Door latch assembly with see-through capabilities

A door latch assembly for a door in which the latch assembly has a member which is transparent or translucent to allow light to pass therethrough and being operable to support a door knob structure.

This invention relates to improvements in latch apparatus for doors and, 
more particularly, to door latch assembly which is decorative in 
appearance as well as functional in operation. 
BACKGROUND OF THE INVENTION 
Swinging doors have latch mechanisms which are concealed in the doors and 
generally there is nothing decorative about the external appearance of 
such a latch mechanism other than to provide for ornate door knobs, 
keyhole plates and the like. Because of the desire of homeowners and 
others to improve the decor of rooms of a home, there is an ongoing need 
to enhance the ornamentation of hardware for doors, windows and the like, 
and especially for doors which, except for door knobs therein, do not get 
sufficient attention of interior decorators when improving a home. The 
present invention is directed to the satisfaction of this need by 
providing an attachment for a door which is both aesthetic in appearance 
and functional in operation and which is easily implemented in existing or 
new doors of all sizes and types. 
SUMMARY OF THE INVENTION 
The present invention is directed to a door latch assembly for a door in 
which the latch assembly has as an integral part a member which is 
transparent or translucent to allow light to pass therethrough. Thus, the 
member, while serving as a functional part of the latch assembly itself, 
also serves to provide an aesthetic effect in that the door knob structure 
coupled to the member appears to be suspended in space and to have no 
apparent mechanical connection with any other part of the latch assembly 
or the door. Thus, the latch assembly of the present invention provides 
ornamentation for a door which serves not only to enhance the decor of a 
room but also serves to stimulate the interest in persons observing the 
door because of the capability of the latch assembly to pass light 
therethrough while seemingly providing no apparent support for the door 
knob structure coupled to the member. 
The primary object of the present invention is to provide a latch assembly 
for a door in which the latch assembly includes a member through which 
light can pass, the member being operable to support a door knob structure 
yet the member is of a material which is such that a door knob structure 
appears to be mounted in space with no apparent mechanical connection to 
any other part of the door latch assembly or the body to thereby enhance 
the ornamentation of the door as well as to stimulate the interest in 
persons observing door and latch mechanism mounted on the door. 
Other objects of this invention will become apparent as the following 
specification progresses, reference being had to the accompanying drawings 
for an illustration of the invention.

The door latch assembly of the present invention is broadly denoted by the 
numeral 10 and is adapted to be used with a door 12 having spaced hinges 
14 for mounting the door for swinging movement about a generally vertical 
axis through the hinges. The door knob assembly 10 includes a door knob 
structure 16 coupled to a see-through member 18 through which light can 
pass. Thus, the panel is transparent or translucent. 
The member 18 can be made of glass, tempered glass or plastic and typically 
is disk shaped as hereinafter described. The member 18 is viewable through 
a pair of spaced holes 20 in door 12 as shown in FIG. 2, the holes 20 
communicating with a mortise 23 extending into the door from the end face 
25 of the door. 
The member 18 is rotated by manual rotation of door knob assembly 16 to 
retract a latch bolt 22 into the door. Release of the turning force on the 
door knob structure 16 causes the latch bolt 22 to return to its extended 
or operative position shown in dashed lines in FIG. 1. 
The fact that the member 18 is transparent or translucent provides not only 
an aesthetic effect but also a functional effect which cannot readily be 
discerned by looking at the door knob structure or at the member 18 
itself. Generally, the surface of the member 18 will be sufficiently clear 
of visible marks so that rotation of the member is not apparent. Thus, the 
average person will not be able to determine how the door latch assembly 
operates, and the assembly will appear to have a seemingly magical effect 
in that door knob assembly 16 appears to be suspended in space. This 
effect will stimulate the interest of the user of the door yet the 
assembly 10 is operative at all times upon rotation of the knob structure 
16. 
Latch assembly 10 includes a support in the nature of a plate having a 
number of bearings 26, 28, 30 and 32 mounted on the inner face 34 of the 
plate for rotation about generally horizontal axes. The bearings are 
adapted to support member 18 at the outer periphery thereof so that the 
member is rotatable about its central axis 36 which is generally 
horizontal when the latch assembly 10 is properly installed in the door. 
To facilitate the support of the member 18, a cylindrical band 38 is 
mounted in any suitable manner in surrounding relationship on the outer 
periphery of member 18, and the band engages the cylindrical outer 
surfaces of bearings 26, 28, 30 and 32 as shown in FIG. 3. 
Plate 24 has a hole 40 therethrough which is generally rectangular or 
square in configuration. Hole 40 is aligned with holes 20 (FIG. 2) in door 
12 when assembly 10 is installed in the door. 
Member 18 has door knob structure 16 thereon to permit manual rotation of 
the member about its central axis 36 in either direction. To this end, 
door knob structure 16 includes a pair of door knob elements 56 and 62 
(FIG. 5). Elements 56 and 62 have sleeves 60 thereon for receiving 
respective ends of a shaft 58 which connects sleeves 60 to shaft 58. The 
shaft has flats on it for engaging the inner surfaces of a hole 61 (FIG. 
3) through member 18 when shaft 58 extends through hole 61. Thus, door 
knob structure 16 is releasably but rigidly secured to member 18 so that 
manual turning or rotation of either element 56 or 62 in either direction 
will cause rotation of member 18 in the same direction. 
A rigid tab 63 is secured to and extends radially outwardly and downwardly 
from band 38 as shown in FIG. 3. Tab 63 has a pair of curved rods 65 which 
extend laterally from the outer end of tab 63 in opposed directions. Coil 
springs 67 receive respective rods 65 and the outer ends of the springs 67 
are secured to pins 66 which are rigid to plate 24. Rods 65 move relative 
to and past pins 66 when member 18 is rotated in opposite directions. As 
the member 18 is rotated in one direction, the corresponding spring 67 is 
compressed to increase the bias force on tab 63, tending to return member 
18 to its equilibrium position shown in FIG. 3. 
A second, rigid tab 68 is rigid to and extends radially outwardly from band 
38 near the top of the band as shown in FIG. 3. Tab 68 extends through a 
slot 70 in a link 72 which is pivotally secured by a pin 74 at one end 
thereof to the inner end of latch bolt 22 (FIG. 3) and at the opposite end 
to a washer 76 which is slidably received on a rod 78 having a coil spring 
80 surrounding the same. One end of the end coil spring and one end of the 
rod 78 are connected to the pin 82 (FIG. 3). Thus, movement of link 72 to 
the right when viewing FIGS. 3 and 4 will cause spring 80 to compress 
further and to increase the bias force on link 72, tending to move it to 
the left when viewing FIGS. 3 and 4. 
A first bearing member 84 is pivotally mounted by a pin 86 on support plate 
24 at a location above link 72 and between tab 68 and latch bolt 22. The 
pin 86 is intermediate the ends of bearing 84, and the bearing is 
pivotally mounted to a pin 88 rigidly carried by link 72 near pin 74 as 
shown in FIG. 3. 
A bearing 90 carried by a projection 92 on tab 68 is normally spaced from 
an inclined bearing surface 94 on bearing 84 yet the bearing 90 is aligned 
with bearing surface 94 so that, for sufficient angular travel of tab 68 
about the central axis 36 of member 18, bearing 90 will engage surface 94 
and rotate bearing 84 in a counter clockwise sense (viewing FIG. 3) about 
the axis of pin 86. This will cause the lower end of bearing 84 to move 
link 72 to the right when viewing FIG. 3, causing latch bolt 22 to be 
pulled to the right and into a retracted position in which the outer end 
of the latch bolt is substantially within or interiorly of a latch plate 
96 secured and extending outwardly from one end margin of support plate 
24. There will be some lost motion of tab 68 in slot 70 before bearing 90 
engages bearing surface 94. This lost motion is provided to allow for an 
average angle of rotation, such as 15 to 20 degrees, of member 18 before 
bearing 84 is pivoted in a clockwise sense about the axis of pin 86, 
tending to retract latch bolt 22. 
As link 72 moves to the right to retract latch bolt 22, spring 80 is 
compressed to increase the bias force on the link 72, tending to return it 
to its equilibrium position shown in FIG. 3. Also, one of the springs 67 
will be compressed and it, too, will tend to return member 18 to its 
equilibrium position shown in FIG. 3. Projection 92 is adjustably mounted 
by a set screw 98 (FIG. 3) in a slot 100 in tab 68 so that bearing 90 can 
adjustably engage any portion of the inclined bearing surface 94 of 
bearing 84 to increase or decrease the amount of lost motion provided by 
tab 68 in slot 70. 
A bearing 102 is carried by a projection 104 on link 72 in alignment with 
the adjacent side edge of tab 68. As soon as the tab 68 has moved through 
the slot 70, the tab will engage bearing 102 and move it and thereby link 
72 to the right when viewing FIG. 3, pulling latch bolt into its retracted 
position against the bias force of spring 80. This occurs when a clockwise 
rotation of member 18 is caused by manual turning of one of the door knob 
elements 56 or 62. Also, one of the springs 67 will be further compressed, 
to increase the bias force on tab 63 and thereby tending to return member 
18 to its equilibrium position shown in FIG. 3. Thus, member 18 can be 
rotated in wither direction to cause retraction of the latch bolt 22. 
In use, assembly 10 is constructed in the manner shown in FIG. 3. Door 12 
is provided with a mortise 23 and with holes 20. Assembly is then inserted 
into mortise 23 and the assembly can be secured in place in a door in any 
suitable manner, such as by long screws 109 having threaded ends 110 and 
heads 112. The heads are countersunk in latch plate 96 and threaded ends 
110 are threaded into the door 12. When so mounted, hole 40 of plate 24 is 
in alignment with holes 20 of door 12 and only member 18 is viewable when 
looking through holes 20. Then, knob structure 16 is coupled to member 18 
to complete the mounting of assembly 10 in the door. 
When properly mounted, the portion of member 18 viewable through hole 40 
and holes 20 will appear to be no structure whatsoever in the hole if the 
member 18 is transparent. If it is translucent, the member will transmit 
light and except for the effect of reflected light, will not appear to be 
connected to the door knob structure. The door knob structure will, 
therefore, appear to be suspended in space. The presence of the member is 
not apparent unless visible marks are on the member and such marks are 
noticeable when door knob structure 16 is rotated. 
When it is desired to move latch bolt 22 to its retracted position from its 
extended or operative position shown in FIG. 3, such as when a door is to 
be opened, one of the door knob elements 56 and 62 is rotated in a 
particular sense, such as a clockwise sense when viewing FIG. 3. This 
causes lost motion of tab 68 in slot 70 until the tab engages bearing 102, 
whereupon the tab further moves the bearing to the right, pulling link 72 
and latch bolt 22 to the right until the latch bolt is retracted into the 
space bounded by latch plate 96. Movement of link 72 to the right 
increases the bias force exerted on the link by spring 80. Also, clockwise 
rotation of member 18 increases the bias force of one of the springs 67 on 
tab 63. Thus, link 72 is biased to the left at all times when viewing FIG. 
3 and springs 67 bias member 18 into an equilibrium position shown in FIG. 
3. 
Counter clockwise rotation of member 18 also retracts latch bolt 22 by 
causing bearing 90 to engage bearing surface 94 after lost motion has been 
caused by movement of tab 68 in slot 70. When bearing 90 engages surface 
94, continued movement of tab 68 to the left when viewing FIG. 3 causes 
counter clockwise rotation of bearing 84 about pin 86, causing pin 88 and 
thereby link 72 to move to the right when viewing FIG. 3, thereby 
retracting latch bolt 22. Again, spring 80 is compressed as is one of the 
springs 67, whereupon release of the turning force on the door knob 
structure returns link 72 and member 18 to their equilibrium positions 
under the bias forces of such springs. 
The assembly 10 can be provided without the lost motion capability 
described above. To this end, link 72 will be without a slot 70 and 
connected directly and pivotally to tab 68, bearing 90 will be directly 
adjacent to surface 94 and bearing 102 will be have a portion directly 
adjacent to tab 68. Thus, for any rotation of member 18 under the 
influence of a manual force on door knob structure 16, there will be 
immediate retraction of tab 22 without any movement of tab 68 relative to 
link 72 longitudinally of the latter.