Floor tile with overmold crush pads

Abstract

A modular plastic floor tile has a body of a first polymer compound and at least one skin overmolded onto the support member core from a second polymer compound. The compounds may be different from each other in hardness and / or color. Crush pads are formed from the first polymer and are disposed to be below the general lower surface of the tile. The crush pads provide a tight overmold shutoff and prevent flashing of the second polymer compound when the support member is formed.

Description

RELATED APPLICATIONS[0001]This application is a continuation in part of copending U.S. patent application Ser. No. 12 / 609,959 filed Oct. 30, 2009, and further is a continuation in part of copending International Patent Application No. PCT / US10 / 54515 filed Oct. 28, 2010, which in turn is a continuation in part of pending U.S. patent application Ser. No. 12 / 609,959 filed Oct. 30, 2009. The present application is further a division of pending U.S. patent application Ser. No. 13 / 217,556 filed Aug. 25, 2011. All of the foregoing applications are owned by a common assignee. The specifications and drawings of each of them are fully incorporated by reference herein.BACKGROUND OF THE INVENTION[0002]Conventional modular injection-molded tiles are known in the art for laying across upper surfaces of garage floors, sports surfaces, outdoor surfaces and other substrates. These tiles typically are twelve to thirteen inches square and can be manually assembled and disassembled. A common feature of...

AI Technical Summary

Benefits of technology

[0007]According to one aspect of the invention, a modular floor tile is provided which may be used to create a flooring surface including a plurality of like tiles. A first polymer compound is used to mold a body of the tile. The body has at least one feature overmolded onto the upper surface of the body from a second polymer compound which is different from the first polymer compound. A second polymer compound gate is disposed to be adjacent a lower surface of the tile body and to be remote from the upper surface thereof. The gate communicates to the upper feature through a through-hole which extends from the lower surface to the upper surface. A vent hole, laterally spaced from the through-hole, extends from the upper surface back to the lower surface and is in communication with the upper feature. During the injection of the second polymer compound, molten polymer makes its way from the gate, through the through hole and into the cavity in which the upper feature will be created. The vent hole permits gas or other fluid to be displaced out of the upper feature cavity, thereby obviating or minimizing any void in the as-molded upper feature which might otherwise occur. In one embodiment a portion of the upper pad extends through the vent hole to be disposed below or protrude onto the lower surface. Preferably, the tile has many such pads on its upper surface, and many such support members downwardly depending from its lower surface. Groups of these pads and support member portions may be molded together in a continuous phase of the second polymer compound.

[0009]In another aspect of the invention, a modular floor tile has a body molded of a first polymer compound, the body including a substantially planar horizontal web with an upper and a lower surface. The floor tile further includes at least one lower feature overmolded onto the lower surface of the tile body from the second polymer compound. The lower feature may, for example, be a “skin” overmolded over a support member core which is disposed below the general lower surface of the horizontal web, the skin and core constituting a support member. A crush pad is formed completely laterally around the lower feature. The crush pad is smooth and is disposed blow the general lower surface of the tile body. The crush pad prevents flash from the molten second polymer compound during the overmolding step.

[0011]In a further aspect of the invention, a method of forming a plastic modular floor tile includes molding a body of a first thermoplastic polymer compound, and then overmolding the body using a second polymer compound that has different characteristics from the first, such as differences in rigidity, coefficient of friction and / or color. The step of overmolding includes the substeps of positioning a gate adjacent the lower surface of the tile body and remote from an upper surface thereof; flowing polymer from the gate through a vent-hole to form an upper feature on the upper surface; and displacing a fluid (such as a gas) out of the volume of the upper feature cavity through a vent hole extending from the upper surface to the lower surface thereof, thereby minimizing or obviating any void which might otherwise appear in the upper feature as molded.

[0012]In one embodiment, the method further includes flowing the molten second polymer compound from the gate, by a path which does not pass through the tile body, to a lower feature which is overmolded on the lower surface of the body. The method may also include the step of flowing molten second polymer compound through the vent hole such that a portion thereof protrudes onto the lower surface of the tile body. In this last instance the method further preferably includes spacing such portion from the lower feature as by a crush pad, so that the flow of polymer creating the lower feature won't conflict with the flow of polymer creating the upper feature, and so that any gas or fluid will be positively displaced from the upper surface through the vent hole. In one embodiment, groups of upper and lower features are each formed from polymer flowing from a single respective gate or fill point. The method may be used to overmold nonslip pads on the tile upper surface and, in one embodiment, to simultaneously overmold support member nonslip skins on the lower surface of the tile.

Problems solved by technology

But manufacturing an injection-molded plastic tile that has two or more perceptible colors per tile is more difficult and to date no such tile has been provided that has proven to be acceptable to the consumer.

But it is believed that the separate molding of these inserts, flash removal from them and physical insertion of them into respective receiving holes in the plastic tile substrate is time-consumptive and greatly increases the cost of manufacture of the resultant tile.

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