US2241179A

US2241179A - Projection lamp

Info

Publication number: US2241179A
Application number: US217385A
Authority: US
Inventors: Brenkert Karl
Original assignee: BRENKERT LIGHT PROJECTION COMP
Current assignee: BRENKERT LIGHT PROJECTION Co; BRENKERT LIGHT PROJECTION COMP
Priority date: 1938-07-05
Filing date: 1938-07-05
Publication date: 1941-05-06
Anticipated expiration: 1958-05-06

Description

May 6, 1941.

K. BRENKERT PROJECTION LAMP Filed July 5, 1938 INVENTOR. BY A7271 E/FE/Y/rE/Y r ATTORNEY.

Patented May 6, 1941 '2,241,179 PROJECTION LAMP Karl Brenkert, Detroit, Mich, assignor to Brenkert Light Projection Company, Detroit, Mich., a corporation of Michigan I Application July 5, 1938, Serial No. 217,385

4 Claims.

The present invention pertains to improvements in projection lamps.

One of the objects of the invention is to provide a more satisfactory door structure for the housing than has hitherto been available. Lamp housings of the general character disclosed herein are provided with doors for access to the reflector, electrodes and other mechanism in the housing. The door must extend substantially the entire length of the housing from front end to rear end for permitting access to the various interior parts. It should also, if possible, be of such height as to clear the top of the reflector so that the latter may easily be wiped.

These doors are usually hinged either at one end or at the upper edge. In either case when swung wide open, the door requires a substantial clearance either at the sides or above the top of the housing, as the case may be. Such-a clearance, however, is not always available in the limited space within a projection booth. C'onsequently, the opening of the doors frequently involves inconvenience to the operator, 2. compromise in the proper construction for operation of the door, or the necessity of moving other apparatus out of the way when opening the door.

The present invention overcomes these difficulties and at the same time enables a full door opening without requiring excessive space at the sides or over the top of the housing. To effect this purpose, the door is constructed in two sections hinged together along a line longitudinal of the housing, the upper end of the section being hinged to the housing at the upper edge of the door opening. A guide link joins the first hinge axis to an end wall of the housing and forms a toggle with the lower section. The link determines the path of the door in its movements, and the toggle constitutes a means for locking the door in open or closed position without the use of latches or the like. In the full open position of the door, the sections stand above the door opening but adjacent or opposite to one another, having swung relatively on their Figure l is aperspective view of the device, with the doors open;

Figure 2 is a vertical section of the door;

Figure 3 is an enlarged detail; and Figure 4 is a side elevation with the door panels omitted.

Reference to these views will now be made by use of like characters which are employed to designate corresponding parts throughout.

In Figure 1 is shown a projection lamp housing having a base I and front and end walls 2 and 3 respectively. The end walls are joined across the top by a roof 4, the complete design of the housing being shown in the United States Design Patent of Henry M. Horldt, No. 111,602, of October 1938. Substantial openings are thus provided between the end walls, on both sides of the housing. These openings are normally covered by doors of the construction presently to be described. The end walls 2 and 3 are substantially circular, and the base I and roof 4 are of substantially equal width. This width may be determined from Figure 2 which shows the angular extent of one of the doors. Since both doors are alike, only one need be described.

Across the top of the side opening, a hinge rod 5 is mounted in the end walls 2 and 3, slightly below the adjacent edge of the roof 4. From the ends of the rod 5, are suspended a pair of curved door frame members 6 having the same radius of curvature as the end walls. Each member 6, when in its downward position; extends slightly below the horizontal center of the side opening, as shown in Figure 2. The lower end of each member 6 is formed with an inwardly extending hinge knuckle 1.

Another hinge rod 8 is passed through the knuckles 1 and supports another pair of curved door frame members 9 depending therefrom by knuckles III at their upper ends. The latter also extend inwardly, while the members 9 form a continuation of'the members 6 on the same radius. Adjacent knuckles are formed with fiat faces H which abut each other when the door is in the closed or lowered position shown in Figure 2, for a purpose that will presently be described. One of the faces ll receives a set screw l2 locked by a nut l3 and engaging in a recess M in the opposite face, for taking up manufacturing tolerances in the construction of the door assembly.

The upper face I I engages either the lower face or the set screw l2 so that the weight of the upper door section bears on the lower section, holding the door firmly closed by preventing the lower section from swinging out. A tie rod l is passed through the lower ends of the member 9 to complete the frame structure. Grooves I! are formed in the end walls 2 and 3, as clearly shown in Figures 1 and 4.

Across each pair of opposed frame members 6 and 9 is laid and secured a sheet metal or other suitable door panel I8 adapted to fill the corresponding portion of the opening. These members extend beyond the outer edges and ends of their supporting frame members to enter the grooves l1 and cover the upper and lower margins of the opening when the door is in the dropped or closed position shown in Figure 2.

Pivot posts of the end walls 2 and 3 at points approximately vertically above the edges of the base I or the.

rods l5 when the latter are in their lowermost position. A guide link 20 extends from each end of each rod l5 to the post IS on the same side of the vertical axis of the nearer wall Each of the lower panels 18' hasa handle 2| 'near its lower edge. To open the door, the

handle is pulled upward and outward,-whereupon the rod I5 follows an arcuate path on the radius of links 29. The mutual engagement of the faces H prevents the lower section from swinging outward independently of the upper section. Consequently, as the handle is pulledupward, both door sections rise together, the upper section hinging on the rod 5 and the lower section on rod 8, with increasing separation of the knuckles 1, '10. I

The upper section precedes the lower section in reaching the full open position. Near the endof the movement, the rod I5 crosses the line A drawn through the pivot l9 and the hinge rod 8 in the full open position of the latter. When the line is crossed, the weight of the mass aids in completing the opening movement. The result of this action is that the door is held in its open position by its own weight, without the use of latches orsimilar devices.

The link 20 and adjacent member 9 may be regarded as a toggle. When the intermediate point E5 of the toggle crosses the line A, or the axis of alinement of the toggle, the weight of the door throws the intermediate point further in the same direction or to the locking position as i1- lustrated. In this position the link 20 holds the rod .8 spaced from the end walls and consequently supports some of the weight of the door.

The lamp housing contains projection'mechanism including a reflector 22. The construction of the door is such that, when in open position,

it clears the top of the reflector, permitting access thereto for cleaning or other purposes, without reaching under the door. By virtue of the folding action of the door, reflector is cleared without bringing the door too high above the housing or too far laterally of the housing, as would be the case with a rigid door. Maintaining the door within comparatively small space limits, during opening and closing, is important in view of the limited space in a projection booth and obstructing objects that may be positioned near the top and sides of the housing.

The absence of latches for holding the door open is also important. Latches frequently fail, or operators neglect to use them when working hurriedly, as a result of which the door is liable.

to fall on the arm of the operator and cause a serious injury since the door has considerable weight.

Although a specific embodiment of the inven- I9 extend inwardly from each I tion has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention, as indicated by the appended claims.

What I claim is:

1. In combination with a housing, a suspended door comprising a section hinged at its upper horizontal edge to said housing, another section hinged to the lower horizontal edge of the first section and adapted. to fold against the first section in open position, and a link hinged to the opposite and free edge of the second section and to said housing at a point between said free edge and the first hinge axis, said link and second section constituting a toggle when both sections are in open position, the first hinge aXis lying at one side of the axis of alinement of said toggle, and the free edge or intermediate toggle pivot being adapted to pass to the same side of the axis of alinement from the other side thereof in the opening movement of the door, whereby the weight of the door holds the door open.

2. In combination with a housing, a suspend ed door comprising a section hinged at its upper horizontal edge to said housing, another section hinged to the lower horizontal edge of the first section and adapted to fold against the first section in open position, and a link hinged to the opposite and free edge of the second section and to said housing at a point between said free edge and the first hinge axis, said link and second section constituting a toggle when both sections are in open position, the first hinge axis lying at one side of the axis of alinement of said toggle, and the free edge or intermediate toggle pivot being adapted to pass to the same side of the axis of alinement from the other side thereof in the opening movement of the door, whereby the weight of the door holds the door open, the second section being slightly shorter than the first section, whereby said free edge clears the first hinge axis in the open position of the door.

3. In combination with a housing, a suspended door comprising a section hinged at its upper horizontal edge to said housing, another section hinged to the lower horizontal edge of the first section and adapted to fold against the first section in open position, and a link hinged to the opposite and free edge of the second section and to said housing at a point between said free edge and the first hinge axis, said link and second section constituting a toggle when both sections are in open position, said sections being curved in continuation of each other outwardly of said housing, with said link and point lying on the concave side thereof, the first hinge axis lying at one side of the axis of alinement of said toggle, and the free edge or intermediate toggle pivot being adapted to pass to the same side of the axis of alinement from the other side thereof in the opening movement of the door, whereby the weight of the door holds the door open.

4. In a projection lamp housing having a reflector therein and a lateral openingadapted to expose substantially the full height of said refiector, a suspended door comprising a section hinged at its upper horizontal edge to said housing at the upper edge of said opening, another section hinged to the lower horizontal edge of the first section and adapted to fold against the first section in open position, and a link hinged to the opposite and free edge of the second section and to said housing at a point between said free edge and the first hinge axis, said linkand second section constituting a toggle when both sections are in open position, the first hinge axis lying at one side of the axis of alinement of said toggle, and the free edge or intermediate toggle pivot being adapted to pass to the same side of the axis of alinement from the other side thereof in the opening movement of the door, whereby the weight of the door holds the door open, said second section being of such length that the free edge takes a position at approximately the level of the first hinge axis in the open position of the door.

KARL BRENKERT.