Key locking indicator

A key locking indicator device usable with a key of conventional design for tactile and visual indication of whether the device was last used to look or unlock the look operated by the key. The device is of simple construction, embodies a minimum number of moving parts, and is easy to use.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to key locking devices. More particularly, 
the invention concerns a key locking indicator usable with a key of 
substantially conventional configuration for indicating whether the lock 
operated by the key has been locked. 
2. Discussion of the Invention 
Many people are uncertain, after leaving their homes or businesses 
establishments, whether or not they have locked the door upon leaving. 
This uncertainty frequently causes the person to return to their home or 
business establishment to verify that the door has been locked. This 
wastes time and creates unnecessary anxiety and frustration. 
In the past, a number of devices have been suggested which indicate to the 
user whether the device was last used to lock the door or to unlock the 
door. Many of the prior art devices comprise a specially constructed key 
often having a key shank portion which is interconnected by a coupling 
mechanism with some type of indicating device. Exemplary of this type of 
device is that disclosed in U.S. Pat. No. 4,432,218 issued to Hoener. The 
Hoener device comprises a head member grippable by the fingers of the 
user, a shank member provided with a lock operating bit and coupling means 
enabling relative rotation of the members. A similar device of this 
character is also disclosed in U.S. Pat. No. 4,631,943 also issued to 
Hoener. This later device includes a head member and a cooperation shank 
member having a lock operating bit. The shank member is also provided with 
a shaft member rotatably lodged in a central bore of the head member. 
Other prior art devices include various types of mechanical indicating 
mechanisms, such as pointers, dials, indicating pins and the like, which 
are connected to a conventional key. Exemplary of this class of device is 
that disclosed in U.S. Pat. No. 1,843,335 issued to Oberfield. 
Still other prior art devices are unduly complex and often embody 
indicating devices that are of a very complicated construction having a 
large number of component parts. 
A fundamental objective of the present invention is to provide a very 
simple indicating device that embodies an absolute minimum of moving 
parts. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a key locking indicator 
device that is usable with a key of generally standard configuration which 
will clearly indicate to the user whether the device has last been used to 
lock or unlock the lock operated by the key. 
Another object of the invention is to provide a device of the 
aforementioned character which is easy to use, embodies a minimum number 
of moving parts and is simple and inexpensive to manufacture and assemble. 
Another object of the invention is to provide a device of the class 
described which provides both a tactile and visual indication to the user 
of whether the device was last used to lock or unlock the key operated 
lock. 
Another object of the invention is to provide a key locking indicator as 
described in the preceding paragraphs which is compact, lightweight, easy 
to use, and highly reliable in operation.

DESCRIPTION OF THE INVENTION 
Referring to the drawings and particularly to FIGS. 1 through 9, one form 
of the key locking indicator device of the present invention is there 
shown. As best seen by referring to FIGS. 1 and 2, the device of this form 
of the invention comprises finger engaging means, generally designated by 
the numeral 12, for engagement by the fingers of the user; a housing 14 
having walls defining a cavity for closing receiving the head portion 16 
of a key 18; and resistance means for yieldably resisting movement of the 
finger engaging means relative to the housing between a first position 
shown in FIG. 6 to a second position shown in FIG. 7. 
The finger engaging means of the present embodiment includes a body 20 
having interconnected top and bottom walls 22 and 24 respectively and side 
walls which cooperate to define a pair of spaced-apart, centrally 
disposed, fulcrums "F" the purpose of which will presently be described. 
The interconnected top, bottom and side walls define an opening in body 12 
generally identified in FIG. 4 by the letter "0". 
In the form of the invention shown in FIGS. 1 through 10, opening "O" in 
housing 20 is defined by first and second pairs of inwardly sloping walls 
which terminate in the previously identified, transversely spaced-apart 
first and second fulcrums "F". More particularly, the upper pair of side 
walls, generally designated in FIG. 1 by the numeral 30, extend downwardly 
from top wall 22 and slope inwardly, each terminating in a fulcrum line 
which extends longitudinally of body 20. A second, lower pair of walls, 
generally designated by the numeral 32, extend upwardly from bottom wall 
24 and slope inwardly to terminate in the same fulcrum lines which define 
the pair of fulcrums "F" (see also FIG. 4). 
As best seen in FIGS. 1 and 4, housing 14 comprises first and second 
generally parallel side walls 36 and 38 which, along with top and bottom 
portions 40 and 42, define a key head receiving cavity 44 (FIG. 1). Side 
walls 36 and 38 are provided with an aperture 45, the purpose of which 
will presently be described. 
Turning to FIG. 3, it can be best seen that head 16 of key 18 is closely 
receivable within cavity 44 of housing 14 and is retained in position 
within the cavity by a split ring 47 which extends through aperture 45 and 
through an aperture 49 provided in key head 16. Split ring 47 is assembled 
with the housing and the key after housing 14 has been inserted into 
opening "O" in the body and fitted in between the transversely spaced 
fulcrums "F" (see also FIG. 4). Housing 14 is also provided with an 
enlarged forward portion 14a which abuts against body portion 12 of the 
finger engaging means when the housing is fully inserted within opening 
"O" so that split ring 47 can be conveniently inserted into locking 
position in the manner indicated in Figure 3. 
Once the key 18 has been assembled to the device of the invention in the 
manner shown in FIG. 2 and 3, the lock operating dit portion 18a of the 
key can be inserted into the lock "L" (FIG. 8). With the key inserted into 
the lock, the user grips the finger engaging means or body 20 and turns it 
in a clockwise direction as indicated by the arrow in FIG. 6. When the key 
reaches its full extent of travel, continuous forces exerted by the user's 
fingers on the finger engaging means will cause the assemblage to move 
into the second position shown in FIGS. 7 and 9. In locks of standard 
construction, the clockwise movement of the key and of the finger engaging 
means from the position shown in FIG. 8 to the position shown in FIG. 9 
will move the lock into a locked position. 
Forming an important aspect of the device of the invention is indicating 
means for indicating whether the finger engaging means is in the first or 
second position. In the form of the invention shown in FIGS. 1 through 10, 
this indicating means is provided in the form of outwardly extending 
protuberances 52 formed on top and bottom walls 22 and 24 of housing 20. 
As best seen by referring to FIG. 1 and 4, the protuberance formed on top 
wall 22 is located along the right edge of body 20 as viewed in FIG. 4, 
while the protuberance formed on bottom wall 24 is located on the left 
margin of body 20 as viewed in FIG. 4. As indicated in FIGS. 6 and 8, when 
the device is ready to be used to perform the key locking operation, 
protuberances 52 are out of alignment with portions 14a of housing 14. 
However, as shown in FIGS. 7 and 9, when the device is moved into locked 
alignment, body portion 20 has pivoted about fulcrums "F" into the 
position where portions 14a of the housing have moved into index or 
alignment with protuberances 52 thereby providing a tactile indication 
that the device has been used to accomplish the key locking step. 
It is apparent that when the device is used to unlock lock "L", the reverse 
action will occur that is, the finger engaging means will pivot about the 
fulcrums "F" from the position shown in FIG. 7 to the position shown in 
FIG. 5. This movement of the finger engaging means about the fulcrum is, 
of course, caused by a rotational force exerted on the finger engaging 
means in an opposite or counterclockwise direction. 
With this unique construction, the user of the device can at once determine 
whether or not the device was last used to lock the lock "L" by simply 
feeling or viewing the device to ascertain whether protuberances 52 are 
aligned or misaligned with portions 14a. 
Also forming an important part of the apparatus of the form of the 
invention shown in FIGS. 1 through 10 is the provision of resistance means 
for yieldably resisting movement of the finger engaging means relative to 
housing 14 about spaced-apart fulcrums "F". In this embodiment of the 
invention, the resistance means is provided in the form of inwardly 
extending protuberances 56 formed on the inner surfaces of top and bottom 
walls 22 and 24. Protuberances 56 are constructed so as to frictionally 
engage walls 40 and 42 of housing 14 as the finger engaging means pivots 
about the fulcrums "F" from the first position to the second position. In 
operation, when the housing 14 engages the protuberances 56 during the key 
operating step, the top and bottom walls of the housing 20 will deform 
slightly permitting the housing 14 to pass by protuberances 56 upon the 
exertion of a sufficient force to slightly deform the upper and lower 
walls of the body 20 thereby permitting movement past the upper and lower 
walls of housing 14. To provide proper spring action, the finger engaging 
means is preferably constructed from a moldable plastic such as 
polyolefin. 
Turning now to FIGS. 10 through 13, another embodiment of the key locking 
indicator device of the present invention is there illustrated. This 
device is similar in many respects to that described in the preceding 
paragraphs and like numerals are used to identify like components. The 
principal difference between this second embodiment of the invention and 
the earlier described embodiment resides in the nature of the resistance 
means which yieldably resists movement of the finger engaging means 
relative to the key receiving housing 14. 
As best seen in FIG. 10, housing 14 is of identical construction to that 
previously described and is retained in position within the finger 
engaging means by a split ring 47 which is also of identical construction 
to that previously described. However, the finger engaging means of this 
latest form of the invention is of a slightly different construction and 
includes a body 60 having interconnected top, bottom and side walls. Top 
and bottom walls 62 and 64 are yieldably deformable out of plane from the 
position shown in FIG. 11 to the position shown in FIG. 12 as the finger 
engaging means pivots about transversely spaced-apart fulcrums 67. As 
before, fulcrums 67 are defined by upper and lower pairs of inwardly 
sloping walls generally designated in FIG. 11 by the numerals 70 and 72. 
Body 60 can also be constructed from a variety of yieldably deformable 
plastics so that upper and lower walls 62 and 64 yieldably resist pivotal 
movement of the body portion from the first position to the second 
position and thereby provide resistance to the relative movement of 
housing 14 and body portion 60 of the finger engaging means during the key 
lock operating step. 
As was the case in the previously described invention, indicating means are 
also here provided for indicating whether or not the finger engaging means 
is in the first or second position. These indicating means here comprise 
upper and lower protuberances 75 which are formed proximate the upper and 
lower edges of housing 60 (FIG. 11). As before, when the finger engaging 
means is pivoted relative to housing 14 to the locked position shown in 
FIG. 13, portions 14a of the housing will align with protuberances 75 
thereby indicating that the device has last been used to accomplish the 
locking step. 
Turning now to FIGS. 14 through 21, still another embodiment of the device 
of the invention is there illustrated. In this form of the invention, both 
the key receiving housing and the finger engaging means are of slightly 
different construction. More particularly, as best seen by FIGS. 14 and 
17, the finger engaging means here comprises a pair of cooperating housing 
defining members 77a and 77b, each having interconnected top, bottom and 
side walls 80, 82, 84 and 86 respectively. These walls define an interior 
chamber 87 within which the key receiving housing is receivable in the 
manner best seen in FIGS. 16 and 17. 
The key receiving housing assembly, generally designated by the numeral 90, 
comprises a first member 92 which is generally U-shaped in cross section 
and includes a side wall 94 and top and bottom walls 96 and 98 (FIG. 21). 
As indicated in FIG. 21, wall 94 is provided with a longitudinally 
extending rib 99, the purpose of which will presently be described. 
Housing assembly 90 also includes a strip of double-sided, foam tape 104 
(FIG. 16), one side of which adheres to the face of member 92 opposite 
face 94 upon which rib 99 is formed. The other side of the doubled sided 
tape holds key head 16 in position within assembly 90. 
Provided on side wall 84 of the finger engaging means is a protuberance 106 
which extends into chamber 87 (FIG. 20) and is adapted to engage key head 
16. In the form of the invention shown in FIGS. 20 and 21, protuberance 
106 comprises one of the fulcrums about which the key and key housing 
pivot in a manner presently to be described. Provided on the interior 
surface of side wall 86 is a protuberance 110 which is provided with first 
and second longitudinally extending, side by side grooves 110a and 110b. 
In the manner indicated in FIGS. 19 and 21, grooves 110a and 110b 
alternately receive rib 99 as the finger engaging means of this form of 
the invention pivots about fulcrum or protuberance 106 from the first 
position shown in FIG. 19 to the second position shown in FIG. 20. More 
particularly, a comparison of FIGS. 19 and 20 show that when the key and 
housing assembly therefor is in the first position, rib 99 resides within 
groove 110a. Conversely, when the key and housing subassembly is in the 
second position shown in FIG. 20, rib 99 resides in groove 110b having 
ridden over the upstanding separation 110c which separates grooves 110a 
and 110b (FIG. 21). 
In assembling the device of this latest form of the invention, the 
double-backed, adhesive foam tape 104 is first affixed to the inner wall 
of member 92 in the manner shown in FIG. 19. Next the key head 16 is 
pressed against the adhesive foam 104 so that the bit portion 18a of key 
18 extends through an opening 110 provided in the forward face 109 of the 
finger engaging means (FIG. 15). The assemblage thus formed is then mated 
with side wall 86 so that rib 99 resides within groove 110a of 
protuberance 110 in the manner shown in FIG. 19. The second half of the 
finger engaging means of this form of the invention is then mated with the 
first half so that fulcrum or protuberance 106 pressurally engages key 
head 16 which adheres to adhesive foam member 104. 
As best seen in FIGS. 19 and 21, wall 92 is provided with a cylindrically 
shaped, outwardly extending indicator element 114 which is aligned with an 
aperture 116 provided in wall 86 of the finger engaging means. This 
indicator element 114 forms a part of the indicating means of this form of 
the invention for indicating whether the finger engaging means is in the 
first or second position. 
With the device assembled in the manner shown in FIG. 19, and with the key 
bit 18a in lock "L", a force exerted on the finger engaging means in the 
direction of the arrow of FIG. 20 will cause rib 99 to snap from groove 
110a into 110b as it overrides central portion 110c. In this position, 
indicator element 114 extends through aperture 116 so that by feel the 
user can determine that the housing and key assemblage are in the second 
or locked position. 
In this latest form of the invention, the indicating means also comprises a 
visual means for identifying the position of the key retaining housing. 
More particularly, as indicated in FIG. 21, wall 96 of the housing 
assembly can be colored as, for example, with a red color which is easily 
visible through an opening 118 provided in top wall 80 of the finger 
engaging means (FIG. 14). When the user can see the red surfaced wall 96 
through the opening 118, he or she knows immediately that the device is in 
the second or key-locked position. Similarly, lower wall 98 of the housing 
assembly can be painted green and can be viewed through an opening 120 
provided in wall 82 of the finger engaging means. When the green surface 
is viewable through opening 120, the indication to the user is that the 
device is in the first or unlocked position. Thusly, in the last described 
embodiment of the invention, the indicating means is both tactile and 
visual. The tactile portion being the ability to perceive indicating 
element 114 extending through aperture 116 and the visual portion being 
the ability to view either the red or green surfaces through apertures 118 
and 120. 
To conveniently carry the device of this latest form of the invention on a 
key ring, the finger engaging housing is provided with an outwardly 
extending apertured portion 115 (FIG. 18). 
Referring to FIGS. 22 through 24, yet another embodiment of the device of 
the invention is there illustrated. This form of the invention is similar 
in many respects to that just described and like numerals are used to 
identify like components. The finger engaging means here comprises a 
housing 130 having interconnected top, bottom and side walls 132, 134, 136 
and 138 respectively. These walls define an interior chamber 140 within 
which the key receiving housing is receivable. 
The key receiving housing assembly, generally designated by the numeral 
141, is very similar to housing 90, and comprises a first member 142 which 
is generally U-shaped in cross section and includes a side wall 144 and 
top and bottom walls 146 and 148 (FIG. 24). As indicated in FIG. 24, wall 
144 is provided with a longitudinally extending rib 99. Housing assembly 
141 also includes a strip of double-sided, foam tape 104 (FIG. 24), one 
side of which adheres to the face of member 141 opposite face 144 upon 
which rib 99 is formed. The other side of the doubled sided tape holds key 
head 16 firmly in position within assembly 141. 
Provided on side wall 138 of the finger engaging means is a protuberance 
106 which extends into chamber 140 (FIG. 24) and is adapted to engage key 
head 16. As before, protuberance 106 comprises one of the fulcrums about 
which the key and key housing pivot in a manner earlier described. 
Provided on the interior surface of side wall 136 is a protuberance 110 
which is provided with first and second longitudinally extending, side by 
side grooves 110a and 110b. As before, grooves 110a and 110b alternately 
receive rib 99 as the finger engaging means of this form of the invention 
pivots about fulcrum or protuberance 106 from the first position to the 
second position. 
Assembly of the key to the key housing in the device of this latest form of 
the invention, is also as previously described. However, the assembly of 
the key housing portion to the finger engaging means is different because 
of the different, one piece construction of the finger engaging means. 
Further, the finger engaging means is provided with an interiorly disposed 
locking shoulder 150 (FIG. 23) which extends inwardly of chamber 140. 
Shoulder 150 is formed at the inner extremity of a ramp-like, 
inwardly-extending element 152 which includes a forward tapered surface 
153. With this construction, the assembled key and key housing can be 
introduced into the open mouth 157 of the finger engaging means and pushed 
over ramp 152 until it snaps in place behind shoulder 150 in the manner 
shown in FIG. 23. 
As best seen in FIG. 24, wall 144 of the key housing is provided with a 
cylindrically shaped, outwardly extending indicator element 160 which is 
aligned with an aperture 162 provided in lower portion of wall 136 of the 
finger engaging means. This indicator element 160 forms a part of the 
indicating means of this latest form of the invention for indicating 
whether the finger engaging means is in the first or second position. 
With the device assembled in the manner shown in FIGS. 23 and 24 and with 
the key bit 18a in lock "L", a turning force exerted on the finger 
engaging means in a clockwise direction will cause rib 99 to snap from 
groove 110a into 110b as it overrides central portion 110c. In this 
position, indicator element 160 will extend through aperture 162 so that 
by feel the user can determine that the housing and key assemblage are in 
the second or locked position. 
In this latest form of the invention, the indicating means also comprises a 
visual means for identifying the position of the key retaining housing. 
More particularly, as shown in FIG. 22, top wall 132 is provided with an 
opening 163 for viewing the top wall 146 of the key housing when the 
device is in the first or unlocked position. 
To conveniently carry the device of this latest form of the invention on a 
key ring, the finger engaging housing is provided with an outwardly 
extending apertured flange portion 165 (FIG. 22). 
Turning now to FIG. 25 of the drawings, yet another form of the key locking 
indicator device of the present invention is there shown. The device of 
this form of the invention is similar in many respects to that shown in 
FIG. 1 save that the housing 14 for receiving the key has been eliminated. 
The finger engaging means, generally designated by the numeral 170 is 
virtually identical to that previously described in connection with the 
FIGS. 1 through 10 and includes a body 172 having interconnected top and 
bottom walls 174 and 176 respectively and side walls which cooperate to 
define a pair of spaced-apart, centrally disposed, fulcrums "F" which 
function in the same general manner as previously described. The 
interconnected top, bottom and side walls define an opening in body 12 
generally identified in Figure 4 by the letter "O". 
As before, opening "O" in the housing is defined by first and second pairs 
of inwardly sloping walls which terminate in the transversely spaced-apart 
first and second fulcrums "F". More particularly, the upper pair of side 
walls extend downwardly from top wall 174 and slope inwardly, each 
terminating in a fulcrum line which extends longitudinally of body. A 
second, lower pair of walls extend upwardly from bottom wall 176 and slope 
inwardly to terminate in the same fulcrum lines which define the pair of 
fulcrums "F". However, in this latest embodiment, the fulcrums are 
slightly closer together to closely accept the head "H" of the key itself. 
With this construction, the head "H" of key "K" is itself closely 
receivable between the fulcrums "F" disposed within cavity "O" of body 172 
and is retained in position within the cavity by a split ring which 
extends through aperture 179 provided in key head "H". Split ring 177 is 
assembled with the housing and the key after the key has been inserted 
into opening "O" in the body and fitted in between the transversely spaced 
fulcrums "F". As indicated in FIG. 25, key "K" is of generally standard 
construction but is here provided with outwardly extending indicating 
protuberances, or ears, 190, the purpose of which will presently be 
described. 
Once the key "K" has been assembled to body 172, the lock operating bit 
portion 182 of the key can be inserted into the lock. With the key 
inserted into the lock, the user grips the finger engaging means or body 
172 and turns it in a clockwise direction. When the key reaches its full 
extend of travel, continuous forces exerted by the user's fingers on the 
resistance means or finger engaging means will cause the key to move past 
the protuberances 183 formed on top and bottom walls 174 and 176 and into 
the second position. 
In the form of the invention shown in FIG. 25, the indicating means is, as 
before, provided in the form of outwardly extending protuberances 185 
formed on top and bottom walls 174 and 176 of body 172. When the device is 
ready to be used to perform the key locking operation, protuberances 185 
are out of alignment with portions 180 of key "K". However, as shown in 
FIGS. 7 and 9 when the device is moved into locked alignment body portion 
172 has pivoted about fulcrums "F" into the position where portions 180 of 
the key have moved into index or alignment with protuberances 185 thereby 
providing a tactile indication that the device has been used to accomplish 
the key locking step. 
When the lock "L" is unlocked, the reverse action will, of course, occur. 
It is to be understood that in all of the previously described embodiments 
of the invention which include indicator members or color bands, the key 
assembly can be turned over to accommodate locks which lock in the 
counter-clockwise rather than clockwise direction. In the embodiments of 
FIGS. 1 through 10 and 25 m the body itself can be turned over to 
accommodate counter-clockwise locking locks. 
Having now described the invention in detail in accordance with the 
requirements of the patent statutes, those skilled in this art will have 
no difficulty in making changes and modifications in the individual parts 
or their relative assembly in order to meet specific requirements or 
conditions. Such changes and modifications may be made without departing 
from the scope and spirit of the invention, as set forth in the following 
claims.