Tool for uncoupling interlocking blocks

Two halves of a tool hinge about an axis. The hinging action causes one end of the tool to expand while the other end contracts. The expanding end is placed in a recess of the interlocking block befor expansion. After expansion, the expanding end of the tool grips the block. Similarly, the contracting end is placed around a post on the block. After contraction, the contracting end of the tool grips the post on the block.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a tool for the uncoupling of interlocking blocks, 
for example, toy blocks used for building various structures. 
2. Related Art 
Interlocking blocks have become very popular, particularly with children, 
for building various structures and shapes. They are also used to 
construct models for evaluation and demonstration, such as buildings or 
machinery. However, a problem arises in that some of the blocks are 
difficult or impossible to separate without the use of some tool. Most 
often, a bladed object such as a knife is used. This damages the blocks 
and presents a hazard to the user. 
SUMMARY OF THE INVENTION 
The present invention provides a tool which may be used to grip a block, 
thus forming a handle to aid in releasing the block which is interlocked 
to another block. 
Two halves of the tool pivot about an axis, being biased into a released 
position by an elastomeric member. Applying pressure to the tool halves at 
the end remote to the pivot axis causes one end of the tool to expand 
while the other end contracts. 
In use, either the expanding end is placed in the block recess or the 
contracting end is placed around a block post. The block is gripped when 
the tool is activated by pivoting the halves using a pinching action. The 
interlocking blocks are separated by pulling the tool with the gripped 
block away from the mating block. 
Broadly, the invention comprises a tool for uncoupling interlocking blocks, 
having two elongate members, each member having a semicylindrical recess 
at one end and a semicylindrical extension at the other end, the two 
members pivoted relative to each other at a position intermediate the 
ends, there being a small clearance between the members to permit 
pivoting. A resilient member, such as an elastmoeric ring retains the 
members together and biases the ends with the semicylindrical extensions 
together. 
Pivoting of the members can cause the extensions to separate and grip the 
inside of a recess in a block, or the recesses to move towards each other 
and grip a post on a block. 
Conveniently, the members are pivoted by hemispherical projections 
positioned in hemispherical recesses.

The drawings illustrate one particular form of tool according to the 
invention. As seen in FIGS. 1 to 6, the tool comprises top and bottom 
elongate halves 1 and 2, with an elastomeric ring 3 positioned in an 
annular groove 4 securing the halves together. At one end of the tool is 
formed a cylindrical extension 5. At the other end is formed a cylindrical 
recess 6. It will be appreciated that half of the cylindrical extension 5 
is formed on each half 1 and 2 and half of the cylindrical recess is also 
formed on each half 1 and 2. This results in semicylindrical extensions at 
one end and semicylindrical recesses at the other end. 
Adjacent the end having the cylindrical extension 5 is formed a pivoting 
arrangement. In the example, and as particularly seen in FIGS. 5 and 6, 
the pivoting is obtained by hemispherical projections 7 which seat in but 
project slightly from hemispherical recesses 8. The projections can be on 
one half and the recesses in the other half, but by having a projection 
and a recess on the same half, both halves are identical from the 
manufacturing aspect. By the projections projecting slightly from the 
recesses, a small clearance is provided between the halves. The 
elastomeric ring is positioned between the ends of the halves having the 
cylindrical extension 5 and the hemispherical projection 7 and thus the 
two halves pivot with the halves inclined away from each other, as seen in 
FIGS. 3 and 4. 
FIGS. 7 and 8 illustrate the provision of annular stress concentrating 
ribs, 10 and 11 at the cylindrical extension and cylindrical recess 
respectively. These ribs ensure a good grip on a member. 
FIG. 9 illustrates the tool in use gripping a post 12 on a block 13. The 
post is gripped by squeezing the two halves together, the post being 
gripped in the cylindrical recess 6. While gripped the tool is pulled as 
indicated by arrow C, separating block 13 from block 14. 
In FIG. 10, the tool is used to grip the inside of a recess 17 in block 15. 
The cylindrical extension 5 is inserted into the recess 17 and then the 
remote ends squeezed together. This expands the extension 5 in the recess 
17, giving a gripping action. By pulling on the tool, in the direction of 
arrow D, the block 15 can be released from block 16.