U.S. patent application number 14/323982 was filed with the patent office on 2015-01-08 for windshield blade locking mechanism.
The applicant listed for this patent is Isaac M. Rabin, Steven Wang. Invention is credited to Isaac M. Rabin, Steven Wang.
Application Number | 20150007406 14/323982 |
Document ID | / |
Family ID | 51901660 |
Filed Date | 2015-01-08 |
United States Patent
Application |
20150007406 |
Kind Code |
A1 |
Rabin; Isaac M. ; et
al. |
January 8, 2015 |
Windshield Blade Locking Mechanism
Abstract
The invention provides an apparatus to hold one or more
windshield wipers stationary against a vehicle window. The
apparatus comprises a window placement module comprising a vacuum
cup that has a vacuum zone and an attachment means that is located
at a point on the cup other than within the vacuum zone. The
attachment means is linked to a first point of each of one or more
arms; a second point of each arm is linked to a clamping module
optionally in a rotatable way. When in use the clamping module
constrains movement of a windshield wiper.
Inventors: |
Rabin; Isaac M.; (Atlanta,
GA) ; Wang; Steven; (Wuxi, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rabin; Isaac M.
Wang; Steven |
Atlanta
Wuxi |
GA |
US
CN |
|
|
Family ID: |
51901660 |
Appl. No.: |
14/323982 |
Filed: |
July 3, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13136242 |
Jul 27, 2011 |
8893349 |
|
|
14323982 |
|
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Current U.S.
Class: |
15/250.16 |
Current CPC
Class: |
B60S 1/0452 20130101;
B60S 1/0491 20130101; B60S 1/185 20130101 |
Class at
Publication: |
15/250.16 |
International
Class: |
B60S 1/18 20060101
B60S001/18; B60S 1/04 20060101 B60S001/04 |
Claims
1) A windshield blade locking mechanism comprising: a) a vacuum cup
comprising a vacuum zone; b) an attachment means that is linked to
the vacuum cup at a position other than within the vacuum zone; c)
an arm that is linked to the attachment means of the vacuum cup at
a first point of the arm; d) a blade retaining assembly that is
linked to a second point of the arm wherein the assembly comprises
a top constraint member that, when in use, rides atop a windshield
wiper, hinders lifting of the wiper and holds the wiper stationary
against a vehicle window surface.
2) The windshield blade locking mechanism of claim 1 wherein the
vacuum zone is circular and has a circumference selected from the
range of 2 inches to 6 inches.
3) The windshield blade locking mechanism of claim 1 wherein the
attachment means is selected from the group consisting of a screw,
bolt, rivet, dowel, hinge, clip, ring, clamp, and cotter pin.
4) The windshield blade locking mechanism of claim 3 wherein the
attachment means is a screw, bolt, rivet or dowel which is linked
at a first end to the vacuum cup and at a second end to a
handle.
5) The windshield blade locking mechanism of claim 1 wherein the
vacuum cup is equipped with a vacuum-breaking modality selected
from: (a) a stopcock that can be opened to allow air to enter the
vacuum zone or (b) a lever that can be pried to lift an edge of the
vacuum cup to allow air to enter the vacuum zone.
6) The windshield blade locking mechanism of claim 1 wherein the
mechanism has one or more arms and at least one may pivot about the
vacuum cup's attachment means.
7) The windshield blade locking mechanism of claim 1 wherein the
mechanism has one or more arms and at least one may not pivot about
the vacuum cup's attachment means.
8) The windshield blade locking mechanism of claim 1 wherein the
mechanism has one or more arms and at least one is extendible in
length.
9) (canceled)
10) (canceled)
11) (canceled)
12) (canceled)
13) The windshield blade locking mechanism of claim 1 wherein the
mechanism has at least one arm, and said arm is linked optionally
rotatably to a hinge component.
14) The windshield blade locking mechanism of claim 13 wherein the
hinge component serves as the linkage to the blade retaining
assembly.
15) The windshield blade locking mechanism of claim 1 wherein the
top constraint member is contoured in a saddle shape and is located
astride a windshield wiper when in use.
16) The windshield blade locking mechanism of claim 1 wherein the
top constraint member is linear and passes through a lock
housing.
17) The windshield blade locking mechanism of claim 16 wherein the
top constraint member is attached to a first lateral constraint
member.
18) (canceled)
19) (canceled)
20) (canceled)
Description
FIELD OF THE INVENTION
[0001] The invention pertains to devices for securing windshield
wiper blades in a fixed position.
BACKGROUND
[0002] Windshields, also known as windscreens, are among the most
important safety elements in vehicles because they are the windows
through which drivers view most traffic. Thus an essential function
is provided when wipers clear these windows of rain, dew, dust,
heavy pollen, insect residues, bird droppings, and fallen botanical
detritus. Typical wipers are loosely stationary when at rest; this
is helpful for accommodating their free wiping movement when the
wiper is activated, but also causes inconveniences that in some
cases pose a safety hazard.
[0003] Because of the loose character of wipers at rest,
enterprising persons commonly place unsolicited coupons,
advertisements, promotional flyers, or other unwanted literature
under the windshield wipers of unattended automobiles that are in
parking lots or along the edges of streets. Those papers must be
removed before safe driving can ensue, indeed if the papers are
torn off by the slipstream while the vehicle is in transit they
represent a potential hazard for other drivers, also. However
drivers who return to their vehicles after such papers are placed
may not notice them until the vehicle is already moving along a
highway or surface street at a high speed, when they flap in a
distracting way but it is no longer convenient to reach out to
remove the offending document or when the vehicle is no longer in a
safe neighborhood. The failure to notice such literature before
departing from the parking spot is particularly common after
dark.
[0004] In addition, vandals commonly steal windshield wiper blades
or the wiper arm itself. The easy deconstruction of the blade
assembly and loose placement of the wiper assembly allows this to
be done quickly and without the perpetrators drawing attention to
themselves. It can be surprisingly expensive for the true owner to
replace those parts. And when such thefts occurs shortly before an
owner must drive the vehicle to an appointment in a downpour or ice
storm along a route where windshield wipers cannot be bought
conveniently, the owners must often choose between the enhanced
risk of driving and the consequences of missing the
appointment.
[0005] Moreover, the looseness of the wiper assembly also allows
leaves, pine needles and other natural detritus to accumulate at
the interface of the windshield and wiper blade; the debris is
commonly then pinned between the windshield and the wiper blade due
to a slight excess in the blade's arch. When the wiping mode is
activated while such debris is trapped there, the sweep of the
blade is far less efficient at removing water or ice from the
windshield, substantially compromising visibility for driving. And
detritus that is carried along beneath the wiper blade in the sweep
of the wiper also increases the wear on the blade, shortening its
useful lifecycle. This affects both the cost and the safety of
their use.
[0006] Thus there is an important ongoing need for means to
constrain windshield wipers in a fixed position when vehicles are
parked.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The invention provides an apparatus to hold one or more
windshield wipers stationary against a vehicle window. The
apparatus comprises a window placement module comprising a vacuum
cup that has a vacuum zone and a first attachment means that is
located at a point on the cup other than within the vacuum zone.
The first attachment means is linked to a first point of each of
one or more arms, wherein the arm(s) optionally may pivot about the
first attachment means along a first zone that is above and
parallel to the window surface when the invention is in use on a
vehicle. Optionally each arm is extendible.
[0008] A second point of each arm is linked to a second attachment
means, to which means is also linked a clamping module, optionally
in a manner that allows the clamping module to pivot about the
second attachment means along a second zone that is above and
parallel to the window surface when the invention is in use on a
vehicle.
[0009] Each clamping module comprises a top constraint member,
wherein when the invention is in use on a vehicle this member rides
above a windshield wiper and prevents its lifting. The top
constraint member optionally also serves as a support for one or
two lateral constraint members that extend downward from the top
constraint member, and in combination with the top constraint
member form an optionally adjustable clamp. When the invention is
in use on a vehicle, lateral constraint members of the clamping
module prevent a windshield wiper from rotating along the surface
of a window.
[0010] In some embodiments, when in use on a vehicle the window
placement module is located at a laterally central point of a
window, the apparatus has two extendible arms, and each clamping
modules constrains the movement of a different windshield wiper at
the wiper's end that is nearest to the window placement module. In
other embodiments, when in use the window placement module is
located near the edge of a window on its left, right or top side,
the apparatus has one arm, and the clamping module constrains the
movement of a windshield wiper at the wiper's end that is nearest
to the window placement module. In other embodiments, when in use
the window placement module is located at a laterally central point
of a window, the apparatus has one arm, and the clamping module
constrains the movement of a windshield wiper at the wiper's end
that is nearest to the window placement module.
[0011] In certain embodiments the invention provides a windshield
blade locking mechanism comprising: [0012] a) a vacuum cup
comprising a vacuum zone; [0013] b) an attachment means that is
linked to the vacuum cup at a position other than within the vacuum
zone; [0014] c) an arm that is linked to the attachment means of
the vacuum cup at a first point of the arm; [0015] d) a blade
retaining assembly that is linked to a second point of the arm
wherein the assembly comprises a top constraint member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a caricature of an upper view of an illustrative,
non-exclusive embodiment of a device according to the invention
when locking windshield wipers on a vehicle window.
[0017] FIG. 2 is a caricature of an illustrative, non-exclusive
embodiment of a device according to the invention illustrating the
outmost end of a lock's housing.
[0018] FIG. 3 is a caricature of an illustrative, non-exclusive
embodiment of a device according to the invention illustrating
relative dimensions of components in one configuration.
[0019] FIG. 4 is a caricature of an illustrative, non-exclusive
embodiment of a device according to the invention illustrating
aspects of an extendible arm in one configuration.
[0020] FIG. 5 is a caricature of an illustrative, non-exclusive
embodiment of a device according to the invention illustrating
additional aspects of an extendible arm in one configuration.
[0021] FIG. 6 is a caricature of an illustrative, non-exclusive
embodiment of a device according to the invention illustrating
internal components of a blade lock in one configuration.
[0022] FIG. 7 is a caricature of views of an illustrative,
non-exclusive embodiment of various parts for a device according to
the invention.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0023] The term "window module" as used herein refers to one or
more components for adhesion to a window surface by means of a
vacuum seal.
[0024] The term "vacuum cup" as used herein has its common and
ordinary meaning in the art. It is used synonymously herein with
the term suction cup. And it includes vacuum cups of any design
that is suitable for forming a vacuum seal with another surface
such as by the application of manual pressure to expel air from
beneath a monolithic cup, or by application of reduced pressure
from a manually or electrically powered vacuum pump.
[0025] The term "vacuum zone" as used herein refers to the surface
of a vacuum cup that is capable of forming a vacuum seal with a
window surface. The vacuum zone may be circular in shape or have
any other shape that is not inconsistent with forming a vacuum. In
many cases it is desirable for the vacuum zone to occupy and be
defined by the great majority of the working surface of a vacuum
cup, i.e., by the side facing a vehicle window, but the invention
is not so limited.
[0026] The term "attachment means" as used herein with respect to a
vacuum cup refers to a means for attachment to a vacuum cup at a
location other than within its vacuum zone. Attachment means as
contemplated herein include screws (screwed into an eye in the
upper surface of the cup), bolts (bolted into an eye in the upper
surface of the cup), rivets (passing through a portion of a feature
on the upper surface of the cup), dowels (having one end in a
close-fitting hole defined by the upper surface of the cup), hinges
(wherein a hinge pin pierces at least one portion of a feature on
the upper surface of the cup), clips (piercing or gripping a
portion of a feature on the upper surface of the cup), rings
(passing through a portion of a feature on the upper surface of the
cup), clamps (gripping a portion of a feature on the upper surface
of the cup), cotter pins (piercing and or gripping a feature on the
upper surface of the cup), and other means for attaching flexible
polymeric compositions to rigid hardware components. Attachment
means may optionally be glued to a vacuum cup, for instance during
installation in a threaded or smooth bore orifice on the upper
structure of a vacuum cup, a dowel or bolt may be treated with a
polycyanoacrylate-based glue to enhance the strength of the
connection. Attachment means may affix a handle by attachment to
its lower surface in a way to one of these.
[0027] The term "arm" as used herein refers to a component that is
attachable to a window module at a first point one point of the
component and attachable to a clamping module at a second point of
the component.
[0028] The term "extendible" as used herein with respect to an arm
refers to an arm that can optionally be lengthened such that the
distance between a window module and a clamping module to which the
arm is attached may be varied at will.
[0029] The term "near end" as used herein with respect to an arm or
other component, refers to a location on a component in a device
according to the invention such that, when the device is in its
most fully extended configuration and an observer is following the
path of the hardware, the position is closer to the vacuum cup than
are most other locations on the component.
[0030] The term "far end" as used herein with respect to an arm or
other component. refers to a location on a component in a device
according to the invention such that, when the device is in its
most fully extended configuration and an observer is following the
path of the hardware, the position is closer to the remote lateral
constraint member than are most other locations on the
component.
[0031] The term "hinge component" as used herein refer to a
component that is held by the far end of an arm and that allows a
first supporting member of the clamping module to rotate about the
hinge component. In some embodiments the hinge component may turn
within the location in which it is held by the arm; in some
embodiments the first supporting member may rotate about its
attachment to the hinge member, in some embodiments both types of
rotation may occur; in some embodiments the hinge member allows no
rotation whatsoever.
[0032] The term "clamping module" as used herein refers to a
combination of components that collectively can serve as a clamp on
a windshield wiper.
[0033] The term "constraint member" as used herein refers to a
component of a clamping module which when in use hinders a
windshield wiper from moving in one or more directions. The term
"top constraint member" as used herein refers to a constraint
member that, when in use, rides the top of a windshield wiper and
hinders its lifting. The term "lateral constraint member" as used
herein refers to a constraint member that, when in use, is along
one side of a windshield wiper and hinders its movement toward that
side.
[0034] The term "lock" as used herein refers to a clamping
module.
[0035] The term "lock housing" as used herein refers to a housing
that covers one or more sides of constraint members.
[0036] The term "tightening screw" as used herein refers to a screw
or bolt by means of which two or more constraint members in a
clamping module may be drawn together.
[0037] The term "spring" as used herein has its usual and ordinary
meaning in the art.
[0038] The term "linked" as used herein refers to linkage in a
manner usual in the mechanical arts for the relative functions of
the components being linked. Linkage of the vacuum cup to an
attache
Illustration from the Figures
[0039] Important features of the invention may be understood by
reference to a non-exclusive illustrative embodiment depicted in
caricature by the drawings.
[0040] Referring now to FIG. 1, the invention provides a vacuum cup
(10) of suitable size, shape, flexibility and composition for
providing and maintaining attachment to a vehicle window surface by
means of a reduced atmospheric pressure between a surface of the
window and the lower surface of the cup. To the upper surface of
the cup is attached the bottom portion of an attachment member such
as a screw, bolt, rivet, pin or dowel, wherein the upper portion of
the attachment member optionally is attached to a handle (20). The
handle may be used to apply pressure to the vacuum cup through the
attachment member to create suction during attachment to a window,
and optionally may be pushed or turned to reduce the distance
between the vacuum cup and the handle. The attachment means may
pass through an orifice defined through the body of the near end of
a first (30) and optionally second (40) arm. In one embodiment
there is only one arm. In another embodiment there are two arms and
one is located above the other at the point where the attachment
member passes through each. In certain embodiments there are two
arms, they are fused, and the attachment member passes through an
orifice through a point at which the arms are fused. In a further
embodiment there is a plurality of arms and they can be rotated
about the attachment member independently of one another. In
certain embodiments there are three or more arms.
[0041] Continuing to refer to FIG. 1, the far end of each arm
supports a hinging component (50) that optionally permits turning
of a locking module through a plane that is approximately parallel
to the surface of the window. A first support member (60) such as a
rod, tab, shim, plate or other support member is attached at a near
end optionally rotatably to the hinging component, and is elsewhere
optionally attached to or passes through a first lateral constraint
member (70), passes through a second lateral constraint member
(100), passes through apertures defined by a lock housing (80), and
is juxtaposed against a second support member (90). The first
support member optionally serves as a top constraint member to
prevent lifting the windshield wiper. Optionally tightening means
(110) having at least one end exposed permits locking of a
windshield wiper (120) into place. An illustrative but
non-exclusive list of suitable tightening means includes screws,
bolts, spring clips, ratcheting triggers, quick-connects, and the
like. In some embodiments there is no lateral constraint member,
second support member, tightening means or housing, and the first
support member when in place acts to hinder lifting of the wiper,
and optionally the first support member in that embodiment is
contoured in a saddle configuration that is seated upon the wiper
and hinders sweeping of the blade.
[0042] Referring now to FIG. 2, additional features of the
invention may be understood. This Figure depicts an embodiment in
which a vacuum cup (10) to which is attached a handle (20) by an
attachment means, wherein at least one extendible arm (30) is
further attached to the attachment means. In this embodiment each
arm has a slotted inner arm (32), a sliding sleeve (34), and a
pinning member (36) that passes through the slotted inner arm and
its respective sliding sleeve to hold them stationary relative to
one another. A hinging component (50) permits turning of a locking
module. A first support member (60) is attached at a near end
optionally rotatably to the hinging member, and is elsewhere
attached to or passes through a first lateral constraint member
(70) and second lateral constraint member (100), passes through
apertures in a lock housing (80), and is juxtaposed against a
second support member (90). A tightening means (110) is a bolt that
can pass through apertures defined at both the near end and far end
of the lock housing.
[0043] Referring now to FIG. 3, illustrative dimension for
components of the invention are illustrated as viewed from below
when the invention is configured as described in FIGS. 1 and 2
above, and is attached to a window surface. The vacuum cup (10) is
attached by an attachment means to at least two extendible arms
(30) and (40), which are in turn attached to hinging components
(50A) and (50B) respectively. First lateral constraint members
(70A) and (70B) and second lateral constraint members (100A) and
(100B) are attached to or passed through by the respective first
support members (60A) and (60B) and reside in troughs defined by
the respective lock housings (80A) and (80B). The vacuum cup
circumference (11), lock housing length (81), and perpendicular
distance (101) between parallel lock housings are shown for a
particular embodiment. Distances depend on the relative placement
of windshield wipers and on the curve and adherence characteristics
of the window; there parameters differ from model to model of
vehicle. Illustrative distances are 50 mm for circumference 11, 35
mm for housing length 81, and 60 mm for perpendicular distance
101.
[0044] FIG. 4 provides additional detail on an extendible arm for
embodiments depicted in FIGS. 1 and 2. This drawing shows an upper
view wherein the slotted inner arm (32A) is exposed for a first
arm, and a sliding sleeve (34B) is exposed and covers the inner arm
of a second arm. A pinning member (36A) and (36B) passes through
the slotted inner arms and the sliding sleeve to hold them
stationary relative to one another.
[0045] FIG. 5 illustrates further features for an extendible arm
for embodiments depicted in FIGS. 1, 2 and 4. This drawing shows a
view from underneath wherein the slotted inner arm (32) is held
stationary within a sliding sleeve (34) of an extendible arm. In
this particular embodiment the slotted inner arm (32) on its lower
side defines a trough having scalloped edges. A key (38) fits
within the scalloped trough. A pinning member (36) passes through
apertures defined by the slotted inner arm's key (38) and the
sliding sleeve (34) to hold them stationary relative to one
another. In some embodiments the pinning member is a dowel that can
be moved independently of the key and the sleeve. In other
embodiments the pinning member is attached to the key in a
permanent fashion. In alternative embodiments the pinning member is
attached to the sleeve in a permanent fashion.
[0046] FIG. 6 illustrates features for the clamping module
according to one embodiment of the invention. In this embodiment
the embodiment is configured similarly but not identically to that
shown in FIG. 1, and for clarity no lock housing is shown. An arm
(30) is attached to a hinging component (50). A first support
member (60) is attached at a near end optionally rotatably to the
hinging component, and is slidably attached to a first lateral
constraint member (70) and a second lateral constraint member
(100). A tightening means (110) comprises a bolt that passes
through apertures defined in the lateral constraint members (70)
and (100), wherein at least one of the apertures is threaded or at
least one aperture of the housing not shown is threaded; tightening
of the bolt locks a windshield wiper (120) into place. The bolt in
this embodiment passes through the length of a coil spring (130)
that is located between apertures of the lateral constraint members
to facilitate their grip on the wiper.
[0047] FIG. 7 illustrates further detail for various parts and
their relationships with one another for an embodiment of the
invention according to FIGS. 1 through 6. This verbal description
begins at the lower right of FIG. 7 and proceeds in clockwise
fashion. The hinging component (50) may be a cylindrical tube
having a lip extending around one end. A hinge pin (52) for fitting
within that hinging component may be attached to the near end of a
first support member (60), which in turn is fitted through a slot
defined by a tombstone-shaped first lateral constraint member (70)
that also defines an eye for a bolt or screw. The inner portion of
a lock housing (80) is shown as defining a trough, wherein the
second support member (90) described in prior paragraphs may
comprise two tabs extending as ledges from the edge of the lock
housing and may be a monolithic piece with it. A key (38) for the
inner arm of an extendible arm is also shown.
[0048] In some embodiments of the invention the first support
member may be removed from the hinging component when the invention
is not in use, such that the clamping module remains affixed to the
wiper but the window module and arm(s) are removed. In certain
embodiments the support member attached to the hinging component is
the second support member instead of the first one.
[0049] In particular embodiments the suction of the applied vacuum
cup may be enhanced by the use of a peripheral vacuum source such
as a manually powered pump or electrically powered pump.
Components
[0050] A vacuum cup, sometimes known as a suction cup or sucker,
uses negative fluid pressure of air or water to adhere to surfaces,
they adhere especially well to nonporous surface. Generally the
working face (defined herein as the vacuum zone) of the vacuum cup
has a curved surface. When the center of the suction cup is pressed
against a relatively flat smooth surface, the volume of the space
between the suction cup and the flat surface is reduced, which
causes the air or fluid between the cup and the surface to be
expelled past the rim of the cup. When the user ceases applying
pressure, the cup's elastic composition tends to resume its
original shape. Because all of the air or fluid has already been
forced out of the inside of the cup, the cavity developed between
the cup and the flat surface has little to no air or water in it,
and thus lacks pressure. The difference between atmospheric
pressure on the outside and the low-pressure cavity on the inside
of the cup sustains the adhesion. The duration of the effect is a
function of how effectively leaks from the outside atmosphere are
controlled.
[0051] The vacuum cup may be comprised of any suitable flexible
material and are widely available. For instance, suitable vacuum
cups are sold by SAS Automation (see
http://www.sasgripper.com/product_sections/section_vacuum_cups.htm).
Particularly suitable materials for the vacuum cup include
chloroprene, polyurethane, nitrile rubber, silicone rubber, and
viton. Chloroprene has good wear resistance, and is useful in the
temperature ranges -40.degree. to 230.degree. F. (-40.degree. to
110.degree. C.). Polyurethane has excellent wear resistance, a very
long life, is oil resistant, and is useful in the temperature
ranges -58.degree. to 248.degree. F. (-50.degree. to 120.degree.
C.). Softer polyurethanes may be used but are best on textured
surfaces whereas a windshield is smooth Nitrile rubber has good
wear resistance properties, is oil resistant, and is useful in the
temperature ranges -20.degree. to 225.degree. F. (-50.degree. to
120.degree. C.). Silicone rubber is a soft material, is especially
good for rough and textured surfaces, and is useful in the
temperature ranges -86.degree. to 392.degree. F. (-65.degree. to
200.degree. C.). Note that windshields are exposed to both the
hottest summer conditions and coldest winter conditions, thus the
extremes of temperature noted here are relevant to choice of
material.
[0052] The design of the vacuum cup may be of any type known in the
art that is suitable for sustaining suction. Suitable suction cup
designs include but are not limited to a flange type, a bellows cup
type, a snap on or bolt type, and a push on or clamp type.
[0053] The force of a vacuum cup when in use follows the
relationship F=AP, where F=force, A=area, and P=pressure. For
example, for a cup of radius 2.0 cm and area .pi.(0.020
m).sup.2=ca. 0.0013 square meters, the result is F=(0.0013
m.sup.2)(100,000 Pa)=ca. 130 Newtons, assuming the pressure inside
the cup is negligible when compared to atmospheric pressure.
However the calculation requires more finesse. The specifications
for sizing vacuum cups additionally focus upon lift capacity and
the margin of safety. Suitable lift capacity at sea level is
determined by the following theoretical relationship; actual lift
capacities should be determined empirically.
C = 0.393 D 2 V N ##EQU00001## [0054] C=Lifting Capacity (lbs.)
[0055] D=Cup Diameter (in.) [0056] V=Vacuum Level (in Hg) [0057]
N=Desired Safety Factor (.gtoreq.2 for horizontal lifting;
.gtoreq.4 for vertical lifting)
[0057] D=1.61.times.[(M.times.N)/(V.times.U)].sup.1/2 [0058]
D=Diameter of vacuum cup (in.) [0059] M=Mass of lifting product
(lbs. of force to be applied) [0060] V=Vacuum Level (in mm Hg)
[0061] N=Safety Factor (.gtoreq.2 for horizontal lifting; .gtoreq.4
for vertical lifting) [0062] U=Number of Cups
[0063] For the present invention a circular vacuum zone having a
circumference D of about 4.+-.2 inches (i.e. .about.50.+-.25 mm)
has been found to be useful; other useful ranges are 4.+-.1 inches,
and more particularly about 4 inches. A manually-attainable lifting
capacity C is desirable (e.g., in the range of 5-50 lbs., or
alternatively 10-40 lbs, or alternatively 20-30 lbs., or
alternatively about 25 lbs.). The lifting capacity can be higher
for instance if the cup is fitted with a stopcock to allow air in
when desired or is equipped with an optionally removable lever that
permits greater force to be applied on one side to break a static
vacuum seal and disengage the cup. A safety factor N of 1 or 2 is
particularly useful but alternatively N may be 3 or 4. For purposes
of the calculation, the lifted mass M may be the same as C. The
figures in this section assume the use of a single vacuum cup
(i.e., U=1) however a plurality of smaller cups may be used to
obtain a comparable result.
[0064] The arms (including the inner arm, sleeve and key) may be
comprised of one or more hard materials. Examples of suitable hard
materials include metals, tough plastics and tough ceramics.
Illustrative metals include aluminum and iron. Illustrative tough
plastics such as nylons, polyaramids, ABS rubber, and the like.
Illustrative tough ceramics include: silicon carbide that has been
sintered as a laminate with graphite; alumina derivatives
co-developed by William Predebon at Michigan Technological
University; nacre-like biomimetic materials such as those
co-developed by Robert Ritchie in the Department of Materials
Science and Engineering at the University of California at
Berkeley, and nacre-like biomimetic materials such as those
co-developed by Antoni P. Tomsia, Sylvain Deville and colleagues at
Lawrence Berkeley National Laboratory.
[0065] The arms may be linked to a hinging component or directly
without rotatability to the clamping module. The tough materials
cited above may be used for the composition of components in the
clamping module.
Variations
[0066] Although specific embodiments of the present invention have
been described above in detail, the description is merely for
purposes of illustration. In addition to the embodiments above
various modifications of, and equivalent elements corresponding to,
the disclosed aspects of the exemplary embodiments, can be made by
those of ordinary skill in the art without departing from the
spirit and scope of the present invention defined in the following
claims, the scope of which is to be accorded the broadest
interpretation so as to encompass such modifications and equivalent
structures.
* * * * *
References