Abstrict A drive unit for adjustable beds of the type which have movable
head and leg sections, and adjustable height, comprises a unidirectional,
rotary motor, and a drive shaft for each adjustable bed function.
The driveshafts are selectively rotated in opposite directions by
the motor. A pair of solenoids operably couple the motor with the
driveshafts, interchangeably, or alternatively with a linear tracking
gear, and thereby adjust the configuration of the bed.
Claims I claim:
1. A fully adjustable bed having an adjustable head section, and
adjustable leg section and adjustable overall height, the bed comprising:
a linearly movable motor;
at least three separate drive shafts, a first drive shaft for controlling
the adjustable head section, a second drive shaft for controlling
the adjustable leg section, and a third drive shaft for controlling
the height of the platform of the bed;
means for positioning the motor adjacent a selected drive shaft;
and
means for selectively coupling the motor with the selected drive
shaft, whereby the motor accomplishes desired adjustment of head
section, leg section and overall height.
2. The bed of claim 1 wherein the means for positioning the motor
adjacent a selected drive shaft comprises a linear track extending
between the drive shafts and a gear portion coupled to the linear
track and engageable with the motor, whereby upon engagement of
the gear portion and the motor, the motor can be positioned along
the track adjacent the selected drive shaft as desired.
3. The bed of claim 1 wherein the means for positioning the motor
adjacent a selected drive shaft comprises a sub-drive assembly.
4. The bed of claim 1 further comprising a controller which prevents
simultaneous linear motion of the motor while coupled to any one
of the drive shafts adjusting the head section, leg section or overall
height of the bed.
5. The bed of claim 4 in which the controller comprises a synchronized,
opposing action pair of solenoid switches.
6. The bed of claim 1 in which the at least three driveshafts have
distinctively shaped ends and the means for selectively coupling
the motor with the selected drive shaft includes correspondingly
distinctively shaped connecting portion, thereby securely coupling
the motor and the selected driveshaft.
7. The bed of claim 1 in which the at least three driveshafts have
tapered ends, thereby securely coupling the motor and the selected
driveshaft.
Description FIELD OF THE INVENTION
This present invention relates to motorized, fully adjustable beds,
and more particularly to a single motor drive assembly which operates
three modes of adjustment, the head and the foot of the bed as the
height of the bed, from a remote control unit.
BACKGROUND OF THE INVENTION
A drive unit for adjustable beds, such as hospital beds and the
like, of the type which have movable head and leg sections, and/or
other adjustment functions, and comprises a unidirectional, rotary
motor, and a drive shaft for each adjustable bed function. Gears
are rotatably mounted on each of the drive shafts, and are rotated
thereon in opposite directions by the motor. A pair of spring clutches
are operably associated with their associated shafts to rotate the
shafts, and thereby adjust the position and/or configuration of
the bed.
For many years, hospital beds have had movable parts, such as an
upper body support part movable between two positions in which it
supports the patient in a sitting position and a prone position.
Movement of these parts originally was effected manually by hospital
personnel, for example by turning a crank provided on the bed.
Motorized operated hospital beds are conventional in which the
head and leg sections of an articulated frame can be adjusted to
a desired inclination by one or more motors. In this fashion, a
patient's back or legs can be adjusted to a desired inclination.
The actuating mechanism for the head section of the articulated
mattress frame may include an electric motor which rotates an elongated
threaded shaft. A nut is threadably mounted for longitudinal movement
along the shaft and is fixed against rotation relative thereto.
Thus, rotation of the shaft produces longitudinal travel of the
nut. A linkage interconnects the nut and the head section of the
articulated frame in such a way as to convert longitudinal motion
of the hut into rotational movement of the head section, thereby
altering the inclination of the latter. The motor can be deactivated
at any time to hold the head section in a given position of adjustment.
U.S. Pat. No. 4559655 describes the conventional motorized hospital
bed in which the head and leg sections of an articulated frame can
be selectively raised and lowered by two or more electric motors.
In this fashion, a patient's back and/or legs can be adjusted to
a desired inclination. The actuating mechanism for the head section
of the articulated mattress frame may include and electric motor
which rotates an elongated threaded shaft. A nut is threadedly mounted
for longitudinal movement along the shaft and is fixed against rotation
relative thereto. Thus, rotation of the shaft produces longitudinal
travel of the nut. A linkage interconnects the nut and the head
section of the articulated frame in such a way as to convert longitudinal
motion of the nut into rotational movement of the head section,
thereby altering the inclination of the head section. The motor
can be deactivated at any time to hold the head section in a given
position of adjustment.
It is well known that hospital and home care and convalescent-type
beds, having independently moveable articulated head, knee and leg
sections are connected to independent drive mechanisms and motors.
U.S. Pat. No. 4970737 teaches us that the adjustable hospital
and nursing home bed, has a three-part support frame for mattresses,
the head, middle and foot part of which are pivotably connected
to one anther via pivot shafts and are supported in a suspension
frame of a bed frame such that they are pivotable in height directly
by means of a force provider via a lever linkage.
U.S. Pat. No. 5317769 teaches a hospital bed having two mechanical
drive mechanisms connected between each end of a bed support frame
and a base, each of which has a respective actuator. Selective operation
of each of the drive mechanisms with the actuators permits either
end of the bed support frame to be raised or lowered to a desired
position.
U.S. Pat. No. 4425674 teaches a transmission for an adjustable
hospital bed for positioning the bed in a plurality of different
positions, the different parts of the bed moving independently and/or
simultaneously, the transmission transmitting power to the adjustment
mechanisms from a single common drive. The drive motor is stationary
or fixed, however, increasing the complexity as well as the likelihood
for mechanical failure of the resultant required apparatus.
U.S. Pat. No. 4472846 further teaches that different hospital
bed functions or adjustments may be made by employing a single reversible
motor to drive selected ones of a series of adjusting mechanisms.
A bedside control unit for a hospital bed is operable from a position
within the bed and also from a bedside chair, as found in U.S. Pat.
No. 5542138.
U.S. Pat. No. 5195198 teaches a hospital bed which has a movable
section, a selectively actuable drive arrangement for moving the
section, a manually actuable control switch, and a control circuit
coupled to the switch and drive arrangement. The control circuit
includes a microprocessor having an input coupled to the control
switch and having an output, and the program executed by the microprocessor
selectively actuates the output of the microprocessor based on a
function which takes into account the current state of a signal
being applied to the microprocessor input.
Thus, as shown by the foregoing brief review of the prior art,
each mode of adjustability, i.e., bed section function, is typically
powered by a small, separate gear motor. Since these small motors
are relatively expensive and have comparatively little actual running
time during the effective life of the bed, such designs are expensive
and inefficient. Multiple motors also increase the weight of such
beds.
Typically, due to lowered reimbursement rates, guidelines and schedules
established by the federal government, beds in use for home care
and home convalescence, as well as beds used in hospitals, nursing
facilities and other commercial facilities have only two motors,
one for raising and lowering the head of the bed and one for raising
and lowering the foot of the bed. A hand crank is used to raise
and lower the overall height of the bed. As a result, it has been
estimated that hundreds if not thousands of injuries occur nationwide
on a yearly basis. Patients and their caregivers are injured attempting
to move the patient from an improperly adjusted bed. Additional
work is required of a caregivers to manually adjust the height of
the bed prior to attempting to maneuver the patient, or have the
patient move himself or herself. A third motor can also be used
for adjusting the overall height of the bed, adding to cost, weight
and gear complexity.
SUMMARY OF THE INVENTION
Accordingly, an advantage of the invention is to provide a single
motor, fully adjustable bed.
Another advantage of the invention is to provide a bed which is
less expensive to build.
Another advantage of the invention is to provide a bed which weighs
less than the conventional bed with complex gear structures and
two or more motors.
It is an advantage of the present invention to provide a drive
for adjustable beds comprising a single, drive motor for efficient
operation and reduced manufacturing cost: to provide an adjustable
bed drive capable of fully powering a multi-function adjustable
bed; to provide an adjustable bed drive which is efficient in use,
capable of a long operating life, and particularly well adapted
for the proposed use.
It is an advantage of the present invention to provide a fully
operational hospital bed for home use with fewer moving parts then
presently used. A single motor bed has less weight than current
beds. They are easier to service. A single motor can be used for
all functions to configure the bed by having the motor ride along
a track that, with the aid of a computer program, will stop at each
correct spot by knowing how many clicks or teeth marks the motor
must move to be in proper alignment. When the motor comes to a stop
in alignment with one of the drive shafts, it will connect an electric
current that will cause a solenoid to pull, thereby causing the
spring loaded connector to extend out and connect with the drive
shaft of the desired adjustment that the user selects via a remote
control unit. The motor is one that is currently found in today's
adjustable beds, with the exception of a different tip on the connector,
the shape of the tip will connect with the female version of the
shape so that when the connector is extended, it will form a strong
link between the motor and the drive shaft of the desired bed adjustment
that is selected by the user by a push of a button on the remote
control unit.
The unique hospital bed of the present invention includes a transmission
which couples a common motor drive only to the selected adjusting
mechanisms that should be operated, the drive being decoupled from
those adjusting mechanisms that should not be operated. Moreover,
and of major importance, the coupling arrangement is extremely reliable
and efficient in operation, and is low in cost, power consumption
and noise. If the electricity is disengaged for any reason all drive
shafts are disengaged. This will allow for free hand movement of
the motor either to the left or the right. This will allow anyone
to insert an emergency crank into any of the drive shafts to move
that drive shaft by hand.
These and many other important advantage, feature and objects of
the present invention will be further understood and appreciated
by those skilled in the art by reference, will become readily apparent
from the following detailed description of the invention and the
embodiments thereof, from the claims and from the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is an representative isometric view of a preferred embodiment
for a motor, fully adjustable bed of the present invention.
FIG. 2 is a representative schematic of a preferred embodiment
of a drive assembly of a single motor, fully adjustable bed of the
present invention.
FIG. 3 is a representative view of a preferred embodiment of a
manual control handpiece for a single motor, fully adjustable bed
of the present invention.
FIG. 4 is a representative isometric view of a preferred embodiment
of a motor driven linear tracking system for a single motor, fully
adjustable bed of the present invention.
FIG. 5 is a representative detail view of a preferred embodiment
of a motor drive coupling for a single motor, fully adjustable bed
of the present invention.
FIG. 6 is a representative detail view of a preferred embodiment
of a motor position selection gear assembly for a single motor,
fully adjustable bed of the present invention.
FIG. 7 is a representative schematic view of a preferred embodiment
of a motor with solenoid-driven coupling drive shaft for a single
motor, fully adjustable bed of the present invention.
FIG. 7A is a representative schematic view of a preferred embodiment
of solenoid-type offset linkage coupling to a drive shaft for a
single motor, fully adjustable bed of the present invention.
FIGS. 8A-8F are a representative schematic view of a preferred
embodiment of a method of operation of a single motor, fully adjustable
bed of the present invention.
DETAILED DESCRIPTION
It will be understood that while numerous preferred embodiments
of the present invention are presented herein, numerous of the individual
elements and functional aspects of the embodiments are similar.
Therefore, it will be understood that structural elements of the
numerous apparatus disclosed herein having similar or identical
function will have like reference numerals associated therewith.
FIG. 1A is an representative isometric view of a preferred embodiment
for a single motor, fully adjustable bed 100 of the present invention.
As shown, the bed 100 has an adjustable head section 102 an adjustable
leg section 104 and an adjustable height H. Three separate drive
shafts 106 108 and 110 are acted upon, as desired and according
to the specifications disclosed herein, by motor 120.
Motor coupling 122 selectively engages one of drive shafts 106
108 or 110 to either raise and/or lower the head section 102 raise
and/or lower the leg section 104 and to raise and/or lower the overall
height H of bed 100. The motor is moved by tracking gear 124 which
rides on toothed track 130 which allows the motor 120 to move linearly,
thus allowing use of the single motor for each of the modes of adjustment,
i.e., head section 102 up and/or down, leg section 104 up and/or
down and bed height H up and/or down. Second solenoid-type coupling
140 is used to control movement of the motor along the track.
FIG. 2 is a representative schematic view of a preferred embodiment
of a drive assembly of a single motor 120 of the fully adjustable
bed 100 of the present invention. The drawing shows motor 120 in
alignment with one of the drive shafts 106 108 or 110. Solenoid-type
coupling 122 comprises an electrically actuated solenoid-type, rotating
contact or other switch which causes the first extendable end 132
of motor shaft 134 to extend and engages the tapered connector 136
of each drive shaft.
Another solenoid-type coupling 140 is used to extend a second extendable
end 142 to engage a tapered connector 144 on the tracking gear 124.
Thus, once engaged, the single motor 120 will cause the tracking
gear to move the motor 120 to a position opposite the desired drive
shaft for operation of the desired mode of adjustment.
FIG. 3 is a representative view of a preferred embodiment of a
manual control handpiece 300 for a single motor, fully adjustable
bed of the present invention. The following table identifies the
mode of operation which can be selected by a user.
______________________________________ Control Button Mode of Adjustment
______________________________________ SW1 Raise head section SW2
Lower head section SW3 Raise leg section SW4 Lower leg section SW5
Raise overall bed height SW6 Lower overall bed ______________________________________
height
FIG. 4 is a representative isometric view of a preferred embodiment
of a motor driven linear tracking system for a single motor, fully
adjustable bed of the present invention. The second extendable end
142 of solenoid-type coupling 140 of the motor 120 couples with
the tracking gear 124 via the tapered connector 144. The motor,
for example rotating in direction shown by arrow A, moves linearly
along the toothed track 130 for example in the direction shown
by arrow B.
FIG. 5 is a representative detail view of a preferred embodiment
of a motor drive coupling for a single motor, fully adjustable bed
of the present invention. FIG. 5 shows a detailed illustration of
the solenoid-type coupling 122 which pushes the extendable end 132
of the motor shaft 134 onto the tapered connector 136 of the desired
drive shaft 106108 or 110. This "unicorn head" design
has been used in other applications of a type of keyed, locking
clutch mechanism. The tapered portion 136 can be any operative geometry,
or have a splined outer surface with a matching grooved or other
shaped opening 138 within the extendable end 132.
FIG. 6 is a representative detail view of a preferred embodiment
of a motor position selection gear assembly for a single motor,
fully adjustable bed of the present invention. Showing close-up
views of the linear tracking function of the single motor 120. The
motor shaft 134 gets extended by solenoid driven coupling 140 which
pushes a second extendable end 142 onto the tapered connector 144
of the shown tracking gear 124 that is engaged to the linear track
130.
FIG. 7 is a representative schematic view of a preferred embodiment
of a motor with solenoid-driven coupling drive shaft for a single
motor, fully adjustable bed of the present invention. FIG. 7 shows
the motor 120 and the motor shaft 134 with two extendable ends 132
and 142. Each end is extended by solenoid type couplings 122 and
140. As described above, each of the extendable ends 132 and 142
engages a tapered connector 136 and 144 respectively, as shown
in FIG. 6. As shown, extendable end 132 is in its retracted state
whereas extendable end 142 is extended
FIG. 7A is a representative schematic view of a preferred embodiment
of solenoid-type offset linkage coupling to a drive shaft for a
single motor, fully adjustable bed of the present invention. It
will be understood by those skilled in the art that the extendable
end may be actuated by a solenoid-type switch such as described
herein, but other designs which will be included within the scope
of the present invention and incorporated herein include providing
an offset linkage 700 which, when actuated by a solenoid-type switch
702 etc., may advance an extendable end 704 linked to the switch.
Any offset, remote, external or otherwise actuable linkage may be
used and will be considered within the scope of the present invention.
FIGS. 8A-8F are a representative schematic view of a preferred
embodiment of a method of operation of a single motor, fully adjustable
bed of the present invention. For the following description, coupling
means 122 and 140 are solenoid-type switches, hereafter referred
to as A and B, respectively, having a normally retracted un-activated
position. Additionally, driveshafts 106 108 and 110 or A, B and
C, respectively, operate to raise and lower the head section 102
the leg section 104 and the overall height H.
Head Section Operation
In a first mode of operation, the head section 102 is to be raised.
An operator depresses switch SW1 in step 400. In step 402 if switch
SW1 is released, then solenoid A is moved into a retracted position
in step 404. In step 406 solenoid B extends extendable end 142
to couple with tapered end 144 to move motor 120 into alignment
with drive shaft 106. In step 408 solenoid B retracts, disengaging
motor 120 from toothed track 130 and solenoid A engages motor 120
and drive shaft A by extending extendable end 122 about tapered
end 136.
In step 402 if switch SW1 is not released, then a determination
is made as to whether motor 120 is in alignment or not with 106
drive shaft A, as shown in step 410. If motor 120 is not in alignment
with 106 drive shaft A, then in step 412 solenoid A is released,
in step 414 solenoid B engages tapered end 144 to move motor 120
into alignment with driveshaft A. Then, in step 416 the extendable
couplings switch, and solenoid B is released so that extendable
end 142 is retracted and solenoid A is activated to extend extendable
end 132 over tapered end 136.
If motor 120 is in alignment with 106 drive shaft A, then a sequence
of individual steps takes place in which the motor is energized
in low speed 415 for a predetermined small time interval 417 after
which the motor's speed is increased to an operational speed 419.
Thus, it will be understood that the motor engages the tapered ends
136 one at a time of course, and then starts to turn slowly to
ensure proper seating between the extendable coupling 122 and the
tapered end 136. Thereafter, the operational speed is greater.
In step 418 once the head section has been raised to the maximum
height possible, then the motor 120 stops, step 420. If however,
the desired height is achieved, and SW1 is released prior to the
head section reaching it's maximum height, as shown in step 422
then the motor 120 will also stop.
To lower the head section 102 an operator depresses switch SW2
in step 500. In step 502 if switch SW2 is released, then solenoid
A is moved into a retracted position in step 504. In step 506 solenoid
B extends extendable end 142 to couple with tapered end 144 to move
motor 120 into alignment with drive shaft 106. In step 508 solenoid
B retracts, disengaging motor 120 from toothed track 130 and solenoid
A engages motor 120 and drive shaft A by extending extendable end
122 about tapered end 136.
In step 502 if switch SW2 is not released, then a determination
is made as to whether motor 120 is in alignment or not with 106
drive shaft A, as shown in step 510. If motor 120 is not in alignment
with drive shaft A, then in step 512 solenoid A is released, in
step 514 solenoid B engages tapered end 144 to move motor 120 into
alignment with driveshaft A. Then, in step 516 the extendable couplings
switch, and solenoid B is released so that extendable end 142 is
retracted and solenoid A is activated to extend extendable end 132
over tapered end 136.
If motor 120 is in alignment with 106 drive shaft A, then a sequence
of individual steps takes place in which the motor is energized
(in the opposite direction as in step 415) in low speed 515 for
a predetermined small time interval 517 after which the motor's
speed is increased to an operational speed 519. Thereafter, the
operational speed is greater.
In step 518 once the head section has been lowered to it's minimum
height, i.e. lowered completely, then the motor 120 stops, step
520. If however, the desired height is achieved, and SW2 is released
prior to being lowered completely, as shown in step 522 then the
motor 120 will also stop.
Leg Section Operation
In a second mode of operation, the leg section 104 is to be raised.
An operator depresses switch SW3 in step 600. In step 602 if switch
SW3 is released, then solenoid A is moved into a retracted position
in step 604. In step 606 solenoid B extends extendable end 142
to couple with tapered end 144 to move motor 120 into alignment
with drive shaft 108. In step 608 solenoid B retracts, disengaging
motor 120 from toothed track 130 and solenoid A engages motor 120
and drive shaft A by extending extendable end 122 about tapered
end 136.
In step 602 if switch SW3 is not released, then a determination
is made as to whether motor 120 is in alignment or not with 108
drive shaft B, as shown in step 610. If motor 120 is not in alignment
with drive shaft B, then in step 612 solenoid A is released, in
step 614 solenoid B engages tapered end 144 to move motor 120 into
alignment with driveshaft B. Then, in step 616 the extendable couplings
switch, and solenoid B is released so that extendable end 142 is
retracted and solenoid A is activated to extend extendable end 132
over tapered end 136.
If motor 120 is in alignment with 108 drive shaft B, then a sequence
of individual steps takes place in which the motor is energized
in low speed 615 for a predetermined small time interval 617 after
which the motor's speed is increased to an operational speed 619.
Thus, it will be understood that the motor engages the tapered ends
136 one at a time of course, and then starts to turn slowly to
ensure proper seating between the extendable coupling 122 and the
tapered end 136. Thereafter, the operational speed is greater.
In step 618 once the leg section has been raised to the maximum
height possible, then the motor 120 stops, step 620. If however,
the desired height is achieved, and SW3 is released prior to the
leg section 104 reaching it's maximum height, as shown in step 622
then the motor 120 will also stop.
To lower the leg section 104 an operator depresses switch SW4
in step 700. In step 702 if switch SW4 is released, then solenoid
A is moved into a retracted position in step 704. In step 706 solenoid
B extends extendable end 142 to couple with tapered end 144 to move
motor 120 into alignment with drive shaft 108. In step 708 solenoid
B retracts, disengaging motor 120 from toothed track 130 and solenoid
A engages motor 120 and drive shaft B by extending extendable end
122 about tapered end 136.
In step 702 if switch SW4 is not released, then a determination
is made as to whether motor 120 is in alignment or not with 108
drive shaft B, as shown in step 710. If motor 120 is not in alignment
with drive shaft B, then in step 712 solenoid A is released, in
step 714 solenoid B engages tapered end 144 to move motor 120 into
alignment with driveshaft B. Then, in step 716 the extendable couplings
switch, and solenoid B is released so that extendable end 142 is
retracted and solenoid A is activated to extend extendable end 132
over tapered end 136.
If motor 120 is in alignment with 108 drive shaft B, then a sequence
of individual steps takes place in which the motor is energized
(in the opposite direction as in step 615) in low speed 715 for
a predetermined small time interval 717 after which the motor's
speed is increased to an operational speed 719. Thereafter, the
operational speed is greater.
In step 718 once the leg section 104 has been lowered completely,
then the motor 120 stops, step 720. If however, the desired height
is achieved, and SW4 is released prior to being lowered completely,
as shown in step 722 then the motor 120 will also stop.
Height Adjustment
In its third mode of operation, the overall height H of the bed
is to be raised. An operator depresses switch SW5 in step 800. In
step 802 if switch SW5 is released, then solenoid A is moved into
a retracted position in step 804. In step 806 solenoid B extends
extendable end 142 to couple with tapered end 144 to move motor
120 into alignment with drive shaft 110. In step 808 solenoid B
retracts, disengaging motor 120 from toothed track 130 and solenoid
A engages motor 120 and drive shaft A by extending extendable end
122 about tapered end 136.
In step 802 if switch SW5 is not released, then a determination
is made as to whether motor 120 is in alignment or not with 110
drive shaft C, as shown in step 810. If motor 120 is not in alignment
with drive shaft C, then in step 812 solenoid A is released, in
step 814 solenoid B engages tapered end 144 to move motor 120 into
alignment with driveshaft C. Then, in step 816 the extendable couplings
switch, and solenoid B is released so that extendable end 142 is
retracted and solenoid A is activated to extend extendable end 132
over tapered end 136.
If motor 120 is in alignment with 110 drive shaft C, then a sequence
of individual steps takes place in which the motor is energized
in low speed 815 for a predetermined small time interval 817 after
which the motor's speed is increased to an operational speed 819.
Thus, it will be understood that the motor engages the tapered ends
136 one at a time of course, and then starts to turn slowly to
ensure proper seating between the extendable coupling 122 and the
tapered end 136. Thereafter, the operational speed is greater.
In step 818 once the height of the bed H has been raised to its
maximum height possible, then the motor 120 stops, step 820. If
however, the desired height is achieved, and SW5 is released prior
to the bed reaching it's maximum height, as shown in step 822 then
the motor 120 will also stop.
To lower the lower the overall height H, an operator depresses
switch SW6 in step 900. In step 902 if switch SW6 is released,
then solenoid A is moved into a retracted position in step 904.
In step 906 solenoid B extends extendable end 142 to couple with
tapered end 144 to move motor 120 into alignment with drive shaft
110. In step 908 solenoid B retracts, disengaging motor 120 from
toothed track 130 and solenoid A engages motor 120 and drive shaft
C by extending extendable end 122 about tapered end 136.
In step 902 if switch SW6 is not released, then a determination
is made as to whether motor 120 is in alignment or not with 110
drive shaft C, as shown in step 910. If motor 120 is not in alignment
with drive shaft C, then in step 912 solenoid A is released, in
step 914 solenoid B engages tapered end 144 to move motor 120 into
alignment with driveshaft B. Then, in step 716 the extendable couplings
switch, and solenoid B is released so that extendable end 142 is
retracted and solenoid A is activated to extend extendable end 132
over tapered end 136.
If motor 120 is in alignment with 110 drive shaft C, then a sequence
of individual steps takes place in which the motor is energized
(in the opposite direction as in step 815) in low speed 915 for
a predetermined small time interval 917 after which the motor's
speed is increased to an operational speed 919. Thereafter, the
operational speed is greater.
In step 918 once the bed has been lowered completely, then the
motor 120 stops, step 920. If however, the desired height is achieved,
and SW6 is released prior to being lowered completely, as shown
in step 922 then the motor 120 will also stop.
It will be understood that the foregoing description of the control
scheme, FIGS. 8A-8F, utilized with the single motor, fully adjustable
bed of the present invention is but one embodiment of any of numerous
control schemes possible. Those skilled in the art will understand
that with the availability of pre-programmed, programmable and semi-programmable
integrated circuits and other micro devices, additional, auxiliary,
enhanced and complementary modes of control may be implemented.
Additionally, as will be understood by those skilled in the art,
that the double extendable ends with dual solenoid design may be
implemented utilizing a sub-motor, such as a very small, electric
powered motor, to track the main motor 120 back and forth along
toothed track 130. This sub-motor will position the main motor 120
adjacent the appropriate driveshaft, 106 108 or 110. Other means
for moving the main motor 120 linearly along track 130 will be known,
and will include sub-motors, pulley assemblies such as found in
printers and print head drive assemblies, for tracking the main
motor linearly, as desired and for enhanced control of the bed of
the present invention.
Unless defined otherwise, all technical and scientific terms used
herein have the same meaning as commonly understood by one of ordinary
skill in the art to which this invention belongs. Although any methods
and materials similar or equivalent to those described can be used
in the practice or testing of the present invention, the preferred
methods and materials are now described.
While the principles of the invention have been made clear in illustrative
embodiments, there will be immediately obvious to those skilled
in the art many modifications of structure, arrangement, proportions,
the elements, materials, and components used in the practice of
the invention, and otherwise, which are particularly adapted to
specific environments and operative requirements without departing
from those principles. The appended claims are intended to cover
and embrace any and all such modifications, with the limits only
of the true purview, spirit and scope of the invention. |