1. IN AN APPARATUS FOR SECURING THE SCREEN FABRIC IN OPERATIVELY RELATIONSHIP WITH A FRAME WHOSE STILES AND RAILS INCORPORATE GROOVES ADAPTED TO RECEIVE THE EDGES OF SAID SCREEN FABRIC AND A RETAINING SPLINE THEREFOR, THE COMBINATION OF: AN ELONGATED BED ADAPTED TO RECEIVE A FRAME; GUIDE MEANS ON SAID BED ENGAGEABLE WITH SAID FRAME TO GUIDE IT ALONG SAID BED; TRANSLATING MEANS ON SAID BED ADAPTED TO MOVE SAID FRAME ALONG SAID BED; A SOURCE OF SCREEN FABRIC ASSOCIATED WITH SAID BED AND ADAPTED TO FEED SAID FABRIC INTO OVERLYING RELATIONSHIP WITH SAID FRAME; A SOURCE OF SPLINE MATERIAL ON SAID BED AND ADAPTED TO FEED SPLINE MATERIAL TO SAID FRAME; MEANS ON SAID BED FOR CRIMPING THE OPPOSITE EDGES OF SAID SCREEN FABRIC OVERLYING THE GROOVES IN THE STILES OF SAID FRAME; SPLINE SETS ASSOCIATED WITH SAID CRIMPING MEANS FOR URGING A SPLINE INTO OVERLYING RELATIONSHIP WITH THE CRIMPED EDGES OF SAID FABRIC AND SAID GROOVES, SAID CRIMPING MEANS AND SAID SETS BEING MOUNTED ON COMMON PIVOTALLY MOVABLE SUPPORT MEANS HAVING SPRING MEANS ATTACHED THERETO ADAPTED TO BIAS SAID SUPPORT MEANS DOWNWARDLY TOWARD SAID BED; AND AUTOMATIC CONTROL MEANS OPERATIVELY CONNECTED TO SAID SUPPORT MEANS AND RESPONSIVE TO EXCESSIVE DISPLACEMENT OF SAID SUPPORT MEANS TO DE-ENERGIZE SAID APPARATUS AUTOMATICALLY.