This invention relates to anti-ligature locks and door handles designed to prevent suicide by preventing the attachment of a ligature to the door handle or the lock mechanism.
Buildings such as hospitals, mental health facilities, prisons, detention centers and the like are locations where patients, inmates and detainees are subject to stress and high levels of emotion. Under such circumstances, there is an increased risk of suicide by those within. Such events may be referred to as “sentinel events.”
A common type of attempted suicide or self-harm is by hanging or strangulation by attaching a ligature, such as clothing or a belt to a conventional door knob or lever handle. Because it is not possible for all patients and inmates to be continuously monitored, public buildings of the aforementioned type are increasingly being provided with specially designed anti-ligature locks and door handles. The use of such anti-ligature locks and handles can significantly reduce or eliminate the occurrence of sentinel events, i.e., suicide and/or self-inflicted injuries.
A conventional knob or lever handle allows clothing or a belt to be attached to the handle of the lock mechanism. Anti-ligature locks and door handles function by eliminating projections and hanging points, which prevents clothing or belts from being attached to the handle.
However, by eliminating such projections conventional anti-ligature handles are often difficult to grasp and operate. This is a particular problem in hospitals where the elderly, those with infirmities and/or those with limited use of their hands must be able to operate the door. There is a need for an anti ligature lock having a handle design that is as easily operated as a lever handle.
Many attempted suicides involve the use of clothing or a belt as a ligature, However, even where an anti-ligature handle has been installed, a patient intent on self-harm may attempt to insert a small diameter ligature, such as dental floss or thread, into joints or spaces between moving handle components.
Such joints would not normally provide a hanging point for clothing, belts or ropes. However, when multiple threads or lengths of dental floss are combined, it may still be possible for a conventionally designed anti-ligature lock or door handle to provide a hanging point. There is a need for an anti ligature lock handle design that prevents small diameter ligatures from being inserted into gaps, spaces or joints in the handle to eliminate all hanging points for such small diameter ligatures.
Another problem with conventional anti ligature lock handles is that they do not have an attractive appearance. There is a need for an anti ligature lock handle design that is attractive and provides a modem appearance.
The present invention provides a handle design that is both attractively modem in appearance and which effectively prevents the handle from providing a hanging point for suicide attempts. The handle is designed such that ligatures of large and small diameter slide off the outer surface of the handle to foreclose use as a hanging point.
In a preferred aspect of the invention, the design of the handle is such that when small diameter ligatures, such as dental floss are inserted into joints in an attempt to attach to the door handle, the ligature is either directly prevented from passing through the joint by closing the gap entirely, or the end of the ligature is guided into a dead end to prevent it from passing through the gap.
This is achieved in one aspect of the invention by providing a handle plate parallel to the surface of the door on which the handle is mounted. The handle plate is connected to the handle and slides behind an escutcheon plate, such that it is not possible to insert a ligature behind the handle without passing it upwards from the handle between the escutcheon plate and the handle plate. The handle plate has a smooth appearance that is exposed as the handle pivots down to open the door. The inner surface of the escutcheon plate has multiple inverted “ligature traps,” preferably in the form of inverted “V” shapes or “U” shapes. The inverted ligature traps prevent a small diameter ligature from passing upwards between the handle plate and the escutcheon plate. This prevents passing a small diameter ligature around the handle.
The ligature traps are fanned as small ridges set in offset rows and have a low height such that the V-shaped surface rides against the moving handle plate with very little space between the handle plate and the repeated surfaces of the ligature traps. The ligature traps are preferably formed of a low friction plastic.
The handle plate is securely attached to the back of the handle or formed integral therewith such that it is not possible for a small diameter ligature to pass between the handle and the handle plate. If an attempt is made to pass a small diameter ligature behind the handle, the handle plate forces the ligature upwards behind the escutcheon plate in the area above the handle.
The ligature traps are fanned on the side of the escutcheon plate that faces the door. Preferably, the back side of the escutcheon plate is provided with a molded anti-friction plastic liner attached to the escutcheon plate, between the escutcheon plate and the handle plate. The anti-friction plastic liner for the escutcheon plate contacts the moving handle plate.
The ligature traps are preferably in the form of low-height, inverted, V-shaped ridges. Inverted U-shaped ridges or similar dead end shapes may also be used. The legs of the U or V-shape guide the ligature into the dead end when a ligature is inserted from below to prevent it from passing any further upwards.
The V-shape acts as a dead end only from below. When seen from above, the inverted V or U-shape acts to guide debris to the gaps between each element and thus out of the lock mechanism. To prevent a ligature from passing through the gaps between adjacent ligature traps, multiple offset rows of ligature traps are provided.
If a ligature passes upwards between two adjacent ligature trap elements of a lower row of traps, it will immediately enter a dead end ligature trap in the offset row above. Thus, no matter where the ligature is inserted, it reaches a dead end.
The anti-ligature handle is pivoted at one end similar to a lever handle to allow for easy operation. The shape of the anti-ligature handle is smoothly curved in such a way that a user may place fingers behind the upper edge of the handle and between the upper edge of the handle and the handle plate, but without providing any opening behind the handle. This allows a pulling force to be easily applied to the door.
In the preferred design, the escutcheon completely surrounds the handle. The escutcheon provides a recessed area where the handle pivots. The recessed area is preferably triangular in shape. The handle plate preferably extends underneath the escutcheon in the area above the handle and extends beyond at least the moving end of the handle. As the handle is rotated down to open the door, the handle plate is exposed from beneath the escutcheon above the handle, while the handle plate at the moving end of the handle passes underneath a lower edge of the surrounding escutcheon plate.
This functions to prevent a small diameter ligature from passing behind the lower end of the handle or behind the handle plate. In a more highly preferred aspect of the invention, the handle plate at the moving end of the handle includes a guide that slides within a guide track formed in the escutcheon along the moving end of the handle.
A preferred embodiment of the present invention will be described below in some detail, but those skilled in the art will understand from the principles described below how to apply the present invention to handle designs having different handle shapes and escutcheons than those described herein.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide an anti-ligature lock having a handle that moves within a triangular recess in an escutcheon where a handle plate extends beneath an escutcheon plate provided with ligature traps.
The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:
In describing the preferred embodiment of the present invention, reference will be made herein to
Referring to
The handle 10 rotates within an approximately triangular shaped recess 20 in an escutcheon 22 that surrounds the handle 10. The lower end 18 slides along an arcuate lower edge 24 of the recess 20 in the escutcheon 22.
As can be seen in
The handle 10 includes an upper edge marked at 10a and 10b. The user may reach beyond this upper edge and place fingertips behind and below this upper edge which allows the handle to be operated more easily. This shape also allows the user to reach behind the upper edge 10a, 10b of the handle and pull the handle towards the user which allows the handle to be used to pull the door 16 towards the user.
Referring to
Referring to
The escutcheon plate 30 which forms the upper surface of the escutcheon 22 is preferably provided with an anti-friction escutcheon liner 34 made of plastic. As will be described below, the opposite surface of the anti-friction escutcheon liner 34 is provided with ligature traps.
The anti-friction escutcheon liner 34 is provided with short studs 36 that project out from the anti-friction escutcheon liner surface to engage correspondingly shaped openings formed on the opposite side of the escutcheon plate 30. The studs 36 couple the liner 34 to the hidden surface of the escutcheon plate 30. The escutcheon 22, including the escutcheon plate 30, the anti-friction escutcheon liner 34 and the backing plate 32 from a stationary unit which is fixed relative to the door 16.
The back surface of the handle plate 28 is provided with an anti-friction handle liner 38, which is also preferably formed of a low friction plastic. The handle plate 28, the anti-friction handle liner 38 and the handle 10 form a moving unit and move together as the handle is rotated. The anti-friction handle liner 38 and the handle plate 28 are tightly attached to the back side of the handle 10 with screws 40.
The escutcheon 22, handle plate 28 and backing plate are all preferably made of stainless steel, although other materials may be used. It can be seen that this construction makes an alternating layered structure of stainless escutcheon plate 30, plastic anti-friction escutcheon liner 34, stainless handle plate 28, anti-friction handle liner 38 followed by stainless backing plate 32. This alternating stainless steel plastic design provides for low friction, great strength and silent operation characteristic of high quality products.
The backing plate 32 is attached to the escutcheon 22 with screws 42. A bushing 44 attaches to the door and long studs 46 pass through the lock and cooperate with screws 48 for final mounting.
The lower edge of the anti-friction handle liner 38 is provided with a raised guide 50 formed as a ridge along the curved edge thereof. The curvature of the ridge matches the curvature of lower edge 24 of the recess 20 in the escutcheon 22. The raised guide enters and slidingly engages a corresponding guide track 58 (see
The raised guide 50 may be formed as part of the plastic anti-friction handle liner 38 or as part of the handle plate 28. The anti-friction handle liner 38 is provided with studs 54 around its perimeter which engage matching holes 56 in the handle plate 38. The short studs 54 and matching holes 56 lock the anti-friction handle liner 38 to the handle plate so that they move together as the handle 10 is rotated.
The handle 10 is typically biased upwards to the closed position by springs located in the lock mechanism. A resilient bumper 52 is provided in the escutcheon which acts to silently stop the upward return motion of the handle when the handle is released.
The space behind the upper edge 10a, 10b of the handle forms a downwardly curved groove or channel which is not open. This prevents attachment of a ligature behind the handle 10. In
The raised guide 50 slides inside the escutcheon just inside the curved edge 24. The thickness of the raised guide 50 is greater than the size of the curved opening along 24. This traps the raised guide 50 inside the lower edge 24 of the escutcheon and prevents ligatures from entering there.
As can also be clearly seen in the side elevational views of
Referring to
In
It can also be seen in
The front surface of the handle plate 28 (which is partially exposed in
The guide track 58 can be seen in the back view of
Referring also to
If by chance the ligature passes through the small gap between adjacent ligature traps, it will project into the dead end formed by the inverted V of the ligature trap in the offset row immediately above the gap. It will be seen that it is not possible to pass ligatures in the upwards direction around the handle. The rows of ligature traps act as a one-way barrier to prevent upward insertion of any ligature even if small diameter or stiff ligatures are used.
The ligature traps are shallow ridges and the surfaces of those ridges ride against and wipe the smooth surface of the handle plate 28 as the handle 10 is operated. This wiping action also wipes off any dirt or debris from the surface of the handle plate 28 as the handle returns. The dirt is wiped into the inverted V and subsequently falls out by the force of gravity.
In the event that any dirt passes into a gap, it will be swept into the inverted V in the next row due to the offset row construction. Any liquid or dirt can eventually work its way down from the upper rows of the ligature traps as the edges of the upper rows funnel liquid or debris into the gaps in those rows, and the inverted V shapes in the subsequent rows then act to move the liquid or contaminants laterally to the gap in that row.
In the preferred design, the V-shaped ligature traps are separate and have small gaps between each trap. Alternatively, the ligature traps may be formed as a continuous horizontal zigzag, but by forming them as individually spaced elements with a small gap between each element, dirt, dust, water and other contaminants are prevented from accumulating on the upper side of the traps.
While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2013/044275 | 6/5/2013 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2013/184773 | 12/12/2013 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
266947 | Marks | Oct 1882 | A |
352213 | White | Nov 1886 | A |
469863 | Zerfas | Mar 1892 | A |
609422 | Fackner | Aug 1898 | A |
633291 | Newell | Sep 1899 | A |
646233 | Newell | Mar 1900 | A |
975037 | Hettwer | Nov 1910 | A |
1090305 | Hoffman | Mar 1914 | A |
1326450 | Howard et al. | Dec 1919 | A |
1434370 | Crompton et al. | Nov 1922 | A |
1738387 | Niessen et al. | Mar 1929 | A |
D114315 | Brodbeck | Apr 1939 | S |
2304145 | Borchers | Dec 1942 | A |
2321724 | Aldeen et al. | Jun 1943 | A |
D145210 | Fisk | Jul 1946 | S |
2531670 | Cain | Nov 1950 | A |
2581606 | David et al. | Jan 1952 | A |
2755120 | Young et al. | Jul 1956 | A |
2813737 | Reiter | Nov 1957 | A |
3038757 | Schulze | Jun 1962 | A |
3713683 | Neary | Jan 1973 | A |
3792887 | Ramsey | Feb 1974 | A |
4064721 | Morgan | Dec 1977 | A |
D267194 | Baker | Dec 1982 | S |
4404709 | Janz et al. | Sep 1983 | A |
4492394 | Dignan | Jan 1985 | A |
4575141 | Burns | Mar 1986 | A |
5303965 | Meehan | Apr 1994 | A |
5348355 | Oyha | Sep 1994 | A |
5797286 | Armstrong | Aug 1998 | A |
5918916 | Kajuch | Jul 1999 | A |
6135512 | Galvin | Oct 2000 | A |
6460906 | Bingle et al. | Oct 2002 | B2 |
7373694 | Kopp | May 2008 | B1 |
7617707 | Chiang | Nov 2009 | B2 |
7802828 | Hopkins et al. | Sep 2010 | B2 |
8052182 | Weinerman et al. | Nov 2011 | B1 |
8122745 | Ramsauer et al. | Feb 2012 | B2 |
D680849 | Berger | Apr 2013 | S |
D690577 | Eller | Oct 2013 | S |
9033375 | Moon | May 2015 | B1 |
20030135956 | Gunthardt | Jul 2003 | A1 |
20030150247 | Talpe | Aug 2003 | A1 |
20060220398 | Ruano | Oct 2006 | A1 |
20100013248 | Keller | Jan 2010 | A1 |
20100072762 | Marks | Mar 2010 | A1 |
20100126239 | Berger | May 2010 | A1 |
20100327611 | Rees | Dec 2010 | A1 |
20110068927 | Berger | Mar 2011 | A1 |
20110120024 | Shilts | May 2011 | A1 |
20110174026 | Salvatore et al. | Jul 2011 | A1 |
20130270844 | Berger | Oct 2013 | A1 |
20140311194 | Berger | Oct 2014 | A1 |
Number | Date | Country |
---|---|---|
1008810 | Aug 1996 | BE |
10053062 | May 2002 | DE |
1927709 | Jun 2008 | EP |
718113 | Nov 1954 | GB |
2276659 | Oct 1994 | GB |
2413068 | Oct 2005 | GB |
2459884 | Nov 2009 | GB |
1970021044 | Aug 1970 | JP |
000492398 | Jan 1979 | JP |
05240972 | Sep 1993 | JP |
000895580 | Apr 1994 | JP |
2004162401 | Jun 2004 | JP |
2004324250 | Nov 2004 | JP |
0003137332 | Oct 2007 | JP |
WO 2010092398 | Aug 2010 | WO |
Number | Date | Country | |
---|---|---|---|
20150130197 A1 | May 2015 | US |
Number | Date | Country | |
---|---|---|---|
61655795 | Jun 2012 | US |