Assembly kit for toy or the like

An assembly kit for use as a toy or the like including plurality of rod elements, each having a pair of half portions and fasteners for fixing together the half portions, the half portions having ends in the axial direction and first and second recessed portions on the ends respectively. The first recessed portions are formed in a semi-arcuate configuration, and the second recessed portions are smaller in diameter than the first recessed portions and extend axially outward from the first recessed portions. A plurality of bolts are provided having head portions and shank portions connected to the head portions, the head portions being formed in a disk shape to respectively fit into the first recessed portions and the shank portions being respectively provided with external threads at a front end of the shank portion to fit in the second recessed portion. A plurality of connecting elements forming spheres in general are provided with a plurality of internal threads with which the bolts are engaged.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an assembly kit for constructing a framework or 
the like and, more particularly, to an assembly kit suitable for use as a 
toy. 
2. Related Art Statement 
A typical related art disclosure of the sort is found in Japanese 
publication of unexamined patent application No. 55-14396. Such assembly 
kit includes a plurality of hollow tubes having a linear axis, and joints 
having juncture portions into which the tubes are fitted at their ends for 
connection aand which are spatially provided in L-shape, T-shape, and 
tridimensional patterns. 
With such a related art assembly kit, one difficulty is that there must be 
joints having types of different structural configurations in order to 
meet the needs for changes in assembly configuration, which naturally 
means a larger number of parts required. Assembly kits of this type are 
often used as toys for younger children in common households, in which 
case comparatively frequent changes are required in assembly 
configuration. Indeed, the procurement of different types of joints for 
such a purpose requires considerable costs to be borne by the toy users. 
Another difficulty with the related art is that when assembling a cube, for 
example, by using tubes and joints, or disassembling the cube, fitting the 
ends of one tube into juncture portions of some joints or pulling the tube 
ends out from the juncture portions may exert some unreasonable force on 
the other tubes and joints, thus causing some strain to them. Furthermore, 
such assembling and disassembling requires the use of considerable force 
and involves some handling difficulty to those who are not experienced in 
such work. 
A further difficulty with the related art assembly kit is that the tube and 
joint elements of the kit are comparatively complicated in configuration 
because they are to be fixedly connected together, with the tubes fitted 
at their ends into corresponding juncture portions of the joints, a 
feature which results in complicated assembling and disassembling work and 
poor productivity. 
SUMMARY OF THE INVENTION 
In order to overcome the aforesaid difficulties, therefore, it is an object 
of the invention to provide a novel and improved assembly kit for toy use. 
It is another object of the invention to provide an assembly kit for toy 
use which has a reduced number of parts and which is easy to assemble and 
disassemble, with not much labor required in such work. 
In accomplishing the above objects, an assembly kit for toy use or the like 
according to an aspect of the invention comprises a plurality of rod 
elements, each formed by a pair of half portions and fasteners for fixing 
together the half portions, the half portions having ends in the axial 
direction and first and second recessed portions on the ends respectively, 
the first recessed portions being formed in semi-arcuate configuration, 
and the second recessed portions being smaller in radius than the first 
recessed portions and extending axially outward from the first recessed 
portions, a plurality of bolts having head portions and shank portions 
connected to the head portions, the head portions being formed in a disk 
shape to respectively fit into the first recessed portions and the shank 
portions being respectively provided with external threads at a front end 
of the shank portion to fit in the second recessed portion, and a 
plurality of connecting elements forming spheres in general being provided 
with a plurality of holes having internal threads with which the bolts are 
engaged. 
In a preferred embodiment, the pair of half portions are formed 
respectively with an identical configuration. 
In another preferred embodiment, a total of six holes having internal 
threads are formed in the connecting elements, having axes on three 
straight lines which are perpendicular to one another. 
According to this invention, as assembly kit comprises half-parted rod 
elements, bolts, and spherical connecting elements; therefore, it is 
unnecessary to provide a large variety of parts, a feature which allows a 
simplified construction and improved productivity. Especially where the 
assembly kit is a toy, this also means reduced cost to general household 
users and it is thus expected that the invention will be widely accepted 
in the market place. 
Each rod element formed from one pair of identical half portions joined by 
fasteners; therefore, when assembling the assembly kit into a cube, for 
example, or disassembling such cube, each rod element is separated into 
two half portions by loosening the fasteners, so that connecting and 
disconnecting may be easily carried out through the fasteners or bolts by 
which the rod element is in screw engagement with one or more of the 
connecting elements. Therefore, not much laborious force is required when 
constructing a cube or the like, it being thus easy to perform assembling 
and disassembling work. As such, the assembly kit in accordance with the 
invention permits unskilled persons to perform such assembling and 
disassembling work without difficulty. 
According to the invention, a disc-shaped head of a bolt fits in a first 
recessed portion of a semi-arcuate configuration formed in each half 
portion of each rod element and a shank portion of the bolt fits in a 
second recessed portion which is smaller in diameter than the first 
recessed portion, so that the bolt head is securely held in the rod 
element. Thus, connecting the rod element to another rod element may be 
easily performed through a connecting element. This, coupled with the fact 
that the assembly kit is simple in construction as a whole, leads to 
improved productivity.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, preferred embodiments of the invention are 
described below. 
FIG. 1 is a perspective view showing one embodiment of the invention. A 
generally spherical connecting element 2 is mounted to each axial end of a 
rod element 1. Another rod element 1 is connected to the rod element 1 
through the connecting elements 2. A toy assembly or the like is 
constructed in this way. 
FIG. 2 is an exploded view in perspective showing one rod element 1. The 
rod element 1 consists of a pair of half portions 1a of identical 
construction coupled together in face to face relation. These half 
portions 1a are fixed together by bolts 3 as a fastener (see FIG. 1). 
FIG. 3 is a perspective view showing a connecting element 2 and a bolt 4 
threadedly engaged therewith. FIG. 4 is a perspective view showing the 
connecting element 2 and the bolt 4 as they appear when separated from 
each other. The bolt 4 has a disk-shaped head 5 and a shank 6 fixed at its 
base to the head 5. The shank 6 is provided with an external thread 7 at 
its front end. The connecting element 2 has a plurality of holes provided 
with internal threads 8 formed therein. One of the internal threads 8 is 
engaged by the external thread 7. 
FIG. 5 is a front view of the connecting element 2. A total of six internal 
threads are formed in the connecting element 2, and the axes of these 
internal threads 8 are either parallel or perpendicular to one another. 
FIG. 6 is a side view of the bolt 4 and FIG. 7 is a plan view thereof. On 
the outer periphery of the head 5 there is formed a series of knurls 9 
extending along the axis thereof, which facilitates manual rotation. An 
outer peripheral edge 10 of the external thread 7 formed on the front free 
end portion of the shank 6 is beveled or tapered and truncated-cone 
shaped, which prevents possible injury during the handling of the kit and 
facilitates screwing the external screw 7 into one of the internal threads 
8. 
FIG. 8 is a plan view showing a half portion 1a of a rod element 1, FIG. 9 
is a side view of the half portion 1a, FIG. 10 is a bottom view thereof 
and FIG. 11 is a section taken along the line XI--XI in FIG. 10. Referring 
to these views, the half portion 1a has an outer periphery which is 
semi-cylindrical in configuration, and both ends thereof in the 
longitudinal direction taper inwardly to form curved portions 11. A first 
recessed portion 17 is defined at one end of the half portion 1a between a 
peripheral wall 14, an axially inwardly located wall 15a and an axially 
outwardly located wall 16, of the half portion 1a. Likewise, at the other 
end of the half portion 1a, another first recessed portion 17 is defined 
between the peripheral wall 14, an axially inwardly located wall 15b and 
an axially outwardly located wall 16. The first recessed portions 17 are 
coaxial with the rod element 1, and have a semi-cylindrical configuration 
the radius thereof being uniform in the axial direction. Second recessed 
portions 18, 19, each having a smaller radius than the first recessed 
portions 17, are respectively formed in the wall 16 and an end wall 12 at 
each end of the half portion 1a. The head 5 of the bolt 4 fits snugly in 
the first recessed portion 17. With the head 5 so held in position, the 
shank 6 of the bolt 4 fits in and extends through the second recessed 
portions 18, 19. The axes of the second recessed portions are coincident 
with the axis of the rod element 1. 
A radially extending barrel portion 21 having an internal thread 20 formed 
therein is provided axially inwardly of one wall 15a of the half portion 
1a. An upwardly protruding annular ledge 22 is formed on the end of the 
barrel portion 21 extending outwardly from a planar surface of the half 
portion which abuts a planar surface of another one of the half portions 
which together comprise the rod element 1. Radially extending, spaced 
apart walls 23, 24, 25, 26 and an axially extending wall 27 are formed in 
the half portion 1a. A positioning recess 28 is formed at the top of an 
intersection between the walls 25 and 27. A radially extending barrel 
portion 30 defining a through hole 29 is provided axially inwardly of the 
other wall 15b of the half portion 1a. At the top of an intersection 
between the walls 26 and 27 there is formed a positioning protrusion 31. A 
notch 32 corresponding to the annular ledge 22 is formed on the end of the 
barrel portion 30 defining the through-hole 29. The protrusion 31 
corresponds to the recess 28. 
FIG. 12 is a section taken along the line XII--XII in FIG. 11. The spiral 
ridges of the internal thread 20 formed in the barrel 21 has a 
comparatively large width in the axial direction of the thread 20 (in the 
vertical direction in FIG. 12), a feature which contributes toward 
improved strength and reduced number of turns required in screwing the 
bolt 3 and facilitates assembling and disassembling. 
FIG. 13 is a section taken along the line XIII--XIII in FIG. 11. The walls 
25, 27 extend to the peripheral wall 14, which fact contributes toward 
increased strength of the half portion 1a, and accordingly of the rod 
element 1. 
FIG. 14 is a section taken along the line XIV--XIV in FIG. 11. A recess 33 
is formed in a connecting zone between the barrel portion 30 and the 
peripheral wall 14. 
The head 34 of the bolt 3 shown in FIG. 1 fits into the recess 33. The 
external thread 36 formed on the shank 35 of the bolt 3 engages the 
internal thread 20 of the other half portion 1a. 
FIG. 15 is a plan view showing a pair of half portions 1a coupled together 
by bolts 3. FIG. 16 is a side view thereof. FIG. 17 is a right end view in 
side elevation showing the coupled configuration in FIGS. 15 and 16. The 
external thread 36 formed on the shank 35 of the bolt 3 extends through 
the through-hole 29 of one half portion 1a and engages the internal thread 
20 of the other half portion 1a. With the shank 35 held in that position, 
the head 34 of the bolt 3 does not protrude radially outwardly of the 
outer periphery of the half portion 1a. The head 34 of the bolt 3 seats on 
the bottom 33a of the recess 33. A cross-shaped arcuate depression 34a is 
formed on the bolt head 34. Therefore, the bolt 3 can be tightened or 
unscrewed with a coin. 
A slight notch 37 is formed on both longitudinal side edges of the half 
portion 1a. The presence of such notch 37 prevents possible injury during 
manual handling of the half portions 1a. No notch 37 is present on the 
curved portion 11 at either end of the half portion 1a. 
The axial peripheral surface of the end wall 12 of the half portion 1a 
forms an arcuate surface 38 which extends along the outer periphery of the 
connecting element 2. Thus, the arcuate surface 38 may be brought into 
close surface contact with the outer periphery of the connecting element 
2, which fact ensures firm connection between the rod element 1 and the 
connecting element 2 and prevents a loose connection. 
As shown in FIG. 10, each half portion 1a is configured generally 
symmetrically relative to a symmetrical plane perpendicular to its axis at 
a medium location thereof, and the internal thread 20 and the through-hole 
29 are equidistant from the symmetrical plane 39, the recess 28 and 
protrusion 31 being also equidistant from the symmetrical plane 39. In 
this way, each rod element 1 is comprised of a pair of half portions 1a 
having an identical configuration, which provides a simplified 
construction and a reduced number of parts. Furthermore, this means that 
only one type of mold is required in the fabrication of such rod element, 
which in turn results in improved productivity. 
FIG. 18 is a side view showing a bolt 3. FIG. 19 is a front view of the 
bolt 3. The outer periphery 40 of the head 34 of the bolt 3 is spherical. 
The outer peripheral edge 41 of the front end of the external thread 36 is 
chamfered or of a tapered truncated cone shape, a feature which ensures 
easy engagement of the external thread 36 with the internal thread 20 and 
eliminates the possibility of any personal injury being caused during the 
handling of the kit, thus assuring handling safety. 
When the rod element 1, in its assembled condition, is seen from above, the 
head 34 of another bolt 3 is out of sight, a feature which adds to the 
beauty of the kit. With the bolt 4 and the connecting element 2 fixed 
together, the bolt 4 and the rod element 1 are angularly displaceable 
about their axes and relative to each other. Therefore, with the rod 
element 1 and the connecting element 2 coupled together through the bolt 
4, it is possible to assemble and disassemble the rod element 1 with the 
bolts 3, a feature which assures improved assembly work. 
FIG. 20 is a perspective view showing an assembly 43 constructed by 
connecting a plurality of the rod elements 1, bolts 3, 4, and connecting 
elements 2 as shown in FIGS. 1 to 19. After such an assembly 43 is 
constructed, it is very easy to construct an assembly 44 shown in FIG. 21, 
according to the invention. In this case, it is possible to remove a rod 
element 45 of the assembly 43 in FIG. 20 by disassembling it into a pair 
of half portions by removing the corresponding bolts 3. Then, bolts 4 may 
be removed from connecting elements 46, 47 by manually rotating the bolts. 
Bolts 4 are brought into threaded engagement with connecting elements 48, 
49 of the assembly 43, and the rod elements 50, 51 for the assembly 44 in 
FIG. 21 are fixed in position. Subsequent assembling work may be continued 
in a similar manner in order to construct the assembly 44. During such 
assembling and disassembling work, no excessively laborious force is 
required; and no unreasonable force will be exerted on the rod elements 
45, 50, 51 or any other rod element. Hence, all work involved may be very 
efficiently performed. 
FIG. 22 is a perspective view showing another form of an assembly according 
to the invention. In this embodiment, plate elements 53 are used. As shown 
in FIG. 23, each plate element 53 has four depending support pieces 54, 
each of which engage a respective inner side periphery of a rod element 55 
of the assembly, as shown in FIG. 24. 
Rod elements 45, 50, 51, 55 have a configuration similar to that of 
aforesaid rod element 1, and connecting elements 46, 47, 48, 49 have a 
configuration similar to that of the connecting element 2. 
In the earlier mentioned embodiment, the axis of the internal threads 8 
formed in each connecting body 2 are either parallel or perpendicular to 
one another, but alternatively they may have other angles such as 
35.degree. and 45.degree. to each other. It is also possible that 
connecting elements 2 having different angles between the axes of the 
internal threads can be differentiated from one another by their color. 
Such differentiation may enable younger children to easily construct an 
assembly in accordance with the invention. Further, differentiating 
connecting elements 2 in color from bolts 3 add to the beauty of the 
assembly kit. Differentiating each pair of half portions 1a constituting a 
rod element 1 in color from one to the other will also add to the beauty 
of the kit. 
FIG. 25 is an exploded view in perspective showing another embodiment of 
the invention. FIG. 26 is a plan view of a connecting element 61. FIG. 27 
is a plan view of a bolt 64. FIG. 28 is a longitudinal sectional view of 
the bolt 64 shown in FIG. 27. FIG. 29 is a plan view of a bolt 65. FIG. 30 
is a longitudinal sectional view showing the bolt 65 shown in FIG. 29. 
This embodiment is similar to the earlier described embodiment, with 
comparable portions given identical reference numerals. In this 
embodiment, the connecting element 61 has a configuration more convenient 
for molding purposes than the connecting element 2 in the earlier 
mentioned embodiment. A protrusion 62 is formed on the top of the wall 25 
of a half portion 81a, the protrusion extending perpendicularly to the 
axis of the half portion 81a and being generally of a rectangular 
parallelepiped configuration, its both ends in the longitudinal direction 
being chamfered. The top of the wall 26 has a recess 63 formed therein 
correspondingly to the protrusion 62. The protrusion 62 and the recess 63 
are larger in size than the protrusion 31 and the recess 28 in the earlier 
embodiment. This ensures more accurate positioning and fitting in 
assembling a pair of half portions 81a. 
Bolts 64, 65 have tool fitting holes 66, 67 respectively formed therein 
which extend therethrough in the axial direction thereof. The radial cross 
section of each of the fitting holes 66, 67 is square. A bolt turning 
device 70 shown in FIGS. 31 to 33 has a fitting portion 71 formed in a 
square rod shape, which fits in the fitting holes 66, 67. By holding and 
turning a handle portion 72 extending from the fitting portion 71, it is 
possible to tighten or loosen the bolts 64, 65 easily. Heads 64a, 65a of 
the bolts 64, 65 have depressions 64b, 65b formed therein as in the case 
of the bolt 3 in the earlier mentioned embodiment, so that the bolts 64, 
65 may be readily turned by using a coin. Thus, working efficiency may be 
improved by suitably using the bolt turning device. The fitting holes 66, 
67 extend through the entire axial length of the bolts 64, 65 from the 
heads 64a, 65a to the front ends 64e, 65e of shanks 64d, 65d having 
external threads 64c, 65c formed thereon, and this prevents the 
possibility of windpipe choking in the event of accidental swallowing by 
an infant and thus assures improved safety. 
FIG. 34 is a bottom view of a plate element 75. FIG. 35 is a plan view 
showing the plate element 75 as it appears when fixed to a rod member 81. 
FIG. 36 is a section taken along the line A--A in FIG. 35. Two diagonally 
extending and intersecting reinforcement ribs 77, 78 are formed on the 
back of a sheet portion 76 of the plate element 75. A peripheral edge 
portion 80 having support pieces 79 formed thereon is provided around 
outer periphery of the sheet portion 76. The plate element 75 formed in 
this way is more durable than the plate element 53 in the earlier 
embodiment, because it is reinforced, and is easy to remove. Support 
pieces 79 are formed in pairs on each side of the plate element 75, and 
therefore they are not prone to slippage in the event of an external force 
being exerted in a direction perpendicular to the thicknesswise direction 
of the plate member 75 (in the direction parallel to the sheet surface of 
FIG. 34). 
FIG. 37 is a bottom view of another form of a plate element 85 
corresponding to FIG. 34 in accordance with another embodiment of the 
invention and FIG. 38 is a section showing the plate element 85 when fixed 
to a rod member 86. Support pieces 87 are fixed to the rod element 86 in 
the condition shown in FIG. 38 by contacting the outer surface of the rod 
element 86. Rib plates 88, 89 extend diagonally to each other and are 
mounted on the sheet portion 85. 
The assembly kit in accordance with the invention may be formed of 
synthetic resins. 
Not only may the assembly kit according to the invention be used as a toy, 
but also it may be used in connection with building shelves or the like. 
According to the invention, as above described, it is possible to 
accomplish a large variety of assembly configurations by using parts of 
identical construction, thereby minimizing the number of different parts 
involved. Further, according to the invention, not much labor is required 
in assembling and disassembling stops using the assembly kit of the 
invention, which naturally means improved working efficiency. Thus, the 
assembly kit according to the invention can be used very widely in common 
households. 
The invention may be embodied in other specific forms without departing 
from the spirit or essential characteristics thereof. The present 
embodiments are therefore to be considered in all respects as illustrative 
and not restrictive, the scope of the invention being indicated by the 
appended claims rather than by the foregoing description and all changes 
which come within the meaning and the range of equivalency of the claims 
are therefore intended to be embraced therein.