Direction reversing actuator apparatus

The problem of providing a simplified actuator apparatus (10) for converting unidirectional motion to multidirectional motion is provided by a driven member (14) rotatable about a first axis (18) and a drive member (12) rotatable about a second axis (28) generally parallel to and spaced from the first axis (18). The driven member (14) has first (20) and second (22) radially disposed, diametrically opposed cam followers. The drive member (12) has first (36) and second (38) radially disposed cam actuators. The first cam follower (20) of the driven member (14) is engageable by the first cam actuator (36) of the drive member (12) for driving the driven member in one direction of rotation in response to rotation of the drive member in one direction. The second cam follower (22) of the driven member (14) is engageable by the second cam actuator (38) of the drive member (12) for driving the driven member in an opposite direction of rotation in response to continued rotation of the drive member in the same, one direction.

FIELD OF THE INVENTION 
This invention generally relates to actuator devices and, particularly, to 
a direction reversing actuator apparatus such as an apparatus for 
converting unidirectional motion to multidirectional motion. 
BACKGROUND OF THE INVENTION 
Actuator devices are used in a wide variety of applications and, in some 
instances, such devices are necessary to convert one form of motion to 
another form of motion. For instance, with a gear train rotating in one 
direction, it might be necessary to create a reversible reaction direction 
for performing a specific function. In another application, it might be 
necessary to rotate the gear train in two directions while creating a 
unidirectional reaction for performing a specific function. 
These general operative parameters are particularly prevalent in aircraft 
and aerospace applications wherein a variety of operative components must 
be actuated in a particular sequence. For instance, one application might 
be a power drive unit which must perform sequenced shifting between two 
separate outlets, such as a pallet output and a door output for loading a 
cargo bay of an aircraft. A door first must be opened, followed by 
"opening" (extending) of the pallet. In reverse sequence, the pallet first 
must be "closed" (retracted), followed by closing of the door. The door 
and pallet are conventionally driven by gear train means and are held in 
closed condition by brakes, such as spring biased brakes. In order to 
effect sequential actuation of such components, problems heretofore have 
arisen because of the complexity involved and packaging required for 
effective actuating devices to perform such various sequential actuating 
programs. Simplicity, weight and size are critical considerations in the 
aircraft and aerospace industry. 
This invention is directed to solving such problems by providing a unique, 
extremely simple actuating apparatus capable of reversing direction 
actuation as well as converting unidirectional motion to multidirectional 
(e.g. reversing) motion. 
SUMMARY OF THE INVENTION 
An object, therefore, of the invention is to provide a new and improved 
actuator apparatus of the character described. 
In the exemplary embodiment of the invention, generally, a driven member is 
rotatable about a first axis and has first and second radially disposed 
follower means. A driven member is rotatable about a second axis generally 
parallel to the first axis and has first and second radially disposed 
actuator means. In essence, the follower means of the driven member can be 
considered as cam followers and the actuator means of the drive member can 
be considered as cams. 
According to the concepts of the invention, the first follower means of the 
driven member is located in a rotational path of movement so as to be 
engageable by the first actuator means of the drive member for driving the 
driven member in one direction of rotation in response to rotation of the 
drive member in one direction. The second follower means of the driven 
member is located in a rotational path of travel so as to be engageable by 
the second actuator means of the drive member for driving the driven 
member in an opposite direction of rotation in response to continued 
rotation of the drive member in said one direction. 
More particularly, the first and second cam follower means of the driven 
member are disposed on diametrically opposite sides of the first axis. As 
disclosed herein, the cam follower means project radially outwardly of an 
inner hub portion of the driven member. The first and second actuator cam 
means of the drive member are spaced at different distances from the 
second axis but on a common side of a diameter through the second axis. 
The first and second actuator cam means project radially inwardly of an 
outer frame portion of the drive member surrounding the hub portion of the 
driven member. 
The invention also contemplates the drive member having a third radially 
disposed actuator cam means for engaging the second cam follower of the 
driven member to drive the driven member in its opposite direction in 
response to rotation of the drive member opposite said one direction. 
Other objects, features and advantages of the invention will be apparent 
from the following detailed description taken in connection with the 
accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings in greater detail, and first to FIG. 1, the 
invention is carried out in the form of an actuator apparatus, generally 
designated 10, which includes a drive member, generally designated 12, and 
a driven member, generally designated 14. It should be understood that 
whatever components the actuator apparatus is to be used with, such as the 
gear trains of an aircraft door/ pallet system, are not shown in the 
drawings because the unique actuator apparatus shown has such a wide range 
of applications. 
More particularly, driven member 14 includes a hub portion 16 rotatable 
about a first axis 18 which may be the axis of a shaft for performing 
specific functions, such as in a gear train. First and second radially 
disposed follower means 20 and 22 project radially outwardly of hub 
portion 16. The follower means effectively form first and second cam 
followers and may include rollers 24 for engaging the cam actuator means 
of the drive member (described below) to provide for ease of operation. 
Drive member 12 also includes a hub portion 26 rotatable about a second 
axis 28 generally parallel to first axis 18 of driven member 14. Axis 28 
may be the axis of a shaft driven by a gear train. A sort of "halfmoon" 
frame is formed integral with hub portion 26 and includes a pair of 
radially projecting leg portions 30 joined by an arcuate segment 32 to 
define an open area 34 surrounded by leg portions 30 and arcuate segment 
32. The operative follower means and actuator means interacting between 
drive member 12 and driven member 14 are located within this open area. 
Specifically, drive member 12 has first, second and third actuator means in 
the form of a first cam actuator 36 projecting radially outwardly from hub 
portion 26, and second and third cam actuators 38 and 40, respectively, 
projecting radially inwardly from arcuate segment 32. Looking at FIG. 1, 
it can be seen that cam actuator 36 of drive member 12 and cam follower 20 
of driven member 14 are located in intersecting rotational paths of travel 
defined by their respective axes 28 and 18, respectively. It also can be 
seen that cam actuators 38 and 40 of drive member 12 are angularly spaced 
relative to axis 28, but the cam actuators are in a common rotational path 
of movement which can intersect the rotational path of movement of cam 
follower 22 of driven member 14. Technically, cam followers 20 and 22 of 
driven member 14 are disposed on diametrically opposite sides of axis 18 
in a concentric rotational path of travel. Cam actuator 36 and cam 
actuators 38,40 of drive member 12 are located in radially spaced paths of 
travel to enable the actuators to engage the differently located cam 
followers 20,22. 
FIGS. 1-3 illustrate a sequence of operation of actuator apparatus 10 
wherein unidirectional rotational motion of drive member 12 in a 
counterclockwise direction (as viewed in the drawings) is effective to 
cause multidirectional motion of driven member 14, i.e. opposite 
rotational motion. More particularly, FIG. 1 shows drive member 12 and 
driven member 14 in what can be called a neutral position, i.e. with cam 
followers 20,22 vertically oriented as shown. As drive member 12 is 
rotated in a counterclockwise direction as indicated by arrow "A" in FIG. 
2, actuator cam 36 rotates into engagement with cam follower 20 of driven 
member 14 to rotate the driven member in a clockwise direction as 
indicated by arrow "B". In whatever appropriate system actuator apparatus 
10 is being used, this can effect a specific function. 
As shown in FIG. 3, continued rotation of drive member 12 in the 
counterclockwise direction, as indicated by arrow "C", will cause actuator 
cam 38 to rotate into engagement with cam follower 22 of drive member 14 
to cause the drive member to reverse direction, i.e. rotate in a 
counterclockwise direction as indicated by arrow "D". Therefore, it can be 
seen that unidirectional motion (or counterclockwise rotation) of drive 
member 12 is effective to convert that unidirectional motion into 
reversing or multidirectional motion of driven member 14. 
FIGS. 4 and 5 show a second sequence of operation which can be effected by 
the same components, i.e. drive member 12 and driven member 14, in 
response to reversing motion of drive member 12. In essence, these 
depictions show that reversing directional motion of the drive member as 
input rotation to the apparatus will effect a unidirectional function of 
driven member 14. More particularly, FIG. 4 is identical to FIG. 2 to 
again illustrate that counterclockwise rotation of drive member 12 in the 
direction of arrow "A" will cause cam actuator 36 to engage cam follower 
20 of drive member 14 to effect clockwise rotation of the driven member in 
the direction of arrow "B". Again, this can effect a given function for 
whatever appropriate system the actuator apparatus is being used. However, 
FIG. 5 shows that drive member 12 now has been reversed to rotate in a 
clockwise direction, as indicated by arrow "E", so that third cam actuator 
40 now comes into engagement with cam follower 22 of driven member 14 to 
cause the driven member to maintain its clockwise position. As seen, this 
reversing direction of drive member 12 is shown to maintain the driven 
member in the same condition as shown in FIG. 4. In other words, there may 
be an instance in an application wherein the function effected by the 
driven member is to be maintained, whereas rotation of the drive member in 
opposite directions can itself effect two different specific functions in 
a system while the function effected by the driven member is maintained. 
As stated above, the actuator apparatus of the invention can be used in a 
wide variety of applications in aircraft and aerospace fields, and one 
such application may be in a loading system for a cargo bay of an 
aircraft, involving an actuation sequence of the door and pallet at the 
entrance to the cargo bay. As stated above, the door would be opened 
first, followed by extension of the pallet, but the pallet would have to 
be retracted before the door is closed. Heretofore, such an actuation 
system involved extremely complicated actuation devices. 
FIGS. 6-11 show how the actuator apparatus of this invention could be used 
with the respective brakes for the door and the pallet. The brakes must be 
released in a particular sequence before any of the mechanisms for moving 
the door and the pallet can be made operational. 
Specifically, FIG. 6 again shows the actuation apparatus 10 in a neutral 
condition as described in relation to FIG. 1, with driven member 14 
vertically oriented as viewed in the drawings. Position arrows 46, 48 and 
50 are shown in FIG. 6 simply to depict positions of driven member 14 
corresponding to various functional characteristics of the door and the 
pallet brakes. Arrow 46 shows a neutral position wherein both the door and 
pallet brakes are applied, with the door and pallet brakes shown 
schematically in FIG. 6 (such brakes normally would be spring biased to 
braking condition). Arrow 48 depicts a position where the door brake is 
released, and arrow 50 depicts a position wherein the pallet brake is 
released. 
These door and pallet systems are commonly operated through gear trains 
which produce a bias, as through a spring on the driven member 14. Arrow 
46 in FIG. 6 shows a neutral position wherein both the door and pallet 
brakes are applied. Actuation of the door and pallet brakes results in the 
application of a spring force on the driven member 14 to place the driven 
member 14 in the neutral position therefor. (See arrow 46 in FIG. 6). 
The inventive structure would operate without this neutralizing spring 
force, however, the sequence of movement of the driven member would be 
slightly different than that shown in the drawings. 
FIG. 7 shows drive member 12 having been rotated in a counterclockwise 
direction, as indicated by arrow "G", which rotates driven member 14 
clockwise in the direction of arrow "H". This motion was described in 
relation to FIG. 4. It can be seen that the driven member now is in the 
"door brake released position" as described above in relation to arrow 
"48" in FIG. 6. Counterclockwise rotation of drive member 12 is also 
linked, by means of an appropriate mechanism not shown, to output rotation 
which will open the door while the door brake is held released by driven 
member 14. Of course, again, it should be understood that the invention 
does not contemplate the various mechanisms for the brakes and drive 
trains, which are not shown. The specific functions performed are door 
brake release by clockwise rotation of driven member 14 about its axis 18, 
and door open rotation associated with counterclockwise rotation of drive 
member 12 about its axis 28. 
Continuing on, drive member 12 can continue to be rotated counterclockwise 
in the direction of arrow "H" in FIG. 8, by any appropriate shaft on axis 
28, such that the actuator apparatus functions as described in relation to 
FIG. 8. In other words, actuator cam 38 now engages cam follower 22 to 
cause driven member 14 to reverse direction and rotate in a 
counterclockwise motion as indicated by arrow "I". It can be seen that the 
driven member now has been moved to the "pallet brake released" position 
as indicated by arrow 50. In this position, with the pallet brake released 
against its spring load, some other appropriate mechanism linked to 
counterclockwise rotation of drive member 12 moves the pallet to its open 
condition, while the door still is being held open by a conventional 
static brake. 
FIG. 9 shows that drive member 12 now has been reversed to rotate in a 
clockwise direction as indicated by arrow "J". However, this does not 
effect driven member 14 for the same reasons as described in relation to 
FIGS. 4 and 5 (simply in an opposite directional relationship), whereby 
the driven member remains in its "pallet brake released" position as 
indicated by arrow 50. However, since drive member 12 can be connected to 
a shaft on axis 28, this reversing direction of the drive member, itself, 
can be used to effect a specific function. In the scheme used as an 
example herein, this function could be used to actuate a pallet closing 
mechanism because driven member 14 still is maintained in its pallet brake 
released condition. 
As drive member 12 continues to rotate in clockwise direction as indicated 
by arrow "K" in FIG. 10, cam actuator 40 now is rotated into engagement 
with cam follower 22 of driven member 14 to cause the driven member to 
rotate in a clockwise direction as indicated by arrow "L". This takes the 
pallet brake out of its released condition whereupon the pallet again is 
braked in position within the cargo bay while the door brake is released. 
The continued clockwise rotation of the drive member about axis 28 again 
is used to actuate a separate mechanism to close the door. By returning 
actuator apparatus 10 back to its original condition as shown in FIG. 11 
(corresponding to FIG. 6), driven member 14 now is normally biased back to 
its neutral position by the pallet/brake system wherein both the door and 
pallet brakes again are applied as indicated by arrow 46. 
From the foregoing, it can be understood that the actuator device has 
utility in a wide range of applications, the illustrations of FIGS. 6-11 
being representative of utilizing the actuator apparatus in conjunction 
with the brakes of an aircraft door and pallet system, keeping in mind 
that other separate mechanisms (not shown) are necessary to effect actual 
opening and closing of the door and pallet. In addition, the axis 28 of 
drive member 12, as it might be connected to a shaft in an appropriate 
gear train, itself could be used to effect various actuating functions, 
such as the initiation of door and pallet opening and closing mechanisms. 
An exemplary prior art pallet/brake system is shown at 100 in FIG. 12. The 
system 100 has a pallet brake 102 and a door brake 104 associated with 
pallet and door drive trains 106, 108, respectively. 
Release ball/ramp assemblies are provided for the pallet brake at 110 and 
for the door brake at 112. A spring element at 114 exerts an axial force 
on the pallet and door brakes 102, 104. This axial spring force is 
converted by the ball ramps 110, 112 into a torque which biases the driven 
member 14 to a neutral position. (See FIG. 11). 
Clockwise rotation of the driven member 14, as indicated by arrow 116, 
releases the door brake 104. Counterclockwise rotation of the driven 
member, as indicated by arrow 118, releases the pallet brake 102. 
A typical prior art brake system, which is spring biased into an applied 
position, is shown in U.S. Pat. No. 4,967,886, incorporated herein by 
reference. In that patent, the springs 24 push through pin 48 of the ball 
ramp 42. A driven member corresponding to the driven member 14 in the 
present case, can be coupled to the ball ramp 42, and resultingly would be 
spring biased to a neutral position. 
It will be understood that the invention may be embodied in other specific 
forms without departing from the spirit or central characteristics 
thereof. The present examples and embodiments, therefore, are to be 
considered in all respects as illustrative and not restrictive, and the 
invention is not to be limited to the details given herein.