Technical field of the invention
-
The present invention relates to a puzzle game cube also known as "magic cube" or "Rubik's cube".
-
In particular, the present invention relates to a puzzle game cube wherein the central blocks of each face of the cube comprise repulsing magnets instead of springs.
State of the art
-
Puzzle game cubes are well known for many years.
-
A puzzle game cube comprises in general at least: a central shaft assembly, six central blocks separately fixedly connected to the central shaft assembly along different axial directions, a plurality of corner blocks (movably connected to the central shaft assembly and the central blocks), and a plurality of edge blocks movably connected to the central shaft assembly and the central blocks.
-
According to prior-art solutions, a spring is located inside each central block in the centre of each face of the cube so that it causes a repulsion force along an axial direction.
-
The use of magnets in puzzle game cubes has already been disclosed for example in patent documents
EP4094814A1 and
EP4257213A1 and it is relatively recent.
-
It is proposed herein to replace each spring with a couple of magnets oriented so that they repulse each other causing a repulsion force along an axial direction.
-
In such innovative magnet-based solutions, a system for adjusting the repulsing force at rest might be used similar to a traditional adjusting system used in prior-art spring-based solutions.
Summary of the invention
-
A traditional adjusting system when used in a spring-based solution provides that a gear is rotated and that the repulsing force at rest is directly proportional to the rotation angle.
-
If a traditional adjusting system is used in a magnet-based solution the repulsing force (at rest) is not directly proportional to the rotation angle but follows a different law, typically an exponential law.
-
Therefore, it is very difficult to achieve an accurate adjustment for any value of the desired repulsing force (at rest).
-
It is a general object of the present invention to provide an adjusting system specifically adapted for being used with a magnet-based solution in a puzzle game cube.
-
This object is achieved through the subject matter set out in the annexed claims that forms an integral part of the present description.
-
In general, the inventive adjusting system is arranged so that the repulsing force (at rest) is directly proportional (exactly or approximately) to the rotation angle. In this way, an accurate adjustment is possible.
Brief description of the drawings
-
A more complete appreciation of the present invention and its advantages will be readily obtained from the following detailed description when considered in conjunction with the accompanying drawings, wherein:
- Figure 1 is an external perspective view of a puzzle game cube according to the prior art as well as according to the present invention;
- Figure 2 is an internal perspective view of a puzzle game cube according to the prior art as well as according to the present invention;
- Figure 3 is an exploded perspective (partial) view of a puzzle game cube according to the prior art as well as according to the present invention;
- Figure 4 is an exploded perspective (partial) view of a puzzle game cube according to the present invention;
- Figure 5 shows a possible shape of the teeth of the toothed coupling according to the present invention but not in scale;
- Figure 6 is a cross-section view of a portion of a puzzle game cube according to the present invention; and
- Figure 7 is a combination of the view of Figure 6 and a plot explaining a possible relation between rotation and adjustment in a puzzle game cube according to the present invention.
-
Neither the following detailed description nor the accompanying drawings should be construed as a limitation of the present invention but only as an exemplification as they refer to one or more possible embodiments.
Detailed description
-
In order to understand the present invention in general and the technical features that are already known from the prior art, (non-limiting) reference may be made to figures from Fig. 1 to Fig. 3.
-
Puzzle game cube 100 comprises at least (see e.g. Fig. 1 and Fig. 2):
- a) a central shaft assembly 110 with a centre,
- b) six central blocks 120 separately fixedly connected to the central shaft assembly 110 along different axial directions,
- c) a plurality of corner blocks 130 movably connected to the central shaft assembly 110 and the central blocks 120, and
- d) a plurality of edge blocks 140 movably connected to the central shaft assembly 110 and the central blocks 120.
-
Each of the central blocks 120 comprises at least (see e.g. Fig. 3):
- ba) a bottom portion 121,
- bb) a top portion 122 fixed to the bottom portion 121,
- bc) an adjustment piece 126 being cylindrically-shaped, located in a room internally defined by the bottom portion 121 below and the top portion 122 above, and connected to the bottom portion 121 through a toothed coupling.
-
In Fig. 3, the toothed coupling can be seen partially but is not associated to any reference numeral.
-
By changing a rotation angle of the adjustment piece 126 with respect to the bottom portion 121 a repulsion force (at rest) inside the central block may be adjusted.
-
What is described above applies both to the prior art and to the present invention.
-
According to the present invention, each of the central blocks 120 comprises further at least (see e.g. Fig. 4 and Fig. 6 wherein the toothed coupling is associated to reference numeral 127):
- bd) a bottom magnet 124 being preferably annular-shaped and in contact with the adjustment piece 126 in a lower region thereof,
- be) a connected element 123 fixed to the central shaft assembly 110, arranged along an axial direction and passing through a hole in the adjustment piece 126 and a hole in the bottom portion 121,
- bf) a top magnet 125 being preferably annular-shaped and in contact with a head of the connected element 123 in an upper region thereof remote from the central shaft assembly 110;
- each or both of the above-mentioned contacts of the magnets may be direct contacts or indirect contacts. For example in Fig. 6, the connected element is a screw 123 and there is a washer between the head of the screw 123 and magnet 125.
-
It is to be noted that, in principle, a magnet may have any shape; the annular shape is a solution that allows a repulsion force along the axis of the relevant central block; alternatively, two or three or four or more small magnets may be positioned symmetrically with respect to the axis of the relevant central block. This consideration relates to both the upper magnet and the lower magnet. In general, these magnets may be different and/or differently shaped.
-
Furthermore, according to the present invention, the adjustment piece 126 is connected to the bottom portion 121 through a toothed coupling 127.
-
The bottom magnet 124 and the top magnet 125 are oriented so that they repulse each other causing an axial force between the adjustment piece 126 and the bottom portion 121 so that the toothed coupling 127 is maintained during use of the (assembled) puzzle game cube 100.
-
The magnitude of such axial repulsion force depends on an axial distance (more details will be provided afterwards) between the bottom portion 121 and the adjustment piece 126 according to a first function, for example an exponential function. It is to be noted that the repulsion between two magnets is known from physics and the corresponding repulse magnitude depends on the distance between the two magnets according to known formulas.
-
By changing a rotation angle of the adjustment piece 126 with respect to the bottom portion 121 said axial distance and said axial force are adjusted.
-
Considering Fig. 4 and Fig. 6, for example, the toothed coupling 127 corresponds to a coupling between two parts, in particular a (upper) profile (see reference 127B) of the bottom portion 121 and a (lower) profile (see reference 127A) of the adjustment piece 126. When the piece 126 rotates a shifting along an inclined surface (precisely, at least one inclined surface) occurs and consequently the piece 126 as well as the magnet 124 translates axially (in fact, the portion 121 cannot move). Such translation causes a change in the distance between the two magnets 124 and 125 and therefore a change in the repulsion force. As it will be better explained in the following, the adjustment is preferably step based, i.e. a first adjustment corresponds to a first rotation step and a first adjustment relative position, a second adjustment corresponds to a second rotation step and a second adjustment relative position, and so on.
-
In particular, according to the present invention, the above-mentioned axial distance depends on the rotation angle of the adjustment piece 126 according to a second function.
-
In mathematical terms, we may say that the second function is, exactly or approximately, inverse of the first function. For example, the difference between the ideal functional relation between the real functional relation may be less than 20% or less than 10% or less than a value between 10% and 20%.
-
In engineering terms, we may say that the adjustment piece 126 and/or the bottom portion 121 is configured so that there is a linear relation between the rotation angle of the adjustment piece 126 and the axial distance between the bottom portion 121 and the adjustment piece 126. Also in this case, the difference between the ideal relation between the real relation may be less than 20% or less than 10% or less than a value between 10% and 20%.
-
The above two interpretations of the technical teaching of the present invention may well fit together.
-
Typically, and as can be seen for example in Fig. 6, the above-mentioned axial distance corresponds (exactly or approximately) to the axial separation between a surface of the adjustment piece 126 in contact with the bottom magnet 124 and a surface of the head of the screw 123 in contact with the top magnet 125. In general, the above-mentioned axial distance may differ from the distance between the two magnets by a constant value.
-
Considering for example the advantageous embodiment of the figures (in particular Fig.s 4-7), the above-mentioned second function may include a plurality of steps due to the teeth of the toothed coupling, and, preferably, the inverse relation applies only to edges or throats of the steps/teeth. According to these figures the steps/teeth are ideal, i.e. there are surfaces of the teeth that are perfectly vertical (i.e. 90°); however, alternatively, these surfaces may be much inclined (e.g. 80°). Other surfaces of teeth are somehow inclined, but not horizontal. Exemplary Fig. 5 helps understanding what is meant by "step"/"tooth" 50 and its "surfaces" 53 and 54, its "edges" 51, and its "throat" 52.
-
The advantageous embodiment of the figures (in particular Fig.s 4-7), including several technical features not strictly linked to each other, will be considered more specifically in the following.
-
The adjustment piece 126 may comprise a first adjustment profile 127A of the toothed coupling 127; the bottom portion 121 may comprise a second adjustment profile 127B of the toothed coupling 127; each of the central blocks 120 may be arranged so that the first adjustment profile 127A and the second adjustment profile 127B are (in particular permanently) in contact with each other (see e.g. Fig. 6) during use of the (assembled) puzzle game cube thanks to e.g. the screw and the magnets.
-
The first adjustment profile 127A may be located laterally and externally all around the adjustment piece 126 (see e.g. Fig. 4).
-
The second adjustment profile 127B may be located laterally and internally all around a cylindrical recess of the bottom portion 121 (see e.g. Fig. 4).
-
The first adjustment profile 127A and/or the second adjustment profile 127B may include one or more inclined portions. This can be understood in particular and for example from Fig. 5 wherein inclined surfaces 54 are shown.
-
The first adjustment profile 127A and/or the second adjustment profile 127B are/is advantageously sawtooth profile (see e.g. Fig. 5). In this case, throat portions (see e.g. reference 52 in Fig. 5) of the sawtooth profile may correspond to stable adjustment conditions of the central block 120 and, preferably, they identify different adjustment positions ate different adjustment (axial) levels. In this case, only throat portions of the sawtooth profile may contribute in defining the above-mentioned second function. In this case, inclined portions (see e.g. reference 54 in Fig. 5) of the sawtooth profile contribute to axial adjustment.
-
Fig. 7 may help in understanding the linear relation between rotation of the adjustment piece and the repulsion force. Fig. 7 shows the same image of Fig. 6 and on its right side a plot of the repulsion force (horizontal axis) vs the axial displacement (vertical axis); it is to be noted that the scale of the vertical axis relating to the axial displacement is enlarged. According to this embodiment, each rotation step corresponds to a displacement step and a force step; all rotation steps have the same (or approximately the same) value and all force steps have the same (or approximately the same) value; on the contrary, all displacement steps have different values (even if this is not particularly evident in Fig. 7 despite the enlarged scale) and these values are chosen so that all force steps have the same (or approximately the same) value.