Collapsible construction set

A collapsible construction set comprises a plurality of parts, each of which includes at least one integrally formed connector. A plurality of connector designs are provided. A first design includes a tapered receptacle and a stabilizing pin at the center of the receptacle. A second design includes a tapered end which fits in the receptacle and a hole which receives the stabilizing pin. A third design includes a ledge which forms a recess, and a fourth design includes a hook which engages the ledge and extends into the recess. The ledge of the third design is preferably formed adjacent the receptacle of the first design, and the second design preferably also includes at least one flange which overlies and holds a hook of the fourth design. To dismember the parts of a structure, a tapered end is moved out of the tapered receptacle until the stabilizing pin disengages from the hole, and then all of the parts of the structure topple.

FIELD AND BACKGROUND OF THE INVENTION 
This invention relates generally to a toy construction set and more 
particularly to a construction set wherein the parts may be assembled to 
form a structure and then the structure may be quickly toppled or 
collapsed. 
There have been numerous types of toy construction sets which have been 
marketed over the years. Such sets include a variety of parts which may be 
assembled to form different structures, such as buildings, bridges, etc. 
Normally fasteners are included in the sets for connecting the parts 
together, and the fasteners may be separate members such as screws and 
nuts or they may be integral with the parts as shown in the H. Gibson U.S. 
Pat. No. 3,168,793, which shows a set wherein the fasteners are integrally 
formed on the ends of columns and beams. 
Construction sets have also been provided which are designed to be quickly 
toppled or dismembered. The C. T. Bonn U.S. Pat. No. 710,560 shows a 
"Knockdown Toy Battle-Ship" formed by a number of stackable parts which 
are designed to be "progressively dismembered by a projectile from a toy 
cannon". The D. A. Glickson et al. U.S. Pat. No. 4,488,373 describes a 
"Stackable Piece Playset" which may be toppled by operation of a detonator 
box. 
The toy construction sets described in the foregoing Bonn and Glickson et 
al. patents are unsatisfactory in that when the parts are assembled to 
form structures, the structures appear to have little stability and may 
topple unintentionally. The parts of the set shown in the Gibson patent, 
on the other hand, appear to have good stability but not easily toppled. 
It is a general object of this invention to provide a construction set 
wherein a structure formed by the parts of the set has good stability but 
may also be readily dismembered on command. 
SUMMARY OF THE INVENTION 
A set in accordance with the present invention comprises a plurality of 
parts, each of which includes at least one integrally formed connector, 
and a plurality of connector designs are provided. A first design includes 
a tapered receptacle and a stabilizing pin at the center of the 
receptacle. A second design includes a tapered end which fits in the 
receptacle and a hole which receives the stabilizing pin. A third design 
includes a ledge which forms a recess, and a fourth design includes a hook 
which engages the ledge and extends into the recess. The ledge of the 
third design is preferably formed adjacent the receptacle of the first 
design, and the second design preferably also includes at least one flange 
which overlies and holds a hook of the fourth design. 
To dismember the parts of a structure, a tapered end is moved out of the 
tapered receptacle until the stabilizing pin disengages from the hole, and 
then all of the parts of the structure topple.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIG. 1 illustrates a specific example of a structure formed by construction 
parts in accordance with the present invention. In this example, the 
structure is a bridge, and the construction parts include a plurality of 
bases 10, vertical columns 11 and 11a, horizontal beams 12 and 12a, and 
diagonal members 13 and 14. Each of the parts 10, 11, 12, 13 and 14 
includes connectors at its ends constructed in accordance with the present 
invention and illustrated in detail in FIGS. 2 through 11. The 
construction set preferably further includes a detonator 16 for causing 
the bridge structure shown in FIG. 1 to topple or detonate quickly on the 
command of a person playing with the construction set, such a detonator, 
of course, serving to enhance the play value of the construction set. 
FIGS. 2 and 3 further illustrate the portion of the bridge structure within 
the dashed lines 18 (see FIG. 1) and shows the connectors at the ends of 
the parts. The base 10 includes a generally cubical outer wall 21 having a 
flat bottom side 22 which is adapted to be placed on a support surface 
such as a floor or table. On the topside of the base 10 is provided a 
receptacle connector 23 which has a square-shaped (in cross section) 
receptacle 24 formed in it. The receptacle connector 23 on the base 10 is 
essentially identical with a receptacle connector 23a on the upper end of 
the column 11 and is also illustrated in FIG. 7. The walls 26 forming the 
receptacle 24 are tapered such that the receptacle 24 increases in width 
in the upward direction. At the center of the receptacle 24 is formed a 
stabilizing pin 27 which is centrally located between the four tapered 
walls 26 and extends generally parallel to the walls. As shown in FIG. 5, 
the upper end of the pin 27 is substantially lower than the upper edges of 
the receptacle walls 26. Length of pin 27 may be increased to gain more 
stability in certain pieces and structures. 
On the bottom end of the column 11 is formed a tapered end connector which 
mates or connects with the receptacle connector 23. The tapered end 
connector includes a substantially square (in cross section) projection 31 
(see also FIG. 8) formed by four slanted walls 32. The tapers or slants of 
the four walls 32 match the slants of the walls 26 of the receptacle 24 so 
that the projection 31 may be received within the receptacle 24. A hole 33 
is formed at the center of the projection 31 and extends generally 
parallel to the walls 32, the hole 33 being located to receive the 
stabilizing pin 27 when the end 31 is inserted into the receptacle 24. 
Stop means is provided for preventing the tapered projection 31 from 
seating tightly within the tapered receptacle 24, and for forming a narrow 
clearance space between the walls 26 and 32. The stop means may be formed 
by the undersides of flanges 46 which engage the upper ends of the walls 
26 or be formed by a seat 45 formed adjacent the bottom of the receptacle 
24, the lower end of the projection 31 being engageable with the seat 45. 
Either type of stop means prevents the tapered end connector from seating 
tightly within the tapered receptacle connector but allows the stabilizing 
pin 27 to extend into the hole 33. 
Around the receptacle connector is provided four walls which form ledges 37 
that are adjacent and parallel with the walls 26. As best shown in FIGS. 
3, 4 and 5, the upper ends of the ledges 37 are displaced downwardly from 
the upper ends of the walls 26 which form the receptacle, and a recess 38 
is formed between each ledge 37 and the adjacent parallel wall 26. Side 
walls 39 are formed at the sides of each ledge 37, the side walls 39 
extending upwardly to the upper level of the walls 26 as shown in FIG. 5. 
Extending transversely of the column 11 are beams 12 and 12a. Each beam has 
a hook connector formed on at least one end, the hook connector including 
a right angle hook 42 which extends perpendicularly to the length of the 
beam. The thickness of the hook 42 is slightly less than the width of the 
recess 38, and the sideways dimension of the hook 42 is such that it fits 
closely between the two side walls 39 at the ends of the ledge 37. 
Further, the portion 43 of the beam 41, which is at the throat of the 
hook, has a vertical height which is such that the upper side 44 of the 
hook is substantially flush with the upper ends of the walls 26 and the 
upper ends of the side walls 39, as illustrated in FIG. 4. 
Further, the tapered end connector at the lower end of a column includes 
laterally extending flanges 46 which extend laterally outwardly from the 
walls 32 and the lengthwise dimension of the column 11. The flanges 46 are 
located at the upper ends of the tapered walls 32, and the flanges 46 rest 
on the upper ends of the walls 26 and 39 of the receptacle connector when 
the tapered end 31 is inserted into the receptacle 24. It will also be 
noted from FIG. 4 that the flanges 46 overlie the upper sides 44 of the 
hooks 42, whereby the hooks 42 cannot be moved upwardly off of the ledges 
37 while the column 11 is held assembled with the crown 23. Further, as 
previously mentioned, the lateral sides of the hooks 42 engage the side 
walls 39 when the hook is assembled in a recess 38. As a consequence, the 
flanges 46 prevent upward movement of the hook and the side walls 39 
prevent substantial lateral movement of the hook, thereby providing a 
degree of stability between a beam 41 and the receptacle connector. 
With reference again to FIGS. 2 and 3, it will be noted that the upper end 
of the column 11 includes a tapered receptacle connector similar to that 
of the base, and that the lower end of the upper column 11a includes a 
tapered end connector similar to that at the lower end of the lower column 
11. By this arrangement, a series of columns may be stacked vertically and 
connected by inserting the tapered end connectors into the tapered 
receptacle connectors. Further, at each of the tapered receptacle 
connectors, up to four beams having hook connectors may be attached to the 
ledges 37 and the flanges 46 of the tapered end connectors overlie the 
hook connectors and restrain withdrawal of the hook connectors from the 
recess connectors. 
FIGS. 2 through 8 illustrate construction parts and connectors wherein the 
construction parts extend either in end-to-end relation or in transverse 
relation. The parts illustrated in FIGS. 9, 10 and 11, on the other hand, 
are designed to extend at 45.degree. angles to a vertical column and to a 
horizontal beam, for example. With specific reference to FIG. 9, a hook 
type connector 51 similar to that shown in FIGS. 3 and 4 is shown formed 
on an end of a construction part 52, and the hook connector 51 is set at a 
45.degree. angle relative to the length of the part 52. Similarly at the 
other end of the part 52, a tapered receptacle connector 53 is shown in 
FIG. 10, this connector 53 also being formed at a 45.degree. angle. This 
arrangement may be referred to as a 45.degree. bottom hook, top receptacle 
part. FIG. 11 shows the reverse arrangement wherein a 45.degree. hook up, 
receptacle down connector on a part 56 is provided. The parts 52 and 56 
illustrated in FIGS. 9 through 11 may be utilized similar to the parts 13 
and 14 shown in FIG. 1. 
The detonator 16 comprises an arm 61 which is pivotably mounted by a pin 62 
on a base 63. The base 63 includes a pneumatic or mechanical arrangement 
for moving the arm 61 upwardly on the axis of the pin 62. For example, a 
pneumatic device including a piston in a cylinder may be provided in the 
base 63 wherein the piston or the cylinder is connected to push the arm 61 
upwardly in response to an air pulse received in the cylinder. The air 
pulse may be received through a tube from a command piston-cylinder 
arrangement (not illustrated), the arrangement being such that when a 
person playing with the set presses on the command piston, an air pulse 
travels through the tube and to the slave cylinder in the base 63, thereby 
causing the arm 61 to swing upwardly. The outer end 64 of the arm 61 is 
engageable with a part of the structure shown in FIG. 1 such as a lower 
beam 12. When the detonator 16 is actuated, the arm 61 lifts the beam 12 
slightly. This causes the hook 42 to move upwardly and lift the associated 
flange 46, which in turn moves the receptacle connector up and causes the 
stabilizing pin 27 to disengage from the hole 33 of the tapered end 
connector. Without the stability provided by the pin 27 in the hole 33, 
because of the increased size of the gap or space between the walls 26 and 
32 (due to the taper of the walls), the coupling between the receptacle 
and end connectors becomes unstable. If the length of pin 27 is increased 
to provide additional stability the receptacle connector must be moved up 
a greater distance to cause the coupling between the receptacle and end 
connectors to become unstable. The column 11 tips and the entire structure 
immediately collapses. Up until this time, however, the structure has good 
stability and may be added onto, played with and moved laterally somewhat 
by a person playing with the set without disturbing the structural 
integrity of the set. 
While a limited number of parts have been illustrated, it will be 
understood that a variety of designs such as additional shapes of columns, 
beams, etc. may be provided, having hook and ledge types of connectors as 
well as tapered end and tapered receptacle types of connectors as 
illustrated and described herein. The construction set parts are 
preferably molded from a relatively rigid plastic. 
It will be apparent from the foregoing that an improved construction set 
has been provided. The parts may be assembled to form a variety of 
structures, and the connectors between the parts have sufficient stability 
that the structure has play value while standing. If desired, the 
structure may be quickly toppled (to simulate, for example, a demolition) 
using a detonator or by hand. The connections between the tapered ends and 
the tapered receptacles are sufficiently loose that the ends may easily be 
lifted out of the receptacles but the connections between the stabilizing 
pins and the mating holes normally maintain the structural integrity of 
the assembly. The structure is toppled by lifting a part enough to move 
the stabilizing pins out of the holes and to increase the looseness of the 
coupling between the tapered ends and receptacles. Disconnection of one or 
two connectors as described above causes the entire structure to collapse.