Multi-drawer cabinet having a drawer lock-out mechanism

A multi-drawer cabinet having a cabinet housing and a plurality of drawers disposed one above the other in the housing and a slide mechanism slidably mounting each of the drawers in the housing for slidable movement between an open position extending outwardly from the housing and a closed position received entirely within the housing includes a drawer lock-out mechanism which binds the slide mechanisms of the closed drawers against slidable movement preventing a closed drawer from being opened when any of the other drawers is open.

BACKGROUND OF THE INVENTION 
The present invention relates to multi-drawer cabinets, and more 
particularly to multi-drawer cabinets which include drawer lock-out 
mechanisms which prevent any closed drawer from being opened when any of 
the other drawers is open. 
BACKGROUND ART 
Multi-drawer cabinets which have drawer lock-out mechanisms are known, per 
se. Such multi-drawer cabinets are used in business establishments for 
storing files and the like. 
However, the lock-out mechanisms for multi-drawer cabinets often are 
relatively complicated and function independently of the drawer slide 
mechanisms which slidably support the drawers in the cabinet housing. 
SUMMARY OF THE INVENTION 
The present invention provides a multi-drawer cabinet having a drawer 
lock-out mechanism which functions with the drawer slide mechanisms to 
prevent any closed drawer from being opened when any other drawer is 
already open. 
More particularly, the present invention provides a multi-drawer cabinet 
having a cabinet housing comprising a first side wall, a second side wall 
spaced from and parallel to the first side wall and an open front, a 
plurality of drawers disposed one above the other in the cabinet housing, 
each drawer comprising a bottom, a first side wall, and a second side wall 
spaced from and parallel to the first side wall, a slide mechanism 
slidably mounting each of the drawers in the cabinet housing for 
individual slidable movement between an open position extending outwardly 
through the open front of the cabinet and a closed position received 
entirely within the cabinet housing, and a drawer lock-out mechanism 
operatively associated with the drawers and the slide mechanisms for 
binding the slide mechanism of the closed drawers against slidable 
movement when any other of the drawers is open.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With reference to FIGS. 1 through 9, there is shown a multi-drawer cabinet 
apparatus, generally denoted as the number 10, incorporating a drawer 
lock-out mechanism, generally denoted as the numeral 12, of the present 
invention. 
With continued reference to FIGS. 1 through 8, the multi-drawer cabinet 
apparatus 10 comprises a cabinet housing 14 containing a plurality of 
drawers 16. The cabinet housing 14 is shown as having a bottom 18, a first 
side wall 20, a second side wall 22, a back wall 24, a top 26, and an open 
front. The drawers 16 are shown as each having a bottom 30, a first side 
wall 32, a second side wall 34, a back wall 36, a front wall 38, and an 
open top 40. The drawers 16 are mounted one above the other in the cabinet 
housing 14 with the first drawer side wall 32 adjacent the first cabinet 
housing side wall 20, the second drawer side wall 34 adjacent the second 
cabinet housing side wall 22 and the drawer back wall 36 adjacent the 
housing cabinet back wall 24. 
Each drawer 16 is slidably mounted in the cabinet housing 14 by a drawer 
slide mechanism for individual slidable movement between an open position 
extending outwardly through the open cabinet housing front and a closed 
position received entirely within the cabinet housing 14 (as can be best 
seen in FIGS. 5 through 8). 
Now with reference to FIGS. 2 through 10, the drawer slide mechanism is of 
a known type and includes a pair of first and second telescoping bracket 
assemblies 42, 43, the first telescoping bracket assembly 42 slidably 
interconnecting the first drawer side wall 32 to the first cabinet housing 
side wall 20, and the second telescoping bracket assembly 43 slidably 
interconnecting the second drawer side wall 34 to the second cabinet 
housing side wall 22. The first telescoping bracket assembly 42 comprises 
a first horizontally disposed stationary elongated cabinet wall mounting 
bracket 44 attached to the cabinet housing first side wall 20, a first 
horizontally disposed elongated drawer mounting bracket 46 attached to the 
drawer first side wall 32 parallel to the first cabinet wall mounting 
bracket 44, and a first horizontally disposed elongated intermediate 
bracket 48 disposed between, parallel to, and interconnecting the first 
cabinet wall mounting bracket 44 and the first drawer mounting bracket 46. 
The first intermediate mounting bracket 48 is connected to the first 
cabinet wall mounting bracket 44 for longitudinal movement along the 
longitudinal axis of the first cabinet wall mounting bracket 44 as the 
drawer 16 is moved between closed and open positions, and is connected to 
the first drawer mounting bracket 46 providing for longitudinal movement 
of the first drawer mounting bracket 46 along the longitudinal axis of the 
first intermediate bracket 48 as the drawer 16 is moved between the closed 
and open positions. Similarly, the second telescoping bracket assembly 43 
comprises a second horizontally disposed stationary elongated cabinet wall 
mounting bracket 50 attached to the cabinet housing second side wall 22, a 
second horizontally disposed elongated drawer mounting bracket 52 attached 
to the drawer second side wall 34 parallel to the second cabinet wall 
mounting bracket 50, and a second horizontally disposed elongated 
intermediate bracket 54 disposed between, parallel to, and interconnecting 
the second cabinet wall mounting bracket 50 and the second drawer mounting 
bracket 52. The second intermediate mounting bracket 54 is connected to 
the second cabinet wall mounting bracket 50 for longitudinal movement 
along the longitudinal axis of the second cabinet wall mounting bracket 50 
as the drawer 16 is moved between the closed and open positions, and is 
connected to the second drawer mounting bracket 52 providing for 
longitudinal movement of the second drawer mounting bracket 52 along the 
longitudinal axis of the second intermediate bracket 54 as the drawer is 
moved between the closed and open positions. 
Now with reference to FIGS. 3 through 10, there is shown the drawer 
lock-out mechanism 12 of the present invention which provides for the 
movement of only one drawer 16 at a time from the closed position to the 
open position. That is, when one drawer 16 is in the open position, all of 
the other drawers 16 are locked in the closed position. The drawer 
lock-out mechanism 12 comprises an aperture 55 (see FIGS. 9 and 10) in the 
first cabinet wall mounting bracket 44 at a predetermined location along 
the longitudinal axis of the bracket 44, pin means 56 associated with the 
first cabinet wall mounting bracket 44 of each first telescoping bracket 
assembly 42, pin activating means 58 associated with the first 
intermediate bracket 48 of each first drawer slide assembly 42 to coact 
with the pin means 56, movable locking rod means 60 (see FIG. 3) at the 
first side wall 20 of the cabinet housing 14 in alignment with the 
aperture 55 and rod moving means 89 operatively interconnecting the 
movable locking rod means 60 and the drawers 16. As one of the drawers 16 
is moved to the open position, the rod moving means 89 of the drawer being 
moved coacts with the movable locking rod means 60 moving the locking rod 
means 60 from an initial unlatched position (see FIG. 5) with a clearance 
space 88 thereabove to a latched position (see FIGS. 6, 7, and 8) into the 
clearance space 88 and creating a pin-receiving space therein adjacent the 
pin means 56 of the drawer 16 being moved. Concurrently, with the movement 
of the locking rod means 60, the pin-activating means 58 of the first 
intermediate bracket 48 of the opening drawer 16 moves the pin means 56 
from a first or locking position (see FIG. 9) to a second or unlocked 
position (see FIG. 10) into the pin-receiving space of the locking rod 
means 60. When the locking rod means 60 is moved to the latched position 
with the pin means 56 of the moving drawer 16 the pin-receiving space 
created in the locking rod means 60, the pin means 56 of the other of 
closed drawers 16 are blocked by the locking rod means 60 from moving from 
the locking position (see FIG. 9) to the unlocked position (see FIG. 10) 
because the locking rod means 60 has been moved into the clearance space 
88 by the moving drawer 16 preventing any further movement of the locking 
rod means 60 by the rod-moving means 89 of the closed drawers 16 and, 
therefore, preventing any pin-receiving space from being created adjacent 
the pin means 56 of the closed drawers 16. 
The following discussion of the pin means 56 and pin activating means 58 
will be in the singular sense speaking to only the first telescoping 
bracket assembly 42 of the drawer slide mechanism of one drawer 16, it 
being understood and clearly shown in the drawings that the description 
applies equally to the first telescoping bracket assembly of each drawer 
slide assembly of each of the drawers 16. As can be best seen in FIGS. 9 
and 10, the pin means 56 comprises a cam follower head 65 with a pin 66 
mounted on the cam follower head 65 and extending in alignment with the 
aperture 55. The locking pin means 56 is mounted to the side of the 
mounting bracket 44 which interfaces with the first intermediate bracket 
48 for movement between the unlocked position whereat the pin 66 protrudes 
through the aperture 55 in the first cabinet wall mounting bracket 44 (see 
FIG. 10) and the locking position whereat the pin 66 is retracted from the 
aperture 55 in the first cabinet wall mounting bracket 44 (see FIG. 9). As 
shown, the movable locking pin means 56 is movably mounted to the cabinet 
wall mounting bracket 44 for pivotal movement by a hinge 67. The hinge 67 
comprises, for example, a hinge joint 68. The cam follower head 65 
includes a first cam follower (or first activating) surface 70 and a 
second cam follower (or second activating) surface 72, which coacts with 
the pin activating cam means 58 of the first intermediate bracket 48 as 
the first intermediate bracket 48 moves with the drawer 16 between opened 
and closed positions. As the drawer 16 moves from the closed position (see 
FIGS. 5-9) to the open position (see FIGS. 5-8 and 10), the pin activating 
cam means 58 coacts with the first activating surface 70 of the locking 
pin means 56 to push the pin means 56 toward the first cabinet wall 
mounting bracket, thereby moving it about the hinge joint 68 and forcing 
the pin 66 through the aperture 55 to the unlocked position. As the drawer 
16 moves from the open position to the closed position, the pin activating 
cam means 58 coacts with the second activating surface 72 of the locking 
pin means 56 to pull the locking pin means 56 away from the first cabinet 
wall mounting bracket 44, thereby moving it about the hinge joint 68 in 
the other direction and pulling the pin 66 back out of the aperture 55 to 
the locking position. Toward this objective, the pin activating means 58 
comprises a first cam surface 74 formed on the first intermediate bracket 
48 and a second cam surface 76 also formed on the first intermediate 
bracket 48 spaced from the first cam surface 74 longitudinally of the 
first intermediate bracket 48. When the drawer 16 is in the closed 
position (see FIG. 9), the cam follower head 65 projects into the space 
between the first cam surface 74 and the second cam surface 76. The first 
cam surface 74 contacts the first cam follower surface 70 of the locking 
pin means 56 as the first intermediate bracket 48 moves with the drawer 16 
from the closed toward the open position forcing the pin 66 through the 
aperture 55 in the first cabinet wall mounting bracket 44 and into 
engagement with the locking rod means 60. The second cam surface 76 
contacts the second cam follower surface 72 of the locking pin means 56 as 
the first intermediate bracket 48 moves with the drawer 16 from the open 
toward the closed position pulling the pin 66 back out of the aperture 55 
and out of engagement with the locking rod means 60. As shown best in 
FIGS. 9 and 10, the first cam surface 70 is a first ramp surface formed at 
the top side of the cam follower head 65, and the second cam surface 72 is 
a second ramp surface formed at the bottom side of the cam follower head 
65. The pin 66 is located generally between the first ramp surface 70 and 
the second ramp surface 72. The first intermediate bracket 48 is formed 
with an opening 78. The first cam surface 74 (which coacts with the first 
cam follower surface 70 of the pin means 56 to force the pin 66 through 
the aperture 55 in the first cabinet wall mounting bracket 44) is defined 
by one end edge of the opening 78. The second cam surface 76 (which coacts 
with the second cam follower surface 72 of the pin means 56 to pull the 
pin 66 out of the aperture 55 to a retracted position) is a cantilevered 
flange at the opposite end of the opening 78 from the edge defining the 
first cam surface 74 and extends from the intermediate bracket 48 toward 
the first cabinet wall mounting bracket 44. As can be best seen in FIGS. 
6, 7, and 8, the ramp defining the second cam surface 76 is formed with a 
notch which receives the pin 66 in the retracted or unlocked position. 
The locking rod means 60 comprises a locking rod channel 84 formed at the 
interior surface of the first side wall 20 of the cabinet housing 14. The 
locking rod channel 84 is vertically oriented and extends essentially the 
height of the cabinet housing 14. Therefore, the locking rod channel 84 is 
perpendicular to and extends past all of the first cabinet wall mounting 
brackets 44. Further, the locking rod channel 84 is in alignment with the 
apertures 55 in the first cabinet wall mounting brackets 44. The locking 
rod means 60 further comprises a plurality of locking rods 86 received in 
the locking rod channel 84 for longitudinal movement therein. The number 
of locking rods 86 is equal to the number of drawers 16, for example as 
shown, there are three drawers 16 and three locking rods 86. When all of 
the drawers 16 are closed, the locking rods 86 are disposed in mutual 
longitudinally coaxial alignment and end-to-end interfacing abutment with 
each abutting rod interface being in alignment with the bottom edge of the 
aperture 55 in a different one of the first cabinet wall mounting brackets 
44. Therefore, the length of each locking rod 86 corresponds to the 
vertical distance between apertures 55 in adjacent first cabinet wall 
mounting brackets 44. Also, when the bottom drawer 16 is in the closed 
position, the bottom end of the lowest locking rod 86 is in abutment with 
a support shown as a stationary support rod 87. The interface of the 
abutment is in alignment with the bottom edge of the aperture 55 in the 
first cabinet wall mounting bracket 44 of the lowest of the bottom drawer 
slide mechanism 42. The locking rods 86 move upwardly to a latched 
position and downwardly to an unlatched position along the longitudinal 
axis of the locking rod channel 84. As can be best seen in FIGS. 3 and 5, 
when all of the drawers 16 are closed, there is a clearance space 88 above 
the top end of the top locking rod 86. 
With reference to FIGS. 3 through 8, each locking rod 86 also includes rod 
moving means, generally denoted as the numeral 89, for moving the locking 
rods 86 upwardly in the locking rod channel 84 as a drawer 16 is moved 
from the closed position to the open position. The rod moving means 89 
comprises a cam follower 90 attached to each of the locking rods 86 
between the ends of the rod 86 adjacent to the first side wall 32 of the 
drawer 16, and a cam 92 attached to the exterior surface of the first side 
wall 32 of the drawer 16 for movement with the drawer 16 as it moves from 
the closed position to the open position. As shown, the cam follower 90 is 
a pin or roller attached to the locking rod 86 and the cam 92 includes a 
ramp structure which contacts the under side of the pin or roller 90 as a 
drawer 16 moves toward the open position pushing the locking rod 86 
associated with that cam follower 90 upwardly in the locking rod channel 
84 into the clearance space 88 and creating a pin receiving space between 
the bottom end of that locking rod 86 and the top end of the next lower 
locking rod 86. 
In operation, with all of the drawers 16 in the closed position (see FIGS. 
5 and 9), all of the locking rods 86 are in the lowered position and in 
end-to-end abutment in the locking rod channel 84 with the clearance space 
88 above the top end of the top one of the locking rods 86, and the pin 66 
of each movable locking pin means 56 is in the retracted position 
retracted from the aperture 55 of the first cabinet wall mounting bracket 
44. FIG. 6 illustrates the top drawer 16 being open and the other drawers 
16 closed, FIG. 7 illustrates the middle drawer 16 being open and the 
other drawers 16 closed, and FIG. 8 illustrates the bottom drawer 16 open 
and the other drawers 16 closed. When any drawer 16 is moved from the 
closed position to the open position, the cam 92 on the first side wall 32 
of that moving drawer 16 contacts the cam follower 90 on the adjacent 
locking rod 86 and moves that locking rod 86 upwardly in the channel 84 
into the clearance space 88 creating a pin receiving space between the 
bottom end of that moved locking rod 86 and the top end of the next lower 
locking rod 86. Of course, as that locking rod 86 associated with the 
drawer 16 being moved to the open position moves upwardly in the channel 
84, it also pushes all of the locking rods 86 above it upwardly in the 
locking rod channel 84. 
As shown in FIG. 6 and with reference to FIGS. 9 and 10, when the top 
drawer 16 is moved to the open position, only the top-most locking rod 86 
associated with the top drawer 16 moves upwardly into the clearance space 
88 due to the coaction of the cam 92 on the top drawer 16 with the cam 
follower 90 on the top-most rod 86 creating a pin receiving space between 
the bottom end of that top locking rod 86 and the top end of the next 
lower or middle locking rod 86 associated with the middle drawer 16, while 
all of the locking rods 86 associated with the other drawers (the middle 
and bottom drawers) remain stationary in end-to-end abutment. As the top 
drawer 16 is moved to the open position, the intermediate mounting bracket 
48 moves with the top drawer 16 outwardly of the cabinet housing 14 and 
the first cam surface 74 coacts with the first cam follower surface 70 
pushing the pin 66 through the aperture 55 in the first cabinet wall 
mounting bracket 44 to the unlocked position projecting into the channel 
84, and projecting into the pin-receiving space (see FIG. 10) caging the 
locking rods 86 of the lower drawers 16 (middle and bottom drawers) 
against movement in the channel 84 between the pin 66 of the top drawer 
movable locking pin means 56 and the support rod 87. Therefore, if one 
were to try to pull any of the closed drawers (i.e. the middle drawer or 
the bottom drawer) to the open position, the first cam surface 74 on the 
first intermediate bracket 48 of the first telescoping bracket assembly 42 
will move into contact with the cam follower surface 70 of the cam 
follower head 65 of the locking pin means 56 projecting into the space 
between the first cam surface 74 and the second cam surface 76 pushing the 
pin 66 into the aperture 55. However, because the locking rod 86 
associated with the closed drawer is caged against movement, a pin 
receiving space cannot be formed between adjacent locking rods 86, and, 
therefore, the pin 66 of the locking pin means 56 cannot move into the 
channel 84 from the locking position (FIG. 9) to the unlocked position 
(FIG. 10). Therefore, the first telescoping bracket assembly 42 binds due 
to the interference of the first cam surface 74 and the cam follower 70 
preventing the closed drawer from being pulled to the open position. 
Additionally, the cam 92 on that closed drawer would contact the cam 
follower 90 on the adjacent or associated locking rod 86, but because that 
locking rod 86 is caged against movement, as discussed above, the cam 
follower 90 functions as a further or secondary stop to the movement of 
the drawer to the open position. 
As shown in FIG. 7, when the middle drawer 16 is moved to the open 
position, the middle locking rod 86 associated with the middle drawer 16 
moves upwardly due to the coaction of the cam 92 on the middle drawer 16 
with the cam follower 90 on the middle rod 86 creating a pin receiving 
space between the bottom end of the middle rod 86 and the top end of the 
next lower or bottom locking rod 86. As the middle locking rod 86 moves 
upwardly, it pushes the top locking rod 86 above it upwardly into the 
clearance space 88, while the bottom locking rod 86 associated with the 
bottom drawer 16 remains stationary in end-to-end abutment with the 
support rod 87. As the middle drawer 16 is moved to the open position, the 
intermediate mounting bracket 48 moves with the middle drawer 16 outwardly 
of the cabinet housing 14 and the first cam surface 74 coacts with the 
first cam follower surface 70 pushing the pin 66 through the aperture 55 
in the first cabinet wall mounting bracket 44 to the locked position into 
the pin receiving space (see FIG. 10) caging the locking rod 86 of the 
bottom drawer against movement in the channel between the pin 66 of the 
middle drawer movable locking pin means 56 and the support rod 87. Also, 
because the top locking rod 86 has moved upwardly in the channel 84, it is 
caged against movement in the channel 84 between the top of the clearance 
space 88 and the top end of the locking rod 86 of the middle drawer 16. 
Therefore, if one were to try to pull any of the closed drawer (i.e. the 
top drawer or the bottom drawer) to the open position, the first cam 
surface 74 on the first intermediate bracket 48 of the first telescoping 
bracket assembly 42 will move into contact with the cam follower surface 
70 of the cam follower head 65 of the locking pin means 56 projecting into 
the space between the first cam surface 74 and the second cam surface 76 
pushing the pin 66 into the aperture 55. However, because the locking rod 
86 associated with the closed drawer is caged against movement, a pin 
receiving space cannot be formed between adjacent locking rods 86 and, 
therefore, the pin 66 of the locking pin means 56 cannot move into the 
channel 84 from the locking position (FIG. 9) to the unlocked position 
(FIG. 10). Therefore, the first telescoping bracket assembly 42 binds due 
to the interference of the first cam surface 74 and the cam follower 70 
preventing the closed drawer from being pulled to the open position. 
Additionally, the cam 92 on that closed drawer would contact the cam 
follower 90 on the adjacent or associated locking rod 86, but because that 
locking rod 86 is caged against movement, as discussed above, the cam 
follower 92 functions as a further or secondary stop to the movement of 
the drawer to the open position. 
As shown in FIG. 8, when the bottom drawer 16 is moved to the open 
position, the bottom locking rod 86 associated with the bottom drawer 16 
moves upwardly due to the coaction of the cam 92 on the bottom drawer 16 
with the cam follower 90 on the bottom rod 86 creating a pin receiving 
space between the bottom end of the bottom rod 86 and the top end of the 
support rod 87. As the bottom locking rod 86 moves upwardly, it pushes all 
of the locking rods 86 above it, i.e. the middle and top locking rods 86, 
upwardly into the clearance space 88. As the bottom drawer 16 is moved 
toward the open position, the intermediate mounting bracket 48 moves with 
the bottom drawer outwardly of the cabinet housing 14 and the first cam 
surface 74 coacts with the first cam follower surface 70 pushing the pin 
66 through the aperture 55 in the first cabinet wall mounting bracket 44 
to the unlocked position into the pin receiving space (see FIG. 10) caging 
the locking rod 86 of the middle drawer and the locking rod 86 of the top 
drawer 16 against movement between the pin 66 of the bottom drawer movable 
locking pin means 56 and the top of the clearance space 88. Therefore, if 
one were to try to pull any of the closed drawers (i.e. the top drawer or 
the middle drawer) to the open position, the first cam surface 74 on the 
first intermediate bracket 48 of the first telescoping bracket assembly 42 
will move into contact with the cam follower surface 70 of the cam 
follower head 65 of the locking pin means 56 projecting into the space 
between the first cam surface 74 and the second cam surface 76 pushing the 
pin 66 into the aperture 55. However, because the locking rod 86 
associated with the closed drawer is caged against movement, a pin 
receiving space cannot be formed between adjacent locking rods 86 and, 
therefore, the pin 66 of the locking pin device 63 cannot move into the 
channel 84 from the locking position (FIG. 9) to the unlocked position 
(FIG. 10). Therefore, the first telescoping bracket assembly 42 binds due 
to the interference of the first cam surface 74 and the cam follower 70 
preventing the closed drawer from being pulled to the open position. 
Additionally, the cam 92 on that closed drawer would contact the cam 
follower 90 the adjacent or associated locking rod 86, but because that 
locking rod 86 is caged against movement, as discussed above, the cam 
follower 92 functions as a further or secondary stop to the movement of 
the drawer to the open position. 
When an open drawer 16 has moved back from the open position to the closed 
position, the second cam surface 76 of the first intermediate bracket 48 
of the first telescoping bracket assembly 42 coacts with the second cam 
follower surface 72 of the locking pin means 56 pulling the pin 66 out of 
the channel 84, that is out of the pin receiving space between the bottom 
end of the rod 46 associated with the moving drawer and the top end of the 
next lowest locking rod 46 and back out of the aperture 55 of the first 
cabinet wall mounting bracket 44, to the retracted or unlocked position. 
This allows the locking rod 86 associated with the moving drawer 16 to 
drop down in the channel 84 back into end-to-end abutment with the next 
lowest locking rod 86 so that another drawer 16 can now be moved to the 
open position. 
The foregoing detailed description is given primarily for clearness of 
understanding and no unnecessary limitations are to be understood 
therefrom for modifications will become obvious to those skilled in the 
art upon reading this disclosure and may be made without departing from 
the scope of the inventions or scope of the appended claims.