Mechanism for moving a heavy object

Abstract: A heavy object, such as a portable toilet (2), is supported on a base (1). At least one wheel (7) is mounted on the base (1) for vertical movement between an upper position in which the wheel (7) is supported above the lower surface of the base and a lower position in which at least a portion of the periphery of the wheel is below the lower surface of the base. The wheel (7) is releasably held in one or the other of those positions. A handle (6) is movably mounted on the object so that the object can be manually swung to permit the wheel to move between those positions.

Description: The present invention relates to a mechanism for moving a heavy object, especially moving the object by manpower. There are many instances in which a heavy object, such as a portable toilet, generator, compressor, prefabricated house, container, oil tank, etc. need to be moved a short distance. The heavy object is not permanently fixed to the ground by an anchor or by being incorporated in a building, but rather, is temporarily fixed at a location where to enable it to be moved to another position. Accordingly, the heavy object is typically lifted and transported by a crane or by a forklift truck. When the object is to be carried for a long distance, the crane or the forklift truck are very effective. However, if the heavy object is to be moved a relatively short distance, e.g., several tens of meters, a crane or a forklift truck is seldom used because they are complex and costly. Furthermore, it is difficult to use a crane or a forklift truck for moving the heavy object a very short distance of several tens of centimetres after the heavy object has been transferred to the general location where it is installed. There is a demand for a simple mechanism by means of which a heavy object can be easily moved without using a crane or a forklift truck and without overburdening the operator. Prior art apparatus for moving a heavy object is disclosed in DE-U-85 05 685.5, with reference to which the claims of this application are characterised. The present invention provides a mechanism for moving a heavy object in accordance with claim 1. Fig. 1 is a perspective view showing a moving mechanism for a portable toilet, as an example of a heavy object, according to a first embodiment of the present invention, Figs. 2(A), 2(B), 2(C) and 2(D) are schematic views for explaining an operation of the moving mechanism in Fig. 1; Fig. 3 is a perspective view showing a part of the moving mechanism in Fig. 1; Fig. 4 is a perspective view showing a part of a moving mechanism according to a second embodiment of the present invention; Fig. 5 is a plan view of the moving mechanism in Fig. 4; First Embodiment (Figs. 1 to 3): A mechanism for moving a heavy object, according to a first embodiment of the present invention, will be described with reference to Figs. 1 to 3 in which a portable toilet is employed as an example of a heavy object. The portable toilet 2, having substantially the shape of an outhouse, is fixedly mounted on a substantially flat base 1. The base 1 and the toilet 2 are integral with each other and are generally rectangular in top plan view said views having substantially similar dimensions. The interior of the base 1 is hollow and the exterior thereof has the same shape as the perimeter of the toilet 2 so that the base, in effect, constitutes a downward extension of the toilet. Accordingly, the base 1 and the toilet 2 are assembled as a single structure when viewed from the outside. The portable toilet 2 has a large door 3 in the central portion of the front wall thereof, through which door a person can enter the toilet. A housing 4 includes lateral leg portions provided in the front wall of the toilet 2 on opposite sides of the door and a horizontal connecting portion in the front wall of the base 1 below the lower edge of the door. The housing groove 4 is substantially U-shaped when viewed from the front and it borders approximately the lower half of the door 3. Handle mountings 5 are fixed in upper ends of the leg portions of the housing groove 4. A U-shaped handle 6 is pivotally supported by the handle mountings 5. The handle 6 has a shape and size substantially the same as the housing groove 4, thus the handle 6 can be entirely received in the housing groove 4 when the handle is pivoted downwardly about the axis of the handle mountings 5. Wheels 7 are positioned in an interior hollow space in the base 1 close to the right and left sides thereof and said wheels are swingable vertically, as described later, between (1) an upper position in which they are received inside the base and above the lower surface thereof and (2) a lower position in which at least a portion of the periphery of the wheels extends below the lower surface of the base. The wheels 7 can be releasably fixed in the upper and lower positions, as will be described hereinbelow. A method for moving the heavy object, i.e., the portable toilet 2, will be described with reference to Figs. 2(A) through 2(D). Fig. 2(A) shows the state wherein the portable toilet 2 is installed on the ground with the lower surface of the base 1 resting on the ground. The toilet 2 may be ready for use or it may be stored, in this state, when it is not in use. The toilet 2 can be moved to a new location spaced from the original position a distance of several meters in the condition as illustrated in Fig. 2(A). When toilet 2 is to be moved to a new site which is close to the original position, the handle 6 is first withdrawn from the housing groove 4 and is raised upwardly as indicated by the arrow X in Fig. 2(B). The handle 6 is raised to a position in which it extends at a right angle relative to the front wall of the toilet 2. The handle 6 is not further pivotable upwardly on the mountings 5, but is maintained in a position in which it extends subtantially at a right angle relative to the toilet 2 when the handle 6 is raised further. Inasmuch as the handle 6 and the toilet 2 are fixed in the state wherein they extend at a right angle to each other, a further force applied for raising the handle 6, as indicated by the arrow Y in Fig. 2(C), is effective to raise the front edge of the toilet 2 relative to the rear edge thereof so that the toilet, as a whole, is inclined upwardly about the rear end edge Z of the base 1. In this condition, the wheels 7 housed inside the base 1 are free to pivot downwardly by gravity, to a limited extent. Thereafter, when the handle 6 is lowered in the direction of the arrow W in Fig. 2(D), while the wheels 7 are suspended below base 1, the lower surfaces of the wheels 7 contact the ground so that the base 1 is rollably supported by the wheels 7. The wheels 7 are rollable along the ground by pushing or pulling the handle 6. Thereby the base 1 and the toilet 2 are movable freely with relatively light force. Inasmuch as the base 1 and the toilet 2 can be supported by the wheels 7 and rolled about, the heavy object, such as the toilet 2, can be moved easily by manpower. If the toilet 2 is moved to a first position wherein it is used while it is still supported by the wheels and thereafter is moved to another position where the portable toilet 2 is then to be fixed, the procedure of operation is reversed relative to that set forth above, i.e. the procedure is in the order of the states as illustrated in Figs. 2(D), (C), (B) and (A). The following description relates to the vertical swinging motion of the wheels 7 inside the base 1 and the mechanism for fixing the wheels. Fig. 3 shows a mechanism for fixing the wheels 7. A long supporting shaft 10 extends between and is supported by right and left sidewalls of the base 1. A pair of elongated holding plates 11 are positioned inside the hollow central portion of the base 1 and they are located close to and extend substantially parallel to the right and left sidewalls of the base. The plates 11 are supported for vertical swinging movement, relative to the base 1, on the shaft 10. The opposite ends of a wheel-supporting shaft 12 are supported by the holding plates 11 so that the shaft 12 can move upwardly and downwardly with the plates 11. A pair of wheels 7 are rotatably supported on the shaft 12 close to the opposite ends thereof. Connection holes 13 and 14 are provided in the holding plates 11 approximately midway between shafts 10 and 12 and close to the upper and lower edges of said plates, respectively. Both sidewalls of the base 1 have insertion holes 15 at positions which are selectively alignable with either the connection holes 13 or the connection holes 14, at one time. Lock pins 16 are slidably insertable into the insertion holes 15 and into either the holes 13 or the holes 14 when they are aligned with holes 15. When the base 1 is positioned as shown in Figs. 2(A) and 2(B), the holding plates 11 are in the raised position wherein the lock pins 16 are inserted into the insertion holes 15 and the lower connection holes 13, whereby the wheels 7 do not extend below the lower edge of the base 1. However, when the lock pins 16 are removed from the connection holes 13 and the moving mechanism is moved from the state as illustrated in Fig. 2(B) to the state as illustrated in Fig. 2(C), both the holding plates 11 will pivot downwardly about the axis of the supporting shaft 10 when the base 1 is raised so that the wheels 7 can hang downwardly and project below the lower edge of the base 1. When the wheels 7 extend below the lower surface of the base 1 so that holes 14 and 15 are aligned, the lock pins 16 can be inserted into the insertion holes 15 and the connection holes 14, thereby fixing the holding plates 11 in a downwardly and forwardly inclined position relative to the base 1. In this condition, wherein at least a portion of the periphery of the wheels 7 extends below the lower surface of the base 1, the base 1 and the portable toilet 2 can be rolled about, in the position as illustrated in Fig. 2(D). Although the structure, according to the first embodiment, is very simple, it requires two operators, namely, one operator to operate the handle 6 and another operator to insert the pins 16 into or remove the pins 16 from the insertion holes 15 and the connection holes 13 and 14. This is not completely satisfactory from the viewpoint of efficent use of manpower. Second Embodiment (Figs. 4 and 5): A moving mechanism for a heavy object, according to a second embodiment, will be described with reference to Figs. 4 and 5. According to the arrangement of the second embodiment, one operator can operate the handle 6 and, also, can fix and release the wheels 7 without assistance. A holding frame 20 is fixed to the base 1 at the inner central portion of the base 1 and it extends between the sidewalls of said base. The frame 20 has upwardly extending wall portions at both lateral ends thereof. The right and left upwardly extending wall portions of the holding frame 20 are spaced from the inner surfaces of the right and left sidewalls of the base 1. The holding frame 20 has a supporting shaft 21 at the rear end thereof which shaft extends through the upwardly extending wall portions at the ends of the frame 20 near the rear thereof. The supporting shaft 21 extends through the swing plates 22 which are positioned in the spaces between the right and left upwardly extending walls of the holding frame 20 and the sidewalls of the base 1. The swing plates 22 correspond to the plates 11 in the first embodiment. The swing plates 22 can be pivoted vertically, relative to the base 1 and the frame 20, about the axis of shaft 21. The swing plates 22 are longer than the width of the holding frame 20. A wheel shaft 23 extends transversely between said swing plates at a location in front of the frame 20. The wheel shaft 23 has wheels 7 mounted thereon at opposite ends thereof. The swing plates 22 have upper and lower connection holes 24 and 25 at the central portions thereof, which holes 24 and 25 penetrate through the swing plates 22. A shaft 26 extends upwardly from the upper surface of the holding frame 20. A lever 27 is pivotally mounted on the shaft 26. Rods 28 and 29 are pivotally connected to opposite ends of the lever 27 by pins 30 and 31, for providing a linkage. The rods 28 and 29 are respectively extended through insertion holes 32 and 33 provided in the right and left side upwardly extending sidewalls of the holding frame 20. The rods 28 and 29 are selectively extendable into either the holes 24 or the holes 25 in the swing plates 22 in order to releasably lock the swing plates in a raised or lowered position. A spring seat 34 extends upwardly from the holding frame 20 at a position close to the pin 30 and on the central portion of the upper surface of the holding frame 20. A wire cable 35 has a cable housing whose tip end contacts the spring seat 34 and said wire cable has a wire 36 inside the cable housing, which is connected to the inner end of the rod 28. A coil spring 37 is interposed between the spring seat 34 and the lever 27 and the wire 36 extends through the coil spring. The lever 27 is always biased by the coil spring 37 counterclockwise as appearing in Figs. 4 and 5. The wire cable 35 extends upwardly from the base 1 to the handle 6 and the cable 35 is secured to a lever receiver 38 which in turn is mounted on the handle 6. A lever 39, adapted to be operated by the operator, protrudes from the lever receiver 38 and is coupled to the wire 36. When the operator operates the lever 39 to pull or release the wire 36 in the wire cable 35, the lever 27 is turned about the axis of shaft 26. The wheels 7 are disposed inside the base 1 in Fig. 4. If the rods 28 and 29 protrude from the insertion holes 32 and 33 and both the rods 28 and 29 are inserted into the lower connection holes 24, the swing plates 22 are locked in place in a raised position and the wheels 7 are entirely received inside the base 1. If the lever 39 is pulled in order to pull the wire 36 against the resilient force of the spring 37 at the time when the base 1 is inclined by the handle 6 as illustrated in Fig. 2(B), both the rods 28 and 29 are withdrawn from the connection holes 24. As a result, the swing plates 22 swing downwardly about the axis of the supporting shaft 21 so that the wheels 7 are lowered together with the swing plates 22. When the lever 39 is released, while the swing plates 22 are swung downwardly about the supporting shaft 21 and the wheels 7 are lowered (Fig. 2(C)), the wire 36 is returned by the resilience of the spring 37. At the same time, the arm 27 is turned counterclockwise about the shaft 26 and the tip ends of the rods 28 and 29 are respectively inserted into the upper connection holes 25 so that the swing plates 22 are fixed to the holding frame 20 in the condition wherein the swing plates 22 are inclined downwardly relative to the holding frame 20. Accordingly, since the wheels 7 are disposed under the lower surface of the base 1 as illustrated in Fig. 2(C), the wheels 7 contact the ground whereby the portable toilet 2 can be moved by the operation of the wheels 7.

Claims: A mechanism for moving a heavy object supported on a base (1), wherein a pair of parallel spaced wheels (7) are coupled together and mounted on swing bodies (22) forming part of a carriage (10, 11, 12; 21, 22, 23) which is pivotally mounted on the base for conjoint pivotal movement between an upper position in which the wheels are supported above the lower surface of the base (1) and a lower position in which at least a portion of the periphery of the wheels extends below the lower surface of the base (1) so that the base (1) and the object are supported for rolling motion along the ground, a maintaining device for maintaining the wheels (7) in one or other of said positions, the device comprising lock pins (16, 24) receivable through openings (15; 32, 33) in the base and the carriage (10, 11, 12, 21) for releasably locking the wheels in one or other of said positions, and characterised in that a handle (6) is provided for raising and lowering the base (1) to permit the wheels to be moved between said positions and in that the maintaining device is provided by the carriage having two vertically spaced pairs of openings (13, 14; 24, 25) one opening of each pair being arranged on respective opposite sides of the carriage and being alternately alignable, by pivoting the carriage (10, 11, 12; 21, 22, 23), with a pair of the openings (15; 32, 33) arranged on respective opposite sides of the base and wherein the locking pins are received. A mechanism as claimed in claim 1 wherein the handle (6) is U-shaped and pivotally mounted on the object to be swung from an inoperative vertical position adjacent the object to an operative substantially horizontal position where a cross member of the U-shaped handle provides a convenient purchase. A mechanism as claimed in claim 2 characterized in that the wall of the object (2) and the base (1) have wall means defining a U-shaped recess for receiving the handle. A mechanism as claimed in claim 1 wherein the carriage is comprised of a pair of parallel swing plates (11, 22) pivotally mounted on the base (1) and a shaft (12, 23) extending between the swing plates, the wheels (7) being mounted on the shaft. A mechanism as claimed in claim 4 wherein the base includes an internal frame (20) disposed between the swing plates (22) and manually operable actuating means mounted on the internal frame for moving the lock pins into and out of the openings in the base and carriage. A mechanism according to claim 5 wherein rods (28, 29) provide the lock pins; a lever (27) is pivotally mounted on the base and one end of each rod (28, 29) is pivotally connected, one to each end of the lever (27), the actuating means comprising a coil spring (37) positioned between a spring seat (34) and the lever (27) to bias the rods (28, 29) to engage in the openings, and a wire cable (35) extending from the lever (27) to a manual operation lever (39) mounted on the handle (6) so that operation of the manual operation lever (39) withdraws the rods (28, 29) from engagement in the openings (24, 25).

Inventors: KISHI MITSUHIRO C O JAPANIC CO, KISHI, MITSUHIRO, C/O JAPANIC CORPORATION
Applicants: JAPANIC CORP, JAPANIC CORPORATION
Application year: 1991
Main classification: B60B33
IPC codes: B60B33, B65G7