Really Right Stuff, LLC v. Amazon.com, Inc. et al

Filing 1

Complaint. Filing fee in the amount of $400 collected. Agency Tracking ID: 0979-4386340 Jury Trial Requested: Yes. Included patents/trademarks: 6,773,172--8/10/2004--Real Right Stuff, LLC, 8,398,037--3/19/2013--Real Right Stuff, LLC, 9,063,397--6/23/2015--Real Right Stuff, LLC. Filed by Real Right Stuff, LLC against All Defendants (Attachments: # 1 Exhibit A, # 2 Exhibit B, # 3 Exhibit C, # 4 Civil Cover Sheet, # 5 Proposed Summons Amazon.com, Inc., # 6 Proposed Summons B&H Foto, # 7 Proposed Summons Desmond Photographic, # 8 Proposed Summons Simmonds). (Pitchford, Susan)

111111

1111111111111111111111111111111111111111111111111111111111111
US006773172Bl

United States Patent

(10)

Johnson et ai.

(12)

(45)

(54)

QUICK-RELEASE CLAMP FOR
PHOTOGRAPHIC EQUIPMENT

(75)

Inventors: Joseph M. Johnson, P.O. Box 6531,
Los Osos, CA (US) 93412; Mark W.
Ames, San Luis Obispo, CA (US)

(73)

Assignee: Joseph M. Johnson, Los Osos, CA
(US)

( * ) Notice:

(21)

Patent No.:
US 6,773,172 Bl
Date of Patent:
Aug. 10,2004

References Cited

(56)

U.S. PATENT DOCUMENTS
2,824,504
2,840,334
3,356,325
3,677,509
4,929,973
5,601,265
5,870,641
6,196,504
6,435,738

Subject to any disclaimer, the term of this
patent is extended or adjusted under 35
U.S.c. 154(b) by 0 days.

(22)

Filed:

Aug. 20, 2003

(51)

Int. CI? ................................................ G03B 17/00

(52)

U.S. CI. ..................................... 396/428; 248/187.1

(58)

Field of Search ................................. 396/419,420,
396/422, 428; 248/187.1

2/1958
6/1958
12/1967
7/1972
5/1990
2/1997
2/1999
3/2001
8/2002

Bethmann
Cauthen
Schnase
O'Connor
Nakatani
Lopez
Chrosziel
Lemke
Vogt

FOREIGN PATENT DOCUMENTS
97395

JP

Appl. No.: 10/645,419

A
A
A
A
A
A
A
B1
B1

4/2000

Primary Examiner-David M. Gray
(74) Attorney, Agent, or Firm---Chernoff,
McClung & Stenzel, LLP

Vilhauer,

ABSTRACT

(57)

A clamp for securely mounting photographic equipment to
a support, such as a tripod.
29 Claims, 10 Drawing Sheets

62
18

38
14

,

A

36

16

57

'1

60 A
28- ______ ~
20

THRUST
WASHER

48

BRONZE

24 ", 5~'
I
I

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0'- 39

~

THRUST WASHER
STAINLESS STEEL

I\l)

~CAMLEVER
DOWEL PIN

EXHIBIT A - Page 1 of 16

46 \
38

~ ASSEMBLY
STUD/BODY

61

~SPRINGS

u.s. Patent

Aug. 10,2004

Sheet 1 of 10

FIG. 1

FIG. 2
EXHIBIT A - Page 2 of 16

US 6,773,172 B1

u.s. Patent

Aug. 10, 2004

us 6,773,172 Bl

Sheet 2 of 10

I

l'-- 26

FIG. 3

18

24
I

~26

28

FIG. 4
EXHIBIT A - Page 3 of 16

u.s. Patent

US 6,773,172 Bl

Sheet 3 of 10

Aug. 10,2004

Force

first
position

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)

FIG. 5

EXHIBIT A - Page 4 of 16

"

second
first
second
intennediate intermediate position
position
position

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61
ASSEMBLY

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STAINLESS STEEL

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EXHIBIT A - Page 5 of 16

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Sheet 5 of 10

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EXHIBIT A - Page 7 of 16

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EXHIBIT A - Page 8 of 16

Sheet 7 of 10

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u.s. Patent

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Sheet 8 of 10

US 6,773,172 Bl

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EXHIBIT A - Page 9 of 16

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EXHIBIT A - Page 10 of 16

Sheet 9 of 10

US 6,773,172 Bl

u.s. Patent

Aug. 10, 2004

EXHIBIT A - Page 11 of 16

Sheet 10 of 10

US 6,773,172 Bl

US 6,773,172 B1
1

2

QUICK-RELEASE CLAMP FOR
PHOTOGRAPHIC EQUIPMENT

lever. This problem is exacerbated with quick release clamps
that use an adjustment screw to adjust the spacing between
the side walls of the channel rather than a lever, as it is
difficult to rotate the screw while the camera is mounted over
it.
It is therefore desired to provide a clamp for easily,
quickly, and securely mounting photographic equipment to
a support.

BACKGROUND OF THE INVENTION

5

The present invention relates to a clamp for mounting
photographic equipment to a support, such as a tripod or ball
head.
Photographic equipment may be mounted to a camera
BRIEF DESCRIPTION OF THE DRAWINGS
stand in a variety of ways. Some camera bodies, for 10
example, have threaded sockets in their base so they can be
FIG. 1 is a perspective view of a clamp that incorporates
directly mounted to a bolt that extends upwardly from the
aspects of the present invention where the clamp has a lever
support. The camera body is positioned over the support so
in a disengaged position where photographic equipment may
that the bolt fits within the socket and the camera body is
be inserted into, or removed from, the clamp.
spun around several times to screw the camera body to the 15
FIG. 2 is a perspective view of the clamp of FIG. 1
support. Alternatively, and particularly when a heavy, elonshowing the lever in a first intermediate position between an
gate camera lens is attached to a camera body, the camera
engaged and disengaged position, where the channel of the
lens will include a support having a threaded socket posiclamp is at its minimum width.
tioned below the lens so that the lens may be mounted to the
FIG. 3 is a perspective view of the clamp of FIG. 1
support in the same manner as a camera body.
20
showing the lever in a second intermediate position between
These methods take an appreciable amount of time and
an engaged and disengaged position, where the channel of
require care to ensure that the threads of the stud are
the clamp is at its minimum width and pivot axis of the lever
properly aligned with the threads in the socket. Further, there
is at its maximum distance form the channel.
is often insufficient time to screw the camera body or lens to 25
FIG. 4 is a perspective view of the clamp of FIG. 1
the tripod before a particular shot should be taken. This lack
showing the lever in an engaged position where the photoof time requires that the camera either be held in-hand,
graphic equipment may be secured to the clamp.
potentially resulting in image blur from the shake of the
FIG. 5 is a graph of a force profile generated by the clamp
hand, or that the shot be missed altogether.
of FIG. 1 as the lever is moved over a range of motion from
These difficulties can be reduced by using a quick-release
clamp to mount photographic equipment to a support. Such 30 a first position to a second position.
FIG. 6 is an assembly drawing of the clamp shown in FIG.
quick-release clamps are typically designed to screw onto
1
the bolt of the support while the photographic equipment is
releasably secured to the upper surface of the clamp so that
FIG. 7 is an assembly drawing of a portion of the clamp
it can quickly be secured to, or released from, the support. 35 shown in FIG. 1 showing the manner in which the stud is
To secure photographic equipment to such a quick-release
secured to the clamp.
clamp, the photographic equipment such as a camera body
FIGS. 8A-8E are views of the cam lever of the clamp of
will typically include two parallel, opposed rails extending
FIG. 1.
from its base. The opposed rails may be provided by the
FIGS. 9A-9C are views of the stud shown in FIG. 6.
equipment or in the form of a plate secured to the equipment. 40
FIGS. 10A-lOE are views of the adjustable arm shown in
The rails are spaced apart so that they fit within an upwardly
FIG. 6.
facing channel defined by the clamp. The clamp includes a
FIG. 11 is a bottom view of the stud shown in FIG. 6
lever that moves between two positions to adjust the spacing
inserted into the body shown in FIG. 6.
between the side walls of the channel so that, when in a first,
locking position, the channel grips the rails connected to the 45
FIGS. 12A-12C are views of a thrust washer shown in
camera system and when in a second, released position, the
FIG. 6.
channel disengages the rails so that the photographic equipDETAILED DESCRIPTION OF THE
ment may be lifted from the clamp. In this manner, the lever
PREFERRED EMBODIMENT
may be used to quickly secure or release the photographic
equipment from the support.
FIG. 1 shows a clamp 10 that comprises a body 12 and an
50
Unfortunately, existing quick-release clamps have certain
adjustable arm 14 (shown in FIGS. 10A-lOE) that together
disadvantages. In order to provide for relative movement of
form a channel 16 having opposed side walls 18 and 20. The
the side walls of the channel, one or more springs apply an
body 12 may define an opening 32 through which the clamp
outward force to the side walls, so that they move apart as
10 may be secured to the upper portion of a tripod or other
the lever is moved to the second position. This outward force 55 support. The adjustable arm 14 is slidably engaged along the
tends to likewise push the lever away from the first, locking
cantilevered portion 59 of a stud 36 (shown in FIGS. 6, 7,
position, thus loosening the fitting between the photographic
and 9A-9C) securely mounted in the body 12, as shown in
equipment and the clamp. Further, as a result of usage over
FIG. 11. Movement of the adjustable arm 14 selectively
time, the lever and the clamp tend to loosen from one
adjusts the width of the channel 16 and is accomplished
another, thereby widening the spacing of the channel walls 60 through manual operation of a lever 22 fastened to the distal
in the locked position and thus loosening the fitting between
end 60 of the stud 36. The lever 22, attached to the adjustable
the photographic equipment and the clamp when in the
arm 14, permits quick adjustment of the spacing between the
locked position.
side walls 18 and 20 so that the channel 16 may selectively
either grip or release a pair of rails attached to the base of a
Further, the lever in existing quick-release clamps is
positioned solely on an outer lateral side of the clamp, 65 camera body (not shown). Each respective side wall 18 and
20 is preferably angled upward and inward to facilitate
underneath one side of the camera body. This position makes
it awkward to reach underneath the camera to operate the
engagement with such rails. In this manner, photographic

EXHIBIT A - Page 12 of 16

US 6,773,172 B1

3

4

equipment may be quickly engaged or released from a tripod
increase over that of the springs 28 because the adjustable
or other support.
arm 14 may not move any further while the locking member
30 will continue to compress.
The lever 22 may be a cam lever that includes a cam
portion 24 that rotates about a pivot axis 26 as the cam lever
FIG. 3 shows the lever 22 in a second intermediate
is moved between a first, unlocked position (shown in FIG. 5 position where the locking member 30 is applying a maximum inward force on the adjustable arm 14. This is a
1) and a second, locked position (shown in FIG. 4). The cam
position where the cam portion 24 preferably abuts the
portion 24 has an asymmetrical shape about the pivot axis 26
locking member 30 at a maximum distance d2 from the pivot
so that the lever 22 pushes the adjustable arm 14 inward as
the lever 22 is moved from a first position for releasing
axis 26. In this position, the inward force applied by the
photographic equipment from the clamp 10 to a second 10 locking member 30 to the adjustable arm 14 is substantially
greater than the outward force applied by the springs 28.
position for gripping photographic equipment to the clamp
Further movement of the lever 22 toward either the first or
10. Conversely, as the lever 22 is moved from the second
second position will relax the locking member 30 with
position to the first position, a pair of counterforce springs
respect to the maximum inward force as the distance from
28, housed within the body 12, push outward on the adjust15 the pivot axis 26 on which the locking member 30 abuts the
able arm 14 so that the channel 16 expands.
cam portion 24 decreases.
The outwardly directed force applied by the springs 28 on
FIG. 4 shows the lever 22 in the second position. In this
the adjustable arm 14 is at a maximum when the lever 22 is
position, the lever 22 is in an over-center detent configurain the second position, i.e. when the channel 16 is intended
tion such that movement of the lever 22 toward the first
to grip photographic equipment. The force applied by the
springs 28 therefore acts to undesirably loosen the grip on 20 position will act to compress the locking member 30. Thus
the locking member 30 resists movement of the lever 22
the photographic equipment. The disclosed clamp 10,
toward the first position. Preferably, when in this position,
however, includes a locking member 30 that prevents any
the inward force applied by the locking member 30 to the
outward movement of the adjustable arm 14 that might
adjustable arm 14 is still greater than the outward force
otherwise result from the force applied by the springs 28.
The locking member 30 may be substantially compressible, 25 applied by the springs 28. Alternatively, the two forces could
be precisely counterbalanced. In this manner, the adjustable
such as a compression spring, and interposed between the
arm 14 is locked into place because the springs 28 do not
lever 22 and the adjustable arm 14. FIG. 6, for example,
apply a sufficient force to overcome that force applied by the
shows a series of Belleville washers 30 that together operate
locking member 30.
as a compression spring. Alternatively, the locking member
30 could be a helical compression spring or any other 30
The locking member 30 preferably applies a force to the
appropriate force generating member. Further, the locking
adjustable arm 14 and the lever 22 that varies with the
member 30 may be interposed between the adjustable arm
position of the lever 22. The force preferably increases as the
14 and the body 12. The locking member 30 may preferably
lever is moved from the first position towards the second
apply an inwardly-directed force on the adjustable arm 14
position. The force preferably reaches a maximum before
that increases as the lever 22 is moved from the first position 35 the lever reaches the second position. More preferably, the
force applied by the locking member 30 is less than that
towards the second position. The inward force applied on the
adjustable arm 14 by the locking member 30 may preferably
maximum when in the second position, so that the force
applied by the locking member also increases as the lever is
be greater than the outward force applied by the springs 28
moved from the second position towards the first position.
when the lever 22 is in the second position. Also, the lever
22 may preferably include an over-center detent position. 40
The locking member 30 together with the lever 22 will
The manner in which clamp 10 may be operated to
achieve a force profile generally depicted in FIG. 5. This
achieve the foregoing advantages is seen in reference to
figure indicates that as the lever 22 is moved over a range of
FIGS. 1-4. FIG. 1 shows the clamp 10 where the lever 22
motion extending from the first position to the second
is in the first position, i.e. the released position. In this first
position, the force increases to a maximum at a second
position, the adjustable arm 14 is spaced apart from the body 45 intermediate position and then decreases as the lever 22
12 by an applied force from the springs 28, thus widening
continues to the second position.
the channel 16 to allow the insertion or removal of photoIt should also be noted from this figure FIG. 5 the
graphic equipment. The cam portion 24 is oriented such that
adjustable arm 14 may cease its inward motion at a first
the locking member 30, which in this instance is a series of
intermediate position before the locking member has
Belleville washers that act as a compression spring, is 50 reached its maximum force. This may be preferable so that
sufficiently relaxed so as to not apply a sufficient inward
the inward force applied by the locking member 30 on the
force on the adjustable arm 14 to overcome the outward
adjustable arm 14, when the lever is in the second position,
force of the springs 14. In this position, the cam portion 24
can still overcome the outward force applied by the springs
preferably abuts the locking member 30 at a minimum
28 even though the force applied by the locking member 30
distance dl from the pivot axis 26. As the lever 22 is moved 55 has fallen from its maximum. It should be further noted that
from the first position toward the second position, the cam
the movement of the adjustable arm 14 corresponds to the
portion 24 pushes the locking member 30 and the adjustable
movement of the lever. Therefore, it is desirable that the
arm 14, inward. The locking member 30 begins to compress
lever move through a large percentage of it range of motion
to counterbalance the outward force of the springs 28
before the adjustable arm ceases to move, and achieve a
applied to the adjustable arm 14 as it moves inward.
60 maximum force in the remaining range of motion of the
lever. For that reason, the force applied by the locking
FIG. 2 shows the lever 22 in a first intermediate position
member 30 in the disclosed clamp 10 achieves its maximum
where the lever 22 has been moved to a position where the
value at approximately 80-90% of the lever's range of
adjustable arm 14 is flush with the body 12. In this position,
the forces applied by the locking member 30 and the springs
motion. It should be understood, however, that other
28 counterbalance each other; further movement of the lever 65 embodiments may achieve a maximum force anywhere
along the lever's range of motion, but preferably greater than
22 towards the second position, however causes the inward
force applied by compression of the locking member to
50%.

EXHIBIT A - Page 13 of 16

US 6,773,172 B1
5

6

12. The adjustable arm 14 may then be pushed against the
The force profile depicted in FIG. 5 is smooth, i.e. as the
springs 28 until the adjustable arm 14 is engaged with the
lever is moved from the first position, the force increases
continuously to a maximum and decreases continuously
body 12 and the stud 36 protrudes through the adjustable
until the lever reaches the second position. Alternative
arm 14. The locking member 30, which may comprise a
embodiments may design a lever that permits the force 5 series of washers 52 and 54, may be engaged over the stud
profile to decrease at certain intervals on the lever's path
36 to fit within the partially bored opening 50 within the
from the first position to the second intermediate position of
adjustable arm 14. The lever 22 may then be secured to the
maximum force, or to increase on the lever's path from that
distal end 60 of the stud 36 to secure the assembly in place.
second intermediate position to a lesser force at the second
Referring to FIGS. 8A-8E, the cam lever 22 comprises a
position, or both. Preferably, however, the force profile is 10 shape that assists the convenient operation of the clamp 10.
increasing over at least 65% of the lever's path from the first
Existing clamps employ levers that are exclusively posiposition to the second intermediate position and is decreastioned to one of the lateral sides of the clamp. Camera bodies
ing over at least 65% of the path from the second intermeare typically positioned directly over these existing levers,
diate position to the second position.
which often makes them difficult to reach when engaging or
Though the force profile depicted in FIG. 5 is achieved by 15 releasing the clamp. The cam lever 22, however, includes a
using a lever 22 in conjunction with the locking member 30,
handle portion 56 that extends from the yoke 58. The handle
it should be understood that levers of other shapes may be
portion 56 is elongate and has a sufficient length to extend
used to achieve the same or similar force profiles. Further,
beyond, and curve around, a lateral corner 61 of the clamp
other structures may be substituted for the lever, such as a
10 when the cam lever is in the second, or locked position
20 as seen in FIG. 4. The cam lever also extends beyond the
plunger or a button.
opposed lateral corner 62 when the cam lever is in the first
Referring to FIGS. 6 and 7, the clamp 10 may comprise
position as seen in FIG. 1. The cam lever 22 therefore is
a body 12 constructed of any sufficiently rigid material such
easily accessible even cured to the clamp.
as metal, plastic, or composite material. The body 12 prefThe terms and expressions that have been employed in the
erably defines the side wall 18 of the channel 16 as well as
a central opening 32 by which the clamp 10 may be secured 25 foregoing specifications are used therein as terms of description and not of limitation, and there is no intention, in the use
to a tripod or other support using a bolt, pin, or other similar
protrusion. The opening 32 may be threaded to receive a
of such terms and expressions, of excluding equivalents of
the features shown and described or portions thereof, it
bolt, or alternately may not be threaded such that interconbeing recognized that the scope of the invented is defined
nection with a tripod or other support may be made using a
30 and limited only the claims that follow.
wing nut or other fastener.
What is claimed is:
The body 12 may also define a sleeve 34 (shown in FIG.
1. An apparatus for engaging photographic equipment to
7) into which the stud 36 may be inserted. The stud 36 and
a support, said apparatus comprising:
the sleeve 34 are preferably threaded to ensure a rigid
connection. If further means are desired to ensure a rigid
(a) a member defining a channel having a first side wall
connection between the stud 36 and the body 12, they may 35
capable of lateral movement with respect to a second
side wall;
each define aligned holes 40 and 42 through which a
fastening pin 44 may be inserted. Alternatively, a thread
(b) a lever capable of causing said lateral movement; and
locking compound may be used. The body preferably also
(c) a substantially compressible member operably interdefines two symmetrically opposed sockets 38 into which
connected between said lever and said first side wall.
the springs 28 may be inserted. The sockets 38 and the 40
2. The apparatus of claim 1 where said lever is a cam
sleeve 34 may also preferably be parts of a slot 46 defined
lever.
by the body 12.
3. The apparatus of claim 1 where said substantially
The adjustable arm 14 preferably defines the side wall 20
compressible member is a spring.
as well as a ledge 48 sized to fit snugly within the slot 46. 45
4. The apparatus of claim 3 where said spring comprises
The springs 28, when inserted into their respective sockets
a series of Belleville washers.
38 will push on the ledge 46 as the adjustable arm is engaged
5. An apparatus for engaging photographic equipment to
with the body 12. The adjustable arm 14 may also define a
a support, said apparatus comprising:
partially bored opening 50 so that the opening 50 may
(a) a member defining a channel having a first side wall
simultaneously retain the locking member 30 within itself 50
capable of lateral movement with respect to a second
while permitting the stud 36 to extend completely through
side wall between a first location and a second location,
the adjustable arm 14.
where said second location is spaced further from said
The locking member 30 may comprise a plurality of
second side wall than is said first location; and
adj acent Belleville washers that together function as a
(b) a lever and a substantially compressible member
compression spring. Optionally, a thrust washer 54 (shown 55
operably interconnected between said lever and said
in FIGS. 6 and 12A-12C) may be located at either or each
first side wall, said lever and said substantially comend of the plurality of Belleville washers.
pressible member together capable of causing said
Referring to FIGS. 8A-8E, the lever 22 may comprise a
lateral movement and said lever moveable between a
handle portion 56 and a yoke 58. The yoke 58 may also
first position associated with said second location and
define the cam portion 24 that, as previously described, 60
a second position associated with said first location,
operates the locking member 30 as the lever 22 is rotated.
said second position being an over-center detent.
The yoke 58 preferably receives the distal end 60 of the stud
6. The apparatus of claim 5 including a substantially
36. The stud 36 may be secured to the yoke 58 using a dowel
compressible member operably interconnected between said
pin 39 that is inserted into aligned openings 57 and 63
lever and said first side wall.
formed by the stud 36 and the yoke 58, respectively.
7. The apparatus of claim 5 where said substantially
65
compressible member maintains said lever in said detent
As can be seen by FIG. 6, the clamp 10 may be assembled
position.
by first inserting the stud 36 and the springs 28 into the body

EXHIBIT A - Page 14 of 16

US 6,773,172 B1
7

8

8. An apparatus for engaging a photographic equipment to
force increases when said lever is moved from said first
position towards said intermediate position and said
a support, said apparatus comprising:
force increases when said lever is in said second
(a) a member defining a channel having a first side wall
position and is moved towards said intermediate posicapable of lateral movement with respect to a second
tion.
side wall between a first location and a second location, 5
18. The apparatus of claim 17 where said force is at a
where said second location is spaced further from said
maximum at said intermediate position.
second side wall than is said first location;
19. The apparatus of claim 18 where said lever has a range
(b) a lever capable of causing said lateral movement and
of motion from said first position to said second position and
moveable between a first position associated with said
said intermediate position is located between 50 percent and
second location and a second position associated with 10 90 percent of said range of motion.
said first location; and
20. The apparatus of claim 18 where said lever has a range
(c) a force generating member capable of applying a force
of motion from said first position to said second position and
to said first side wall and said lever where said force
said intermediate position is located between 60 percent and
increases when said lever is in said first position and is
90 percent of said range of motion.
15
moved towards said second position.
21. The apparatus of claim 18 where said lever has a range
9. The apparatus of claim 8 where said force generating
of motion from said first position to said second position and
member is a compression spring.
said intermediate position is located between 70 percent and
10. The apparatus of claim 8 where said compression
90 percent of said range of motion.
spring comprises a plurality of Belleville washers.
22. The apparatus of claim 18 where said lever has a range
11. An apparatus for engaging photographic equipment to 20 of motion from said first position to said second position and
a support said apparatus comprising:
said intermediate position is located between 80 percent and
90 percent of said range of motion.
(a) a first member defining a channel having a first side
23. An apparatus for engaging photographic equipment to
wall capable of lateral movement with respect to a
second side wall;
a support, said apparatus comprising:
25
(b) a second member capable of causing said lateral
(a) a member defining a channel having a first side wall
movement and moveable between a first position and a
capable of lateral movement with respect to a second
side wall;
second position;
(c) a third member capable of applying force to said first
(b) a lever capable of causing said lateral movement and
side wall and said second member where said force 30
moveable between a first position and a second position
increases when said second member is in said first
and through an intermediate position;
position and is moved towards said second position and
(c) a force generating member capable of applying force
said force increases when said second member is in
to said first side wall and said lever, where said force
said second position and is moved towards said first
increases when said lever is moved from said intermeposition.
diate position towards said second position and said
35
12. The apparatus of claim 11 where said second member
first side wall does not move with respect to said second
is moveable to an intermediate position between said first
side wall when said lever is moved from said intermeposition and said second position and where said force
diate position to said second position.
decreases when said second member is moved from said
24. An apparatus for engaging photographic equipment to
intermediate position towards either said first position or 40 a support, said apparatus comprising:
said second position.
(a) a member defining a channel having a first side wall
13. The apparatus of claim 12 where said second member
capable of travel with respect to a second side wall
has a range of motion from said first position to said second
from a first location to a second location in response to
position and said intermediate position is located between 50
actuation of an actuator, said first side wall capable of
percent and 90 percent of said range of motion.
remaining in said second location without further
45
14. The apparatus of claim 12 where said second member
actuation of said actuator;
has a range of motion from said first position to said second
(b) said actuator being capable of causing said lateral
position and said intermediate position is located between 60
movement by transmitting a force to said first side wall
percent and 90 percent of said range of motion.
where said force increases over a major portion of said
15. The apparatus of claim 12 where said second member 50
travel, said force varies over an interval from a first
has a range of motion from said first position to said second
time to a second time while said second side wall
position and said intermediate position is located between 70
remains in said second location, said force reaches a
percent and 90 percent of said range of motion.
maximum value between said first time and said second
16. The apparatus of claim 12 where said second member
time, and said force at said second time is greater than
has a range of motion from said first position to said second 55
said force at said first time.
position and said intermediate position is located between 80
25. The apparatus of claim 24 where said actuator is a
percent and 90 percent of said range of motion.
lever.
17. An apparatus for engaging photographic equipment to
26. The apparatus of claim 25 where said lever is capable
a support, said apparatus comprising:
of movement between a first and a second position through
(a) a member defining a channel having a first side wall 60 an intermediate position, said first position is associated with
capable of lateral movement with respect to a second
said first location and said intermediate position through said
side wall;
second position is associated with said second location and
(b) a lever capable of causing said lateral movement and
said interval.
moveable between a first position and a second position
27. The apparatus of claim 24 where said force increases
and through an intermediate position;
65 over at least 65% of said travel.
28. The apparatus of claim 24 where said force increases
(c) a force generating member that capable of applying
force to said first side wall and said lever where said
over all of said travel.

EXHIBIT A - Page 15 of 16

US 6,773,172 B1

9
29. An apparatus for engaging photographic equipment to
a support, said apparatus comprising:
(a) a member defining a channel having a first side wall
capable of lateral movement with respect to a second
side wall;
5
(b) a lever capable of causing said lateral movement and
movable between a first position and a second position,

EXHIBIT A - Page 16 of 16

10
said lever engaged on a side of said member, said side
defining opposed first and second corners; and
(c) a handle portion of said lever where said handle
portion extends beyond said first corner when in said
first position and extends beyond and around said
second corner when in said second position.

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