Implements or apparatus for applying pushing or pulling force – Single throw lever – Special engaging feature
Reexamination Certificate
1998-06-18
2001-01-09
Scherbel, David A. (Department: 3723)
Implements or apparatus for applying pushing or pulling force
Single throw lever
Special engaging feature
C254S130000, C254S120000, C254S129000
Reexamination Certificate
active
06170803
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of this invention is that of leverage tools. The disclosed invention is a leverage tool for opening firmly sticking bottom halves of double-hung windows using an assembly of a specially designed lever and fulcrum.
2. Description of the Prior Art
The principles and applications of the lever and fulcrum as a contrivance for lifting or moving large weights or resistive objects a small distance with each throw of the lever has been known and used by laborers as well as sophisticated riggers, engineers, and builders from earliest civilizations until the present. In modern times there has been a proliferation of leverage tools for use in all manner of applications. However there is no known prior art in a lever and fulcrum assembly designed specifically for leveraging open firmly stuck bottom halves of double-hung windows.
SUMMARY OF THE INVENTION
When lower halves of double-hung windows slide freely in their frame guides they are easy to open manually by moderate upward finger and hand pressure against upper or lower horizontal window frame members. Some of these windows are manufactured with a fingerhold on a lower frame member to help in their opening. Some householders attach special hardware made in the form of fingerholds for the same purpose, especially if the windows are held a little to tight by frame guides. When, fogy of a number of reasons lower half of a double-hung window becomes firmly stuck in the closed position it generally cannot be opened by manual force alone. If screwdrivers and other inappropriate tools are used as levers in an attempt to pry open a sticking window, considerable damage to its frames and sills may result.
One of the purposes of the disclosed invention is to provide householders and handy persons with a tool that minimizes almost entirely the chances of damage when it is used to force open a sticking window. Use of initial force in such situations generally must precede other means to restore the ease with which a properly installed window should yield to routine opening and closing.
The disclosed invention consists essentially of two parts: a separate lever and fulcrum that can be temporarily assembled as an embodiment for placement on inner window sills of sticking lower window frames to leverage them open when they are firmly stuck in the closed or partially open position. The lever has two sets of horizontal crossbars. One set is located at the tip end opposite the handle area. The other set is approximately one inch above. The fulcrum has a level rectangular base, and an upright four sided body ninety degrees verticle to the base; the two wider verticle sides are pierced by a central, narrow, aperture. One of the wider sides has upwardly stepped ratcheting type indents along most of its length. The indents straddle the aperture.
When the disclosed tool is properly assembled and placed in a central position on an inner window sill of a sticking window frame that is fully closed, the crossbars at the tip of the lever are designed to fit under an existing fingerhold which may be used as a focal point or a focal point that has been installed on a lower horizontal window frame member by a user. When the lever's lower cross bars are in that position, the upper crossbars are spacially located to fit into the lowest ratcheting indent on the side of the fulcrum facing the window frame. If a lower window frame is stuck in a partially open position of only a few inches, the lever's lower crossbars may still be placed under a usable focal point on the lower horizontal window frame member, but the choice of a ratcheting indent on which the upper cross bars should be placed will depend on the height of the opening at which the window frame became stuck.
In either case, whether a stuck window frame is fully closed or partially open, when the disclosed leverage tool is positioned on an inner window sill in one of the operational positions described above, a firm downward thrust of the lever handle will force the lever's lower set of crossbars to exert an upward force against the focal point being used. This upward force, if strong enough, should overcome the forces causing the window frame to stick, resulting in a small initial upward movement of the window frame.
With the lever's lower set of crossbars still under the focal point being used, repeated repositioning of the lever's upper crossbars into a higher ratcheting indent on the fulcrum after each downward throw of the lever handle should increase the height of the window opening until the upper indent on the fulcrum is reached. This height is approximately five inches. If the window frame is still sticking firmly at this point additional opening height may be gained by placing a level block of wood or other available material several inches thick under the base of the fulcrum and restarting the leveraging operation from this added height.
There is, however, practical limit to the height above a window sill at which the disclosed tool can be operated. To gain additional height by using more than one block of material on top of another does not provide as stable a base for operation as the window sill itself. Instability might also occur because of excessive height of operation. An attempt to operate the disclosed tool above say eight or nine inches is not recommended because instability during its operation may result in overturning. If this should happen there is a possibility of damage to window elements and injury to a user.
The intended task of the disclosed leverage tool is not to force open mildly sticking windows. Such cases can usually be dealt with by manual efforts and subsequent use of window lubricants and other means. Nor can the tool be used to close lower window frames that are stuck in an open position. The primary purpose of the disclosed invention is to serve as a basic do-it-yourself tool for helping householders and handy persons return a badly sticking lower window frame to a normal operating condition. In all cases, the user of the disclosed tool will have to exercise some independent judgement as to the best way to accomplish this. To completely remedy a sticking window problem a householder may have to use other practical measures in conjunction with use of the disclosed tool.
The lever portion of the disclosed tool has already been briefly described. It may also be characterized as multi-purpose in that it is adaptable to various kinds of focal points including fingerholds built into lower horizontal window frame members or accessory focal points attached by a householder. When there is a suitable focal point already in place, the disclosed tool can be quickly assembled and deployed with little further preparation. For window frames lacking a suitable focal point the accessory focal point fittings which are part of the disclosed invention are available for user installation. The availability of these accessory focal points should prove to be important for householders whose homes are of an older vintage because wood frame windows in older homes are more likely to stick because of age related problems. The most suitable position for attaching one of the accessory focal point fittings supplied with the disclosed invention is in a central position on a lower horizontal window frame approximately an inch above an inner window sill when the window frame is in the closed position.
The accessory focal point fittings are supplied in two variations. Both are alike in all respects except that one variation is made of high tensile strength aluminum out of consideration for similarity of metals if the fitting is to be left permanently on an aluminum framed window after being attached as a focal point for leveraging purposes. The non-aluminum fitting should be made of high tensile strength brass or other ornamental metal for use on the more numerous wood and wood composition windows found in conventional housing. Some high tensile strength synthetic materials may also be considered for use as accessor
Mirick O'Connell DeMallie & Lougee LLP
Scherbel David A.
Wilson Lee
LandOfFree
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