U.S. patent number 3,840,041 [Application Number 05/109,248] was granted by the patent office on 1974-10-08 for magnetic lock and wrench.
Invention is credited to Bud A. McMurray.
United States Patent |
3,840,041 |
McMurray |
October 8, 1974 |
MAGNETIC LOCK AND WRENCH
Abstract
A magnetic lock and wrench, particularly adapted for fire
hydrants in which one of the members of the lock, namely, the inner
member is secured to the lug of the fire hydrant, with the outer
member positioned thereover and rotatable relative thereto when in
an unlocked position, and coupling means therebetween operated by a
wrench having magnetic means which when applied to the outer member
will cause the coupling means to couple the inner and outer members
so that rotation of the outer member by the wrench will rotate the
inner member and the fire hydrant lug to open and close the fire
hydrant valve and/or like member.
Inventors: |
McMurray; Bud A. (Deerfield,
IL) |
Family
ID: |
22326631 |
Appl.
No.: |
05/109,248 |
Filed: |
January 25, 1971 |
Current U.S.
Class: |
137/296;
81/121.1; 192/108; 251/89; 137/382; 251/65; 251/291; 192/84.3 |
Current CPC
Class: |
F16K
35/06 (20130101); E03B 9/02 (20130101); F16K
35/16 (20130101); Y10T 137/5468 (20150401); Y10T
137/7062 (20150401) |
Current International
Class: |
E03B
9/00 (20060101); F16K 35/00 (20060101); E03B
9/02 (20060101); F16K 35/06 (20060101); F16K
35/16 (20060101); F16k 035/06 () |
Field of
Search: |
;192/84PM,108
;251/65,89,291,292 ;137/272,296,377,382 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Cohan; Alan
Assistant Examiner: Gerard; Richard
Attorney, Agent or Firm: Kraus; Max R.
Claims
What is claimed is:
1. In a device for opening and closing a valve, said device
comprising an inner member adapted to be attached to a valve
operating member, said inner member having a hollow interior
corresponding to the shape of the valve operating member so that
said inner member may be secured to said valve operating member, an
outer member adapted to fit over said inner member, said inner and
outer members each having recesses, coupling means comprising
locking pins between said inner and outer members and adapted to
normally be positioned in said recesses of said inner member to
permit said outer member to be rotated relative to said inner
member without imparting a corresponding rotation to the inner
member, and magnetic means adapted when positioned relative to said
outer member to cause said coupling means to move into engagement
with the recesses in said outer member while remaining in
engagement with the recesses in said inner member to couple said
outer and inner members so that when said outer member is rotated a
corresponding rotation will be imparted to said inner member to
rotate the valve operating member for opening and/or closing a
valve, said coupling means adapted when the magnetic means is
removed to be moved entirely into the recesses in said inner member
to uncouple the outer and inner members to permit said outer member
to be rotated relative to said inner member without a corresponding
rotation of said inner member.
2. A structure as set forth in claim 1 in which the inner member is
adapted to be secured to a lug operating a valve of a fire hydrant
so that when the outer member is rotated and the coupling means are
in position to couple the outer and inner members a corresponding
rotation will be imparted to the lug of the fire hydrant to open or
close the valve of the fire hydrant.
3. A structure as set forth in claim 2 in which a skirt is
rotatably supported on said outer member so that said skirt is
rotatable at all times relative to said outer member without
imparting a rotation to said outer member.
4. A structure as set forth in claim 1 in which the inner member
has means for locking same to a fire hydrant lug, operating a valve
of a fire hydrant.
5. A structure as set forth in claim 1 in which the inner member
has a central opening and in which the outer member has a central
projection extending into said central opening, and means for
securing said outer and inner members relative to each other to
prevent separation therebetween but permitting relative rotation
therebetween when said coupling means are in uncoupled
position.
6. A structure as set forth in claim 1 in which the magnetic means
is part of a wrench which wrench cooperates with a lug of the outer
member to rotate said outer member but no corresponding rotation is
imparted to said inner member unless said coupling means are
magnetically attracted to couple the inner and outer members.
7. In a device for opening and closing a valve, said device
comprising an inner member adapted to be attached to a valve
operating member, an outer member, coupling means between said
inner and outer members and adapted to normally be positioned to
permit said outer member to be rotated relative to the inner member
without imparting a corresponding rotation to the inner member, and
magnetic means adapted when positioned relative to said outer
member to cause said coupling means to couple said outer and inner
members so that when said outer member is rotated a corresponding
rotation will be imparted to said inner member to rotate the valve
operating member for opening and/or closing a valve, said magnetic
means being part of a wrench head which is applied to the outer
member for rotating same, and in which the thickness of the
magnetic means is substantially that of the wrench head so that the
wrench head may be applied with either side adjacent the top of the
outer member for magnetic attraction of the coupling means.
8. In a device for opening and closing a valve, said device
comprising an inner member having an internal surface corresponding
to the shape of a lug operating a valve of a fire hydrant, said
inner member adapted to be attached to said fire hydrant lug, an
outer member adapted to be positioned over said inner member but
rotatably secured with respect thereto, coupling means comprising a
plurality of locking pins between said inner and outer members and
adapted to be normally supported on said inner member in uncoupled
relation to said outer member to permit said outer member to be
rotated relative to the inner member without imparting a
corresponding rotation to the inner member, and magnetic means
adapted when positioned relative to said outer member to cause said
coupling means to couple said outer and inner members so that when
said outer member is rotated a corresponding rotation will be
imparted to said inner member to rotate the fire hydrant lug for
opening and/or closing a valve.
9. In a device for attachment to a lug for operating a valve of a
fire hydrant, said device comprising an inner member having an
interior shape complementary to the shape of the fire hydrant lug
and adapted to be attached to said fire hydrant lug, an outer
member positioned over said inner member, said outer member having
a head corresponding in shape to the shape of the fire hydrant lug,
coupling means between said inner and outer members and adapted to
normally be positioned to permit said outer member to be rotated
relative to the inner member without imparting a corresponding
rotation to the inner member, and magnetic means comprising a
wrench having a magnetic element, said magnetic element having an
opening corresponding in shape to that of the head of said outer
member to be accommodated on the head of said outer member and when
positioned thereon adapted to attract the coupling means to couple
said outer and inner members so that when said wrench rotates said
outer member, said inner member will be correspondingly rotated and
when said wrench is removed said coupling means will drop by
gravity into said inner member to uncouple the outer and inner
members relative to each other.
Description
BRIEF SUMMARY OF THE INVENTION
It is well recognized, particularly in connection with fire
hydrants, that the unauthorized opening of the valve will result in
a tremendous waste of water, as well as other objectionable
results, all of which are well known. One of the objects of this
invention is to provide a device which is readily attachable to the
lug of a standard fire hydrant which will not operate to either
open or close the fire hydrant valve unless a wrench having
magnetic properties is applied, which wrench would be in the
possession of authorized personnel, such as members of the fire
department or others who are authorized to open and/or close fire
hydrants.
The lock includes an inner member which is attached to the fire
hydrant lug, an outer member, and coupling means therebetween, with
the coupling means movable into coupling position when a wrench
having magnetic means is applied to the outer member so that
rotation of the outer member will rotate the inner member and with
it the fire hydrant lug to open or close the fire hydrant valve. In
the absence of the application of the magnetic wrench, the coupling
means will remain in uncoupled position and no rotation can be
imparted to the inner member and the fire hydrant valve will remain
unaffected.
Other objects will become apparent as this description
progresses.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a view of my invention applied to a fire hydrant.
FIG. 2 is an exploded view of certain of the components forming
this invention.
FIG. 3 is a sectional view taken on line 3--3 of FIG. 2.
FIG. 4 is a sectional view similar to FIG. 3, but with the magnetic
wrench applied to couple the cooperating parts to operate the fire
hydrant valve.
FIG. 5 is a sectional view taken on line 5--5 of FIG. 3, and
FIG. 6 is a view partly in section of the magnetic wrench.
While the lock is described in relation to a fire hydrant it is not
limited thereto as it may be used in connection with other valve
means which may be similarly operated.
The conventional fire hydrant 10 has a standard lug or head 12
which in most instances is five-sided or of pentagon shape and is
exposed to be normally engaged by a conventional wrench so that the
lug is rotated to open and close the fire hydrant valve. In some
instances the lug may be of square shape. The present invention is
directed to means which are secured to said lug 12 to rotate same
when it is done by authorized personnel who have the special
magnetic wrench.
The invention includes an inner member or a lock base generally
indicated by the numeral 14 and an outer member or lock cap
generally indicated by the numeral 16 and locking or coupling pins
18 positioned therebetween, which locking pins are moved into
coupling position to couple the inner and outer members 14 and 16
respectively when a wrench, generally indicated at 20, having
magnetic properties is applied to the outer member 16 to rotate
same. The foregoing is a general description of the operating
elements which will now be described in greater detail.
The inner member or lock base 14 can be either a machined casting
or machine part of some non-magnetic metal, such as bronze. It is
of cylindrical shape and is provided with a hollow lower portion
22, the interior of which has five sides or is of pentagon shape as
indicated by the numeral 23. The upper end of the inner member or
lock base 14 has a horizontal top wall surface 24 which is provided
with four holes or recesses 26 which are located 90.degree. apart,
and these holes or recesses are adjacent the outer circumference of
the top wall surface 24. They are preferably drilled but may be
otherwise formed and they extend perpendicular to the top surface.
The upper edge of each of these holes is chamfered as at 27 and the
bottom of said hole slopes downwardly as at 28 towards the axis of
said hole. These holes or recesses serve to receive the locking or
coupling pins 18, which pins serve to couple and uncouple the outer
member 16 with respect to the inner member 14.
A central vertical bore or opening 30 is provided to extend through
the top wall 24 and said bore communicates with an enlarged annular
recess 32, which in turn communicates with the interior 22 of the
inner member 14. The lower outer portion 34 of the inner member or
lock base 14 is of a reduced diameter for a portion of its height,
whereas the outer portion 35 extending upwardly thereof to the top
is of a larger diameter. The lower portion 34 is provided with a
plurality of equally spaced transversely extending internally
threaded holes 36 which extend into the interior 22 of the inner
member or lock base 14. The hole is countersunk as at 37. An
annular groove 38 is formed on the outer surface of the upper
portion 35 of the lock base 14 to accommodate a sealing O-ring
39.
The inner member or lock base 14 is adapted to be positioned on the
five-sided conventional fire hydrant lug 12, with the inside
five-sided wall 23 of the inner member or lock base 14 loosely
engaging the sides of the fire hydrant lug 12. The inner member or
lock base 14 is secured to the fire hydrant lug 12 by means of set
screws 40 (FIG. 5) passing through said transversely extending
openings 36, with said set screws engaging the five sides of the
lug 12 of the fire hydrant. The set screws 40 which are threaded
into the transversely extending openings 36 in the inner member or
lock base 14 are of a material such as steel and of a length
adequate to extend through the lower portion of the lock base, and
of a diameter sufficient to provide the necessary strength to
resist the removal of the device by methods other than the one
provided for in its design. The outer end or head 41 of the set
screw is accommodated in the countersunk portion 37 and the
interior of the head and has a five-sided indentation 42 to
accommodate the installation key 44.
The outer member or lock cap, generally indicated by the numeral
16, can be a machined casting or a machined part formed of a
non-magnetic metal, such as bronze. It is cylindrical in shape and
has an annular wall 46 which provides a hollow lower portion 48.
The upper end of the lock cap 16 is closed by a horizontally
extending top wall 50, which top wall is of a suitable thickness to
accommodate four equally spaced holes or recesses 52 located on the
underside of the top wall 50, which holes or recesses are in
alinement with the holes 26 in the top surface of the inner member
or lock base 14. The holes 52 do not extend through the closed top
wall 50. The holes 52 serve to accommodate a portion of the
coupling pins 18 when the pins are magnetically attracted to the
magnetic wrench, as shown in FIG. 4, and as will be subsequently
described.
The locking or coupling pins 18 are cylindrical in shape, solid and
flat on each of its opposite ends, with the top and bottom edges
slightly chamfered, as best seen in FIGS. 3 and 4. They are of a
material such as hardened steel, which is subject to magnetic
force. These locking pins are of a size to provide a loose fit in
the holes or recesses 26 and 52. The locking pins 18, therefore,
are of a smaller diameter than the diameter of the holes or
recesses.
When the locking or coupling pins 18 move upwardly into the holes
or recesses 52 in the outer member 16, the lower portion of said
pins will be in engagement with the holes or recesses 26 in the
inner member 14 and thus when in such position will couple the
outer member 16 to the inner member 14 to lock them together for
simultaneous rotation. However, when there is no magnetic wrench
applied to the outer member, as shown in FIG. 3, then the coupling
pins 18 will be located in the holes 26 of the inner member 14 and
the inner and outer members 14 and 16 respectively, will be
uncoupled so that rotation of the outer member 16 will not impart a
corresponding rotation to the inner member 14.
The inside diameter of the wall 46 of the outer member 16 is
slightly larger than the outside diameter of the exterior wall 35
of the inner member or lock base 14. The sealing O-ring 39 is of a
soft, pliable and weatherproof material, such as neophrene, and of
a diameter to provide a tight fit in the groove around the upper
portion of the inner member 14 and of a thickness to provide a
tight seal between the inner member 14 and outer member 16.
The outer member or lock cap 16 is centrally provided with an
annular depending projection or stem 54 which extends downwardly
from the center of the underside of the top wall 50 and is received
in the central bore 30 of the inner member 14. The stem has an
internally threaded bore 56 to accommodate a threaded screw 57, the
head of which engages a washer 58 which rests against a shoulder 59
formed by the enlarged recess 32. The screw and washer are made
preferably of steel and are of a size to provide sufficient
strength to hold the inner member to the outer member. By this
means the outer member or lock cap 16 is connected to the inner
member or lock base 14 and this permits the outer member 16 to be
rotated relative to the inner member 14 without disengaging or
separating them.
Extending centrally upwardly of the top wall 50 of the outer member
16 is a five-sided lug or head 60 which is adapted to be engaged by
the wrench 20, to be subsequently described. A vertically extending
slot 62 is provided at the bottom of the annular wall 46 of the
outer member 16 to allow the installation key 44 to be slid up and
engage the heads of the set screws 40 on the inner member or lock
base 14 when the lock base is initially installed on a fire hydrant
lug or, if necessary, to remove it therefrom. The installation key
44, as best seen in FIG. 5, has a reduced annular portion 45 which
permits the key to be inserted from the bottom of the vertical slot
62 as well as the vertical slot in the skirt, to be described, so
that the key can engage the set screws 40 to rotate same.
The outer member or lock cap 16 has an annular groove 64.
Positioned around the exterior of the outer member 16 is a
cylindrical skirt or shell 66 having an inwardly extending lip or
flange 68 which rides within the annular groove 64. The bottom of
the skirt is provided with a vertically extending slot 69. Said
cylindrical skirt is rotatable relative to said outer member 16 to
prevent any unauthorized person from applying any wrench to the
cylindrical exterior of the outer member or lock cap 16. If an
unauthorized wrench were applied to engage the skirt 66 on the
outer member, the outer member 16 could not be manually rotated by
said wrench by virtue of the loose skirt with which the wrench
would come into engagement and rotation of the skirt by said
unauthorized wrench would still not rotate the outer member 16.
As is clear from the foregoing description, the lock cap or outer
member 16 is placed over the inner member or lock base 14, with the
stem 54 projecting into the bore 30 in the center of the inner
member or lock base and the two are connected together by means of
the screw 57 and washer 58. With the coupling pins 18 resting
within the holes 26 of the inner member 14, the outer member 16 may
be rotated relative to the inner member 14 without rotating the lug
12 of the fire hydrant.
The specially constructed wrench for operating this device is
generally indicated at 20 and comprises a head 70 made of cast iron
or other suitable material having an annular opening 72 extending
through the thickness of the head which receives an Alnico magnet
74. The Alnico magnet is provided with a five-sided central opening
76. A handle 78, preferably of steel, to be manually engaged, has a
threaded end 79 which engages an internally threaded transversely
extending bore 80 in the head 70. The magnet is also provided with
a transversely extending bore 82 which is alined with the bore 80
to receive the end 79 of the handle to thus securely lock the
magnet to the head of the wrench. The five-sided opening 76 in the
magnet is slightly larger than the dimension of the standard fire
hydrant lug 12. The magnet 74 is of a diameter equal to the
diameter of the top of the outer member or lock cap 16 so that when
the wrench is positioned on the lug or head 60 of the outer member
or lock cap, the magnet 74 will be adjacent the top of the lock cap
and will be in alinement with the locking pins 18 to attract and
draw them upwardly. The magnet is of a thickness of that of the
head 70 of the wrench so that whichever side of the head is applied
to the top of the lock cap there will be sufficient magnetic force
to attract the locking pins 18.
As can be understood from the foregoing description, the
installation key 44 is an Allen-type wrench having five sides
instead of the standard six sides and the installation key has a
reduced cylindrical portion 45 which slides into the slot 62 of the
outer member 16 and the slot 69 of the skirt 66 when the
corresponding slots 62 and 69 are alined. Transversely extending
indentations or recesses 84 are formed in the sides of the standard
lug 12 of the fire hydrant to be engaged by the screws 40 to lock
the inner member or lock base 14 to the lug 12 of the hydrant and
said screws are tightened by the Allen-type wrench 44, best shown
in FIG. 5, to secure the inner member or lock base to the lug of
the fire hydrant.
OPERATION
The wrench 20 is placed on the lug or head 60 of the outer member
or lock cap 16 so that the five-sided opening 76 of the magnet 74
surrounds the five-sided head 60 of the outer member 16. The
surface of the magnet will be positioned adjacent the top wall 50
of the outer member 16. The magnet 74 will attract and pull up the
locking pins 18 from the position shown in FIG. 3 to the "up"
position shown in FIG. 4, where the locking pins 18 couple the
inner and outer members 14 and 16 to establish a solid connection
therebetween. When the wrench is manually rotated, rotating the
outer member 16, it will then simultaneously rotate the inner
member 14 which is secured to the lug 12 of the fire hydrant and
thus turn the lug 12 of the fire hydrant to open or close the valve
of the fire hydrant. When the wrench 20 is removed from the top
wall 50 of the outer member the locking pins 18 fall back into the
recesses 26 of the lock base or inner member 14 and the lock cap 16
can then be turned freely relative to the lock base 14 without
rotating the lock base 14.
It should be noted that before the locking pins 18 can move into
the "up" position of FIG. 4, the outer member 16 must first be
rotated by the wrench so that the recesses 52 in the outer member
16 are in alinement or registry with the recesses 26 in the inner
member 14, for unless they are in registry the locking pins 18
cannot move into the recesses 52 in the outer member 16 to couple
the two members to impart a rotation to the inner member 14.
Once the wrench is applied to the head 60 the pins 18 will move
into coupling position with hole 52 when the outer member is
rotated so that the holes 52 register with holes 26. In other
words, coupling takes place automatically when the magnet of the
wrench pulls the pins 18 upwardly as the holes pass over the holes
26.
The rotatable skirt 66 serves to make the device foolproof in that
the outer member 16 cannot be rotated by engaging the cylindrical
wall of the outer member with a wrench and using a conventional
magnet to move up the locking pins 18 to coupling position. A
wrench 20 like that described must be used for operating the
device.
* * * * *