The term"door"is used to indicate, throughout this description and the appended claims, a door of any type having one or more panels turning on pintles, such as entrance and access doors, door windows, security doors, fire doors, gates, and the like, and made to any shape and/or construction and/or weight from any materials, including wood, wood and glass, glass, steel, and any other materials commonly entering a door construction.

It is well known that, in taking a door down from its case, the operations involved basically consist of hoisting the door off the doorjamb pintles and shifting it, typically but a short distance away from the doorcase.

These operations are only deceivingly simple to perform where a door or the like happens to be of substantial size and weight, or where the door structure lacks adequate handholds for the operators. Also, once the door has come off its pintles, it must be held up by strength of arms to avoid scoring the floor surface, and this in a rather insecure condition of balance.

Even more awkward may prove to be mounting a door panel the first time or returning it to its case. In order for the door to become ultimately seated onto the doorjamb pintles, it is first necessary to take it by the doorjamb in an upright position while raised off the floor, and then align it true to the pintles, again by hand power alone.

These difficulties are enhanced by the above operations being carried out with unskilled help, or by unfamiliar persons with the tricks of the trade. It should be further considered that mounting or dismounting a heavy type of door, such as a security door, is usually a job for two or

more skilled operators.

It is a primary object of this invention to provide a door lifting device with suitable structural and functional characteristics to overcome the above difficulties, even where a door is to be mounted or dismounted by an unskilled person.

These and other objects to become apparent from the following description are achieved by a device for mounting and dismounting a door to/from a doorjamb, which device is, according to the invention, characterized in that it comprises: a plate-like base formed, along opposite sides thereof, with upturned edges effectively defining a door lifting deck therebetween; a first class lever having its resistance end mounted pivotally on at least one of said upturned edges about a lever pivot axis lying parallel to said door lifting deck and perpendicular to said lever, said axis being situated a predetermined distance away from said door lifting deck; a fulcrum support, essentially consisting in a truck being rigidly attached to said lever and having at least one wheel mounted for free rotation about a fulcrum axis which lies parallel to said lever pivot axis; a handgrip defined at the power end (9b, 1 Ob) of said lever (1).

Advantageously, said lever comprises a rigid frame comprising two straight sectional members extending parallel to each other and being held apart by stiffening crosspieces, as well as having first ends which constitute said resistance end of the lever and are pivoted, about a common axis, on respective upturned edges of said plate-like base, and having second ends, opposite from the first, which constitute said power end of the lever.

Preferably, the plate-like base of the device according to the invention is of small thickness, so that it can easily fit through the gap between the underside of a mounted door and the floor, the upturned edges of said base being spaced apart to accommodate the thickness of said door.

The features and advantages of the invention can be more clearly

understood by reading the following description of an exemplary embodiment of the device according to the invention, given with reference to the accompanying illustrative and non-limitative drawings.

In the drawings: Figure 1 is a perspective view of a door lifting device according to the invention; Figures 2 to 4 are schematic front, side and rear views, respectively, of the device shown in Figure 1; Figures 5 to 8 show the device of this invention at different stages of its operation; Figures 9 to 11 show modified embodiments of the inventive device.

Referring to the drawing views, a device according to this invention, useful for mounting and dismounting a door from a doorjamb, comprises a rectangular plate-like base 1 having the edges 2,3 of its long sides turned upward square to it, so as to lend a U-shaped cross-section to said base.

A flat surface is defined between said edges 2 and 3 which forms a door lifting deck la, as explained in further detail hereinafter.

The gap between the upturned edges 2 and 3 is selected to loosely accommodate the thickness of a door or the like to be lifted.

The plate-like base 1 has small thickness and bevelled short side edges in order to be easily slid under a door, through the clearance space between the door and the floor.

The device of this invention further comprises a lever of the first class, generally designated 8, which consists, in a preferred embodiment, of a frame 8a comprising a pair of straight sectional members 9 and 10 which extend parallel to each other and are held apart by stiffening crosspieces 11,12.

Advantageously, said sectional members 9,10 are angle bars, and in the preferred embodiment of the frame 8a, are laid with their concavities

facing outward of the frame.

A first pair of ends (or first ends) 9a, lOa of said sectional members 9, 10 constitute the"resistance end"of the lever 8, whereas a second pair of ends (or second ends) 9b, lOb, opposite from the first, constitute the lever "power end".

Said first ends 9a, lOa are mounted for free pivotal movement on respective upturned edges 2,3 of the plate-like base 1, have their pivot axis R laid perpendicular to the lever 8, and are mounted advantageously to the outside of said edges a suitable distance away from the door lifting deck la.

The ends 9b, 1 Ob of the second ends, are interconnected by the stiffening crosspiece 12 which is advantageously fashioned as a handgrip for handling the lever 8.

Generally shown at 13 and 14 are two identical trucks, each comprising, in a preferred but not limitative embodiment, an essentially triangular plate-like support and two pairs of identical wheels, 17-17,18- 18 (19-19,20-20) mounted on two apical tips of said plate-like support for free rotation about perpendicular axes to the support.

Each one of said plate-like supports 15,16 is conventionally attached, at its respective third apical tip, to a corresponding one of the sectional members 9 and 10, perpendicularly to the plane of the frame 8a so as to jut out of one side thereof.

It should be noted that the wheel pairs 17-17 and 19-19 of the trucks 13 and 14 lying closest to the axis of pivotal connection of the lever 8 to the door lifting deck have a common pivot axis extending perpendicularly to the lever 8; this axis is designated F since it also forms the fulcrum axis of said lever, as explained hereinafter.

Advantageously, a third truck 21 is attached to the middle of the stiffening crosspiece 11 of the frame 8a which extends intermediate the handgrip 12 and the fulcrum axis F. The third truck 21 comprises at least one wheel 22 mounted for free rotation about a respective axis 21a which lies parallel to said fulcrum axis F.

The operation of the inventive device will now be described with reference to Figures 5 to 8.

In order to dismount a door P from a doorjamb I, i. e. to lift said door P off the pintles C on said doorjamb, the device of this invention is brought to the door P in a condition of raised lever 8 (Figure 5), and is pushed towards the door to engage the door lifting deck 1 nicely under the door. It should be noted that the stiffening crosspiece 11 is so placed on the frame 8a that the plate-like base 1 will be located substantially symmetrically about the vertical centerline of the door as the crosspiece 11 contacts the latch side of the door. At this point, the lever 8 is swung down about its axis R of pivotal connection to the base 1, until the set of wheels 17-17,19-19 of the fulcrum axis F"touch"the floor. Then, by exerting a suitable force on the power end of the lever (which end is embodied by the lever handgrip 12), the deck la can be raised correspondingly, and the door P with it.

This lifting action is guided initially by the door sliding along its pintles, and is continued until the other set of wheels 18-18,20-20 come to rest on the floor. The distance of the pivot axis of this wheel set from the fulcrum axis F is selected to have the door positively disengaged from its pintles upon the wheels of the trucks 13 and 14 contacting the floor surface. In this condition, the door must be held upright, while still applying a suitable force to the power end of the lever 8. This is accomplished by the lifting operator grasping the door edgewise with a hand to hold it upright by application of a minor amount of balancing force.

It should be noted that the wheel 22 of the truck 21 will be in contact with the floor surface at the same time as the wheels 18-18,20-20, so that the whole frame 8a (Figure 7) is turned into a dolly bearing an off-center load P (the door) just counterbalanced by the force maintained on the power end 12 of the lever 1. In this condition, the dismounted door P can be readily shifted elsewhere risking no damage to the floor.

At the intended place, the force on said power end is gradually decreased until the plate-like base 1 bears on the floor (Figure 8). At this point, the lever 8 can be returned to its original position by pivoting it

about the axis R on said base.

When the door P is to be mounted back to its doorjamb, i. e. re- engaged on the corresponding pintles, the door-bearing base 1 is lifted slightly off the floor and rolled to the doorjamb with the door P just braced upright thereon. At the doorjamb, the door is raised further to a suitable level for engagement with said pintles and aligned above the pintles. At this point, by gradually decreasing the force applied to the power end of the lever 1, the door is dropped gently onto its pintles.

Now, by returning the lever 1 to the vertical position (the original setting of the inventive device while not in use), the plate-like base can be withdrawn from under the door P and the device made available for further use.

Many design changes and modifications may be made unto the invention as described, all within the scope of this innovative concept.

For example, the trucks 13 and 14 could be provided with a plate-like support (Figure 9) of rectangular or any selected polygonal or circular form. Alternatively (Figure 10), the device could be provided with a single truck, itself having one wheel for each of the sectional members 9,10, which would be mounted on a simple bracket for free rotation about a respective fulcrum axis F.

Also, said single truck (Figure 11) could comprise twin wheels freely rotatable about pins carried on respective sectional members 9 and 10 of the frame 8a.

Although having the upturned edges 2,3 span the full length of the plate-like base can be of advantage, these edges could be a somewhat smaller form, e. g. that of simple ears bearing the lever pivot pin R.

Further changes and modifications, well within the capabilities of a skilled person in the art, may be made unto the present invention, as well as the dimensions and materials for its implementation, without in so doing departing from the protection scope of the invention as defined in the appended claims.