[0001] The present invention relates to a closure opening mechanism. Specifically, the present
invention relates to a door panic or emergency exit device which is arranged to latch
and unlatch a door via a primary and, selectively, a secondary latching mechanism.
[0002] Exits such as emergency exits to industrial buildings comprise doors which can be
opened in an emergency by the use of a panic exit device or an emergency exit device.
Such doors have an open state (when the door can be freely opened), a latched state
(when the door is secured relative to the door frame but readily openable with an
exit control) and a locked state in which the door cannot be readily opened without
the aid of e.g. a key.
[0003] A typical panic or emergency exit will always only be latched from the inside- that
is to say exit is always possible from the inside. Typically, the panic or emergency
exit mechanism will comprise a retractable bolt in the door which engages with a keep
on the frame to latch the door. A panic exit device control such as a push bar or
touch bar (typically spanning the width of the door), or an emergency exit device
control such as a touch pad positioned on the inside surface of the door will allow
the user to retract the bolt to unlatch and open the door. Such devices commonly comprise
large surfaces to aid visibility and usability. Such devices are often configured
to automatically relatch once the door is pushed into the closed position. This is
often achieved with the use of an angled bolt which is forced to retract as it passes
the door frame and resiles to an extended position once it is opposite the keep.
[0004] Typical exits featuring emergency exit or panic exit devices will open outwards from
the building such that opening can be achieved simply by pushing on the exit control
to both unlatch and open the door. Often, these exits will only be openable from the
inside- i.e. there is no method of bolt control on the exterior surface of the door.
This is a security measure to prevent unauthorised access.
[0005] Some exits featuring emergency exit or panic exit devices however have outside access
devices, through the use of which the latch can be retracted to open the door. Often,
these outside access devices require locking arrangements to prevent unauthorised
access. Such locking arrangements act on the mechanism of the outside access device
to prevent it moving the bolt- e.g. by disconnecting a mechanism between the handle
and bolt or simply preventing movement of the handle (movement of the bolt will not
be restrained as the door still needs to be openable from a latched state from the
inside). It should be noted that unlike traditional locks, the door must remain only
in the latched state from the inside- i.e. the door must remain openable by activation
of the emergency exit control and must not be locked from the inside.
[0006] Exits featuring emergency exit or panic exit devices have traditionally been constructed
from timber or metal framed doors, which provide a sufficiently stiff and secure barrier
to unauthorised entry with a single, primary, latch bolt. PVC (polyvinyl chloride)
and uPVC (unplasticised polyvinyl chloride) - which will be collectively referred
to hereinafter as "PVC" - are increasingly being used as an alternative to timber
and metal frames. PVC closures are generally lighter, cheaper to manufacture and less
easily susceptible to corrosion and damp effects than their metal and timber counterparts.
They are also more common in the more domestic industrial setting such as hospices,
care homes and student or holiday accommodation.
[0007] One problem with PVC doors is that they are less stiff than timber or metal doors.
This makes it easier to force PVC doors open, as they can be deformed sufficiently
to insert a lever between the door and frame and prize the door open.
[0008] It is known to provide standard (non-emergency) PVC doors and closures with multi-point
locking mechanisms, which comprise a secondary locking system having a number of separately
actuable lock bolts spaced apart from the primary lock mechanism. Such multi-point
mechanisms provide better security than the single lock bolt systems by anchoring
the door to the frame at several positions.
[0009] One problem with such mechanisms is that they require actuation to secure the secondary
locking mechanism. To provide the required level of security these secondary locking
mechanisms do not automatically relatch when the door is closed. Instead, the actuation
is brought about by the turning of a key (usually through several rotations) which
advances the bolts of the secondary locking mechanism into their keeps. Other types
of secondary locking mechanisms are also known, for example sliding esplagnottes and
rotating hooks which provide an increased level of security over simple bolts.
[0010] If multi-point mechanisms are used in emergency exits to latch PVC doors, the secondary
latching mechanism must be actuable by the emergency exit control to unlatch and open
the door in an emergency. It is also a requirement that the secondary latching mechanism
securely holds the door in place to prevent unauthorised access. As such it is desirable
to retain the form of the secondary locking mechanism of the non-emergency exit version
(e.g. sliding esplagnotte, hook formations). Unlike the primary latch bolt, such secondary
latch formations cannot be simply be automatically relatched upon closure of the door
and require manual actuation to set them to the latched position.
[0011] This has been achieved with the use of a multi-turn key or knob of which several
rotations are required to actuate the secondary latching mechanism.
[0012] As such the door has three conditions- open, latched (in which only the primary latch
bolt is engaged it its keep) and superlatched (in which the primary and secondary
latch bolts are engaged). The superlatched condition can only be achieved by turning
the key or knob several times to engage the secondary latch mechanism.
[0013] A problem with this system is that several turns of a key or knob are required to
superlatch the door, which takes time and which is prone to insufficient latching
as the user may think that the secondary locking mechanism has engaged before it actually
has. Also, relatively little torque can be transferred to the secondary locking mechanism
via a key or knob due to their small radii. As such, if the alignment between the
secondary locking mechanism and the frame is slightly off, it may be very difficult
to superlatch the door.
[0014] A problem with panic or emergency exit devices is that the moving parts of the device
(often between the control and the housing) can create a gap in which user's fingers
can be trapped. As such the range of movement of the control is limited to prevent
gaps appearing in which fingers can be trapped.
[0015] It is an aim of the present invention to overcome or at least mitigate at least one
of the above problems.
[0016] According to a first aspect of the invention there is provided a panic or emergency
exit device for opening a closure,
the closure having a primary latch movable between an open condition and a latched
condition and a secondary latch movable between an open condition and a latched condition,
the emergency exit device having a first control manually actuable to move the primary
latch and the secondary latch from the latched condition to the open condition, wherein;
the first control is manually actuable to move the secondary latch from the open condition
to the latched condition to supplement the primary latch.
[0017] By integrating control of the secondary locking mechanism into the control (e.g.
a push bar), actuation of the secondary locking mechanism is made easier. The control
is generally of significant size, and as such the secondary locking mechanism can
be latched with a single motion. The provision of a separate control (e.g. a key or
knob) is not required and as such operation of the door latching mechanisms is simpler.
[0018] An example panic or emergency exit device in accordance with the present invention
will now be described with reference to the accompanying drawings in which:
Figure 1 is a perspective view of the inside of a door comprising a panic exit device
in accordance with the present invention,
Figure 2 is an exploded side view of a part of the panic exit device of figure 1,
Figure 3 is an exploded perspective view of a part of the panic exit device of figure
1,
Figure 3a is a perspective view of a part of the panic exit device of figure 1,
Figure 4 is a detailed exploded perspective view of a part of the panic exit device
of figure 1,
Figure 5 is a perspective view of a cover plate of the panic exit device of figure
1,
Figure 6 is a schematic exploded view of a part of the panic exit device of figure
1 in a latched condition,
Figure 7 is a schematic exploded view of a part of the panic exit device of figure
1 in an open condition,
Figure 8 is a schematic exploded view of a part of the panic exit device of figure
1 between a latched and a superlatched condition,
Figure 9 is a schematic exploded view of a part of the panic exit device of figure
1 in a superlatched condition,
Figure 10 is a schematic exploded view of a part of the panic exit device of figure
1 between a superlatched and an open condition,
Figure 11 is a schematic side section view of a part of the panic exit device of figure
1 in an anti-lock condition, and
Figure 12 is a schematic side section view of a part of the panic exit device of figure
1 in a free lock condition.
[0019] Figure 1 shows a door 100 comprising a frame 102 and glass panes 104. The frame 102
is primarily constructed from PVC. The door 100 is mounted to a frame (not shown)
via hinges 106. An panic exit control in the form of a push bar 108 is mounted on
the door frame 102. The push bar 108 is connected to a latching mechanism (134) to
retract a primary bolt 110. The push bar is rotatable about a push bar axis 109. The
primary bolt 110 is engageable in a primary keep 112 (shown schematically) on the
door frame to latch the door 100.
[0020] The door comprises a first and second secondary bolt 114, 116 which engage respective
first and second secondary keeps 118, 120 to supplement the latching effect of the
primary bolt 110. When the primary bolt 110 alone is engaged in the primary keep 112,
the door is latched. When the primary bolt 110 and the secondary bolts 114, 116 are
engaged in their respective keeps, the door is superlatched. When the door 100 is
superlatched, it is more difficult to force it open as the door 100 is secured to
the frame in multiple positions.
[0021] The primary bolt 100 is biased into the extended position, and comprises an angled
face (not shown) to engage the door frame and automatically retract and extend into
the primary keep 112 when the door is pushed closed. In order to retract the primary
bolt 110 and release the door 100 from a latched condition, the push bar 108 is rotated
from a nominal position (as shown) downwards in direction U about the push bar axis
109. As will be described in detail below, the rotation of the push bar simultaneously
retracts the primary bolt 110 and rotates the door about the hinges 106 to open it.
[0022] The secondary bolts 114, 116 provide supplementary latching. They are engageable
with their respective keeps 118, 120 by rotating the push bar from the datum position
in a direction L, opposite to the direction U whilst the door is closed. Such action
extends the secondary bolts 118, 120 as will be described below to superlatch the
door 100.
[0023] The door 100 can be opened from a superlatched condition by rotating the push bar
in the direction U to disengage the primary and secondary bolts 110, 114, 116 and
open the door. Upon closing the primary latch 110 will automatically resile into the
keep 112 however the secondary bolts 114, 116 require a further actuation of the push
bar 108 in direction L to extend them and achieve the superlatched state.
[0024] As such, the user can leave the door in a latched or superlatched state depending
on preference. For example, the door 100 may be latched at times when the premises
are occupied and superlatched when the premises are unoccupied. It should be noted
that a basic level of latching is always automatically provided by the primary bolt
110, although increased security can be provided by superlatching the door 110 without
impairing the ability to open the door 100 in an emergency.
[0025] Referring to figure 2, an exploded view of the frame 102 with a latching assembly
122 is shown. The latching assembly 122 comprises a primary mechanism 124 which engages
with the push bar 108 and the primary bolt 110. Two secondary mechanisms 126, 128
are also provided which retract and extend the secondary bolts 114, 116. The primary
mechanism 124 is connected to the secondary mechanisms 126, 128 via a first slide
bar 130 and a second slide bar 132 to extend the secondary bolts 114, 116 when the
push bar 108 is rotated in direction L and retract them when the push bar is rotated
in direction U (if they are extended).
[0026] Figures 3 and 3a show a more detailed view of the push bar mechanism 134. The push
bar mechanism comprises a push bar subassembly 136, a gear subassembly 138, an anti-lock
subassembly 140 and an indicator subassembly 142. The subassemblies 136, 138, 140
and 142 are mounted to a back plate 144 and concealed by a cover plate 146.
[0027] The push bar subassembly 136 comprises an operating arm 148, the push bar 108 and
an end cap 150. The operating arm 148 is shown in more detail in figure 4, and comprises
a lever arm portion 152 terminating in a push bar receiving portion 154 at a first
end and a drum portion 156 at a second end.
[0028] The push bar receiving portion comprises a bore 158 to receive both the end cap 150
and the push bar 108.
[0029] The operating arm 148 comprises an operating arm gear 160 and an operating arm locator
162. The operating arm gear 160 has a disc shaped body 164 with a bevel gear 166 defined
thereon and a bore 161 defined therethrough. The bevel gear 166 defines the push bar
axis 109 at its centre coincident with the bore 161. The operating arm locator 162
defines a bore 163 therethrough. The operating arm gear 160 and the operating arm
locator 162 fit at each end of the drum portion 156 of the operating arm 148.
[0030] The lever arm portion 152 of the operating arm 148 further comprises a rib 168 proximate
the drum portion 156 whose function will be discussed below.
[0031] The gear subassembly 138 comprises a spindle drive 170, also shown in more detail
in figure 4. The spindle drive 170 comprises a shaft 172 terminating in a bevel gear
174. The shaft 172 defines a square cross section bore (not shown) open at the end
opposite the bevel gear 174 for receiving a latch shaft 222 (see figure 3a).
[0032] The anti-lock subassembly 140 comprises a dogging knob 176, a release actuator 178,
a return spring 180 and an anti-lock plate 182. The anti-lock plate 182 comprises
a slide plate 184, a pair of upper guides 186 and a pair of lower guides 188. The
guides 186, 184 project from the slide plate 184. The slide plate 184 defines a main
orifice 190 situated between the guides 186, 188 and three guide slots 192 below the
lower guides 188.
[0033] The release actuator 178 comprises a cammed surface 179.
[0034] The slide plate 184 comprises a spring abutment 194 and a bottom flange 196 projecting
from the slide plate 184 at its lower edge.
[0035] The indicator subassembly 142 will not be described in detail.
[0036] The back plate 144 comprises a base plate 198 and a pair of parallel bearing arms
200 projecting therefrom and each defining a bearing hole 202. A drive orifice 204
is defined between the bearing arms 200. Three slide pins 206 and a spring pin 209
project from the base plate 198. The base plate 198 also defines a release actuator
bearing orifice 208 therethrough.
[0037] The cover plate 146 (as shown in figure 5) defines an indicator orifice 210, a lever
orifice 212 and an anti-lock orifice 214. The lever orifice 212 is generally rectangular
with a slot 216 extending from a bottom edge thereof.
[0038] The push bar mechanism 134 is assembled as follows.
[0039] The anti-lock plate 182 is mounted with the slide pins 206 of the back plate 144
passing through the guide slots 192 such that the anti-lock plate 182 can slide on
the backplate 144. The return spring 180 is attached to the spring abutment 194 and
the spring pin 209 to resile the anti-lock plate 182 to a lower position. The release
actuator 178 is engaged in the actuator bearing orifice 208 of the back plate 144
such that upon rotation of the release actuator 178 the cammed surface 179 contacts
the flange 196 of the anti-lock plate 182 to urge the anti-lock plate 182 upwards
against the bias of the return spring 180.
[0040] The spindle drive 170 is then rotatably mounted into the drive orifice 204 such that
the shaft 172 projects from the rear of the back plate 144. The operating arm 148
is then rotatably mounted to the bearing arms 200 with a pin 218 which passes through
the bearing holes 202 and the bores 161. 163 of the operating arm 148. The pin 218
lies on the push bar axis 109.
[0041] As the operating arm 148 is mounted to the bearing arms 200, the bevel gears of the
spindle drive 170 and the operating arm gear 160 engage such that rotation of the
operating arm 148 about the push bar axis 109 brings about rotation of the spindle
drive 170 about a spindle axis 220.
[0042] The cover plate 146 is then placed over the entire assembly with the lever arm portion
152 and part of the release actuator 176 protruding from the lever orifice 212 and
the anti-lock orifice 214 respectively. The dogging knob 176 is then attached to the
release actuator 176 to provide user control of the anti-lock subassembly 140.
[0043] It should be noted that the lever orifice 212 permits motion of the operating arm
148 both upwardly and downwardly from a nominal position as will be described below.
It should also be noted that when the operating arm 148 is actuated into a lower position,
the rib 168 of the operating arm 148 engages the slot 216. The rib 168 and the slot
216 are specifically dimensioned to be less than 10mm (i.e. below the size of a human
finger) to prevent finger trapping.
[0044] Referring now to figures 6 to 10, the operating sequence of the push bar mechanism
134 is shown schematically. As shown, the spindle drive is connected to a latch shaft
222. A primary pinion gear 224 and a secondary pinion gear 226 are mounted to the
latch shaft 222. The primary pinion gear 224 engages with a primary rack 228 which
is attached to the primary bolt 110. The secondary pinion gear 226 engages with a
secondary rack 230. The secondary rack 230 defines a slot 232. Adjacent the secondary
rack 230 is a slide plate 234 comprising a slide pin 236 projecting therefrom and
through the slot 232. The slide plate 234 is functionally linked to the first and
second slide bars 130, 132 configured to actuate the secondary bolts 114, 116.
[0045] Figure 6 shows the push bar mechanism 134 in a latched state with the primary bolt
110 engaging the primary keep 112. It will be noted that the secondary bolts 114,
116 are not engaging their respective keeps 118, 120.
[0046] To open the door 100, the push bar 108 (and hence the operating arm 148) is rotated
in direction U and about the push bar axis 109. As shown in figure 7, the meshed bevel
gears 174, 166 cause corresponding rotation of the spindle drive 170 and the pinion
gears 224, 226. The primary rack 228 pulls the primary bolt 110 free of the primary
keep 112 to enable opening of the door 100. The secondary rack 230 also moves but
merely slides over the slide pin 236 via the slot 232.
[0047] Referring to figure 8, the push bar mechanism 134 is moved from the latched condition
of figure 6 to a superlatched condition. The push bar 108 (and hence the operating
arm 148) is rotated about the push bar axis 109 in latching direction L. The meshed
bevel gears 174, 166 cause corresponding rotation of the spindle drive 170 and the
pinion gears 224, 226. The secondary rack 230 moves and pushes the slide pin 236 and
the slide plate 234 upwardly to actuate the first and second slide bars 130, 132 and
engage the secondary bolts 114, 116 in their respective keeps 118, 120.
[0048] The primary bolt 110 is unaffected, which may be achieved by a lost motion connection
between the primary gear 224 and the primary rack 228. In this embodiment the primary
gear 224 comprises a section of its perimeter 225 on which no gear teeth are defined
and as such may move freely with respect to the primary rack 228 whilst the secondary
bolts 114, 116 are actuated.
[0049] Following this step, the push bar 108 (and hence the operating arm 148) is rotated
back to its nominal position as shown in figure 9 to leave the mechanism 134 superlatched.
As can be seen the only difference between the latched condition of figure 6 and the
superlatched condition of figure 9 is the position of the slide plate 234, the first
and second slide bars 130, 132 and the secondary latch bolts 114, 116.
[0050] Referring to figure 10, the mechanism 134 can be moved to the open position from
the superlatched position by rotation of the push bar 108 (and hence operating arm
148) in the direction U. In this instance, the secondary pinion gear 226 urges the
secondary rack 230 downwards, and due to the position of the slide pin 236 also actuates
the first and second slide bars 130, 132 to retract the secondary bolts 114, 116 at
the same time as the primary bolt is retracted (as described above with reference
to figure 7).
Turning to figures 11 and 12, the mechanism 134 is shown in anti-lock and free lock
conditions respectively. To engage the anti-lock condition, the dogging knob 176 is
oriented such that the cammed surface 176 of the release actuator 178 does not contact
the bottom flange 196 of the anti-lock plate 182. As such the return spring 180 urges
the anti-lock plate 182 into the lower position as shown in figure 11. It will be
noted that in this position, the operating arm cannot be lifted above the nominal
position (as shown) due to the interaction between the operating arm gear 160 and
the upper guides 186. As such, the superlatched condition cannot be entered.
[0051] To enter the free lock condition, the dogging knob 176 is rotated to engage the cammed
surface 179 with the flange 196 and lift the anti-lock plate 182 against the bias
of the return spring 180. This repositions the upper guides 186 to permit movement
of the operating arm in direction L to enter the superlatched condition.
[0052] It should be noted that the failsafe condition of the anti-locking subassembly is
in the anti-lock condition. That is to say that the return spring 180 naturally biases
the anti-lock plate 182 into the lower position and the anti-lock plate 182 naturally
falls under gravity to the lower position.
[0053] The anti lock feature therefore prevents unintentional superlatching of the door.
The push bar may be able to swing up in the direction L when the door is closed vigorously
which may cause problems with the secondary bolts fouling on the frame. This can be
avoided with the use of the anti-lock feature in which the push bar is prevented from
movement in direction L.
[0054] Variations of the above embodiment fall within the scope of the present invention.
[0055] For example, the anti-lock feature may be positioned on the push bar or the operating
arm to allow the user to simultaneously operate the anti-lock function and the push
bar. It may take the form of a dead-man's handle in which it is necessary to depress
a button on the push bar in order to lift it to superlatch the mechanism.
[0056] The system may be used in conjunction with an outside access device (OAD).
[0057] The secondary locking mechanism need not be on the same edge of the door as the primary
locking mechanism. The secondary locking mechanism may be a shoot bolt that emerges
from the top or bottom of the door.
[0058] The invention may be applied to any type of closure and may be used on e.g. windows.
1. An panic or emergency exit device for opening a closure,
the closure having a primary latch movable between an open condition and a latched
condition and a secondary latch movable between an open condition and a latched condition,
the emergency exit device having a first control manually actuable to move the primary
latch and the secondary latch from the latched condition to the open condition, wherein;
the first control is manually actuable to move the secondary latch from the open condition
to the latched condition to supplement the primary latch.
2. A panic or emergency exit device according to claim 1, in which the first control
is arranged to be moved;
in a first direction to move the primary latch and the secondary latch from the latched
condition to the open condition and,
in a second direction, substantially opposite the first direction, to move the secondary
latch from the open condition to the latched condition.
3. A panic or emergency exit device according to claim 2 in which the first control is
rotatably mounted.
4. A panic exit device according to claim 3 in which the first control is a push bar
mounted to be pushed in the first direction and lifted and / or pulled in the second
direction.
5. A panic or emergency exit device according to any preceding claim further comprising
a further control configured to selectively prevent movement of the secondary latch
from the open condition to the latched condition.
6. A panic or emergency exit device according to claim 5 in which the further control
is configured to selectively prevent actuation of the first control to move the secondary
latch from the open condition to the latched condition.
7. A panic or emergency exit device according to claim 5 or 6 in which the further control
has a failsafe position in which it prevents movement of the secondary latch from
the open condition to the latched condition.
8. A panic or emergency exit device according to claim 7 in which the further control
is a dead man's handle on the first control.