U.S. patent application number 10/718349 was filed with the patent office on 2006-08-17 for shock absorbing support system.
Invention is credited to Feng Li.
Application Number | 20060179729 10/718349 |
Document ID | / |
Family ID | 36814182 |
Filed Date | 2006-08-17 |
United States Patent
Application |
20060179729 |
Kind Code |
A1 |
Li; Feng |
August 17, 2006 |
Shock absorbing support system
Abstract
A Shock absorbing support system isolates vibrations that would
otherwise pass through the important instrument mounted on the
vibration source. The isolation includes springs and dampers under
the bottom of the instrument while dampers around tops of the
instrument. The combination of the springs and the dampers results
in a dissipation of kinetic energy caused by vibrations that would
otherwise pass through the instrument and cause significant dynamic
load and damages to the support and the instrument.
Inventors: |
Li; Feng; (Parsippany,
NJ) |
Correspondence
Address: |
Feng Li
28 Mitchell Road
Parsippany
NJ
07054
US
|
Family ID: |
36814182 |
Appl. No.: |
10/718349 |
Filed: |
November 21, 2003 |
Current U.S.
Class: |
52/167.7 |
Current CPC
Class: |
E04H 9/0235 20200501;
E04H 9/02 20130101; F16F 15/06 20130101 |
Class at
Publication: |
052/167.7 |
International
Class: |
E04H 9/02 20060101
E04H009/02 |
Claims
1. A shock absorbing support system comprising: lower supporting
members that support the shock absorbing system that support a
instrument; instrument frame for tightly fits of said instrument;
upper framing members for damping vibrations transmitted to said
instrument frame; said upper members having first connection
assembly means for being vertically supported to bottom frame of
said instrument and second connection assembly means for being
horizontally connected to the upper frame of said instrument in at
least two directions; said lower supporting members comprising
steel or aluminum members that connect said shock absorbing system
to a structure that has dynamic vibration source; said instrument
frame comprising rigid connection points to said instrument with or
without frame members that surrounding said instrument.
2. The first connection assembly of claim 1 further including:
Spring assembly with damper assembly vertically standing side by
side connecting bottom of said instrument frame and said lower
supporting members.
3. The second connection assembly of claim 1 wherein horizontally
damper assembly includes means for being pivotally connected to
said instrument frame and said upper framing members.
4. The spring assembly of claim 2 further including a coil spring
with said coil spring being restrained with an inner steel rod
inside said coil spring. One end of said steel rod is rigid
connected to said lower supporting members and one end has thread
for nut. Said steel rod with said thread goes through a hole in a
steel plate. Said steel plate is rigid connected to said instrument
frame. The size of said hole in said steel plate is large enough to
let said steel rod free move horizontally, but smaller than the
size of said nut. Said nut would lock said steel rod through said
thread of said steel rod above said steel plate within certain
distance. Therefore, said steel rod can freely move vertically and
horizontally within the dynamic move limits.
5. The damper assembly of claim 2 & 3 further including a
damper and two damper mounting assemblies at each end of said
damper. Said damper mounting assembly comprises a u-shape seat, two
shim plates, and a pin assembly, said u-shape seat defining a
bearing plate rigid connected to two vertical plates with hole that
forms a u-shape, said pin assembly defining two retaining rings and
a pin with two recess at each end of said pin.4 One end of said
damper being press fit between said vertical plates and said shim
plates and said pin connects one end of said damper through holes
of said vertical plates, holes of said shim plates, and hole at the
end of said damper. Said two retaining rings clamp into said
recesses for retaining ring.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the significant reducing of
the dynamic loads produced by earthquake, vibration, or collision.
The present invention prevent structure failures for subjects, such
as electrical boxes on top of bridges, or any important instruments
that subject dynamic loads induced by earthquake, truck traffic,
sudden acceleration or collision.
[0003] 2. Description of the Related Art Including Information
BRIEF SUMMARY OF THE INVENTION
[0004] Since vibrations created by the heavy trucks, earthquakes,
vibrations, or collisions induce significant dynamic force to the
supports of an object; an isolation supporting system is proposed
to reduce the dynamic impact to the supporting system and
instrument itself. The system is isolated through four spring
supports from bottom of the object.
[0005] At the same time, dampers are attached between the
supporting structure and the instrument vertically and
horizontally. The functions of the dampers are to convert the
kinetic energy of the system to the heat energy through a special
liquate confined inside of the dampers. The manufacture claims that
the damper can create 50% of the damping factor. The dynamic loads
of the object are substantially reduced by the combination of
spring and damper system.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0006] The invention is better understood by reading the following
Detailed Description of the Preferred Embodiments with reference to
the accompanying drawing figures, in which like reference numerals
refer to like elements throughout, and in which:
[0007] FIG. 1 illustrates a front elevation view of the shock
absorbing support system with springs and dampers at bottom and
dampers at the top portion according to the present invention.
[0008] FIG. 2 illustrates a side elevation view in cross-section of
the shock absorbing support system with springs at bottom and
damper at the top portion.
[0009] FIG. 3 is a schematic damper location plan, top view of the
shock absorbing support system.
[0010] FIG. 4 is a schematic spring and damper location plan,
bottom view of the shock absorbing support system.
[0011] FIG. 5 is an enlarged elevation view of damper and spring
assemble at the bottom support.
[0012] FIG. 6 is an enlarged elevation view of damper assemble at
the top support.
[0013] FIG. 7 is an enlarged view of the spring assembles in FIG.
1.
[0014] FIG. 8 is an enlarged view of the damper assembles in FIG.
1.
[0015] FIG. 9 is an enlarged view of the damper support in FIG.
1.
[0016] FIG. 10 is an enlarged view of the pin and retaining ring
for the damper support in FIG. 1.
[0017] FIG. 11 is a flow chart of model analysis
DETAILED DESCRIPTION OF THE INVENTION
[0018] In describing preferred embodiments of the present invention
illustrated in the drawings, specific terminology is employed for
the sake of clarity. However, the invention is not intended to be
limited to the specific terminology so selected, and it is to be
understood that each specific element includes all technical
equivalents, which operate in a similar manner to accomplish a
similar purpose.
[0019] Referring initially to FIG. 1, a preferred embodiment of the
shock absorbing support system is shown. Vertical members 7 sit on
a horizontal member 8 that is fixed attached to a structure that
has vibration source. Horizontal members 6 sit on the vertical
members 7. The horizontal members 6 function as a platform that
supports the instrument 3. The vertical upper members 4 are fixed
attached to the horizontal members 6. Rigid frame 5 functions as a
cage that hold the instrument 3. Between the frame 5 and horizontal
platform, springs 1 and dampers 2 isolate the instrument 3 from the
support 7 and 8. Upper end of members 4 are connected to upper
portion of frame 5 through several dampers 2.
[0020] In the FIG. 2, a preferred embodiment side elevation of the
shock absorbing support is shown. Vertical beams 7 sitting on
horizontal member 8 support the platform 6. Springs 1 isolating
instrument 3 from the vibration source are guided through steel
rods 20. Steel rods 20 prevent instrument 3 vibrate erratically
without restrains. Vertical dampers 2 at the bottom support of
instrument 3 convert vertical kinetic energy of the vibration into
heat energy dissipated to the surrounding atmosphere. Thus the
vertical load from instrument 3 transfer back to the supporting
system is significantly reduced. Horizontal dampers 2 at the top
portion of instrument 3 connecting instrument 3 to vertical members
4 convert the horizontal kinetic energy into the heat energy
dissipated to the surrounding atmosphere. Thus the horizontal load
from instrument 3 transfer back to the supporting system is
significantly reduced.
[0021] FIG. 3 shows a preferred embodiment with schematic location
of top horizontal dampers 2 in two directions of horizontal plain.
Horizontal dampers can transfer horizontal vibrating energy
(kinetic energy) into heat energy from any horizontal direction in
this configuration. There are no dampers 2 at front face 10 of
instrument 3 because instrument 3 can be removed or installed from
the system. At back face 9, dampers 2 are attached to instrument 3.
Two section views are shown in FIG. 1 and FIG. 2.
[0022] FIG. 4 shows a preferred embodiment with schematic location
of bottom vertical dampers 2 and springs 1 at each bottom corner of
instrument 3. Vertical springs 1 isolate the system from the
vibration source and support the weight and dynamic load of
instrument 3. Vertical dampers 2 can transfer vertical vibrating
energy (kinetic energy) into heat energy in this configuration. Two
section views are shown in FIG. 1 and FIG. 2.
[0023] Members 6 provide a platform for springs 1 and dampers 2. In
FIG. 5, bottom of steel rods 20 are welded to members 6. Spring
coils 21 are placed around steel rods 20 as shown in FIG. 7. Top of
steel rods 20 is free standing. Plate 14 welded to member 12 of
instrument rigid frame 5. A hole in the center area of plate 4 is
large enough to let steel rods 20 through and some room for lateral
movement. Steel nuts 23 lock steel rods 20 after steel rods 20 go
through the hole of plate 14.
[0024] By the side of springs 1, dampers 2 are connecting members 6
and members 12 through damper mounting assemblies 10. Damper
mounting assemblies 10 are welded or bolted to members 6 and
members 12. Dampers 2 are pined to damper mounting assemblies 10 by
pin assembles 31. Pin assembles 31 are composed of steel rods 51
with two recesses for retaining ring at each end and locked by
retaining rings 52 in FIG. 10.
[0025] FIG. 6 shows a preferred assemble of horizontal dampers 2.
Damper mounting assemblies 10 are welded or bolted to members 4 and
members 41. Members 41 are part of rigid frame 5. FIG. 8 shows a
typical damper, which is preferred to be manufactured by Taylor
Devices Inc. FIG. 9 shows a preferred damper mounting assemblies
10. Damper mounting assemblies 10 are composed by steel u frame 30,
two shim plates 32, and pin assembles 31.
[0026] The requirement for a dynamic analysis often leads to a
direct need by the engineer for a sophisticated general-purpose
computer software system such as GTSTRUDL. GTSTRUDL permits the
engineer to utilize all of the member, finite element, graphical
display, and steel design features available in static analysis in
conjunction with the dynamic analysis capabilities in those
structures subjected to strong wind, seismic, heavy truck traffic,
or vibrating machinery loadings. Using combinations of these
features, dynamic analysis results may be obtained for a large
variety of structures and loading conditions.
[0027] The dynamic analysis of the shock absorbing support system
can best be summarized by FIG. 11. First geometry (Joint
coordinates) 101 of the system is input into the computer. Topology
(member and finite element incidences), support boundary
conditions, member and finite element boundary conditions, material
properties, and member and finite element properties 102 are also
needed for the input. Dynamic information, such as structure
damping and dynamic loadings (time history or spectrum) 103, may be
collected from the field or from lab experiment. If the dynamic
loading is from time history, it can be converted to spectrum
104.
[0028] Static loads 108 are inputted to perform static analysis
109. The static analysis result 112 can be outputted independently
from dynamic output 107. With dynamic data 103, computer first
perform eigensolution without initial stress 105, then dynamic
analysis through one of the following method: (1) Response spectrum
analysis (Including Missing Mass, Base Shear, and Shear Wall
Analysis calculations) or (2) transient time history analysis 106.
After the dynamic analysis 106, the program creates pseudo static
loading 111 results from dynamic analysis results. Dynamic analysis
results such as dynamic data output, eigensolution results output,
response spectrum analysis results output and transient analysis
results output 107 can be outputted independently. Program combines
static analysis result 112 and dynamic analysis results 107 into
shock result 113. After the combination, program also can perform
member design and/or code checking 114.
[0029] The dynamic analysis is based on the following theories. The
dynamic equilibrium equation may be written in the following matrix
form: [M]{a}+[C]{v}+[K]{x}={F(t)} (1-1) where [M], [C], AND [K] are
matrices representing the mass, damping, and stiffness of the
structure, respectively. The vectors {a}, {v}, and {x} represent
the acceleration, velocities and displacement of the joint degree
of freedom. The vector {F(t)} represents the applied transient
forces.
[0030] Response spectrum analysis is an approximate method of
dynamic analysis that uses the know response of single degree of
freedom systems with the same natural frequency and percents of
critical damping as the modes of vibration of the structure being
analysis when subjected to the same transient loading.
[0031] For applied support acceleration, {F(t)}=-[M]{E}a.sub.G(t)
(1-2) Where, [0032] a.sub.G(t) is the time dependent support
acceleration [0033] {E} is a vector containing one's for degrees of
freedom in the direction of the applied ground motion and zeroes
otherwise.
[0034] Then {a.sub.t(t)}={a(t)}+{a.sub.G(t)} (1-3)
[0035] Where, [0036] a.sub.t(t) contains the total acceleration
where the subscript t indicates total [0037] a(t) contains the
nodal point acceleration relative to the supports
[0038] Therefore,
[M]{a.sub.t}+[C]{v.sub.t}+[K]{x.sub.t}=-[M]{E}a.sub.G(t) (1-4)
[0039] As in the modal analysis method, the equation of motion must
be uncoupled and transformed to normal coordinates for the response
of each mode to be calculated. In a modal time history analysis,
Eq. 1-4 would be solved in order to evaluate the response at each
time step. However, in a response spectrum analysis, it is assumed
that we know the maximum value of the integrals from either
previous computation or experimental results.
[0040] Once the maximum response for each mode is obtained, the
maximum total response must be computed. GTSTRUDL computes response
spectra maximum response by combining the modal responses by seven
different approaches. These seven methods are root mean square,
absolute summation, peak root mean square, complete quadratic
combination, nuclear regulatory commission grouping method, nuclear
regulatory commission ten percent method, and nuclear regulatory
commission double sum method. Each of the seven combination
techniques may be performed for each response spectra loading
condition. In addition, the root mean square method may be used to
combine the results of two or more response spectra loadings, which
may represent statistically independent dynamic components.
[0041] An instrument with 800 pounds of static load was modeled
with vibration generated by heavy truck load using this shock
absorbing support system. A model without this system is also
analyzed. The next table shows the juxtaposition of two models. It
demonstrates the system with dampers and springs has significant
advantages over the model having no dampers and springs.
TABLE-US-00001 COMPARISON OF RESULTS w/ springs w/o springs Model
and dampers and dampers Acceleration 148.5 in/sec{circumflex over (
)}2 614.64 in/sec{circumflex over ( )}2 At vertical direction
Acceleration 60.5 in/sec{circumflex over ( )}2 250.4
in/sec{circumflex over ( )}2 At horizontal direction Velocity 8.9
in/sec 11.69 in/sec At vertical direction Velocity 5.7 in/sec 4.76
in/sec At horizontal direction Max. stress of support 0.168 ksi 3.9
ksi member Max. dynamic force of 176 lbs 703 lbs support member
Max. dynamic force at each 102 lbs 356 lbs VMS box support
* * * * *