Control valve for door closer

A door closer including:

• a door closer body formed with first and second channels for flow of a pressure medium controlling operation of the door closer and also formed with a first bore that intersects the first channel and has first and second segments at opposite respective sides of the first channel, and with a second bore that intersects both the first channel and the second channel and has first and second segments at opposite respective sides of the second channel,
• a first control device fitted in the first bore and having first and second opposite ends, the first control device comprising a guiding part at its first end, the guiding part being located in the first segment of the first bore and having a thread fillet engaging the door closer body and supporting the first control device relative to the door closer body, a support part at the second end of the first control device, the support part being located in the second segment of the first bore, a collar of resilient material located in the second segment of the first bore and surrounding the support part of the first control device, the collar being under compression whereby the collar supports the second end of the first control device relative to the door closer body and restrains the first control device against rocking and swaying movement relative to the door closer body due to flow of pressure medium in said first channel, and a control part between the guiding part and the support part and having a beveled inner end for cooperating with the door closer body to restrict pressure medium flow in said first channel,
• a second control device fitted in the second bore and having first and second opposite ends, the second control device comprising a guiding part at its first end, the guiding part being located in the first segment of the second bore and having a thread fillet engaging the door closer body and supporting the second control device relative to the door closer body, a support part at the second end of the second control device, the support part being located in the second segment of the second bore, and a control part between the guiding part and the support part and having a beveled inner end for cooperating with the door closer body to restrict pressure medium flow in said second channel,
• whereby the first control device can be moved in its axial direction by turning the first control device supported on the door closer body for adjusting the restriction of the pressure medium flow by the control part of the first control device and the second control device can be moved in its axial direction by turning the second control device supported on the door closer body for adjusting the restriction of the pressure medium flow by the control part of the second control device,
• wherein the collar has at least one chase to reduce its thickness at a certain part of the collar, and
• wherein the control part, the guiding part and the support part of the first control device are made of metal and the collar is made of plastic, and the control part, the guiding part and the support part of the first control device are axially movable relative to the collar.