U.S. patent application number 15/814633 was filed with the patent office on 2018-03-15 for actuator for an elevator brake.
The applicant listed for this patent is Inventio AG. Invention is credited to Josef Husmann.
Application Number | 20180072536 15/814633 |
Document ID | / |
Family ID | 47356034 |
Filed Date | 2018-03-15 |
United States Patent
Application |
20180072536 |
Kind Code |
A1 |
Husmann; Josef |
March 15, 2018 |
ACTUATOR FOR AN ELEVATOR BRAKE
Abstract
An elevator installation braking device is actuated and reset by
an electromechanical actuator including an energy store, a
retaining device, a resetting device and at least one connecting
element for connecting the actuator to the elevator brake. The
resetting device retains the connecting element, via the retaining
device and counter to the action of the energy store, in a first
operating position, corresponding to a standby position of the
brake, or guides the actuator back into this position. The energy
store acts as required, upon release of the retaining device, on
the connecting element to actuate the brake and to bring it into a
corresponding engagement position. The resetting device has a
recoil-prevention device to relieve recoil forces. The energy store
can have a stop buffer to reduce the force impact when the energy
store strikes an end position.
Inventors: |
Husmann; Josef; (Luzern,
CH) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Inventio AG |
Hergiswil |
|
CH |
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|
Family ID: |
47356034 |
Appl. No.: |
15/814633 |
Filed: |
November 16, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14358264 |
May 15, 2014 |
9850094 |
|
|
PCT/EP2012/074702 |
Dec 6, 2012 |
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15814633 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B66B 5/18 20130101; F16D
65/28 20130101; F16D 2121/26 20130101; B66B 5/16 20130101 |
International
Class: |
B66B 5/16 20060101
B66B005/16; F16D 65/28 20060101 F16D065/28; B66B 5/18 20060101
B66B005/18 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 2011 |
EP |
11194963.2 |
Claims
1. An electromechanical actuator for attachment to a travel body of
an elevator installation and for actuating an elevator brake of the
travel body, the actuator comprising: an energy store; a retaining
device; a resetting device; a return lever; and a connecting
element connecting the actuator with the elevator brake, wherein
the retaining device is arranged on the return lever and the return
lever is connected to the resetting device, whereby the connection
of the return lever to the resetting device includes a play,
wherein the resetting device acts, through the return lever and the
retaining device, on the energy store and the connecting element to
retain and/or return the energy store and the connecting element
respectively to a first operating position corresponding with a
readiness setting of the brake, wherein the energy store upon
release of the retaining device acts on the connecting element to
actuate the brake into an applied setting, and wherein a counter
spring acts on the return lever to draw the return lever toward a
first end of the play and forming thereby a spring-loaded recoil
prevention device and relieving the resetting device of recoil
forces.
2. The actuator according to claim 1 wherein the play in the
connection of the return lever to the resetting device is formed by
a guide pin arranged in a slot and the first end of the play is
defined by an end of the slot.
3. The actuator according to claim 2 wherein the resetting device
includes a return carriage and the slot is formed in the return
carriage for co-operating with the guide pin arranged on the return
lever.
4. The actuator according to claim 3 wherein the resetting device
includes a spindle drive with a spindle nut arranged in the return
carriage, a return spindle engaging the spindle nut being driven by
a geared motor for forward and backward movement of the return
carriage.
5. The actuator according to claim 3 wherein the counterspring
urges the return lever together with the retaining device and the
guide pin into a position corresponding with a force transmission
direction of the recoil prevent device, and wherein a force action
of the counterspring is small compared with a force action of the
energy store.
6. The actuator according to claim 1 wherein the resetting device
for resetting and retaining the actuator in the first operating
position corresponding with the readiness setting of the brake acts
on the retaining device by the recoil prevention device, wherein
the recoil prevention device is constructed to transmit a force
merely in one direction.
7. The actuator according to claim 1 wherein the energy store acts
on the connecting element by a trigger lever and the trigger lever
is held in a readiness setting at a connecting point of a retaining
electromagnet arranged at the retaining device, wherein a fulcrum
of the return lever and a fulcrum of the trigger lever are arranged
on a common axis so that a pivot radius of the connecting point of
the trigger lever and a retaining point of the retaining device are
the same.
8. The actuator according to claim 7 wherein the connecting element
is guided by the fulcrum of the trigger lever and the connecting
element includes a connecting strap connected with the fulcrum of
the trigger lever.
9. The actuator according to claim 1 wherein the energy store
includes a first part, a second part and a first spring with a
first spring tensioning force, wherein the first spring is
tensioned between the first and second parts, wherein the first
part and the second part are displaceable relative to one another
over a displacement range and the displacement range is bounded by
at least one of a front abutment and a rear abutment and the at
least one abutment ensures a minimum first spring tensioning force,
wherein an impact buffer is integrated into one of the first and
second parts, and wherein the one of the first and second parts
includes a first sub-member and a second sub-member and the impact
buffer connects the first sub-member with the second
sub-member.
10. The actuator according to claim 9 wherein the impact buffer
includes a spring arrangement with a second spring tensioning
force, which spring arrangement connects the first sub-member with
the second sub-member and holds the first and second sub-members
together, and wherein the second spring tensioning force is set to
a greater value than the first spring tensioning force.
11. The actuator according to claim 10 wherein one of the first and
second sub-members includes a threaded plate and another one of the
first and second sub-members includes an impact plate and the
spring arrangement tightens the impact plate relative to the
threaded plate by a draw screw.
12. The actuator according to claim 9 wherein the first part is
connected with the connecting element by a trigger lever, and the
second part is connected with an actuator support, and wherein the
second part includes a guide for the first part so that the first
part is guided in and displaceable relative the second part.
13. The actuator according to claim 9 wherein the first part
includes a further slot that co-operates with a guide pin of the
second part and which determines the front and rear abutments that
form the displacement range.
14. The actuator according to claim 9 wherein the first and second
parts are pivotably connected by one of a trigger lever, the
connecting element and an actuator support.
15. An elevator installation with the travel body being one of an
elevator car and a counterweight, the travel body having at least
two of the elevator brakes and the electromechanical actuator
according to claim 15 coupled to the elevator brakes.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of the co-pending U.S.
patent application Ser. No. 14/358,264 filed May 15, 2014, which
application is a 371 of PCT/EP2012/074702 filed Dec. 6, 2012, which
application claims the benefit of European patent application
Serial No. 11194963.2 filed Dec. 21, 2011.
FIELD
[0002] The invention relates to an actuator for actuating an
elevator brake.
BACKGROUND
[0003] The elevator installation is installed in a building. It
essentially consists of a car which is connected by way of support
means with a counterweight or with a second car. The car is moved
along substantially vertical guide rails by means of a drive which
selectably acts on the support means or directly on the car or the
counterweight. The elevator installation is used to convey persons
and goods within the building over individual or several
floors.
[0004] The elevator installation includes devices in order to
safeguard the elevator car or also a counterweight in the case of
failure of the drive or support means or in the case of other
faulty behavior. For that purpose, use is usually made of elevator
brakes which when required can brake the elevator car or the
counterweight on the guide rails. These elevator brakes are
increasingly actuated by electromechanical actuators.
[0005] An actuator of that kind is known from International
Application WO2011/113754, which can actuate a pair of elevator
brakes synchronously. This actuator counteracts possibly arising
impact and shock loads by use of damping devices such as hydraulic,
pneumatic or magnetic damping devices. Impact noise and material
loads are thus reduced. It is unsatisfactory in that regard that
actuation speed is slowed down by the use of damping devices of
that kind.
SUMMARY
[0006] The invention has the object of providing an actuator which
can accept impact and shock loads without negative influence on
actuation speed.
[0007] In one embodiment an electromagnetic actuator for attachment
to an elevator car of an elevator installation is provided. The
electromechanical actuator is provided for actuation of a brake.
For that purpose it includes an energy store, a retaining device, a
resetting device and at least one connecting device for connecting
the actuator with the brake or the brake equipment. The resetting
device serves for resetting the electromechanical actuator into a
first operating position corresponding with a readiness setting of
the brake. It is also intended to transmit a retaining force for
retaining the brake in the first operating position corresponding
with the readiness setting. The resetting device in that case
preferably acts, for retaining as well as resetting, on the energy
store and the connecting element by way of the retaining device.
The energy store for its part is so arranged that when required and
when the retaining device is released it can act on the connecting
element in order to actuate the brake and bring it into a
corresponding applied setting.
[0008] Advantageously, the energy store acts on the connecting
element by way of a trigger lever. This trigger lever is held in
the readiness setting at a connecting point of a retaining
electromagnet arranged at the retaining device. The retaining
device is preferably arranged on a return lever, and a fulcrum of
the return lever and a fulcrum of the trigger lever are arranged on
a common axis. It is thus ensured that a pivot radius of the
connecting point of the retaining device and of the trigger lever
are the same. The connecting points can thus be moved synchronously
with respect to one another in simple manner.
[0009] Advantageously, the connecting element for connecting the
actuator with the brake is guided by way of the fulcrum of the
trigger lever. The connecting element for that purpose includes a
connecting strap which is connected on the one hand with the
fulcrum of the trigger lever and on the other hand with the brake
or brakes.
[0010] The resetting device of the electromechanical actuator
advantageously includes recoil prevention means, preferably
spring-loaded recoil prevention means, which relieves the resetting
device of recoil forces. This is advantageous and useful, since the
brakes can on occasion press back the connecting element of the
electromechanical actuator. This can happen during a resetting
process or it can also be the case that the connecting element is
positioned in an intermediate position if, for example, a brake is
not completely applied, since the elevator car has already come to
a stop beforehand. In such cases the recoil prevention means
prevents overloading or even damage of the resetting device and the
entire actuator.
[0011] Advantageously, the energy store includes an impact buffer
which reduces force shock when the energy store impinges in an end
position. This is advantageous, since the energy store has stored a
large amount of energy. In the usual case this energy is
transmitted to the brake by way of appropriate connecting rods for
actuation of the brake. In special cases, if, for example, a brake
is not yet installed or when operations are carried out at the time
of placing into service, this energy cannot be transmitted. The
impact buffer in cases of that kind prevents overloading of
material.
[0012] Advantageously, the resetting device, for the purpose of
resetting the actuator into and retaining it in the first operating
position corresponding with the readiness setting of the brake,
acts on the retaining device by way of the recoil prevention means.
The recoil prevention means is constructed for transmitting force
in merely one direction. The recoil prevention means of the
resetting device thus ensures that the resetting device is not
subjected to uncontrolled loading. Insofar as, as previously
stated, the connecting element is in an intermediate position it is
thus ensured that the resetting device can operate and transmit
force only in one line of action of force. Depending on the form of
construction of the actuator and the resetting device this
direction can be pulling or pushing. The resetting device is
preferably designed for transmitting a tension force.
[0013] Advantageously, the resetting device is connected with the
retaining device by way of a return carriage and this return
carriage includes the recoil prevention means. For that purpose,
the recoil prevention means includes, for example, a slot which
co-operates with a guide pin integrated in the retaining device. An
embodiment of that kind is advantageous with respect to production.
In addition, the resetting device advantageously includes a spindle
drive with a spindle nut. The spindle nut is arranged in the return
carriage. A geared motor drives a return spindle co-operating with
the spindle nut. The return carriage can thus be moved back and
forth.
[0014] Advantageously, the retaining device is connected with a
counterspring, which urges the retaining device together with the
guide pin into the position corresponding with the first direction
of the recoil prevention means. The recoil prevention means is thus
a spring-loaded recoil prevention means. The force effect of the
counterspring is in that case small by comparison with the force
effect of the energy store.
[0015] The energy store of the electromechanical actuator is
advantageously connected with the connecting element by way of a
trigger lever. The energy store accordingly acts on this connecting
element by way of the trigger lever. This trigger lever includes a
connecting point. The trigger lever is held in the readiness
setting at this connecting point by a retaining electromagnet
arranged at the retaining device. The retaining device is in turn
arranged on a return lever. A fulcrum of the return lever and a
fulcrum of the trigger lever are arranged on a common axis or shaft
so that a pivot radius of the connecting point of the retaining
device and that of the trigger lever are the same. This is
advantageous, since it is ensured by this arrangement that in the
case of return or resetting of the trigger lever into the readiness
setting the retaining device transits a path identical to the
connecting point of the trigger lever.
[0016] The connecting element is advantageously guided by way of
the fulcrum of the trigger lever and the connecting element further
includes a connecting strap which is connected with the fulcrum of
the trigger lever. The connecting element is preferably a shaft,
which, for example, is rotatably or pivotably mounted in a housing
of the actuator and to which the trigger lever and the connecting
strap are secured. This shaft forms the fulcrum of the trigger
lever. Use of a connecting strap of that kind is advantageous,
since adaptation to required actuation paths can be carried out by
the geometric form of this strap. The actuator itself can thus be
left at that; it only has to be adapted to the connecting
lever.
[0017] Advantageously, the energy store of the electromechanical
actuator, in addition to the previous solutions or also as an
alternative design, includes the impact buffer. For that purpose
the energy store includes, for example, a first part, a second part
and a first spring with a first spring stressing force. In that
case, this first spring is stressed between the first part and the
second part. The first part and the second part are assembled
together to be displaceable over a displacement range. The
displacement range is bounded by at least one first, i.e. front,
abutment or second, i.e. rear, abutment. This at least one abutment
is used for ensuring a minimum first spring stressing force. The
energy store is correspondingly so assembled and stressed that it
can, over a displacement range, be compressed against the force of
the first spring, wherein the at least one abutment determines a
minimum biasing force.
[0018] The impact buffer is integrated in the first or second part.
The relevant first part or second part additionally includes a
first sub-member and a second sub-member and the impact buffer
connects the first sub-member with the second sub-member. It is
thus achieved that a buffer zone able to absorb impact peaks in the
energy store can be provided.
[0019] The aforesaid impact buffer advantageously includes a spring
arrangement. This spring arrangement is biased by a second spring
stressing force, which connects and holds together the first
sub-member and the second sub-member. The second spring stressing
force is set to a value greater than that of the first spring
stressing force. The two sub-members are consequently so held
together by means of the spring arrangement that they deflect only
in the case of higher dynamic forces such as occur in the event of
impact of the energy store on an abutment. This is advantageous,
because the energy store in the normal actuating process can
respond rapidly, since no damping components are effective. An
impact is effectively absorbed merely in the case of impinging of
the energy store on its end abutment.
[0020] Advantageously, one of the two first and second sub-members
includes a threaded plate and the other one of the two sub-members
includes an impact plate. The spring arrangement biases the impact
plate with respect to the threaded plate by means of a tightening
screw. This makes possible economic joining together of the two
parts and the biasing force of the spring arrangement can thus be
set in simple manner. The spring arrangement preferably comprises a
plate spring column. This is a laminar arrangement of individual
plate springs. High biasing force can thus be achieved.
[0021] Advantageously, the first part is connected with the
connecting element and the second part is correspondingly connected
with the housing of the actuator or with an actuator support. The
first part includes a guide for the second part so that the second
part is guided in the first part to be displaceable.
[0022] The first part advantageously includes a further slot, which
co-operates with a guide pin of the second part. This further slot,
together with the guide pin, determines the first and second, or
front and rear, abutments, which abutments define the displacement
range. The energy store itself can thus be simply assembled within
the scope of preassembly.
[0023] Advantageously, the first and second parts are pivotably
connected with the connecting element or with the housing of the
actuator or an actuator support. The energy store thus ideally
follows a movement of the connecting element or a trigger lever
guiding the connecting element. It can execute required pivot
movements without hindrance.
[0024] Overall, an electromechanical actuator with the
afore-described features is suitable for effectively absorbing
possible shock loads, which arise both during resetting of the
actuator and during triggering of the actuator, and thus preventing
damage of the actuator.
DESCRIPTION OF THE DRAWINGS
[0025] An exemplifying embodiment with advantageous features is
explained in the following by way of examples and schematic
embodiments, in which:
[0026] FIG. 1 shows a schematic view of an elevator installation in
side view,
[0027] FIG. 2 shows a schematic view of the elevator installation
in cross-section,
[0028] FIG. 3 shows an arrangement with two elevator brakes and
actuators,
[0029] FIG. 4 shows an actuator in a perspective view without
cover,
[0030] FIG. 5 shows a plan view of an actuator in a readiness
setting,
[0031] FIG. 6 shows a plan view of an actuator in an actuated
setting,
[0032] FIG. 7 shows a plan view of an actuator in a restoring
situation,
[0033] FIG. 8 shows a function view of an actuator in recoil
prevention,
[0034] FIG. 9 shows a plan view of an actuator in buffered
setting,
[0035] FIG. 10 shows a detail view of an energy store in unbuffered
setting and
[0036] FIG. 11 shows a detail view of an energy store in buffered
setting.
[0037] The same reference numerals are used for equivalent parts
over all figures.
DETAILED DESCRIPTION
[0038] FIG. 1 shows an elevator installation 1 in an overall view.
The elevator installation 1 is installed in a building and serves
for transport of persons or goods within the building. The elevator
installation includes an elevator car 2, which can move upwardly
and downwardly along guide rails 6. The elevator car 2 is for that
purpose provided with guide shoes 8 which guide the elevator car as
accurately as possible along a predetermined travel path. The
elevator car 2 is accessible from the building by way of shaft
doors 12. A drive 5 serves for driving and stopping the elevator
car 2. The drive 5 is, for example, arranged in the upper region of
the building and the car 2 hangs at the drive 5 by support means 4,
for example support cables or support belts. The support means 4
are guided over the drive 5 to a counterweight 3. The counterweight
compensates for a mass proportion of the elevator car 2 so that the
drive 5 for the main part merely has to compensate for an imbalance
between car 2 and counterweight 3. In the example, the drive 5 is
arranged in the upper region of the building. It could obviously
also be arranged at a different location in the building or in the
region of the car 2 or the counterweight 3.
[0039] The elevator installation 1 is controlled by an elevator
control 10. The elevator control 10 receives user requests,
optimizes the operating sequence of the elevator installation and
controls the drive 5.
[0040] The elevator car 2 and, if required, also the counterweight
3 are additionally equipped with at least one brake suitable for
safeguarding and/or retarding the elevator car 2 in the case of an
unexpected movement or in the case of excess speed. In the example,
two identically constructed brakes 13, 13' are attached to the
travel body 2, 3 on either side thereof. The elevator brakes 13,
13' are, in the example, arranged below the car 2 and are actuable
by an actuator 20 arranged between the two brakes 13, 13'. The
actuator is electrically activated by a brake control 11. This
brake control 11 preferably also includes an electronic speed or
travel path limiter, which monitors travel movements of the
elevator car 2. A mechanical speed limiter, such as is usually
used, can accordingly be eliminated.
[0041] FIG. 2 shows the elevator installation of FIG. 1 in a
schematic plan view. The brake system includes the two elevator
brakes 13, 13'. The two elevator brakes 13, 13' are, as illustrated
in detail in FIG. 3, coupled with the actuator 20 by way of
adjusters 14, 14' and connecting rods 9, 9' so that the two
elevator brakes 13, 13' can be constrainedly actuated together. An
unintended braking at one side can thus be avoided and the two
elevator brakes 13, 13' are actuable in simple manner by way of the
common actuating unit 20, which is controlled by the brake control
11. The two elevator brakes 13, 13' are preferably constructed
identically or in mirror image and they act on the brake rails 7
arranged at the two sides of the car 2. In the detail explanations
with respect to the elevator brake only one elevator brake 13 is
mentioned in the following, but the left-hand and right-hand
elevator brakes are always signified. The brake rails 7 in the
example are identical with the guide rails 6.
[0042] FIGS. 4 and 5 show an actuator 20 in the so-called readiness
setting. As readiness setting there is to be understood that the
actuator retains the brakes in open setting so that the travel
body, or the car or the counterweight, can be moved. The actuator
is attached to an actuator support 21 or it includes the actuator
support 21. Auxiliary means 37, which inter alia are provided for
fastening a cover 24 (not illustrated in the drawings), are
preferably arranged on the actuator support 21. The actuator
support 21 is provided with mounting elements 22, which allow the
actuator 20 to be so arranged at the travel body that it is
provided with lateral freedom of movement. The actuator 20 can thus
be arranged between two brakes 13, 13' and can when required draw
adjusters 14, 14' of the brakes towards one another (or push them
away from one another). The mounting elements 22, for example slide
pins, make lateral compensation possible. An actuator holder 23 in
that case limits the lateral slide path.
[0043] A trigger lever 27 is arranged on the actuator support 21.
The trigger lever 27 is pivotable about a fulcrum determined by a
connecting element 26. By way of example, a connecting strap 25 is
connected with the trigger lever 27 by way of the connecting
element 26 and the connecting strap 25 enables connection with the
brakes 13, 13' by way of appropriate connecting rods 9, 9'.
Pivoting of the trigger lever 27 thus causes pivoting of the
connecting strap 25 and thereby causes the corresponding connecting
rods 9, 9' to be drawn together or pushed apart. In the example,
the connecting element 26 is a shaft which is rotatably or
pivotably mounted in the actuator support 21 of the actuator and to
which the trigger lever 27 and the connecting strap 25 are secured.
This shaft forms the fulcrum of the trigger lever 27. An energy
store 40 acts on one end of the trigger lever 27 and can introduce
force into the trigger lever 27 by way of a front connecting point
35. This force is introduced into the actuator support 21 by way of
a rear connecting point 36. The energy store 40 seeks to pivot the
trigger lever 27. In the readiness setting of the actuator 20 this
is prevented by a retaining device 30, which engages another end of
the trigger lever 27 and restrains the trigger lever 27 against the
force of the energy store 40. The retaining device 30 consists of a
latch 29, which fixes a connecting point 28 of the trigger lever
27. The latch 29 is kept in the readiness setting by an
electromagnet 31 (FIGS. 4 and 5).
[0044] When required, the brake control 11 switches the
electromagnet 31 to be free of current, as is apparent from FIG. 6.
The latch 29 can thereby be urged away from the connecting point 28
or from possible spring elements and the energy store 40 can
correspondingly actuate the trigger lever and obviously the
connected connecting element 26 and connecting strap 25, etc.
[0045] The energy store 40 includes an impact buffer 53. The impact
buffer 53 has the purpose of absorbing or deflecting a possible
shock when the energy store reaches its end abutment or the rear
abutment. The construction of an exemplifying energy store 40 with
impact buffer is illustrated in FIGS. 10 and 11.
[0046] In the illustrated example the energy store 40 consists of a
first part 41 and a second part 42. These two parts 41 and 42 are
urged apart by a first spring 43. The spring 43 generates the
actual force of the energy store 40 for actuation of the brakes.
The two parts 41, 42 are held together by means of a guide pin 57.
Disposed for that purpose in the first part is a slot 51 which in
conjunction with the guide pin 57 integrated in the second part 42
defines a displacement range between the first part 41 and the
second part 42. If the energy store in the actuator is stressed,
the trigger lever compresses the energy store and the guide pin 57
is in the vicinity of the front abutment 52v of the slot 51. FIG.
10 shows the energy store in this stressed state. If the trigger
lever 27 is released, the first spring 43 relaxes or it expands the
energy store and the guide pin 57 migrates in the direction of a
rear abutment 52h in the slot 51. If now an actuator is triggered
without, for example, a brake being connected, whether it be for
test or modification purposes, the guide pin impinges at high
trigger speed and force at the end abutment or the rear abutment
52h. That can to lead to destruction of the actuator. In order to
avoid this the impact buffer 53 is integrated in the first part 41.
For that purpose the first part 41 includes a first sub-member 44
and a second sub-member 48. The two sub-members are pressed
together by means of a resilient body, in the example a spring
arrangement 54. This pressing together takes place by a compression
force which is greater than the force of the compressed first
spring 43. If now the guide pin 57 impinges on the rear abutment
52h of the slot 51--see FIGS. 9 and 11--when the first spring 43 is
relaxed the first sub-member can move further within the scope of a
spring stroke L of the spring arrangement 54 and the impact load in
the actuator is thereby reduced.
[0047] In the embodiment, the second sub-member 48 includes a
second guide tube 49, which is slidably mounted in the second part
42 and is held by way of the guide pin 57. The second part 42 is
secured, preferably pivotably, in the actuator 20 by way of the
rear connecting point 36. The second part 42 includes a receiving
region for the first spring 43. In the embodiment the guide pin 57
and the rear connecting point are realized by the same component.
Additionally disposed in the second sub-member 48 is a thread, for
example in the form of a threaded plate 50, for connection of the
first sub-member 44.
[0048] The first sub-member 44 similarly includes a first guide
tube 58, which is provided for connection with the trigger lever 27
and which has a corresponding receiving zone 58a for accepting the
spring force of the spring 43. The receiving zone 58a and the first
guide tube 58 can obviously be of single-part or multi-part
construction. The first sub-member 44 includes an impact plate 47.
The impact plate 47 is biased by way of the spring arrangement 54
with respect to the second sub-member 48 by a draw screw 55 as well
as possible thrust washers 56. Advantageously, a biasing force of
the spring arrangement 54 is set by means of a spring tube 46. The
spring arrangement 54 is preferably assembled in the form of a
column of plate springs.
[0049] If the actuator is in the actuated setting as illustrated in
FIG. 6, the actuator can be reset by means of a resetting device
60. The resetting device 60 includes a return lever 32. The return
lever 32 is, in the example, arranged to be pivotable about the
fulcrum defined by the connecting element 26. The return lever 32
and the trigger lever 27 are thus arranged to be pivotable about
the same fulcrum and they can thus follow the same pivot radius R.
The retaining device 30 together with electromagnet 31 and latch 29
is arranged on the return lever 32. The return lever 32 is
connected by way of a guide pin 63 with a return carriage 65, which
can be moved forwards and back by means of spindle drive 64.
[0050] The spindle drive 64 includes a geared motor 68 which can
drive a return spindle 67. A spindle nut 66 is arranged in the
return carriage 65. The spindle nut 66 and thus the return carriage
65 are therefore moved by rotating the return spindle 67. The
resetting device 60 or the actuator 20 includes recoil prevention
means or device 61 in order to protect the resetting device 60 and
the connected parts from overloading. Disposed in the return
carriage 65 for that purpose is a slot 62--see FIGS. 7 and 8--which
defines a play tolerance between return carriage 65 and return
lever 32 with guide pins 63. A counterspring 34 draws the return
lever 32 towards a first end of the range of play defined by the
slot 62. The counterspring 34 is stressed by way of a counter-pin
33 arranged at the actuator support 21.
[0051] For the purpose of resetting, the electromagnet 31 is now
preferably activated and the spindle drive 64 moves the return
lever 32, together with the retaining device 30, through the pivot
radius R with respect to the trigger lever 27 or the latch 29 with
respect to the connecting point 28. The return lever 32 is in that
case correspondingly drawn by the counterspring 34. As soon as the
retaining latch 29 has reached the connecting point 28 the
connecting point 28 presses the retaining latch 29 back and the
electromagnet 31 can retentively hold the latch 29.
[0052] Through return of the return carriage the actuator can now
be stressed in the operating setting shown in FIG. 5. The resetting
device 60 is of sufficiently strong design in order to stress the
energy store 40. The travel paths of the return carriage 65 are
obviously controlled by way of switches (not illustrated).
[0053] The combination of the slot 62 and the return carriage
together with the counterspring 34 now forms the recoil prevention
means 61 for the actuator 20. It is a spring-loaded recoil
prevention means. If in the course of resetting an external recoil
force is exerted on the connecting strap 25, the trigger arm 27 can
press back the return lever 32 by way of the resetting device 60 in
that--see FIG. 8--the guide pin 63 is displaced in the slot 62 of
the return carriage 65 against the force of the counterspring 35.
This is achieved through the fact that the recoil prevention means
61 is designed to transmit force merely in a retraction direction,
thus only in the direction of a force line of action, and to enable
play in the other direction. The spindle drive 64 and therefore the
resetting device are thus effectively protected, since external
forces cannot cause overloading of the resetting device 60.
Correspondingly, connected parts and levers are also protected from
overloading.
[0054] The illustrated embodiments can be varied by the expert. For
example, use can also be made of a pneumatic device instead of the
spindle drive. The recoil prevention means, which in the example is
arranged by means of slot and guide pin between return lever and
return carriage, could also be in the region of the fastening of
the spindle drive in the actuator support.
[0055] In the present description the energy store 40 and the
recoil prevention means or device 61 are used together in the
actuator 20. However, it is also possible to employ and use the two
items independently. The energy store protected by the impact
buffer can be used for numerous purposes where protection of energy
store from destruction is concerned. However, the best effect is
achieved by use of both items, since an actuator is thus
comprehensively protected.
[0056] In accordance with the provisions of the patent statutes,
the present invention has been described in what is considered to
represent its preferred embodiment. However, it should be noted
that the invention can be practiced otherwise than as specifically
illustrated and described without departing from its spirit or
scope.
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