The specialized pivot stud has a conical-shaped tip with an extended surface around the body of the stud. The pivot stud is mounted into the knuckle from beneath. An arm locking hex screw is tightened to secure the pivot stud in the knuckle.
The pivot stud seats into a sealed thrust bearing raceway that is press fit into the bronze floor mounted plate of the 147. As the door swings open or closed, the bottom pivot stud carries the weight of the door against the thrust bearing. The bearing rotates, turning the door as it swings open and closed.
A properly installed door using a top, intermediate (if present) and bottom pivot should have the following:
1. The door should be plumb, with a uniform clearance between the vertical edges of the door stop and the face of the door of about 1/8”.
2. The door should not be warped.
3. The top of the door should clear the jamb, and the bottom of the door should clear the threshold/floor.
4. The leaves of the top and intermediate (if present) should be neither more than 3/16” apart nor tight together. If they are tight together, the intermediate pivot is carrying load of door.
When examining the opening, also check the condition of the door and jamb. For example, aluminum doors can become out of square. Sometimes you will see welds at the connection between the stiles and rails. These welds are probably a result of wind and/or wear damage to the door assembly. At some point in time, instead of replacing the door, a decision was made to weld it back together. If the door is out of square, there are rarely any adjustments for this situation other than welding the door.
Once the door and the jamb have been inspected, check the operation of the door.
Does the door properly close and latch? If not, then the door may require service. There could be a number of problems; however, start with the most benign. Check the location and condition of the weather stripping. Obstructions such as weather strip or a misaligned latch and strike can cause the door to not properly close or latch. Correct any of these conditions first.
The problem could be resolved as simply as tightening the arm locking screw, the mounting screws, or may require replacement of components such as the bottom pivot or more.
This situation can be caused by a number of problems including the arm locking screw becoming loose, building settling, or worn bottom pivot/closer.
The first step is to check the condition of the arm locking screw:
Step 1. Remove the arm cover screw and the arm cover.
Step 2. Open the door slightly.
Step 3. With the door open, lift up and push in on the door. Does the door raise up and/or the arm knuckle slide around the pivot stud? If yes, wiggle the door back and forth while tightening the screw until it is fully seated.
Step 4. Try opening and closing the door. Does the door close and the lock latch? If yes, the problem is solved. However, continue to check the condition of the door.
The next step is to check if the pivots are in adjustment. This can also result in the door dragging along the floor/threshold or scrape along the header. To check pivot adjustment:
Step 1. Open the door and look for signs of dragging or scraping.
Step 2. Close the door and check the alignment within the opening. The gap from the top to the bottom of the door should be approximately the same distance. Usually the gap will vary along the top of the door if the top pivot is worn.
Next, determine if the top pivot needs replacement.
Step 1. Open the door to a slight angle.
Step 2. Place both hands on the latch edge of the door and push inward and upward. If there is any play in the door, the top pivot should probably be replaced. If there is no play in the door, the top pivot is probably in good operating condition.
Check the condition of the bottom pivot.
Open and close the door a number of times. As the door is being closed, does it scrape along the threshold or the header? Does the lock latch when the door closes?
If the door scrapes along the threshold or the header, the door may be out of height adjustment. The door height is determined by the bottom pivot. Most bottom pivots have height adjustment capabilities. The Rixson 147 bottom pivot can be height adjusted using “C” shims. Each of these shims is 1/16” thick. To raise the door height in order to provide the 3/16” clearance between the bottom of the door and the top of the threshold, Rixson uses 1/16” thick “C” shims.
I was invited to the retrofitting of the lock hardware on a pair of wide stile aluminum doors equipped with rim exit devices latching onto a mullion.
Floor closer conversion & surface mounted door closer is installed.
RIXSON's new Light Duty Pivot Series helps bring high-end door control to lightweight, narrow and low-frequency doors. Model 173, for offset applications, and Model 176 for center-hung doors, offer...