U.S. patent number 3,592,041 [Application Number 04/770,590] was granted by the patent office on 1971-07-13 for chair-testing apparatus.
This patent grant is currently assigned to Burris Manufacturing Compnay. Invention is credited to William H. Spencer.
United States Patent |
3,592,041 |
Spencer |
July 13, 1971 |
CHAIR-TESTING APPARATUS
Abstract
A chair-testing apparatus for testing the operability and/or
durability of the elements and construction of a reclining chair,
including means for applying forces to movable seat, back and leg
rest portions of a chair under test and thereby simulating use of
the chair by an occupant be causing the movable portions to cycle
between a generally upright seating position and a generally
inclined reclining position and further including means for
engaging occupant-supporting surfaces of a chair under test to
simulate wear imposed thereon by an occupant seating himself in the
chair and arising from the chair. Testing sequences are under the
control of a control means governing the cycling of forces applied
to portions of the chair under test in such a manner as to permit
full simulation of use of the chair by an occupant or suspension of
certain test functions as may be desired.
Inventors: |
Spencer; William H. (Vale,
NC) |
Assignee: |
Burris Manufacturing Compnay
(Lincolnton, NC)
|
Family
ID: |
25089076 |
Appl.
No.: |
04/770,590 |
Filed: |
October 25, 1968 |
Current U.S.
Class: |
73/7; 73/161;
73/816; 73/819; 73/865.9 |
Current CPC
Class: |
G01M
99/001 (20130101) |
Current International
Class: |
G01M
19/00 (20060101); G01n 003/56 (); G01m
019/00 () |
Field of
Search: |
;73/432,7,94,161,172 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
778,222 |
|
Jul 1957 |
|
GB |
|
6,406,271 |
|
Dec 1965 |
|
NL |
|
Primary Examiner: Gill; James J.
Claims
I claim:
1. Apparatus for testing the durability of elements of a chair
having occupant-supporting seat and back portions with cushioning
and upholstery materials thereon by simulating the wear imposed by
an occupant on supporting portions of the chair and comprising:
pad means movable between a withdrawn position and a
supporting-surface-engaging position and adapted to engage the
occupant-supporting surface of the seat portion of a chair for
initial frictional sliding movement relative thereto and subsequent
imposition thereon of a force simulating the weight of an occupant
of the chair, said pad means comprising means engaging a portion of
the chair for limiting the extent of sliding movement, and
control means operatively connected to said chair-engaging means
for controlling the operation thereof to repeatedly cycle said
engaging means between the withdrawn and engaging positions and
thereby test the durability of at least the cushioning and
upholstery elements of the seat portion of the chair.
2. Apparatus according to claim 1 wherein said control means
includes adjustable means governing the imposition of force by said
chair-engaging means on the occupant-supporting surfaces of the
chair under test for accommodating adjustment of such force and
thereby facilitating simulation of the varying weights of a
plurality of potential occupants of the chair.
3. Apparatus according to claim 1 wherein said chair-engaging means
is adapted to engage the occupant-supporting surfaces of both the
seat and back portions for sliding movement relative thereto and
imposition of forces thereon.
4. Apparatus for testing the durability of elements and
construction of a reclining chair having upholstered
occupant-supporting seat, back and leg rest portions mounted on a
frame and operatively interconnected by a linkage mechanism for
movement between a seating position and a reclining position, the
testing apparatus simulating the wear imposed by an occupant on
supporting elements of the chair and comprising
means adapted to engage the back portion of the chair for moving
the movable portions between the seating and reclining
positions,
means movable between withdrawn and supporting-surface-engaging
positions and adapted to engage occupant-supporting surfaces of the
seat and back portions of the chair for sliding movement relative
thereto and imposition thereon of forces simulating the weight and
backward bias of an occupant of the chair, and
control means operatively connected to said chair-engaging means
for controlling the operation thereof to repeatedly cycle said
chair-moving means to move the movable portions of the chair
between the seating and reclining positions while simultaneously
repeatedly cycling said surface-engaging means between the
withdrawn and engaging positions, whereby the actions of an
occupant seating himself in the chair, reclining in the chair,
returning to a generally upright seating position and arising from
the chair are simulated.
5. Apparatus according to claim 4 wherein said chair-engaging means
comprises a plurality of double-acting, extensible and retractable
devices mounted in predetermined relation to each other.
6. Apparatus according to claim 5 wherein said devices are
pressure-fluid-actuated cylinder devices and further wherein said
control means includes fluid flow control valves operatively
connected to said cylinder devices, each of said flow control
valves governing the flow of actuating fluid to a corresponding one
of said jack devices.
7. Apparatus according to claim 5 wherein said devices are
air-pressure-actuated cylinder devices and further wherein said
control means comprises adjustable air-pressure-regulating means
operatively connected to said cylinder devices for governing the
pressure of actuating air supplied thereto and thereby governing
the forces imposed on portions of the chair under test.
8. Apparatus according to claim 4 wherein said chair-engaging means
comprises first, second and third extensible and retractable
devices, said first and second devices being arranged to provide
motive force for said surface-engaging means and mounted in
predetermined relation one to the other for exerting force
respectively on the occupant-supporting surface of the back portion
of the chair under test and on the occupant-supporting surface of
the seat portion of the chair under test, said third device being
arranged to provide motive force for said moving means and mounted
in relation to said first and second devices for exerting force on
the back portion of the chair under test, and further wherein said
control means includes operational mode selection means for varying
operative interconnections among said first, second and third
devices and thereby permitting selective suspension of the testing
functions performed thereby.
9. Apparatus according to claim 8 wherein said control means
further includes hesitation timing means for delaying actuation of
said third device relative to actuation of said first and second
devices in such a manner as to simulate the hesitation of an
occupant of the chair between seating in the chair and reclining in
the chair.
10. Apparatus according to claim 8 wherein said chair-engaging
means further comprises a fourth pushing-pulling device mounted in
predetermined relation to said third device and arranged for
exerting a downward pulling force on the leg rest portion of the
chair under test in coordination with exertion of force by said
third device for moving the movable portions of the chair under
test from the reclining toward the seating position.
11. Apparatus for testing the operability and/or durability of
elements of a reclining chair, these elements including
occupant-supporting seat, back and leg rest portions mounted on a
frame and operatively interconnected by a linkage mechanism for
movement between a seating position and a reclining position, and
for simulating the wear imposed by an occupant on the cushioning
and upholstery materials on the occupant-supporting seat and back
portions of the chair under test, the testing apparatus
comprising:
means adapted to engage at least the back portion of a reclining
chair for moving the movable portions of the chair between the
seating and reclining positions, including pad means movable
between withdrawn and supporting-surface-engaging positions and
adapted to engage the occupant-supporting surface of at least one
of the seat and back portions of the chair for sliding movement
relative thereto and imposition thereon of forces simulating the
weight and backward bias of an occupant of the chair, and
control means operatively connected to said chair-engaging means
for controlling the operation thereof to repeatedly cycle the pad
means between withdrawn and engaging positions and the movable
portions of the chair under test between the seating and reclining
positions and thereby test the operability and/or durability of the
linkage mechanism cushioning materials and upholstery of the chair.
Description
In recent years, a large and growing portion of business in the
furniture industry has involved chairs of a type known as reclining
chairs or recliners. Reclining chairs may be characterized as
having movable seat, back and leg rest portions mounted upon a
frame for movement relative thereto between a seating position
wherein an occupant of the chair is in a generally upright seated
position and a reclining position wherein the occupant of the chair
is supported in a more nearly horizontal or inclined position. As
the volume of sale of such chairs has increased, it has become of
increasing importance to manufacturers of such chairs that control
be exercised over the quality of the finished product and of the
component parts which are assembled into that product, including
the linkage mechanism which operatively connects the movable
portions of the reclining chair with the frame, cushioning
materials, and upholstery materials.
Heretofore, while the necessity for quality control over the final
product and as to the components thereof has been recognized, the
means of obtaining basic information as to the durability of the
chairs and elements thereof for such quality control has not been
readily available to reclining chair manufacturers. In particular,
a means has not been available for readily testing an assembled
chair in full simulation of the use of a chair by a consumer. More
specifically, any test cycling of a reclining chair through a
sequence of movements between seating and reclining positions has
heretofore been accomplished manually and, while perhaps somewhat
satisfactory in simple testing of operability of reclining chairs,
has not been appropriate for testing the durability of the chairs.
Further, it is recognized that availability of capabilities for
testing all of the elements incorporated into a chair necessarily
requires the capability of testing the durability of cushioning and
upholstery materials used on the occupant-supporting portions of
the chair.
It is accordingly a principal object of the present invention to
provide an apparatus for testing a reclining chair of the type
described by full simulation of the use of the chair by a
consumer.
A more specific object of the present invention is to provide
chair-testing apparatus operable to cycle movable portions of a
reclining chair between seating and reclining positions in a manner
substantially the same as that typical during use of the chair by
an occupant and in controlled sequence for determination of the
operability and/or durability of the finished chair and its
components.
A further specific object of the present invention is to provide a
chair-testing apparatus operable for imposing wear on
occupant-supporting surfaces of a chair under test in simulation of
frictional sliding and weight loading on cushioning and upholstery
materials which occur as an occupant seats himself in the chair and
arises from the chair.
Some of the objects and advantages of the invention having been
stated, others will appear as the description proceeds, when taken
in connection with the accompanying drawings, in which
FIG. 1 is a front elevation view of the apparatus of the present
invention, illustrating a reclining chair under test;
FIG. 2 is a plan view of the apparatus of FIG. 1, in partial
section, taken generally along the line 2-2 in that FIG.;
FIG. 3 is a side elevation view, in partial section, through the
apparatus of FIG. 1 and a chair under test, showing the chair in
the inclined position;
FIG. 4 is a view similar to FIG. 3, showing the apparatus as
disposed with the chair under test in the seating position;
FIG. 5 is a schematic diagram of a pressure fluid flow circuit
included in a control means arrangement for the apparatus of FIGS.
1 through 4;
FIG. 6 is a schematic diagram of an electrical circuit included in
the control means arrangement for the apparatus of FIGS. 1 through
4; and
FIG. 7 is an enlarged elevation of the face of the control panel
for the control arrangement of FIGS. 5 and 6.
Referring now more particularly to the drawings, an apparatus in
accordance with the present invention for testing the operability
and/or durability of elements of a reclining chair in full
simulation of use by a consumer is there indicated by the reference
character 10. Apparatus 10 is illustrated in connection with a
chair C of the type known as a reclining chair, which includes a
back portion B, a seat portion S and a leg rest portion L which are
mounted on a frame F and operatively connected together for
movement relative thereto between a generally upright seating
position (as shown in FIG. 4) and a generally inclined reclining
position (as shown in FIG. 3).
In the specific embodiment illustrated, a mechanical linkage
arrangement operatively connects the leg rest L, the frame F, and
the seat portion S for moving the leg rest portion L between an
extended position while the chair is in a reclining position and a
retracted position disposed beneath the seat portion S while the
chair is in the seating position. Further, in the illustrated
embodiment, the seat portion S and the back portion B are pivotally
mounted on the frame F, but do not move one relative to the other
during the cycle of movement of the movable portions of the chair
between the seating and reclining positions.
While the chair C used in illustrating the present subject
invention is thus one of the several types of reclining chairs
known and commercially available, specifically being that type
known as a "two-way" chair, it is to be understood that the
apparatus of the present invention is contemplated as being equally
useful with the other types of reclining chairs, such as those
wherein the seat portion and back portion do move one relative to
the other during the cycle of the movable portions of the chair
(known as "three-way" chairs), those wherein extending movement of
the leg rest portion is accomplished in a different manner, and
those wherein movement of the leg rest portion is accomplished
independently of movement of the seat portion or back portion.
Apparatus 10 includes a base means for receiving and supporting a
chair to be tested, and preferably, the base means is in the form
of a platform 11 which, for convenience, is preferably mounted upon
a plurality of casters 12 to permit readily moving the apparatus 10
about from point to point within a plant, as may be required. The
upper surface of the platform 11 provides a supporting floor or
surface on which a chair C under test may be received and
supported.
To insure that the chair C is properly positioned for the testing
procedures which are described hereinafter, the base means includes
a plurality of clamping devices 14, 15, 16 and 17 mounted upon the
floor surface of the platform 11 for clamping engagement with the
legs 19 of the frame of the chair C. As best shown in FIG. 2, the
end portions of the clamp means 14, 15, 16 and 17 which engage with
the legs 19 preferably are forked or cut to provide an angle for
engaging the legs 19 and securely locking the chair C in a desired
position. Also, clamp means 14-17 are adjustably mounted on
platform 11 for accommodating different sizes of chairs.
In order to retain the chair C in the desired position during the
testing procedure, holddown means (FIG. 1) are provided for
engaging a portion of the frame of the chair and, as illustrated,
comprise a pair of cable members 20 and 21, each being connected to
platform 11 by a corresponding one of two eyes 22 and 23 and a
corresponding one of two turnbuckles 25 and 26. By tightening the
cable members 20 and 21 through use of the turnbuckles 25 and 26, a
downward force may be applied to the frame of the chair C to firmly
secure the same in place in the desired position on the supporting
floor provided by the platform 11.
The apparatus 10 of the present invention further includes motive
means supported in predetermined relation to the platform 11 for
applying to portions of the chair C forces which fully simulate
wear imposed on the chair when a consumer causes the seat S, back B
and leg rest L portions of the chair C to cycle between the seating
and reclining positions. In particular, the motive means includes
means adapted to engage the occupant-supporting surfaces of a chair
under test and means adapted to engage at least the back portion of
a reclining chair for moving the movable portions. Preferably,
these means include at least first, second and third pushing
devices 30, 31 and 32.
Of these three pushing devices, the first and second devices 30 and
31 are arranged for movement between withdrawn and
supporting-surface-engaging positions and to act downwardly on the
back and seat portions of the chair C. Particularly, the firs and
second pushing devices 30 and 31 are supported by a pair of
vertically uprising standards 34 and 35 rising from the platform 11
and a crossbeam 36 extending horizontally between the standards 34
and 35 above the chair C. The crossbeam 36 additionally supports
other components of the apparatus 10 as discussed more fully
hereinafter.
The third pushing device 32 is mounted directly on the floor
surface provided by the platform 11, for acting against the back
portion B of the chair C and exerting thereon forces for moving the
movable portions of the chair.
Preferably, each of the pushing devices 30, 31 and 32 is a
double-acting, pressure-fluid-actuated, extensible and retractable
device, comprising an elongate cylinder, a piston movable within
the cylinder (not shown in the drawings) and a piston rod
extensible relative to the cylinder with movement of the piston
therewithin. In mounting each of the devices, pivotal connections
are made between the opposite ends of the cylinder and the piston
rod and the other structural elements which support the jack device
and engage the chair C under test. More specifically, referring now
to the first pushing device 30 as an example, that device includes
a cylinder 38 and a piston rod 39 extensible relative to the
cylinder. The end of the cylinder 38 remote from the piston rod 39
is pivotally connected to a mounting plate 40, which is in turn
secured to and extends upwardly from the crossbeam 36 (see FIGS. 1,
3 and 4). The free end of the piston rod 39 is pivotally connected
to a pushing pad 41, particularly adapted for engagement with the
occupant supporting surface of the back portion B of the chair C.
By means of these pivotal connections, angular movement between the
back portion B of the chair C and the support plate 40 is
accommodated (as seen by comparing the positions of the members in
FIG. 3 with the position of the members in FIG. 4).
As to the second pushing device 31, the cylinder 42 and piston rod
43 thereof are respectively pivotally connected to the crossbeam 36
and to a pushing pad 44 particularly adapted for engagement with
the occupant-supporting surface of the seat portion S of the chair
C. The seat portion pushing pad 44 (as shown in FIGS. 3 and 4)
preferably includes a hook portion 45 for engagement with the
forward side edge of the sea portion S.
In similar fashion, the third pushing device 32 includes a cylinder
48 and piston rod 49, respectively pivotally connected to a
mounting plate 50 and a pushing bar 51 adapted to be bolted to or
otherwise be connected to the back portion B of the chair C.
Positioning of the third pushing device 32 for cooperation with the
other elements of the apparatus 10 in cycling the movable portions
of the chair C is accommodated by the mounting plate 50 to which
the cylinder 48 is pivotally connected being received within a
trackway means 52 mounted on the platform 11, for adjustment of the
mounting plate 50 therealong.
As to certain types of reclining chairs, the application of a
downward force on the leg rest portion of the chair is necessary in
order to initate movement from the reclining position to the
upright seating position. In order to adapt the apparatus 10 of the
present invention to testing a reclining chair of this type, the
motive means of the apparatus 10 further include a fourth
extensible and retractable device 33 mounted on the platform 11
adjacent the trackway 52 on which the third device 32 is mounted.
Preferably, the fourth device is also a pressure fluid device
including a cylinder 53 and a piston rod 54, and has connected
thereto an elongate cable 55 guided along the platform 11 and
terminating at an attachment plate 56 particularly adapted for
connection to the leg rest portion of a chair under test. When so
connected, the piston rod 54 of the fourth device 33 is extended as
the chair is positioned in the reclined position (similar to the
position of FIG. 3). Upon initiation of movement of the elements of
the chair from the reclining position toward the seating position,
the piston rod 54 of the fourth device 33 is withdrawn, pulling on
the cable 55 and retracting the leg rest portion of the chair under
test.
In the illustrated embodiment, the four devices 30--33 which are
employed to apply forces to elements of the chair C under test are
preferably pneumatically actuated cylinder devices, to facilitate
adjustment of the forces applied against the portions of the chair
C during testing procedures. Where the pushing pads 41 and 44 are
constructed to have predetermined areas for engagement with the
upholstery and cushion of the chair C, and are surfaced with a
suitable material, the total force imposed on and movement relative
to elements of the chair C during testing procedures may be
adjusted to simulate the forces and wear resulting from a user
being seated in the chair and leaning against the back portion
thereof through adjustment of the air pressure applied to the first
and second cylinders 30 and 31.
The application of forces to the movable portions of the chair C
under test is governed, in the apparatus 10 of the present
invention, by control means operatively connected to the various
chain-engaging means discussed above. In particular, the control
means are connected to the devices 30, 31, 32 and 33, for governing
the movements thereof relative to stationary elements of the
apparatus 10 and thereby governing the sequencing of movement of
the piston rods thereof and of the chair under test where the test
sequence used involves movement. As preferably arranged, the
control means in a preferred mode of operation causes the
chair-engaging means to apply forces to the back portion B, the
seat portion S, and the leg rest portion L of the chair under test
which cause the movable portions of the chair to repeatedly cycle
between the upright seating position of FIG. 4 and the generally
inclined reclining position of FIG. 3, in simulation of use of the
chair by a consumer. By the inclusion in the control means of
appropriate timing devices, as discussed more fully hereinafter,
the repeated cycling of the chair may be continued for controlled
intervals of time in order to determine the effect of such usage
upon the durability and operability of the chair. Further, by the
inclusion of a mode selector, the repeated cycling of selected ones
of the chair-engaging means may be individually suspended to select
particular forces to be applied to the chair under test.
A specific arrangement of control means for the illustrated
embodiment of the apparatus 10 is best understood by a discussion
with reference to the schematic diagrams of FIGS. 5 and 6. As
therein shown, each of the pneumatically actuated devices 30, 31,
32 and 33 has an associated pneumatic control valve means,
respectively identified by the reference characters 60, 61, 62 and
63. Each of the control valves is preferably of the well-known type
wherein a spool moving within a valve body is shifted to control
operative communication between a pair of exhaust ports, a pressure
input port, and an associated cylinder device. In the form
illustrated, movement of the spools within the valve devices 60,
61, 62 and 63 is in response to the energization of first and
second solenoid coils operatively associated with the valve spools
of each of the valve devices and respectively identified by the
addition of the postscripts A and B to the reference character
identifying the particular valve. As an operational example,
energization of the first solenoid coil 60A (FIG. 5) of valve 60
shifts the spool thereof to the left, opening operative
communication between a source of pneumatic pressure and the
cylinder 38, to cause extension of the piston rod 39 thereof.
Energization of the corresponding second solenoid coil 60B reverses
the operative communication, to cause retraction of the associated
piston rod 39. Similar energization of the other solenoid coils 61A
and 61B; 62A and 62B; and 63A and 63B causes similar extension and
retraction of the corresponding piston rods.
In order to govern the energization of the solenoids of the valves
60, 61, 62 and 63, and thereby govern operative communication
between a source of air under pressure and the extensible devices,
the control means of the present invention further includes
electrical circuitry (FIG. 6) for controllably energizing the
solenoids. An important feature of the circuitry is the inclusion
therein of a mode switch 65 arranged to vary the electrical
connection of the solenoids of the valves 60 through 63 and thereby
permit selection of a particular mode of operation for the
apparatus 10 of the present invention as discussed more fully
hereinafter. The mode switch 65 preferably is a multideck
rotational switch of the multiposition type, including seven switch
wafers identified by the reference characters SW-1 through
SW-7.
Electrically connectable by manipulation of the mode switch 65 are
a plurality of control relays, identified by the reference
characters CR-1, CR-2 and CR-3; a time delay relay identified by
legend, and a plurality of limit switches LS-1, LS-2, LS-3 and LS-4
which function as reversing means for controlling the directions of
forces imposed on the chair under test. The limit switches are
mounted adjacent certain of the pushing devices 30, 31 and 32, to
be actuated by movement of the piston rods thereof indicative of
movement of the chair under test and control the energization of
the solenoids of the valves 60, 61, 62 and 63 in response to
completion of certain movements. In order to provide a relatively
low voltage level, such as 10 volts, for operation of the solenoids
60A and 60B through 63A and 63B, the circuitry includes a
transformer T to which an appropriate line voltage such as 110
volts may be applied and which in turn supplies the required lower
control voltage.
With the mode switch 65 in a selected first position, wherein the
electrical switching arrangements provided on the seven switching
wafers thereof, SW-1 through SW-7, are all in the open circuit
position, manual control may be exercised over the movements of the
piston rods of the cylinder devices 30--33. More particularly,
manual actuation of low voltage pushbuttons PB-1, PB-2, PB-3 and
PB-4 provides control over the extending and retracting movements
of the second, third and fourth cylinders 31, 32 and 33. This
manual control will facilitate insuring that the chair C under test
is properly positioned for test procedures to follow. While it has
thus far been found that adjustment of the position of a chair C
with reference to these three cylinders will insure proper
cooperation between the chair and the pushing pad 41 operated by
the first cylinder device 30, it is additionally contemplated that
manual control pushbutton switches may be added to the circuitry to
provide manual control over the first cylinder device 30 if so
desired.
Turning now to the full automatic sequence which exposes a chair C
under test to a full simulation of the occupation and use of the
chair by a person, the mode switch 65 when placed in switching
position for full automatic operation establishes connection which
places the energization of the solenoids of the valves 60--63 under
the control of the limit switches LS-1 through LS-4, the control
relays CR-1 through CR-3, and a time delay relay. More
particularly, a circuit is completed through normally closed
contacts of a hand auto switch 66 which permits energization of the
winding of the third control relay CR-3 upon closure either of a
limit switch LS-1 associated with the third cylinder device 32 or
by a cycle start pushbutton 68. Upon energization of the third
control relay CR-3 by closure of either of these two switches,
closure of a first associated contact set 69 completes a circuit
energizing solenoid coils 60A and 61A to result in extension of the
piston rods of the first and second cylinder devices 30 and 31.
Another contact set 70 of the third control relay CR-3 completes a
circuit energizing the first control relay CR-1, and resulting in
closure of a pair of contact sets 71 and 72 associated therewith.
Of these contact sets, one contact set 71 completes a circuit in
parallel with the contact set 70 of the third control relay,
through a normally closed contact set 73A of a time delay relay.
This holding circuit maintains the coil of the first control relay
CR-1 energized for sufficient period of time for energization of
the time delay relay to occur, upon closure of the second contact
set 72 of the first control relay.
On energization of the soleniid coils 60A and 61A governing
extension of the piston rods of the first and second cylinder
devices 30 and 31, air is admitted thereto under pressures
determined by associated adjustable pressure-regulating valves
(FIG. 5) set to cause the forces exerted on the areas of the pads
41 and 44 to simulate the weight and backward bias of an occupant
of the chair under test. As the pads are moved from the withdrawn
position (FIG. 4) to the extended position in engagement with the
occupant-supporting surfaces of the chair, sliding motion of the
pads on the surfaces of the chair simulates the friction occurring
as such an occupant seats himself.
Energization of the time delay relay provides a controlled period
of hesitation or waiting between the instant of such energization
and the closure of a normally open contact set 73B thereof to
complete a circuit energizing the second control relay CR-2, and
thus simulates an occupant hesitating before moving the chair
toward the reclining position. At the end of a preset timing period
established by a dashpot or similar timing device in the time delay
relay, such as 10 seconds, the normally closed contacts 73A thereof
open and the normally open contacts 73B thereof are closed,
energizing the second control relay CR-2. Energization of the
second control relay results in closure of an associated contact
set 74 which is placed, by contact through switch wafers SW-4 and
SW-7 of the mode switch 65, into a circuit controlling solenoids
62A and 63A. Thus, at a predetermined short interval after weight
is imposed on the back B and seat S portions of the chair C
undergoing test, the chair is pulled from the upright seating
position toward the inclined reclining position by retraction of
the piston rod of the third cylinder device 32. During movement of
the chair from the seated to the reclining position, weight
continues to be imposed thereon by the first and second cylinder
devices 30 and 31, in continued simulation of use of the chair by
an occupant.
With the retraction of the piston rod of the third cylinder device
32 to such a point that the linkage mechanism of the chair is in
the fully opened position (with the chair in the fully reclining
position), a limit switch LS-4 positioned adjacent the cylinder
device 32 is engaged by an abutment member 75 moving with the
piston rod 49 thereof and closed to initiate movement returning the
chair to the upright seating position. This movement is initiated
by energization of the solenoids 62B and 63B controlling admission
of air to the third and fourth cylinder devices 32 and 33 so as to
cause extension of the piston rod 49 of the third cylinder device
to move the back portion B of the chair C under test upwardly and
the exertion of a pulling force downwardly on the leg rest portion
L of the chair C where the fourth cylinder device 33 is being
employed. At the same time, by an appropriate connection between
the solenoid coil 60B of control valve 60 and the limit switch LS-4
through a switch wafer SW-6 of the mode switch 65, retracting
movement of the piston rod 39 of the first cylinder device 30 is
begun. Retracting movement of the piston rod of the second cylinder
device 31 is placed under the control of a limit switch LS-3
positioned for actuation by an abutment member 76 moving with the
piston rod 49 of the third cylinder device 32 and electrically
connected to the solenoid 61B through a switch wafer SW-3 of the
mode switch 65. Upon return of the piston rods of the cylinder
devices 30--33 to their respective starting positions, be they
retracted or extended, the limit switches LS-1 and LS-2 are closed
by abutment members 77 and 78 moving with the piston rods 39 and 43
of the first and second cylinder devices 30 and 31 and the next
succeeding cycle of operation is initiated.
The present invention contemplates that the switch wafers SW-1
through SW-7 of the mode switch 65 may be arranged to interconnect
the various elements of the control circuitry in several manners,
in order to provide various controlled testing sequences as needed
to test the elements of the chair C. In particular, it is
contemplated that test sequences and electrical interconnections as
set forth in table 1 may be employed. ##SPC1##
While the mode switch 65 as thus arranged provides a testing
operator with the choice of suspending the operation of various
ones of the cylinder devices 30, 31, 32 and 33, it is contemplated
that the choices open to the testing operator may be enlarged by
providing more positions for the mode switch. In particular,
individual cycling operations for each of the three primary
pushing-pulling devices 30, 31 and 32 may be provided i so desired,
with such a range of capability permitting use of the apparatus 10
in testing either complete chairs or any component of those chairs
prior to completion of the chair.
Recognizing that continuous and repeated cycling of the cylinder
devices 30, 31 and 32 will not necessarily fully simulate the wear
imposed on a chair under test by an occupant, inasmuch as a user of
a chair does not normally repeatedly cycle the chair in that
manner, the apparatus of the present invention further includes
timers 80 and 81 incorporated in the control means for determining
the intervals of testing. In particular, one timer 80 is an "on"
cycle timer, which determined the duration of an interval during
which the testing procedure cycles go on repeatedly. The other
timer 81 is an "off" cycle timer, which determines a rest interval
alternating with test intervals as determined by the one timer 80.
In operation, upon initiation of the testing procedure the one
timer 80 begins running for a predetermined time period, preferably
within the range of 0 to 30 minutes. Upon the testing procedure
having run for the number of minutes set on the one timer 80, as
for example 25 minutes, the interval of testing is interrupted by
an interval of rest determined by the other timer 81, as within the
range of from 0 to 120 seconds. Upon the conclusion of the interval
of rest, as after 100 seconds during which no testing movements are
carried out, an interval of testing begins again under the control
of the one timer 80.
From the above discussion, it is to be noted that the apparatus 10
of the present invention provides quality control personnel
supervising the quality of reclining chairs with capabilities of
testing all elements incorporated into such a chair, and that such
testing may proceed either with a completely finished sample of the
chair being produced, or with various elements which are
incorporated into such a finished chair. The testing procedures may
have as their object determining the durability of all the elements
incorporated within the chair or of only certain elements, such as
the linkage mechanism, cushioning materials, or upholstery covering
material.
In the drawings and specification, there has been set forth a
preferred embodiment of the invention, and although specific terms
are employed, they are used in a generic and descriptive sense only
and not for purposes of limitation, the scope of the invention
being define in the claims.
* * * * *