of male ali~nment members 35 of ~enerally cylindrical cross-section with rounded tops, and complimentary female ali~nment members 37 (recesses), which male and female alignment members are moulded respectively with portions of the bowl unit 22 and holding tank 24.
The bowl unit 22 and holding tank 24 are releasably secured by means of a snap lock latch 36 and keeper 38 at the back of the toilet 20 and a friction fit at the front. The meanS
for providin~ the friction fit include two elon~ate projections 39 of generally inverted U-shaped peripheral cross-section moulded with the top of the holding tank 24. These projections 1 ~720'~

have sidewalls with raised criss~cross patterns that provide vertical friction surfaces 41. When the bow]. unit 22 is seated in the holdi:ng tank 24, the projections 3~ are received in a recess 43, moulded in the bottom of the bowl unit 22. The recess 43 has an i~nner wall with raised criss-cross patterns that provide two vertical friction surfaces 45, positioned for engagement against the surfaces 41 The friction surfaces can be any type of suitably ~'rouyhened" surface.
The friction fit between the projections 39 and the recess 43 can be effected in alternative ways. The recess 29 can be dimensioned (as illustrated in Fig. 3) to closely receive the projections 39, thereby bearing down simultaneously on opposing-sidewalls of the projection 39. Elastic deformation of the bowl unit 24 will then tend to occur primarily in the vicinity of the recess 43. In such circumstances the relative dimensioning of the projections 29 and the recess and their relative positions are fairly critical in obtaining a satisfactory fit.
Alternatively the recess 43 is dimensioned to be wider than the projections 39, and the friction surfaces are positioned relative to the alignment members 35, 37 to effect a bracing of the projections 39 against the male alignment members 35, thereby ensuring that the friction surfaces are pressed generally horizontally against one another when the bowl unit 22 is properly is properly seated. In such an arrangement the friction surfaces 45 of the recess are spaced slightly further from the female alignment members 37, than the friction surface 41 of the projections 39 are from the male alignment members 35, Additionally, to facilitate the overlapping of the friction surfaces 41, 45 when the bowl unit 22 is seated, _ 7 _ 1~5~7 the edge formed between the top of each projection 39 and the sidewall defining the friction surface 41 of each projection 39 is rounded, as at 47 (in Fig. 3). This ensures that the projections 39 can in fact be enserted into the recess 43, despite the fact that the projections 41 tend to strike thé
bottom of the bowl unit 24 adjacent the recess 43 (at the wall defining the friction surfaces 45).

It will be appreciated that with this latter arrangement friction surfaces can be located on the sidewall of each projection 39 opposite to the one presently bearing the friction surface 41. The corresponding friction surfaces of the recess 43 would then be located on the sidewall of the recess 43 opposite the sidewall presently bearing the friction surfaces 45. The compressive and tensile forces produced in the bowl unit and holding tank portions between the alignment members 35, 37 and the friction surface 41, 48 upon seating of the bowl unit 22 would then be reversed in direction, but would still bias the friction surfaces 41, 45 against one another.
Additionally, in the latter arrangement, a recess is not in fact required (as one sidewall of the recess 43 would not in fact engage the projections 39) and it is sufficient to provide a structure defining a substan~ially vertical friction surfaces to mate with those of the projections 39. Vertical removal of the bowl unit 26 from the seated position is resisted at the front of the toilet by the friction fit, and at the back by the latch 36 and holder 38. At the same time, lateral movement of the.bowl unit 22 is prevented by the alignment members 35, 37 and the presence of the bowl outlet ~8 in the holding tank inle:t 32. Once the latch 36 has disengaged from the hol~er 38, the friction fit can be released by forcing the - 8 - I lS7~,07 bowl unit 22 upwardly against the friction. The tank 24 can then be emptied. The bowl unit 24 can then be reseated by pushing it into the male alignment members 35, thereby, biassing the friction surfaces against one another, and automatically engaging the latch 36 with the keepers 38.

L~tch 36 and keeper 38 are disposed 50 that the latch is accessible at a side of the assembled toilet, in this case, the rear side. The friction fit is provided at a ~ide of the holding tank inlet 32 opposite to the latch and k-eper, in this case, adjacent the front of the toilet. In this way, the holding tank and bowl unit are held together at two locations disposed on respectively opposite sides of the holding tank inlet, so as to ensure good sealing of outlet 28 and inlet 32. The arrangement above may be varied. For e~ample, the latch 36 and keeper 38 may be positioned at one lateral side of the toilet and the friction fit provided Adi~cent the opposite side, Additionallyt the projections ~.

1 157~7 39 (or perhaps one elongate projection) can be foxmed in the bowl unit 22 (instead of the tank 241, with the recess 43 in the tank 24. Furthermore, it will be apparent that a recess for receiving the projection is not strictly required, and a projection bearing the friction surfaces 45 can be substituted.
Referring now more particularly to Figs. 2 and 3, it will ~e seen that latch 36 takes the ~orm of a relatively wide strip, the cross-sectional shape of which can be seen in Fi~, 3, The latch is moulded in a plastic material which is relatively rigid and yet flèxible and which has a plastic memory. In this embodiment, an acetal resin material is used. The latch is secured to the underside of the bowl unit by three screws received in a suitable housing moulded into the structure of the bowl unit. One of these screws is visible at 46 in Fi~. 3, With continued reference to that view, it will be seen that the latch includes a base portion 36a through which the securing screws extend. The remainder of the strip forms the altch proper and normally extends generally vertically downwards from bowl unit 22.
Keeper 38 takes the form of a bar or bridge 48 which is integrally moulded as part o the holding tank and is disposed above the level of the upper wall of the tank, as best shown by Fig. 2. Referring back to Fig. 3, it will be seen that the cross-sectional shape of latch 36 is such as to include a rearwardly directed ledge or rib 50 which engages below bar 48 when the latch is in its engaged position and a sloping "cam" surface 51 below this rib, Cam surface 51 co-operates with the outer edge of the keeper so that the latch is deflected outwardly (as indicated in ghost outline) - lo - ~ ~S7~7 by the keeper when do~ward pressure is applied to the bowl unit ~n the vicinity of the latch and keeper. The plastic memory of the latch material will then cause the latch to snap inwardly below the keeper, Latch 36 extends outwardly and downwardly below ~b 15 (see Fig. 2~ and defines a lip 36b which acts as a ~in~er grip for facilitating movement of the latch. Thus, the latch is shown in Figs. 2 and 3 in the position i~
occupies when engaged with the keeper and it will be appreciated that a user can simply reach down and grasp below lip 36c and pull the latch outwardly to disengage the latch. When the bowl unit is in position on the holding tank but the latch is not engaged, such engagement can be simply effected by applying slight downward pressure on the bowl unit in the vicinity of the latch. The latch is normally disposed substantially flush with the rear surface of the toilet by virtue of being located in a recess 52 moulded into the rear of the bowl adjacent its edge.
Keeper bar 48 is similarly disposed inwardly from the rear face of the holding tank 24 and it will be seen from a comparison of Figs. 2 and 3 that the holding tank is in fact moulded to define an arcuate shaped passageway 54 which extends from the rear face of the holding tank inwardly around keeper 38 and opens into the top wall o~ the holding tank~ The shape of this passageway is-best seen in Fig. 3 and it will be seen that its lower wall is defined by part of the top wall of the holding tank (denoted 30a) and that the upper wall definin~ the passageway is formed by an arcuate shaped moulded panel section 56 which extends downwardly from keeper ~,ar 48 t~ the rear end face of the holding tank, The purpose ~ lS72Q7 of this desigll is to provide a grip or handle by which the holding tank. can conveniently be carried so as to facilitate transportation of tbe tank for emptying, Thus~ after latch 36 has been released, the bowl unit can be lifted off the holdint tank and the user can then insert his hand into passageway 54 either from ~he rear end face of the holding tank~ or preferably fro1n above (so that the tank valve will be held away from the person's legs during carrying). The ~andle ormed by keeper 38 can then be grasped and used for carryin~ the holding tank, ~ owl unit 22 is essentially of conventional con-struction apart from the projections 40 and latch 36 and constructional details of the bowl unit have therefore been omitted, For present purposes it is sufficient to note that th.e bowl unit also includes a seat 58 which surrounds the mouth.of the bowl 26~ and a hinged lid 60 which can be raised and lowered so that the top of the bowl can be covered when the toilet is not in use. The bowl unit also defines, around bowl 26, a reservoir for flushing liquid and a manually operable pump 26 is provided for dispensing flushing liquid into the bowl. The liquid then leaves the bowl through outlet 28 along with the waste being flushed from the to.ilet. Reference 64 indicates a cap for the filling orifice of the reservoir.
Bowl unit 22 is manufactured as the number of plastic mouldings which are secured together by adhesive again as is conventional in the art. By way of example, Fig, 2 illustrates the fact that the bowl unit includes an outer housing made up of upper and lower shell sections 66 and 68 respectively secured together along a joint line 70.
Part of th.e hous;ng has been broken away at 72 to show the 1 ~572~7 interior of the flush li~uid reservoir. It can also be seen that the bottom wall 74 of the bowl unit ~s formed with two ~enerally conically shaped formations, which define the ~emale alignment members ~recesses) in the undersurface of the ~owl unit, It will also be appreciated that the bottom of the bowl unit is appropriately contoured to accoJ~modate the valve mechanism 34 of the holding tank and also an emptying spout 80 which projects from the top wall of the holding tank which is fitted with a screw cap 82. The top wall of the holding tank otherwise defines a flat peripheral area generally indicated at 84 around the valve means 34 which provides a firm and even seating surface on which the bowl can be supported.
The holding tank 24 simply comprises upper and lower moulded plastic shells 78 and 80 secured together at a joint 82. The top wall of the tank is shaped to define an upwardly protuberant portion 34b which accom~odates the valve mechanism of the toilet. That mechanism forms the subject matter of a co pending patent application entitled 'Portable Toilet" ~iled June 17, 1981 under Serial No.
380,039 and forms no par-t of the present invention. The valve mechanism, therefore, will not be described in detail here. For the present purposes it is sufficient to notP that the mechanism includes a valve member, a part of which is visible through the holding tank inlet 32 at 86. A valve operating handle is provided at the front of the holding tank and is denoted 88. An actuating rod shown in ghost outline at ~0 extends inwardly from handle 88 and is secured inside the holding tank to a valve operating mechanism including valve member 86~ When handle 88 is pulled outwardly to the position -13 ~ l~572~

in which it is shown in ghost outline in Fig. 1~ valve member 86 ~s moved away from inlet 32 so that the inlet is open to receive material from valve 26. Conversely, when handle 88 is pushed in, valve member ~6 closes inlet 32.
Details of this particular valve mechanism are disclosed in the co~pending patent application referred to above. Alternative valve mechanisms may be used; for example, valve mechanims may be of the form disclosed in United States Patent No.
4,091,475. Reference may also be made to that patent for constructional details of the bowl unit.
Referring finally to Fig. 3 it will be seen that the bowl unit outlet 28 takes the form of an integral sleeve which depends from the bottom wall of the bowl unit. Holding tank inlet 32 is defined by an opening in the upper wall 34 of the holding tank, which opening is fitted with a neoprene rubber insert 92 of annular form which receives bowl outlet 2 and which is designed to act as a seal against the external surface of the bowl outlet 28. Details of the valve mechanism of the toilet have been omitted from this figure.
It will be appreciated that the preceeding description relates to a preferred embodiment of the invention and that many modifications are possible within the broad scope of the invention.

Claims

I CLAIM:

1. A two piece portable toilet comprising:
a bowl unit including a toilet bowl having an outlet at the bottom of the bowl unit;
a holding tank for supporting the bowl unit, including an inlet in communication with the outlet of the toilet bowl when the bowl unit is seated on the holding tank to receive waste;
valve means for regulating the movement of waste from the bowl unit to the holding tank;
alignment means for use in positioning the bowl unit in a predetermined position atop the holding tank; and, securing means for releasably securing the bowl unit to the holding tank, including a bowl unit portion located generally at the bottom of the bowl unit having a first generally vertical, friction surface and a holding tank portion located generally at the top of the bowl unit having a second generally vertical, friction surface, the bowl unit and holding tank portions being so positioned that the first friction surface is pressed horizontally against the second friction surface in overlapping frictional engagement as the bowl unit is seated in the predetermined position atop the holding tank, whereby, the frictional engagement of the surfaces resists vertical removal of the bowl unit from the holding tank.

2. A portable toilet claimed in claim 1 in which the bowl unit portion and holding tank portion are located to a first side of the bowl unit and holding tank when the bowl unit is seated in the predetermined position atop the holding tank; and, the securing means include a latch and keeper located at a second side of the bowl unit opposite the first side when the bowl unit is seated in the predetermined position atop the holding element, the latch and keeper adapted to snap fit together as the bowl unit is seated on on the holding tank.

3. A portable toilet as claimed in claim 2 in which the alignment means comprise a male alignment member extending in substantially vertical orientation from one of the bowl unit and the holding tank and a complementary female alignment member located in the corresponding one of the bowl unit and holding tank, the male and female alignment members being located between the latch and keeper and the bowl unit and holding tank portions, whereby, substantially elastic deformation of the bowl unit and holding tank between the alignment members and the bowl unit and holding tank portions, biases the friction surfaces against one another.

4. A portable toilet as claimed in claim 1, 2 or 3 in which:
the bowl unit portion comprises an elongate recess with an inner sidewall that defines the first friction surface;
and;
the holding tank portion comprises an elongate projection extending upwardly from the top of the holding tank, which projection is receivable in the recess when the bowl unit is seated atop the holding tank, the projection having a top surface, and a sidewall which defines the second friction surface, the edge formed between the top surface and the sidewall of the projection being rounded to facilitate overlapping engagement of the first friction surface and the second friction surface.

5. A two piece portable toilet comprising:
a bowl unit including a toilet bowl having an outlet at the bottom of the bowl unit;
a holding tank for supporting the bowl unit, in-cluding an inlet in communication with the outlet of the toilet bowl when the bowl unit is seated on the holding tank to receive waste;
valve means for regulating the movement of waste from the bowl unit to the holding tank; and, securing means for releasably securing the bowl unit to the holding tank, including a bowl unit portion located generally at the bottom of the bowl unit having a first generally vertical friction surface and a holding tank portion located generally at the top of the bowl unit having a second generally vertical friction surface, the bowl unit and holding tank portions being so positioned that the first friction surface is pressed horizontally against the second friction surface in overlapping frictional engage-ment as the bowl unit is seated in a predetermined position atop the holding tank, whereby, the frictional engagement of the surfaces resists vertical removal of the bowl unit from the holding tank.

6. A portable toilet as claimed in claim 5, in which one of the bowl unit portion and the holding tank portion defines a projection and the corresponding one of the bowl unit portion and the holding tank portion defines a recess positioned and dimensioned to closely receive the projec-tion when the bowl unit is seated in the predetermined position, the friction surfaces being located within the recess and on the projection whereby the friction surfaces are placed into overlapping frictional engagement when the projection is received in the recess.

7. A portable toilet as claimed in claim 6, com-prising alignment means for use in positioning the bowl unit in the predetermined position atop the holding tank.