BACKGROUND OF THE INVENTION
The present invention relates generally to window-locking devices and more particularly to window-locking devices which use magnetic parts.
A great variety of window-locking devices, both of the magnetic and nonmagnetic type, have been described in the prior art. One of the simplest types, disclosed in U.S. Pat. No. 370,235, Brady, issued Sept. 20, 1887, uses a pair of sliding bolts connected at right angles on the top of the lower window sash. One bolt engages a recess in the window frame to keep the lower sash from moving while the other bolt engages a groove in the upper sash to keep the upper sash from moving relative to the lower sash. In Brady, both bolts are spring-biased and none of the parts is magnetic.
Other nonmagnetic types of window locks, such as disclosed in U.S. Pat. No. 532,935, Woolery, issued Jan. 22, 1895, disclose spring or cam actuated bolts embedded in the sash and engageable with a recess in the frame to prevent movement of the sash relative to the frame.
Magnetic window retaining devices, such as disclosed in U.S. Pat. No. 1,289,315, Thomas, issued Dec. 31, 1918, and U.S. Pat. No. 2,524,924, Pampallona, issued Oct. 10, 1950, use magnets which coact with metal strips in the window frame. This type of device, however, does not provide a secure lock and rather serves to retain the window in a preset position.
It is the object of the present invention to provide a magnetic locking device for a window sash and frame that is simple to use and install and which is hidden from view.
It is a further object of the present invention to provide a window-locking device that may not be simply disengaged or released with one's fingers.
SUMMARY OF THE INVENTION
The window lock of the present invention includes a first rod member that is inserted in a channel drilled horizontally through the window sash. The rod projects through the inner end of the channel and into a corresponding recess in either the window frame or an adjacent window sash. The length of the rod is less than the combined length of the channel and the recess so that when the rod is inserted the outer end of the rod is recessed within the channel. In operation, the rod resides in both the channel and recess to lock the window in a closed position. Since the end of the first rod is recessed within the sash, it may not be easily removed with one's fingers and is not observable from the outside so that a burglar would be unaware of where the rod is located if he desired to cut through the window or otherwise render the lock useless.
In a preferred embodiment of the invention the first, or locking rod, is removed from the channel in the sash by means of a second rod which is magnetically attractive to the first rod. In general, either of the rods, or both, may be conventional permanent magnets in order to provide the magnetic force to remove the locking rod from the sash. In the case when only one of the rods is magnetic, however, the other must be a magnetically attractive substance, such as iron. For maximum flexibility it is preferred that both rods be identical so that either may be used for locking while the other is reserved to retrieve the locking rod.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view showing a window frame and upper and lower window sashes equipped with the window-locking device of the present invention;
FIG. 2 is a sectional view taken along the line 2--2 shown in FIG. 1;
FIG. 3 is a perspective view of the rod used in the locking device of the present invention shown in FIG. 1; and
FIG. 4 is a sectional view taken along the line 4--4 shown in FIG. 1.
In FIG. 1, a pair of the present window-locking devices 10 are shown in locking engagement between the window frame 12 and upper and lower window sashes 14 and 16, respectively. The window frame 12 and sashes 14 and 16, shown in FIG. 1, are of the conventional type wherein each sash moves in guides contained on each vertical side of the window frame 12.
In accordance with the invention, the upper and lower sashes 14 and 16 have channels 18 and 20 which continue through the side of the respective sashes on the indoor side of the upper and lower window panes. The window frame 12 has recesses 22 and 24 which form extensions of the channels 18 and 20 when the upper and lower sashes are in closed positions. As will be appreciated from the discussion below, it is preferred that the channels 18 and 20 and recesses 22 and 24 be in substantially horizontal planes to insure optimum functioning of the present locking device.
A pair of rods 30 of the type shown in perspective view in FIG. 3 are inserted through the channels 18 and 20 and into the corresponding recesses 22 and 24. The rod in the channel 18 is engaged in the recess 22 to lock the upper sash into position and the rod in the channel 20 is engaged in the recess 24 to lock the lower sash into position with respect to the window frame 12. Each of the rods 30 has a length greater than the length of the recesses 22 and 24 to insure that each rod resides in both the recess and its corresponding channel. Thus, both the upper and lower sashes are locked by the use of two rods. It may be appreciated, however, that either the upper or lower sash may be locked individually through the use of a single rod in a corresponding one of the channels 18 or 20.
The combined length of the channel 18 and recess 22 is greater than the length of the rods 30 so that when one of the rods is inserted in the channel 18 and recess 22 the rod is recessed within the upper sash 14. Similar measurements hold for the channel 20 and recess 24 associated with the lower sash 16. The fact that the rods 30 are recessed within the upper and lower sashes insures that they may not be removed with one's fingers. In addition, because the rods are recessed the position of each rod is hidden from view so that a burglar cannot simply determine the position of each lock, in order to cut through the window or otherwise render the lock useless.
In a preferred embodiment of the present invention, the means for removing the rods 30 from the channels 18 and 20 and recesses 22 and 24 is an identically shaped rod 31 which is magnetically attractive to the rods 30 and which may be inserted into the channels 18 and 20 to retrieve the rods 30. For maximum retrievability, it is preferred that both the retrieving rod and the locking rods 30 be permanent magnets to insure that there will be sufficient magnetic attractive to retrieve the rods 30 from each channel and recess. In general, however, it is only necessary that one of the rods be a magnet if the other rod is magnetic, such as iron.
Maximum flexibility is achieved when the retrieving rods 31 have the same shape and length as the locking rod 30 and when all of the rods are magnetic since in that case all the rods are suited for use in the channels 18 and 20 and any of the rods may be retained to retrieve the locking rods in the sashes. In addition, when all the rods are identical, manufacture and packaging may be more uniform and economical.
As shown in FIG. 3, the channels 18 and 20 and recesses 22 and 24 of the window shown in FIG. 1 are cylindrical. The rods 30 are also cylindrical in order to conform to the cross-sectional shape of the channels 18 and 20 and the recesses 22 and 24. It may be observed, of course, that any shape may be used for either the channels, the recesses or the rods so long as each rod is easily inserted within a channel and serves to lock the window sash in position relative to the window frame. The clearance between the rod and the channel and recesses must be such that the locking rod may be removed by the magnetic attractive force of the retrieving rod. As indicated above, the channels 18 and 20 preferably are positioned in a horizontal plane. This positioning insures that the rods will remain in the locking position within the channel without the need of a positive retaining force while at the same time being retrievable from the channel with a minimum magnetic force.
Each of the rods 30 and 31 has a hole 32 through one end to permit the ready storage of the rods on a conventional hook 34 near the window frame, as shown in FIG. 1, when the rods are not in use. The edges of the hole 32 are flush with the sides of the rod so that there are no protrusions which affect the movement of the rod in the channels 18 or 20. In the case when the rods 30 and the retrieval rods are identically shaped magnets, the holes 32 may be made on the ends of the rods which have the same magnetic polarity. Thus, the hole 32 may serve, in addition, as an indicator for the user to determine which ends of the rods will attract. The user may then establish a convention for use of the rods so that a predetermined end of the retrieval rod will always attract the locking rod in the sash. Alternatively, each of the rod magnets may have each end color coded to distinguish the positive and negative ends so that the polarity of each end may be determined by color even when the rod is inserted in the sash.
As may be seen for the conventional window sashes 14 and 16 shown in FIG. 1 the top horizontal section of the lower sash 16 overlaps the bottom horizontal section of the upper sash 14 when both windows are closed. An alternative method by which the magnetic rod 30 may be used to lock the window sashes 14 and 16 is to provide the top horizontal section of the sash 16 with a channel 36 and the lower horizontal section of the sash 14 with a recess 38, as shown in FIGS. 1 and 4. In this alternative the rod 30 resides in both the channel 36 and the recess 38 to prevent relative movement of the upper and lower window sashes when both windows are closed. The rod 30 operates in the same manner in the channel 36 and recess 38 as the remainder of the rods 30, described above, except that the use of a single rod residing in both the upper and lower sashes, as shown in FIG. 4, serves to lock both windows instead of one. Thus, the channel 36 and recess 38 may be used either singly with the rod 30 or to lock both windows together in conjunction with other rods 30 in the manner earlier described.
In conclusion, therefore, it may be seen from the above description that a magnetic locking device is disclosed for a window sash and frame that is easy to install and use and that is hidden from view when in use. The present window lock, therefore, has the distinct advantage that a burglar would be unaware of where the rod or rods were located so that he could not simply render the lock useless. Finally, the lock has the additional advantage that it does not form an unsightly protrusion on the window sash which would tend to have a displeasing aesthetic effect on the viewer.