U.S. patent number 3,749,435 [Application Number 05/145,672] was granted by the patent office on 1973-07-31 for electric strike.
This patent grant is currently assigned to Eaton Corporation. Invention is credited to Alfiero F. Balzano.
United States Patent |
3,749,435 |
Balzano |
July 31, 1973 |
ELECTRIC STRIKE
Abstract
An electrically operated strike for coacting with a bolt of a
door lock includes a casing adapted to be mounted on a door frame
and a bolt member slidable between a projected position engaging
the door lock bolt, and a retracted position. Spring means are
provided for biasing the bolt member toward the projected position
and a solenoid is provided for effecting movement of the bolt
member against the biasing effect of the spring to its retracted
position. Dogging means are interconnected between the solenoid and
the bolt member and have a dogging position holding the bolt member
in its projected position when the solenoid is not energized and a
release position providing for movement of the bolt member to its
retracted position when the solenoid is energized. The dogging
means is operable when in its dogging position to transfer external
forces applied to the bolt member to the casing to thereby render
the external forces ineffective to move the bolt member toward its
retracted position.
Inventors: |
Balzano; Alfiero F. (Anaheim,
CA) |
Assignee: |
Eaton Corporation (Cleveland,
OH)
|
Family
ID: |
22514062 |
Appl.
No.: |
05/145,672 |
Filed: |
May 21, 1971 |
Current U.S.
Class: |
292/341.16 |
Current CPC
Class: |
E05B
47/0047 (20130101); Y10T 292/699 (20150401) |
Current International
Class: |
E05B
47/00 (20060101); E05c 011/00 () |
Field of
Search: |
;292/341.16,144,341.15,153,254 ;70/283 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Moore; Richard E.
Claims
I now claim:
1. An electrically operated strike adapted to be mounted on a door
frame for controlling opening movements of a door and comprising a
casing, a bolt member mounted in said casing and slidable relative
thereto between a projected position for engaging a part on the
door and a retracted position releasing the part on the door, said
casing including a guide surface limiting the movement of said bolt
member to a substantially linear direction, spring means biasing
said bolt member toward said projected position, electrical means
effective when energized to slide said bolt member against the
biasing effect of said spring means to said retracted position, and
interconnecting means interconnecting said bolt member and said
electrical means for sliding said bolt member and through which
said spring means and said electrical means act relative to said
bolt member, said interconnecting means including dogging means
having a dogging position holding said bolt member in said
projected position and a release position permitting said bolt
member to move toward said retracted position, said dogging means
when in said dogging position acting to transfer external forces
that may be applied in retracting direction to said bolt member to
said casing in a direction transverse to said retracting direction
to thereby render said external forces ineffective to retract said
bolt member, said electrical means being operable to effect
movement of said dogging means to said release position to thereby
enable said bolt member to move to said retracted position, said
dogging means including a plate member pivotably attached to said
bolt member and a groove disposed in said casing, said plate member
including a shoulder portion engaging said groove when said dogging
means is in said dogging position to transfer forces exerted on
said bolt member in a transverse direction toward said casing, said
plate member being pivotable when said dogging means is in said
release position to effect disengagement of said groove and said
shoulder portion of said plate member to permit movement of said
plate member with said bolt member toward said retracted
position.
2. An electrically operated strike as defined in claim 1 wherein
said electrical means includes a solenoid having a plunger and
spring means for biasing said plunger toward said bolt and said
dogging means further includes a pin attached to said plunger
member and movable therewith and an opening disposed in said plate
member and through which said pin extends, said spring means
biasing said plunger and said pin to engage said opening to
pivotably bias said plate member in a first direction to position
said shoulder of said plate member in engagement with said groove
when said solenoid is deenergized, said pin engaging with said
opening and effecting rotation of said plate member in a direction
opposite said first direction to remove said shoulder from said
groove upon energization of said solenoid to prevent movement of
said bolt member inwardly of said casing.
3. An electrically operated strike as defined in claim 2 further
including a stop member disposed in said casing and an opening
disposed in said bolt member, said stop member extending into said
opening in said bolt member and acting to limit movement of said
bolt member between said projected position and said retracted
position.
4. An electrically operated strike adapted to be mounted on a door
frame for controlling opening movements of a door and comprising a
casing, a bolt member mounted in said casing and slidable relative
thereto between a projected position for engaging a part on the
door and a retracted position releasing the part on the door, said
casing including a guide surface limiting the movement of said bolt
member to a substantially linear direction, spring means biasing
said bolt member toward said projected position, electrical means
effective when energized to slide said bolt member against the
biasing effect of said spring means to said retracted position, and
interconnecting means interconnecting said bolt member and said
electrical means for sliding said bolt member and through which
said spring means and said electrical means act relative to said
bolt member, said electrical means including a solenoid having a
plunger and a spring for biasing said plunger toward said bolt
member when said solenoid is deenergized, said interconnecting
means including dogging means having a dogging position holding
said bolt member in said projected position and a release position
permitting said bolt member to move toward said retracted position,
said dogging means when in said dogging position acting to transfer
external forces that may be applied in retracting direction to said
bolt member to said casing in a direction transverse to said
retracting direction to thereby render said external forces
ineffective to retract said bolt member, said electrical means
being operable to effect movement of said dogging means to said
release position to thereby enable said bolt member to move to said
retracted position, said dogging means including a first plate
member attached to said plunger and movable therewith, and a second
plate member pivotably mounted on said casing, said second plate
being disposed between said first plate member and said bolt member
and having a first surface engageable with said bolt member and a
second surface opposite said first surface for engaging with said
first plate member, said first plate member preventing rotation of
said second plate member and acting to hold said first surface of
said second plate member in engagement with said bolt member to
prevent movement of said bolt member toward said retracted position
when said solenoid is deenergized, said first plate member
disengaging with said second plate member to enable said second
plate member to rotate upon energization of said solenoid to enable
said bolt member to move toward said retracted position.
5. An electrically operated strike as defined in claim 4 further
including a stop member attached to said bolt member and an opening
disposed in said casing, said stop member cooperating with said
opening to limit movement of said bolt member between said
projecting and retracted positions.
6. In an electrically operated strike for coacting with a bolt of a
door lock, a casing adapted to be mounted on a door frame, a bolt
member slidable relatively to a projected position on the casing
for engaging the bolt of the door lock, said casing having guide
surfaces that support the bolt member for movements in a linear
direction while sliding on the casing, a solenoid mounted on said
casing and equipped with a spring pressed plunger normally pressing
the bolt member to its projected position and sliding the bolt
member on its guide surfaces to a retracted position when the
solenoid is energized, dogging means movable to position engaging
between the bolt member and the casing to dog the bolt member in
its projected position, connecting means whereby the solenoid
plunger moves the dogging means to dogging position each time the
plunger slides the bolt member to projected position, and
comprising surfaces through which the spring pressure of the
plunger acts to hold said dogging means in dogging position, so
that external forces that may be applied to the strike or its bolt
member will be ineffective to release the bolt member for sliding
away from projected position, the solenoid plunger being effective
by said connecting means to move the dogging means to release
position when its plunger moves to retract the bolt member.
7. In an electrically operated strike as defined in claim 6 wherein
said dogging means include a plate member pivotably attached to
said bolt member and a groove disposed in said casing, said plate
member including a shoulder portion engaging said groove when said
dogging means is in said dogging position to transfer forces
exerted on said bolt member in a transverse direction toward said
casing, said plate member being pivotable when said dogging means
is in said release position to effect disengagement of said groove
and said shoulder portion of said plate member to prevent movement
of said plate member with said bolt member toward said retracted
position.
8. In an electrically operated strike as defined in claim 7 wherein
said connecting means includes a pin attached to said solenoid
plunger and movable therewith and an opening disposed in said plate
member and through which said pin extends, said spring pressed
plunger acting to bias said pin to engage said opening to pivotably
bias said plate member in a first direction to position said
shoulder of said plate member in engagement with said groove when
said solenoid is deenergized, said pin engaging with said opening
and effecting rotation of said plate member in a direction opposite
said first direction to remove said shoulder from said groove upon
energization of said solenoid to permit movement of said bolt
member inwardly of said casing.
9. In an electrically operated strike as defined in claim 8 further
including a stop member disposed in said casing and an opening
disposed in said bolt member, said stop member extending into said
opening in said bolt member and acting to limit movement of said
bolt member between said projected position and said retracted
position.
10. In an electrically operated strike as defined in claim 8
wherein said dogging means includes a first plate member attached
to said solenoid plunger and movable therewith, and a second plate
member pivotably mounted on said casing, said second plate member
being disposed between said first plate member and said bolt member
and having a first surface engageable with said bolt member and a
second surface opposite said first surface for engaging with said
first plate member, said first plate member preventing rotation of
said second plate member and acting to hold said first surface of
said second plate member in engagement with said bolt member to
prevent movement of said bolt member toward said retracted position
when said solenoid is deenergized, said first plate member
disengaging with said second plate member to enable said second
plate member to rotate upon energization of said solenoid to enable
said bolt member to move toward said retracted position.
11. In an electrically operated strike as defined in claim 10
further including a stop member attached to said bolt member and an
opening disposed in said casing, said stop member cooperating with
said opening to limit movement of said bolt member between said
projected and retracted positions.
Description
This invention relates to strikes for door locks, and more
particularly to a novel strike of the class that is electrically
operated.
Those skilled in the art will appreciate that the strikes of this
class comprise a retractable catch or strike member that is mounted
on a door frame for engaging the bolt of a lock on the door. The
strike member or catch of the strike is retracted electrically to
permit the door to open, and must resist attempts to retract it by
externally applied force or manipulation. Due to limitations of
space and other design considerations, the amount of operating
power that can be applied is relatively small. Nevertheless, the
strike should operate without fail while also being able to
withstand attacks by unauthorized persons. All of this has caused
serious problems in the design of electrically operated
strikes.
The designers of the prior art generally have thought that an
electrically operated strike should engage the lock bolt through a
catch that rotates. In some instances the prior art merely utilizes
a catch that is rotated to a retracted position by the bolt of the
door lock when the door opens, the catch merely being controlled by
a solenoid operated dog. In other instances, the solenoid acts to
rotate the catch, first moving a dog to release the catch.
Actually, the prior art contains many examples of electrically
operated strikes, but those strikes have not been fully
satisfactory because it has been found that it is possible through
certain procedures, such as "rapping" , to release the catch of the
strike. There is an increasing need for security and many persons
today equip doors with locks of high quality, but the lock
obviously is of little consequence when it is used with a strike
that is not secure. Through the novel concept of my invention, I am
able to construct an electrically operated strike that will operate
extremely well, while also offering a high degree of security.
Accordingly, an object of the present invention, is to provide a
strike with a bolt member that will slide in a linear direction on
the strike casing for coacting with the bolt of the lock. A
solenoid is mounted in the casing and has a spring pressed plunger
that presses the bolt member linearly to a projected position. The
solenoid upon energization slides the bolt member to a retracted
position releasing the bolt of the lock. Dogging means are provided
engaging between the bolt member and the strike casing, and acting
to dog the bolt member each time the member slides to a projected
position. Particularly, the dogging means provides surfaces through
which the spring pressure of the solenoid plunger will act to
maintain the dogging means in dogging position, effectively holding
the bolt member in its projected position despite external forces
that may be applied to the strike.
Preferably, the solenoid is mounted to act in a direction that is
aligned relatively to the linear sliding of the bolt member on the
strike. Moreover, as a further feature the dogging means is formed
with surfaces interlocking so as to accept the external forces that
may be applied to the bolt member, while transferring a part of
those forces in a transverse direction binding parts of the strike
to one another.
Another object of the present invention is to provide a new and
improved electrically operated strike for coacting with a bolt of a
door lock including a casing adapted to be mounted on a door frame,
a bolt member slidable between a projected position engaging the
bolt of the door lock and a retracted position releasing the bolt
of the lock, spring means biasing the bolt member toward the
projected position, electrical means effective when energized to
move the bolt member against the biasing effect of the spring means
to the retracted position, and interconnecting means
interconnecting the bolt member and the electrical means, the
interconnecting means having a dogging position for holding the
bolt member in the projected position, and a release position
providing for movement of the bolt member to the retracted
position, the interconnecting means when in the dogging position
act to transfer external forces applied to the bolt in a transverse
direction toward the casing to render the external forces
ineffective to move the bolt to the retracted position, and wherein
the electrical means effects movement of the interconnecting means
to the release position upon energization of the electrical
means.
Further objects and advantages of the present invention will become
apparent from the following dscription of preferred embodiments
thereof taken in conjunction with the following drawings
wherein:
FIG. 1 is a sectional view of one embodiment of the electric strike
of the present invention;
FIG. 2 is a partially longitudinal sectioned view taken
approximately along the lines 2--2 of FIG. 1 and showing the door
and door bolt in phantom lines;
FIG. 3 is a cross sectional view taken approximately along the line
3--3 of FIG. 1 more fully illustrating the dogging means;
FIG. 4 is a view similar to the view illustrated in FIG. 1 showing
the strike in a retracted condition;
FIG. 5 is a longitudinal sectional view of another embodiment of
the electric strike of the present invention;
FIG. 6 is a cross sectional view taken approximately along the line
6--6 of FIG. 5 more fully illustrating the dogging means; and
FIG. 7 is a longitudinal sectional view similar to the view
illustrated in FIG. 5 and illustrating the bolt of the strike in a
retracted position.
Referring now more particularly to FIG. 1 of the drawings, the
electric door strike 10 includes a bolt member 12 and a casing 14.
The casing 14 is adapted to be mounted in a well known manner in
the frame of a door and the bolt member 12 is positioned so as to
engage the bolt 16 of the door lock, illustrated in phantom lines
in FIG. 2, in a well known manner to prevent relative movement
between the door and the bolt member 12 of the electric strike 10.
The bolt member 12 includes a roller 13 located at one end thereof
to provide for smooth cooperation of the bolt 12 and the bolt 16 of
the door lock. Where the lock is equipped with a deadlatching guard
bolt 16a, the bolt member 12 or its roller 13 will hold guard bolt
16a depressed as will be understood by those skilled in the
art.
A solenoid 18 having a coil 20 and a plunger 22 is provided to
effect movement of the bolt 12 from its projected position shown in
FIG. 1 to its retracted position illustrated in FIG. 4 upon
energization of the solenoid 18. The casing 14 has a screw 15
engaging a slot 17 in bolt member 12 whereby to form a limit stop
for the projecting and retracting movements of member 12. A spring
24 is provided to bias the plunger member 22 outwardly from the
coil 20 of the solenoid 18. The spring 24 engages with an annular
shoulder portion 26 disposed on the plunger member 22 and with a
plate 28 of the casing 14. The spring 24 is an expansion spring and
acts to bias the plunger member 22 outwardly from the coil 20.
Energization of the coil 20 will effect the movement of the plunger
member 22 inwardly thereof against the force of spring 24 to effect
movement of the bolt 12 to its retracted position illustrated in
FIG. 4 as will be more fully described hereinbelow.
Dogging means 30 is provided interconnecting the plunger member 22
and the bolt 12. The dogging means acts to effect movement of the
bolt 12 to its retracted position upon movement of the plunger
member 22 inwardly of the coil 20. The dogging means 30 also
cooperates with the casing 14 to prevent movement of the bolt 12
toward its retracted position when the solenoid 18 is not
energized. The dogging means 30 includes a plate 32 pivotably
supported by a pivot pin 34 which extends through an opening 36 in
the plate 32 and into the bolt member 12. The pivot pin 34 enables
the plate 32 to rotate relative to the bolt 12. The plate 32
includes an elongate opening 38 which engages a pin 40. The pin 40
is fixed to the plunger member 22 and cooperates with the elongate
opening 38 to form a lost motion connection between the plunger 22
and the bolt 12. The pin 40 and a cam surface 39 of opening 38 also
cooperate to form cam means for biasing the dogging means 30 into a
condition preventing movement of the bolt 12 to its retracted
position when the solenoid 18 is not energized. The plate 32
includes a projecting arm portion 42 having a shoulder portion 44
thereon. The shoulder portion 44 is adapted to engage with a groove
46 disposed in the casing 14 when the bolt is in its projected
position.
When the bolt 12 is in its projected position the spring 24 will
act to continually bias the shoulder 44 of the plate 32 into
engagement with the groove 46. The spring 24 exerts a force on the
plunger 22 in a direction parallel to the longitudinal axis of the
plunger 22 and the bolt 12. The force of the spring 24 is
transferred to the plate 32 by the pin 40 which is fixed to the
plunger 22 and which moves therewith. The pin 40 which is biased by
the spring 24, transfers the force of the spring to the cam surface
39. The cam surface 39 and pin 40 act to bias the plate 32 in a
clockwise direction about the pin 34. Thus, the force of the spring
24 acts to continuously bias the plate 32 in a clockwise direction
when the solenoid 18 is not energized to thereby maintain the
shoulder portion 44 of the plate 32 in engagement with the groove
46 in the casing 14.
The shoulder portion 44 cooperates with the groove 46 in the casing
14 to hold the bolt member 12 in its projected position. Thus,
external forces that may tend to effect relative movement of the
bolt 12 toward its retracted position will be applied through pivot
pin 34 to the plate 32, while the spring pressure of plunger 22
acts in an opposed direction through pin 40 on plate 32 to press
shoulder 44 against groove 46 on the casing. Thereby shoulder 44
will transfer the external forces in a transverse direction to the
casing 14. Procedures such as "rapping" , where an external
pressure is maintained on the bolt while blows are applied to the
strike or door frame, will not shift the bolt member 12 from its
projected position, due to the fact that the forces acting will
merely bind the bolt member to its casing.
When the solenoid 18 is energized, the plunger 22 moves against the
force of the spring 24 and the pin 40 first acts on the opening 38
in the plate 32 to pivot the plate 32 in a counterclockwise
direction about the pivot pin 34, thereby removing the shoulder
portion 44 from the groove 46 and permitting a movement of the bolt
12 to its retracted position. It should be apparent that the pin 40
and opening 38 form a lost motion connection which enables the
shoulder 44 to be removed from the groove 46 prior to movement of
the bolt 12 inwardly of the casing 14. After the plate 32 has been
pivoted by the linear movement of the pin 40, the pin 40 engages
with the end portion of the opening 38, as is illustrated in FIG.
4, so that further linear movement of the plunger 22 will effect
movement of the bolt 12 to its retracted position as is shown in
FIG. 4.
The electric door strike 10 will offer very high security requiring
that solenoid 18 be energized before bolt member 12 can move to its
retracted position. The dogging means 30 increase the security of
the device by transferring external forces acting on the bolt 12 in
a transverse direction toward the casing 14. Moreover, the spring
24 cooperates with the opening 38 and pin 40 to continuously urge
the dogging means 30 into a condition in which movement of the bolt
12 to its retracted position cannot be effected unless the solenoid
18 is energized. Even "rapping" of the door frame while applying
pressure to the bolt 12 will be ineffective to compromise the
security of the device.
FIGS. 5 to 7 illustrate a further form of the present invention in
an electric door strike 50. The strike 50 includes a bolt member 52
and a casing 54. A solenoid 56 is provided for effecting linear
sliding movement of the bolt 52 from its projecting position
illustrated in FIG. 5 to its retracted position illustrated in FIG.
7. The solenoid 56 includes coil 62, a plunger 58 and a spring 60.
The spring 60 abuts against a shoulder portion 61 disposed on the
coil 62 of the solenoid 56 and against an annular shoulder portion
64 disposed on the plunger member 58 to bias the plunger member 58
outwardly from the solenoid 56 when the coil 62 is not energized. A
pin 53 is disposed in the bolt 52 and engages a slot 55 inside of
the casing 54, so that slot 55 will form a limit stop for the
sliding of the bolt member 52 and will limit its movements at
projected and retracted positions relative to the casing 54.
Interconnecting the plunger member 58 and the bolt member 52 is
dogging means 66. The dogging means 66 include a plate member 68
attached by a pin 71 to the end of the plunger member 58 so as to
move integrally therewith. The plate member 68 cooperates with a
plate member 70 which is pivotably supported by a pin 72 which is
fixed to the casing 54. The plate member 70 includes a shoulder
portion 74 which engages with a shoulder portion 76 of the plate
member 68, and a shoulder portion 78 which engages a rearward
surface portion 80 of the bolt member 52.
When the bolt member 52 is in its projected position as is
illustrated in FIG. 5 the dogging means 66 prevents movement of the
bolt member 52 toward its retracted position. That will be
understood when it is seen that the plate 68 prevents rotation of
the plate 70 about the pivot pin 72 by the engagement of the
cooperating portions 74 and 76 of the plates 70 and 68
respectively. External forces applied to the bolt member 52 cannot
then effect movement of the bolt member inwardly of the casing 54
due to the fact that the engagement between shoulders 78 and 80 on
the plate 70 and bolt member 52 respectively will hold the bolt
member 52 in its projected position. More in detail the external
forces acting on the bolt member 52 will tend to rotate the plate
70, which will transfer those forces in a transverse direction
through the portions 74 and 76 and the plate 68 to a side wall of
the casing 54. In other words, the side wall of the casing 54 will
effectively oppose a movement of bolt member 52 toward its
retracted position.
Upon energization of the solenoid 56, the plunger member 58 will
move inwardly against the biasing force of the spring 60. Inward
motion of the plunger member 58 will effect movement of the plate
68 relative to the bolt member 52 until the plate 68 engages with
the pins 82 disposed on the bolt member 52 as is shown in FIG. 7.
When the plate 68 has engaged with the pins 82, the shoulder
portions 74 and 76 of the plates 70 and 68, respectively, will no
longer be in engagement and the plate 70 will be free to rotate
about the pivot pin 72. Further movement of the plunger 58 inwardly
of the solenoid 56 will effect movement of the bolt member 52 due
to the fact that the plate 70 will no longer oppose retracting
movement of the bolt member 52.
It should be apparent that the pins 82 and the plate 68 form a lost
motion connection in that initial movement of the plate 68 and
plunger 58 will not effect movement of the bolt member 52. After
the plunger 58 has moved so that the plate 68 has moved to engage
with the pins 82, further movement of the plunger member 58
inwardly of the solenoid 56 will effect movement of the bolt member
52. Movement of the bolt 52 toward the retracted position will
effect pivotal movement of the plate 72 by a force exerted on the
shoulder portion 78 thereof by the surface 80 of the bolt member
52, as is illustrated in FIG. 7.
It should be apparent that the embodiment of the invention
illustrated in FIGS. 5-7 comprises dogging means 66 which transfers
external forces that may be exerted on the bolt member 52, when the
solenoid is not energized, in a transverse direction to the casing
54 of the electric strike 50. The dogging means 66 thus will
prevent movement of the bolt 52 to its retracted position at all
times when the solenoid 56 is not energized. The embodiment
illustrated in FIGS. 5-7 will utilize the contribution of the
present invention to offer a high degree of security, in much the
same way as has been described in connection with FIGS. 1-4.
From the foregoing, it should be apparent that the concept of the
invention makes it possible to construct an electric strike that
will operate very well, while being able to resist attack much
better than has been the case with the electric strikes of the
prior art. It is believed that the very considerable value of the
invention will be understood, and that its merits will be fully
appreciated by those skilled in the art.
* * * * *