Besides the class of sliding door hangers that roll on a track, there is also a distinct type of hangers which operate the door by means of a frame working on the principle of a parallelogram, the corners of which must always be at the same level. This frame is attached to the back edge of the door and the door slides by it.
The first hanger invented of this type was the Prescott Brace Hanger, which was placed on the market during the year 1880, and at once gained considerable popularity, due to the great ease and smoothness with which it works. Since then this hanger has been quite extensively used for hanging parlor doors, elevator doors and the large doors of stables, warehouses, freight sheds, etc. The form of hanger used for doors 4 feet and under is shown in Fig. 362. As may be seen, it consists essentially of two flat bars joined scissors fashion in the centre. The lower end of the bar X is fastened by an angle iron to the face of the jamb stud, as shown at A, and the lower end of Y is fastened to the back edge of the door in the same way. The upper end of each bar has a pulley which works between two parallel bars attached, one to the face of the jamb stud at E, and the other to the back edge of the door at D. The weight of the door comes principally upon the pivoted hinges at A, B and C. When the door is opened the hanger spreads out like a pair of shears, at the same time raising the door about ¼ inch, and as the door is closed the hanger shuts up until the two bars are parallel. In practice, the hanger, when properly set, works to perfection. The door can never bind, but can be operated by the slightest pressure in either direction. The doors are hung after the plastering is done.
An objection to the use of this hanger in parlor doors, however, is that it requires a wider pocket than the track hangers and it is necessary to remove the jambs in order to adjust it in case of settling.
Where the hanger is exposed, as on elevator doors, barn doors, etc., it may be used to great advantage, as it works with the greatest ease, however large or heavy the door may be. This hanger has been found especially serviceable on elevator doors, as it permits of an opening the entire width of the car when desired. This is obtained by hanging a door across half of the opening with ordinary butts, and closing the rest of the space by a door hung with Prescott hangers to the first. The sliding door can then be operated in the usual way for passengers, or both doors may be swung on the butts to give the full opening for taking in boxes, furniture, etc.
Fig. 362. - Prescott Door Hanger.
For wide doors a compound hanger, consisting of two single hangers joined by bolts, is used, and for very heavy doors the bars are trussed, the operation being essentially the same as with the single hanger.
The American Trackless Door Hanger, shown in Fig. 363, is, the author believes, the latest device in the way of a trackless hanger, and is especially designed for doors intended to slide into a pocket. As may he seen from the illustration, it consists of four arms pivoted at four points, the centre of the hanger being placed just one-half of the width of the door back from the jamb, so that when the door is pushed clear back, the position of the arms is exactly reversed. The arms work in the pocket between the door and the studding, as shown by the plan. The width of pocket between studding should be 3 inches plus thickness of doors.
The moving gear is attached to a rectangular cast iron frame, screwed to the studding in such a way that it can be adjusted or removed from the pocket without disturbing the plastering, the adjust-ment being done entirely by turning the two bolts A and B, which are easily accessible.
It is claimed that the operation of this hanger is noiseless and extremely easy, and that the hanger can be put up in less time than is required for overhead hangers. Trackless hangers have the advanfig. 365.
tage that no opening in the head jamb is required and no overhead work.