direction by engaging the male coupling devices of one cushion block into the female coupling devices of another the deformable body is deformable in the linking direction to compensate expansion of the strips due to absorption of moisture application_number US 41129603 A description referring to fig1 a cushion block 10 is a flat rectangular block molded from synthetic resin for example polyacrylic resin or polyethylene resin in integrity having a base 20 disposed at one end two male coupling devices 40 arranged in parallel at the other end a deformable body 30 connected between the base 20 and the male coupling devices 40 two female coupling devices 50 arranged in parallel in an outer side of the base 20 remote from the deformable body 30 a retaining device 60 located on the top side of the base 20 and spaced between the deformable body 30 and the female coupling devices 50 and two pairs of springy supporting devices 70 located on the top side of the base 20 and symmetrically disposed at two sides of the retaining device 60 the retaining device 60 projects upwards from the top side of the base 20 except the retaining device 60 the top sides of the other parts of the cushion block 10 are maintained in flush the springy supporting devices 70 are normally disposed in a sloping position partially protruding over the top side of the base 20 however they become flush with the top side of the base 20 when forced downwards according to the present preferred embodiment the thickness of the cushion block 10 is about 1 cm the height of the protruding retaining device 60 excluded the length of the cushion block 10 i e the length front the outer end of the male coupling device 40 to.