type
  TOpenQuery = Class(TThread)
  Public
    constructor Create(Q: TADOQuery;sSQL: String);
  protected
    tQry: TADOQuery;
    tSQL: String;
    procedure Execute; override;
  end;
.
.
.
{ TOpenQuery } 

constructor TOpenQuery.Create(Q: TADOQuery; sSQL: String);
begin
  inherited Create(False);
  FreeOnTerminate:=True;
  tQry:=Q;
  tSQL:=sSQL;
end;

procedure TOpenQuery.Execute;
begin
  inherited;
  Screen.Cursor:=crAppStart;
  with tQry do
  Begin
    SQL.Text:=tSQL;
    Open;
  End;
  Screen.Cursor:=crDefault;
end;