Door closer

A door closer comprising a substantially horizontally extending non-magnetic housing with an outer wall having a recess;

• compression coil spring means disposed within said housing and having first and second ends;
• a spring plate disposed at said second end of said spring means and having a permanent magnet arranged thereon;
• means carrying said spring plate for adjustment movement within said housing to thereby adjust the position of said spring plate and said second end within said housing and relative to said first end to adjustably vary said spring bias;
• actuation means cooperating with said carrying means and accessible from outside of said housing for adjusting the position of said spring plate;
• a movable indicator device the position of which is readable from outside of said housing and consisting at least in part of a steel ball arranged in a transparent tubule secured in said recess and magnetically coupled to said permanent magnet, the tubule having a diameter which is largest at the center thereof and continuously reduces towards its two ends, whereby adjustment movement of said spring plate results in corresponding movement of said indicator device, thereby providing a reading of the selected level of said spring bias, the capture region of the permanent magnet being at least the same as one half of the length of the tubule.