Claims:
1. In an electric door holder, a housing mounted on a door frame, a holder lever mounted to rotate about an axis on the housing and operatively connected to the door so as to rotate incidentally to movements of the door as the door moves between an open position and a closed position, an end portion of said holder lever rotating in an arcuate path that is spaced a considerable distance relatively to the axis in which the lever rotates, a latch member having a surface movable into cam relation to said end portion of the holder lever in said arcuate path when the door is in the open position relatively to the door frame, electrically controlled means for applying to said latch member a predetermined amount of pressure to hold a surface of said latch member in said cam relation with the end portion of said holder lever thereby holding the door in the open position, and said surface of the latch member being formed at an angle that will enable the end portion of the holder lever to override the predetermined pressure applied by the electrically controlled means when a pressure sufficient to overcome the predetermined pressure applied to the
2. The construction set forth in claim 1 in which said latch member has a detent on said surface of said latch member for engaging the end portion
3. The construction set forth in claim 1 wherein said latch member has a first and second surface facing in opposed directions relatively to each other whereby to be effective for holding the door against movements in one direction relatively to the door frame when the holder lever is so connected to the door as to rotate in opposed directions during said
4. The door holder construction set forth in claim 1, in which said latch member is a latch lever having on its medial portion the surface that moves into cam relation to the end portion of the holder lever, said electrically controlled means being connected to an end portion of said
5. The construction set forth in claim 4 in which said latch lever has an effective length that equals at least the effective length of the holder lever, and in which said surface of the latch lever when in cam relation to the end portion of the holder lever lies at an angle in the range between 2° and 6° relatively to the longitudinal axis of the
6. The construction set forth in claim 5 in which said electrically controlled means comprise an electromagnet and means connecting the latch
7. In an electric door holder, a housing mounted on a door frame, a shaft mounted on the housing and connected to the door through an arm that will rotate the shaft in a first and a second direction incidentally to movements of the door as the door moves between a closed and an open position, a holder lever mounted to rotate with said shaft, a latch member movable to position engaging said holder lever and having a first and a second detent surface for holding said lever against rotation in each of opposed directions in said housing, and electrically controlled means for holding said lever in either the first or the second detent surface thereby to hold the door in two selectively open positions, said lever being held in the first detent surface to prevent said shaft from being rotated in the first direction and being held in the second detent surface
8. The construction set forth in claim 7 in which said latch member is a latch lever having an end portion pivoted on the casing, said detent surfaces being formed on a medial portion of the lever, and said electrically controlled means acting relatively to the opposed end portion
9. The construction set forth in claim 8 in which said electrically controlled means apply yielding pressure to the latch member, and said detent surfaces comprise cam surfaces for engaging the holder lever and formed each at an angle that will enable the holder lever to override said yielding pressure when a predetermined amount of pressure is applied to
10. The construction set forth in claim 9 in which said electrically controlled means comprise an electromagnet connected to said opposed end portion of the latch lever, said latch lever having an effective length that equals at least the effective length of the holder lever, and each of said cam surfaces when engaging the holder lever lying substantially at an angle of 3° relatively to the longitudinal axis of said holder lever.
Description:
My invention relates to a novel door holder of a kind that has electrical means for controlling its operation.
Where electrical control of door holding is desired, it has been thought most satisfactory in recent years to utilize an electromagnet acting directly between the door and a wall or bracket toward which the door moves when opening. An electromagnet acting in that way holds the door in open position and releases the door when deenergized, so that by utilizing a switch or an appropriate sensor to break a circuit the door will be permitted to close, as by the spring action of a usual type of door closer. That is a mode of operation which is desired or even necessary in many locations, because it causes the door to close promptly through the action of a person at a remote point, or automatically by a sensor when a fire or other critical condition exists.
Despite the value of those door holders, there have been objections that have discouraged their use. Thus, an electromagnet that is positioned between a door and a wall forms an obstruction that may be unacceptable. Moreover, such an electromagnet cannot well be utilized where the open position of the door is to be somewhat distant from a wall or bracket, and it also has presented problems due to the amounts of power consumed.
The prior art does contain electrically controlled door holders that act between the door and door frame, sometimes being mounted on the frame, but the earlier holders of that description have not found wide acceptance because they generally utilize mechanisms that are complex, and do not offer dependable operation in some instances. I now contribute by my invention a novel door holder that will be electrically controlled while offering very satisfactory performance, and that will effectively overcome the objections found in the electric door holders that the prior art has been able to develop.
In my inventive concept, a holder lever will rotate about an axis on a housing that is mounted on the door frame, and will be so connected to the door as to rotate incidentally to movements of the door. An end portion of the holder lever will move in a line that is spaced a considerable distance from the axis about which the lever rotates, and I mount a latch member in position to engage in cam relation to the end portion of the lever in that line. Electrically controlled means will apply yielding pressure for holding the latch member in its cam relation so that holding of the door will be controlled in part electrically and in part by pressures that may be applied directly to the door.
Through that concept, I am able to build an electric door holder that actually is simple in construction, yet offering extremely good performance while forming no obstruction between the door and a wall. What also is important, my holder will require relatively little electric power.
Further, it is easily possible by my invention to achieve more than one effective holding position of the door while requiring little or no change in the construction of the holder. Thus, it will merely be necessary to equip the latch member of my novel holder with detent surfaces that will engage the end portion of the holder lever when the door is in different positions relatively to the door frame, all while preserving the simple nature of my holder construction. As a preferred feature of this part of my invention, I form the detent surfaces in relatively reversed shapes that will be effective when the holder lever rotates in each of opposed directions about its axis. I then may connect my door holder to a door through a type of door closer on which an arm reverses its motion during a movement of the door in one direction, achieving effective holding of the door in two widely spaced holding positions with no need to increase the size or the quantity of parts.
I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows may be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of my invention, in order to prevent the appropriation of my invention by those skilled in the art.
In the drawings:
FIG. 1 shows a perspective view of a preferred form of my door holder mounted on a door frame and connected to a door closer on the door;
FIG. 2 shows a plan view, partly in section, of the holder construction;
FIG. 3 shows a sectional view substantially on the broken line 3--3 in FIG. 2; and
FIG. 4 shows a schematic view illustrating the motion of a type of connecting arm that may be utilized with my holder.
Referring now more particularly to FIG. 1 of the drawing, I show my door holder H mounted on a top portion of a door frame F and connected to the door D through a usual type of door closer C, having a main arm 10 pivotally connected to a forearm 11. Those skilled in the art will understand that the closer arms 10, 11 will go through the motions indicated in FIG. 4 during movements of the door D. I shall refer further to FIG. 4 while explaining a part of my invention in due course.
The door holder H comprises a housing 12 that may have a simple box-like shape, and a shaft 13, FIGS. 2 and 3, that is mounted through bearings 14, 15 to rotate in a vertical axis in openings formed through upper and lower walls of the housing 12. Tapered end portions 16 and 17 extend beyond the housing walls, permitting a connecting arm such as the closer arm 11 to be integrally secured to either end of shaft 13, depending upon the hand of operation that is required by a particular installation. For the purpose of description I show the closer arm 11 secured to the lower shaft end 17, utilizing a screw 18 engaging a threaded bore 19 that extends longitudinally through shaft 13.
On the shaft 13 I mount a holder lever 20 that has a considerable length. For the purpose, a set screw 21 is threaded into the bore 19 of the shaft to secure an end portion 22 of lever 20 in position in a cross bore 23. When shaft 13 rotates, an opposed end portion 24 of holder lever 20 then will rotate in a line that is spaced a considerable distance relatively to the axis of shaft 13. Upper and lower sleeves 25, 26 assembled on the shaft 13 form spacers engaging between holder lever 20 and the housing walls to hold the shaft in assembled position on the casing.
A latch lever 27 is mounted for movement relatively to the line in which the end portion 24 of the holder lever rotates, one end of the latch lever being pivoted on a pin 28 that a screw 29 holds in assembled position on the housing 12. A medial portion of lever 27 is formed with detent surfaces 30, 31 that will engage in cam relation to the end portion 24 of holder lever 20, and the opposed end of latch lever 27 is connected to electrically controlled means comprising an electromagnet 32. I show that electromagnet mounted by screws 33 on the housing 12, and equipped with an armature 34 connected through a link 35 to a pin 36 on latch lever 27. Thereby the electromagnet 32 when energized will act for holding the detent surface 30 or 31, as the case may be, with yielding pressure against the end portion 24 of holder lever 20.
In order that my invention may be fully understood, I call attention to the fact that the latch lever 27 has an effective length that equals at least the effective length of holder lever 20. In addition, each detent surface 30, 31 is formed to offer a cam surface which, when engaging the holder lever 20, will lie at an angle in the range from 2° to 6° relatively to the longitudinal axis of lever 20. Once that is understood and appreciated, persons who are skilled in the art will be able to design more specific dimensions of holder lever 20, latch lever 27 and cam angle, as may be necessary to meet differing conditions of use. Actually, I have found that my door holder operates well when the effective length of holder lever 20 is approximately two inches, that of latch lever 27 approximately 25/8 inches and the cam angle of each detent surface 30, 31 is 3° relatively to the longitudinal axis of the holder lever.
While the coaction between the levers 20, 27 may appear rather simple, I believe that they do form a contribution of importance because they will enable me to achieve holding of a door under electrical control that will be extremely effective, but that may nevertheless be overridden by a predetermined pressure against the door, all while permitting the use of electrical means that require relatively small amounts of electric power. Also, while utilizing little power, my invention enables me to utilize a holder lever that need have no great range of angular movement while being effective for holding a door in widely spaced angular positions, as I shall explain.
Referring to FIG. 2 of the drawing, it will be seen that the detent surfaces 30, 31 are formed to face in opposed directions relatively to each other on latch lever 27. Thereby the surfaces 30, 31 will be effective for holding the door against movement in the same closing direction from each of two different positions. That will be understood when considering the conventional closer arm movements shown schematically in FIG. 4. Thus, when the door D moves from its closed position toward its 90° position Dy, which for purposes of my description we may consider its full open position, the closer forearm 11 first will rotate to a particular position 11x. In that position 11x the arm 11 will reverse its direction of rotation, going toward position 11y, while the door continues to move toward its full open position Dy.
Each movement of arm 11 naturally will take place in the opposed direction when the door closes. In other words, the rotation of the arm 11 in door closing direction will first be clockwise from position 11y to position 11x as shown in FIG. 4, and then counterclockwise from position 11x to position 11 while the door moves in a single closing direction. When the closer arm 11 is connected to the shaft 13 of my novel door holder, as indicated in FIG. 3, the holder lever 20 naturally will rotate integrally with it. To illustrate, I show in full lines in FIG. 2 the position of holder lever 20 corresponding to full open position Dy of the door. Position 20x corresponds to the position 11x at which the arm reverses its direction of rotation, and position 20z corresponds to a door holding position of the arm intermediate the positions 11x and 11.
I believe it will be apparent, then, that the opposed shapes of the detent surfaces 30, 31 on the latch lever 27 will be effective for holding the door D in two positions selectively, as for example at 10° or 90° relatively to its closed position. Moreover, that may be done while the holder lever 20 merely need move through a relatively small angle between its extreme positions, and with no need to complicate the parts or increase the size of the door holder.
The holding positions of my door holder actually may be adjusted rather easily, it merely being necessary to relieve the pressure of the screw 18 and to loosen the closer arm 11 on the tapered end portion 17 of the holder shaft so that the arm may be rotated and again secured in a desired position on the shaft.
It will be understood also that my invention enables the electromagnet 32 to be one that will consume a relatively small amount of power, since it merely need apply a moderate amount of pressure for holding latch lever 27 engaged with the holder lever 20. That moderate pressure, acting through the detent cam surfaces 30, 31 will be ample to oppose normal closing pressures of the door. Then, due to those cam surfaces 30, 31, electromagnet 32 will yield when a predetermined closing pressure is applied to the door, enabling the door to be closed manually. Should the electromagnet be deenergized, the cam surfaces 30, 31 will easily enable holder lever 20 to move latch lever 27 to release position permitting the door to close, no spring being necessary for moving lever 27.
I believe that the construction and operation of my novel door holder now will be understood, and that the very considerable value of my contribution to the art will be appreciated. I believe, therefore, that those who are skilled in the art will fully understand the merits of my invention.