AU2017268644B2 - A safety cabinet and an associated door controlling mechanism - Google Patents
A safety cabinet and an associated door controlling mechanism Download PDFInfo
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- AU2017268644B2 AU2017268644B2 AU2017268644A AU2017268644A AU2017268644B2 AU 2017268644 B2 AU2017268644 B2 AU 2017268644B2 AU 2017268644 A AU2017268644 A AU 2017268644A AU 2017268644 A AU2017268644 A AU 2017268644A AU 2017268644 B2 AU2017268644 B2 AU 2017268644B2
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- door
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- cam
- connector member
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Abstract
The cabinet performs 'door selection', which means that when the doors are free to close, the
slave door 2 must close first and the master door 3 second. The slave cam 6 is operative with
the slave door 2 so as to displace the connector member 8 to a first position away from the
master cam 7 in response to closure of the slave door 2. In response to opening of the slave
door 2, the slave cam 6 displaces the connector member 8 to a second position closer to the
master cam 7, which includes a locking arrangement 9 to which the connector member 8 is
connected. The locking arrangement 9 is configured so as to retain the master door 3 at one
of a plurality of possible opening positions when the connector member 8 is in the second
position and so as to release the master door 3 when the connector member 8 is in the first
position. Hence, the door closure mechanism of the present invention functions as not only a
door selector, but also as a door stay.
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Fig.2
Description
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The present invention relates to mechanisms that may be used to control the doors of a safety cabinet. Embodiments of the present invention find application, though not exclusively, in controlling the doors of safety cabinets that may typically be used for the storage of dangerous goods such as chemicals and flammable substances.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in this specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia or elsewhere before the priority date of this application.
Design standards for two-door safety cabinets in some jurisdictions dictate that when not being held open, the doors should automatically close in a specified order; which is the initial closure of the so-called 'slave' door, followed by the subsequent closure of the so called 'master' door. Such fixed ordering for the door closure is known as 'door selection'. Prior art arrangements typically utilise a mechanical arrangement to hold the master door slightly open (typically at an angle of approximately 25) until the slave door has closed and then the master door is released so that it may close.
It has been appreciated by the inventor of the present application that such prior art arrangements, whilst capable of meeting the necessary designs standards, are nevertheless quite inconvenient for a single user wishing to load larger sized materials into or out of the cabinet. This is because the user must use both of their hands to hold the two doors open, which makes the loading or unloading process difficult or impossible. This may prompt the user to utilise one hand to hold one door open and to use a foot to hold the other door open, leaving a hand free for the loading and unloading. However, it is highly undesirable for a person to attempt to balance on a single foot whilst handling dangerous goods.
It is an object of the present invention to overcome, or substantially ameliorate, one or more of the disadvantages of the prior art, or to provide a useful alternative.
In one aspect of the present invention there is provided a safety cabinet having at least two doors, a first of said doors being a slave door and a second of said doors being a master door; the cabinet including the following: the slave door and the master door each being subject to the action of at least one door closing mechanism; a slave cam operative with the slave door so as to displace a connector member to a first position in response to closure of the slave door and so as to displace the connector member to a second position in response to opening of the slave door; and a master cam operative with the master door and including a locking arrangement to which the connector member is connected, the locking arrangement being configured so as to retain the master door at one of a plurality of possible opening positions when the connector member is in the second position and so as to release the master door when the connector member is in the first position.
In one embodiment the locking arrangement includes a pivotally mounted rod that is engageable with the master cam at one of a plurality of possible engagement positions, the plurality of possible engagement positions corresponding to the plurality of possible opening positions. In this embodiment the engagement between the rod and the master cam is by a meshing of teeth.
Preferably the master cam includes a plurality of teeth, each of the plurality of teeth corresponding to one of said plurality of possible engagement positions and wherein the rod has at least one tooth shaped so as to mesh with the plurality of teeth on the master cam.
Preferably the connector member is connected to the rod so as to position the at least one tooth within a meshing proximity relative to the plurality of teeth on the master cam when the connector rod is in the second position and so as to position the at least one tooth outside the meshing proximity relative to the plurality of teeth on the master cam when the connector rod is in the first position.
Preferably the rod is resiliently biased towards engagement with the master cam.
In one embodiment the engagement between the rod and the master cam is configured so as to ratchet the meshing of the teeth in response to opening of the master door. Preferably the master cam is resiliently biased towards a rotational direction that advances ratcheting of the meshing of teeth. In the use of this embodiment, a line of force results from the meshing of the teeth and a pivot point at which the rod pivots is disposed on the same side of the line of force as the master cam.
Preferably the master cam defines a seat shaped so as to releasably receive an element that is mechanically coupled to the master door so as to move in response to movement of the master door, the element being moveable along a first track in which the element is seated within the seat and wherein the element is constrained from being released from the seat by a defined boundary, the element also being moveable along a second track in which the element is remote from the defined boundary and is therefore free to be displaced out of the seat.
Preferably the element is a circular bearing and the seat is an open notch having a curvature substantially matching, or being slightly greater than, a curvature of the circular bearing.
Preferably the first track corresponds to an opening range of the master door that encompasses said plurality of possible opening positions and the second track corresponds to an opening range of the master door that extends beyond said plurality of possible opening positions.
In one embodiment the slave cam is pivotally mounted adjacent to the slave door and the connector member is pivotally connected at a first end to the slave cam and at a second end to the rod. In this embodiment the slave door, or a projection disposed on the slave door, displaces the slave cam in response to closing of the slave door to thereby displace the connector member to the first position. Opening of the slave door provides clearance for the slave cam to move, thereby allowing movement of the connector member to the second position due to the resilient biasing of the rod.
In another aspect of the present invention there is provided a door controlling mechanism for use with a safety cabinet having at least two doors, a first of said doors being a slave door and a second of said doors being a master door and wherein the slave door and the master door are each subject to the action of at least one door closing mechanism; the door controlling mechanism including the following: a slave cam operative with the slave door so as to displace a connector member to a first position in response to closure of the slave door and so as to displace the connector member to a second position in response to opening of the slave door; and a master cam operative with the master door and including a locking arrangement to which the connector member is connected, the locking arrangement being configured so as to retain the master door at one of a plurality of possible opening positions when the connector member is in the second position and so as to release the master door when the connector member is in the first position.
The features and advantages of the present invention will become further apparent from the following detailed description of preferred embodiments, provided by way of example only, together with the accompanying drawings.
Figure 1 is an isometric view of afirst embodiment of a safety cabinet according to the invention in which the doors are both closed and a top cover has been removed so as to reveal the door controlling mechanism;
Figure 2 is an isometric view of the safety cabinet in which the doors are both fully opened;
Figure 3 is a plan view of the safety cabinet in which the doors are both closed;
Figure 3A is a detail view of the region marked A in fig 3;
Figure 3B is a detail view of the region marked B in fig 3;
Figure 4 is a plan view of the safety cabinet in which the slave door is fully open and the master door is being retained at an open position of approximately 15;
Figure 4A is a detail view of the region marked A in fig 4;
Figure 4B is a detail view of the region marked B in fig 4;
Figure 5 is a plan view of the safety cabinet in which the slave door is fully open and the master door is being retained at an open position of approximately 30°;
Figure 5A is a detail view of the region marked A in fig 5;
Figure 5B is a detail view of the region marked B in fig 5;
Figure 6 is a plan view of the safety cabinet in which the slave door is fully open and the master door is being retained at an open position of approximately 70;
Figure 6A is a detail view of the region marked A in fig 6;
Figure 6B is a detail view of the region marked B in fig 6;
Figure 7 is a plan view of the safety cabinet in which the slave door is closed and the master door has been released by the locking mechanism so as to allow the master door closing mechanism to pull the master door closed;
Figure 7A is a detail view of the region marked A in fig 7;
Figure 7B is a detail view of the region marked B in fig 7;
Figure 8 is a plan view of the safety cabinet in which the slave door is closed and the master door is swinging closed;
Figure 8A is a detail view of the region marked A in fig 8;
Figure 8B is a detail view of the region marked B in fig 8;
Figure 9 is a plan view of the safety cabinet in which the slave door is fully open and the master door is being retained at its outermost locked open position of approximately 90°;
Figure 9A is a detail view of the region marked A in fig 9;
Figure 9B is a detail view of the region marked B in fig 9;
Figure 10 is a plan view of the safety cabinet in which the doors are both fully opened;
Figure 1OA is a detail view of the region marked A in fig 10;
Figure 1OB is a detail view of the region marked B in fig 10;
Figure 11 is a front view of the safety cabinet in which the doors are both fully opened;
Figure 11A is a detail view of the region indicated by the line to fig 11;
Figure 11B is a detail view of the region indicated by the line to fig 11;
Figure 11C is a detail view of the region indicated by the line to fig 11;
Figure 12 is a detail plan view of the master cam assembly showing the location of two springs that provide resilient biasing;
Figure 13 is a top left rear perspective view of the safety cabinet with both doors closed;
Figure 13A is a top left rear perspective detail view of the master cam assembly as shown in figure 13;
Figure 13B is a top left rear perspective detail view of the slave cam assembly as shown in figure 13;
Figure 14 is a top left rear perspective view of the safety cabinet with the master door open and the slave door closed;
Figure 14A is a top left rear perspective detail view of the master cam assembly as shown in figure 14;
Figure 14B is a top left rear perspective detail view of the slave cam assembly as shown in figure 14;
Figure 15 is a top right front perspective view of the safety cabinet with the master door open;
Figure 15A is a top right front perspective detail view of the master cam assembly as shown in figure 15;
Figure 15B is a top right front perspective detail view of the slave cam assembly as shown in figure 15;
Figure 16 is a top left rear perspective view of the safety cabinet with the both doors open;
Figure 16A is a top left rear perspective detail view of the master cam assembly as shown in figure 16;
Figure 16B is a top left rear perspective detail view of the slave cam assembly as shown in figure 16;
Figure 17 is a plan view of the master cam assembly;
Figure 18 is a perspective view of the master cam assembly;
Figure 19 is a side view of the master cam assembly;
Figure 20 is a bottom view of the master cam assembly;
Figure 21 is an exploded perspective view of the master cam assembly;
Figure 22 is an exploded side view of the master door closing assembly;
Figure 23 is an exploded perspective view of the slave cam assembly;
Figure 24 is a plan view of the master cam;
Figure 24A is a detail view of the region marked K on figure 24;
Figure 25 is a perspective view of the master cam;
Figure 26 is a perspective view of the master door bracket;
Figure 27 is a perspective view of the slave door bracket;
Figure 28 is a plan view of a second embodiment of the safety cabinet in which the doors are both closed;
Figure 28A is a detail view of the region marked A in fig 28;
Figure 28B is a detail view of the region marked B in fig 28;
Figure 29 is a front view of the second embodiment of the safety cabinet in which the doors are both fully opened;
Figure 29A is a detail view of the region marked F in fig 29;
Figure 29B is a detail view of the region marked G in fig 29;
Figure 29C is a detail view of the region marked H in fig 29;
Figure 30 is a detail plan view of the master cam assembly of the second embodiment showing the location of two springs that provide resilient biasing;
Figure 31 is a top left rear perspective view of the second embodiment of the safety cabinet with both doors closed;
Figure 31A is a top left rear perspective detail view of the master cam assembly marked K in fig. 31;
Figure 31B is a top left rear perspective detail view of the slave cam marked L in figure 31;
Figure 32 is an exploded side view of the master door closing assembly of the second embodiment; and
Figure 33 is a perspective view of the master door bracket of the second embodiment.
With reference to the drawings, the safety cabinet 1 has two doors 2 and 3. The first door is referred to as a 'slave' door 2 and the second door is referred to as a 'master' door. The slave door 2 and the master door 3 are each subject to the action of respective hydraulic door closing mechanisms 4 and 5.
In overview, the door control mechanism of the safety cabinet 1 is housed under a cover (not shown) towards the top of the safety cabinet 1. The door control mechanism has a slave door closing mechanism 4 pivotally mounted at its proximal end to the rear of a platform 16 on the slave door side. The distal end of the slave door closing mechanism 4 is pivotally connected to a pair of rods 17 by means of a bolt 19 and a nut 13. The pair of rods 17 are pivotally connected to a slave door bracket 18, which is disposed on the slave door 2. The nut 13 interacts with the slave cam 6, which is in the form of an L-shaped member 10. A connector member 8 communicates movement of the slave cam 6 to the rod 20, which causes the rod 20 to engage, or disengage, with the master cam 7. The master cam 7 is rotatably mounted and includes a seat 28, into which an element, in the form of a circular bearing 29, is releasably received. The bearing 29 is located at the pivotaljoint of a pair of rods 30 and the distal end of the master door closing mechanism 5. The pair of rods 30 extend from the bearing 29 to the master door bracket 33, which is disposed on the master door 3. The proximal end of the master door closing mechanism 5 is pivotally mounted to the rear of the platform 16 on the master door side.
One of the requirements for the invention to perform is known as 'door selection', which in the context of this safety cabinet 1, means that when the doors are free to close, the slave door 2 must close first and the master door 3 second. Two important components that assist with the door selection are the slave cam 6 and master cam 7, which are interconnected by connector member 8. More specifically, the slave cam 6 is operative with the slave door 2 so as to displace the connector member 8 to a first position in response to closure of the slave door 2. In this first position the connector member 8 is positioned further away from the master cam 7. In response to opening of the slave door 2, the slave cam 6 displaces the connector member 8 to a second position, which is closer to the master cam 7. The master cam 7 is operative with the master door 3 and the master cam 7 includes a locking arrangement 9 to which the connector member 8 is connected. The locking arrangement 9 is configured so as to retain the master door 3 at one of a plurality of possible opening positions when the connector member 8 is in the second position and so as to release the master door 3 when the connector member 8 is in the first position.
The ability of the master cam 7 to retain the master door 3 at one of a plurality of possible opening positions means that the door closure mechanism of the present invention functions as not only a door selector, but also as a door stay. This means that a user wishing to load or unload items from the safety cabinet 1 can firstly open the master door 3 to one of the plurality of possible opening positions. Then the user opens the slave door 2 and uses one hand, or another part of their body such as their back, to keep the slave door 2 open. Whilst the slave door 2 is open, the locking arrangement 9 keeps the master door 3 open without the user needing to do so, which frees at least one hand for loading or unloading of the safety cabinet 1. Once completed, the user simply lets go of the slave door 2, at which point the door selection functionality described above ensures that the slave door closes first, followed by closure of the master door 3.
The entire door controlling mechanism of the preferred embodiment is mounted to platform 16 and is hidden immediately below a top cover. However, the top cover is not shown in the drawings so as to reveal the workings of the door controlling mechanism.
An exploded view of the slave cam assembly is shown for example in figure 23. The slave cam 6 is in the form of L-shaped member 10 which is pivotally mounted on bearing 14 by central bolt 11. Spacers 15 position the L-shaped member at the desired height. The other four bolts 12 are used to mount the slave cam assembly to platform 16. The distal end of the L-shaped member 10 is adjacent to the slave door 2. More specifically, the distal end of the L-shaped member 10 is positioned so that it contacts against nut 13 when the slave door 2 is closed. The nut 13 is screwed onto bolt 19 so as to fasten one end of the pair of rods 17 to the slave door bracket 18, which is disposed on the slave door 2. The slave door bracket 18 is illustrated for example in figure 27. The other ends of the pair of rods 17 are pivotally connected to the slave door closing mechanism 4.
The connector member 8 is pivotally connected at a first end to the L-shaped member 10 of the slave cam 6 and at a second end to rod 20 of the master cam 7. As shown for example in figure 13B, when the slave door 2 is closed, nut 13, which effectively acts as a projection disposed on the slave door 2, pushes the distal end of the L-shaped member 10 inwardly. This causes the L-shaped member 10 to rotate in a clockwise direction when viewed from above. This clockwise rotation of the L-shaped member displaces the connector member 8 to the right as seen from above (i.e. away from the master cam 7 and into the first position).
Opening of the slave door 2, as shown for example in figures 16 and 16B, moves the nut 13 away from the distal end of the L-shaped member 10, which provides clearance for the L-shaped member 10 of the slave cam 6 to rotate anti-clockwise as viewed from above. This rotation occurs due to the resilient biasing provided by spring 21, which is a part of the master cam assembly as shown in figure 12. This spring 21 is connected to the opposite end of rod (i.e. opposite to the end that is connected to the connector member 8). As shown infigure 12, spring 21 resiliently urges the end of the rod 20 to which it is connected to the left, which applies a torque to rod 20, which rotates about pivotal mounting 22 such that the other end of the rod 20 exerts a force to the right as illustrated in figure 12. This force is communicated along connector member 8 so that when nut 13 is removed due to opening of the slave door 2, the connector member 8 moves to the second position (i.e. closer to the master cam 7).
The resilient biasing provided by the spring 21 biases the pivotally mounted rod 20 towards engagement with the master cam 7 at one of a plurality of possible engagement positions defined by the plurality of teeth 24 on the master cam 7. As described in more detail below, each of the engagement positions corresponds to one of the plurality of possible opening positions of the master door 3. The action of the slave cam 6 can place the single tooth 23 on the rod 20 into, and out of, meshing proximity with the plurality of teeth 24 on the master cam 7. If the tooth 23 on the rod 20 meshes in between the first tooth 25 and the second tooth 26 on the master cam 7, as shown in figures 4 and 4A, then the master door 3 is retained by the locking arrangement 9 at a position that is approximately 150 open. Whilst the slave door 2 remains open, the master door 3 will continue to be thus retained.
As shown in figures 5 and 5A, the tooth 23 on the rod 20 is meshing in between the third and fourth teeth on the master cam 7. Whilst the slave door 2 remains open, this retains the master door 3 at a position that is approximately 30 open.
As shown in figures 6 and 6A, the tooth 23 on the rod 20 is meshing in between the sixth and seventh teeth on the master cam 7. Whilst the slave door 2 remains open, this retains the master door 3 at a position that is approximately 70° open. However, as shown in figures 7, 7A and 7B, once the slave door 2 is closed, the connector member 8 is displaced away from the master cam 7 into the first position, which positions tooth 23 outside of meshing proximity with the teeth 24 on the master cam 7. This allows the master cam 7 to rotate, which frees up the master door closing mechanism 5 so as to pull the master door 3 closed.
It is necessary to ensure that the door closing mechanisms 4 and 5 have sufficient damping; particularly at or toward the end of their contraction. This ensures that when the doors 2 and 3 are being closed under the action of the door closing mechanisms 4 and 5, they do not close dangerously fast, which could otherwise potentially damage the cabinet 1.
The engagement between the tooth 23 on the rod 20 and the plurality of teeth 24 on the master cam 7 is configured so as to allow ratcheting of the meshing of the teeth in response to opening of the master door 3. Hence, for example, if the system is in the state shown in figures 4, 4A and 4B, then the user may simply pull the master door 3 open, whilst keeping the slave door 2 open, and the tooth 23 on the rod 20 will ratchet over the teeth 24 of the master cam 7. The ratcheting occurs because the force provided by opening of the master door 3 is sufficient to rotate the master cam 7, which causes the tooth 23 on the rod 20 to slide across which ever tooth it is currently engaged upon on the master cam 7. As a result of this sliding, the rod 20 rotates about its pivotal mounting 22 away from the master cam 7. This rotation of the rod 20 is against the resilient biasing provided by spring 21. Thisrotationof the rod 20 continues until the end of the tooth 23 on the rod 20 clears the end of the tooth of the master cam 7. At this point, the second spring 27 rotates the master cam 7 clockwise as illustrated in figure 12 until the tooth 23 on the rod 20 aligns with the next gap between teeth on the master cam. That is, spring 27 resiliently biased the master cam 7 towards a rotational direction that advances ratcheting of the meshing of the teeth. Thus, the ratcheting has caused the tooth 23 on the rod 20 to be indexed one position further along the teeth 24 of the master cam 7 in a direction that corresponds to greater opening of the master door 3. The master door 3 is then retained in this more open position until such time as either the slave door 2 is closed, or until the tooth 23 on the rod 20 is ratcheted further along the teeth of the master cam 7.
The shape of teeth 23 and 24 is specifically tailored to enhance the ratcheting process. More specifically, rack is added to each tooth to assist the teeth on the rod 20 and the master cam 7 to slide past one another during ratcheting. Additionally, to assist in the maintenance of a secure locking engagement between the tooth 23 on the rod 20 and the teeth 24 on the master cam 7, a positive camber of 2° is present on the teeth 24 of the master cam 7 and an equal negative camber is present on the tooth 23 of the rod 20.
Another feature that assists in the secure locking engagement between the tooth 23 on the rod 20 and the teeth 24 on the master cam 7 is the positioning of the pivotal mounting 22 of the rod 20 relative to a line of force that results, in use, from the meshing of the teeth 23 and 24. Specifically, the pivotal mounting 22 of the rod 20 is disposed on the same side of the line of force as the master cam 7 such that a torque is induced upon rod 20 which further tightens the engagement of the teeth 23 and 24. If the pivot point is positioned on the other side of this line of force, there is a substantial risk that slippage will occur and the door control mechanism may fail.
The manner in which the master door 3 is mechanically coupled to the master cam 7 allows for the master door to be opened beyond the outermost position at which the locking arrangement 9 can retain the master door 3. Whereas the locking arrangement 9 can only retain the master door at a maximum opening position of around 90, this feature allows the user to fully open the master door 3 to an opening position of approximately 180. The mechanical coupling of the master door 3 to the master cam 7 is best shown, for example, in figure 12. The master cam 7 defines seat 28 which has an open semi-circular shape so as to releasably receive an element in the form of circular bearing 29. In other words, the seat 28 is an open notch having a curvature substantially matching, or being slightly greater than, the curvature of the circular bearing 29. As best shown in figure 22, the circular bearing 29 is rotatably mounted immediately below the junction between the master door closing mechanism 5 and pair of rods 30 that are pivotally mounted to the end of the master door closing mechanism 5. Hence, the bearing 29 moves in response to movement of the master door 3.
The bearing 29 is moveable along a first track in which the bearing 29 is seated within the seat 28. Whilst within the first track, the bearing 29 is constrained from being released from the seat 28 by a boundary that is defined by an arcuate edge 32 of a boundary member 31. The bearing 29 is shown within the first track in figures 3, 3A, 4, 4A, 5, 5A, 6, 6A, 7, 7A, 8 and 8A. However, infigures 9, 9A, 10 and1OA, the bearing 29 is illustrated as moving along a second track in which the bearing is remote from the boundary defined by the arcuate edge 32. Whilst in the second track, the bearing 29 is free to be displaced out of the seat 28, as shown for example in figures 10 and 10A. As shown for example in figure 17, the distal end of the boundary member 31 includes a relief 34, which helps to ameliorate the forces generated as the bearing 29 transitions from the first track to the second track (i.e. as the bearing 29 transitions from a 'controlled state' to a 'free state'). Additionally, as the bearing 29 transitions from the second track back to the first track, the relief 34 helps to guide the bearing 29 toward the seat 28.
It will be appreciated that the first track corresponds to an opening range of the master door 3 that encompasses the plurality of possible opening positions in which the locking arrangement 9 can retain the master door 3. However, the second track corresponds to an opening range of the master door 3 that extends beyond the plurality of possible opening positions in which the locking arrangement 9 can retain the master door 3.
Another function provided by the second spring 27 is to ensure the master cam 7 locks on the uppermost tooth 37 (i.e. the tooth corresponding to the outermost position in which the master door 7 can be retained by the locking arrangement 9) because otherwise the bearing 29 may escape the seat 28 before the master cam 7 has been rotated enough for its last tooth 37 to be engaged. If so, the spring 27 completes this rotation. It also stops the master cam 7 from rotating freely once the bearing 29 has left the seat 28 if the user chooses to open the master door 3 beyond the outermost position in which the master door 7 can be retained by the locking arrangement 9.
The master cam assembly is illustrated in figure 21, which shows the manner in which the rod 20, master cam 7 and boundary member 31 are mounted to mounting plate 35. The use of the mounting plate allows the master cam 7 and the boundary member 31 to be mounted low within the plane in which movement is occurring, which assists to reduce twisting of the master cam 7 and also assists to avoid slipping of the bearing 29 under or over the seat 28. The use of the mounting plate 35 also allows many of the components associated with the master cam 7 to be pre-assembled during manufacture of the safety cabinet 1. The low profile mounting of these components can also assist with the provision of lubrication onto the moving parts. As illustrated in figure 21, the master cam assembly also makes use of press studs 36, which are press fit into holes, which also helps to keep the profile of the master cam assembly low.
The door brackets 33 and 18, as shown in figures 26 and 27 respectively, are used to help buttress the otherwise thin sheet metal forming the doors 2 and 3 from the forces that can be generated when the rods 17 and 30 impact against the doors 2 and 3 when the doors are opened beyond 90. The brackets 33 and 18 are made from a thicker, stronger material than that of the doors and are shaped so as to receive the forces from the rods 17 and 30 that may otherwise deflect the thin door sheet metal.
Each of the slave cam 6 and the master cam 7 in the above-described embodiment involve rotational movement. However, it will be appreciated by those skilled in the art that the door control mechanism can be altered to make use of cams involving other types of movement. For example, in another embodiment, the slave cam moves in a linear fashion in response to movement of the slave door. In this document, including the claims, the term "cam" is to be construed broadly enough so as to include cams involving various styles of movement including rotational and linear for example.
A second embodiment of the invention is illustrated in figures 28 to 32. This second embodiment is essentially identical to the above-described first embodiment; except it has some minor detail differences that will be outlined below.
In the first embodiment one of the ends of the pair of rods 17 is pivotally connected to the slave door closing mechanism 4 by means of a bolt and the other end of the pair of rods 17 is pivotally connected to the slave door 2 by means of another bolt (which is labelled 19 in figure 3B). However, in the second embodiment, as best illustrated for example in figures 28B, 29C and 31B, these bolts are replaced with rivets 40 and 41. It has been appreciated by the inventor that the use of rivets 40 and 41 in the second embodiment in the place of the bolts of the first embodiment contributes to quicker and easier manufacturing of the second embodiment of the cabinet because the threading of nuts onto the bolts is comparatively time consuming and fiddly as compared to making the connection via the simple expedient of riveting.
Similarly, with regard to the master door closing mechanism, the bolts at the pivoting joints at either end of the pair of rods 30 in the first embodiment have been replaced with rivets 42 and 43 in the second embodiment, as shown for example in figures 28A, 29A, 29B, , 31A and 32. This also contributes to ease and speed of manufacture for the reason outlined in the preceding paragraph.
It will be recalled that in thefirst embodiment the distal end of the L-shaped member is positioned so that it contacts against nut 13 when the slave door 2 is closed. It has, however, been appreciated by the inventor that this arrangement runs a risk that the nut 13 may catch upon the L-shaped member, with a potential to compromise the door control offered by the cabinet. This has been addressed in the second preferred embodiment by replacing the nut 13 with a ball bearing 44, which has a smooth rolling action that minimises this risk. The ball bearing 44 is best illustrated, for example, in figures 29C and 31B.
The master door bracket 33 of the first embodiment is illustrated in figure 26 and this may be contrasted with the master door bracket 45 of the second embodiment as best illustrated in figure 33. In the first embodiment, the master door bracket 33 has two mounting holes that are spaced apart from each other identically to the spacing of two analogous mounting holes on the slave door bracket 18. However, it has been appreciated by the inventor that this potentially allows an inattentive assembly worker to install the two brackets incorrectly (i.e. by putting the master door bracket 33 onto the slave door 2 and vice versa). To address this risk the spacing of the mounting holes on the master door bracket 45 of the second embodiment differs from the spacing of the mounting holes on the slave door bracket of the second embodiment. More specifically, the mounting holes 46 on the master door bracket 45 of the second embodiment are positioned closer together, and are off-set from each other, as compared to the mounting holes on the slave door bracket 18.
As shown in figure 26, the master door bracket 33 of thefirst embodiment includes a slot which indicates a position at which the bracket is to be welded to the master door 3 during assembly of the cabinet. However, it has been appreciated that this is of minimal practical value and, for this reason, the slot has been omitted from the master door bracket 45 of the second embodiment, as shown in figure 33. Advantageously, this avoids the need to stamp or otherwise form the slot in the master door bracket 45.
The master door bracket 33 of the first embodiment includes a lug having a rounded triangular profile with a hole centrally disposed therein. The triangular profile defines a pointed end that, in the first embodiment, is welded to the master door 3. However, it has been appreciated that the manufacture of the cabinet can be simplified, and sufficient strength obtained, by utilising a lug 47 having a rounded rectangular profile as best shown in figure 33. Advantageously, this avoids the need to weld the pointed end onto the master door 3.
While a number of preferred embodiments have been described, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
Claims (14)
1. A safety cabinet having at least two doors, a first of said doors being a slave door and a
second of said doors being a master door; the cabinet including the following:
the slave door and the master door each being subject to the action of at least one door
closing mechanism; a slave cam operative with the slave door so as to displace a connector member to a first
position in response to closure of the slave door and so as to displace the connector member to a
second position in response to opening of the slave door; and
a master cam operative with the master door and including a locking arrangement to which
the connector member is connected, the locking arrangement being configured so as to retain the
master door at one of a plurality of possible opening positions when the connector member is in the
second position and so as to release the master door when the connector member is in the first
position, the locking arrangement including a pivotally mounted rod that is engageable with the
master cam, by a meshing of teeth, at one of a plurality of possible engagement positions, wherein
the plurality of possible engagement positions corresponds to the plurality of possible opening
positions.
2. A safety cabinet according to claim 1 wherein the locking arrangement includes a pivotally mounted rod that is engageable with the master cam at one of a plurality of possible engagement
positions, the plurality of possible engagement positions corresponding to the plurality of possible
opening positions.
3. A safety cabinet according to claim 2 wherein engagement between the rod and the master
cam is by a meshing of teeth.
4. A safety cabinet according to claim 3 wherein the master cam includes a plurality of teeth,
each of the plurality of teeth corresponding to one of said plurality of possible engagement positions
and wherein the rod has at least one tooth shaped so as to mesh with the plurality of teeth on the
master cam.
5. A safety cabinet according to claim 4 wherein the connector member is connected to the rod so as to position the at least one tooth within a meshing proximity relative to the plurality of teeth
on the master cam when the connector rod is in the second position and so as to position the at
least one tooth outside the meshing proximity relative to the plurality of teeth on the master cam
when the connector rod is in the first position.
6. A safety cabinet according to any one of claims 2 to 5 wherein the rod is resiliently biased
towards engagement with the master cam.
7. A safety cabinet according to claim 3 wherein the engagement between the rod and the master cam is configured so as to ratchet the meshing of the teeth in response to opening of the
master door.
8. A safety cabinet according to claim 7 wherein the master cam is resiliently biased towards a
rotational direction that advances ratcheting of the meshing of teeth.
9. A safety cabinet according to claim 7 or 8 wherein, in use, a line of force results from the
meshing of the teeth and wherein a pivot point at which the rod pivots is disposed on the same side
of the line of force as the master cam.
10. A safety cabinet according to any one of the preceding claims wherein the master cam
defines a seat shaped so as to releasably receive an element that is mechanically coupled to the
master door so as to move in response to movement of the master door, the element being moveable along a first track in which the element is seated within the seat and wherein the element
is constrained from being released from the seat by a defined boundary, the element also being
moveable along a second track in which the element is remote from the defined boundary and is
therefore free to be displaced out of the seat.
11. A safety cabinet according to claim 10 wherein the element is a circular bearing and wherein
the seat is an open notch having a curvature substantially matching, or being slightly greater than, a
curvature of the circular bearing.
12. A safety cabinet according to claim 10 or 11 wherein the first track corresponds to an
opening range of the master door that encompasses said plurality of possible opening positions and
wherein the second track corresponds to an opening range of the master door that extends beyond
said plurality of possible opening positions.
13. A safety cabinet according to claim 6 wherein the slave cam is pivotally mounted adjacent to
the slave door, wherein the connector member is pivotally connected at a first end to the slave cam
and at a second end to the rod, wherein the slave door, or a projection disposed on the slave door, displaces the slave cam in response to closing of the slave door to thereby displace the connector member to the first position and wherein opening of the slave door provides clearance for the slave cam to move, thereby allowing movement of the connector member to the second position due to the resilient biasing of the rod.
14. A door controlling mechanism for use with a safety cabinet having at least two doors, a first
of said doors being a slave door and a second of said doors being a master door and wherein the
slave door and the master door are each subject to the action of at least one door closing
mechanism; the door controlling mechanism including the following:
a slave cam operative with the slave door so as to displace a connector member to a first
position in response to closure of the slave door and so as to displace the connector member to a
second position in response to opening of the slave door; and
a master cam operative with the master door and including a locking arrangement to which
the connector member is connected, the locking arrangement being configured so as to retain the
master door at one of a plurality of possible opening positions when the connector member is in the
second position and so as to release the master door when the connector member is in the first
position, the locking arrangement including a pivotally mounted rod that is engageable with the master cam, by a meshing of teeth, at one of a plurality of possible engagement positions, wherein
the plurality of possible engagement positions corresponds to the plurality of possible opening
positions.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU2016905050A AU2016905050A0 (en) | 2016-12-07 | A safety cabinet and an associated door controlling mechanism | |
| AU2016905050 | 2016-12-07 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2017268644A1 AU2017268644A1 (en) | 2018-06-21 |
| AU2017268644B2 true AU2017268644B2 (en) | 2022-12-08 |
Family
ID=62566583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2017268644A Active AU2017268644B2 (en) | 2016-12-07 | 2017-11-30 | A safety cabinet and an associated door controlling mechanism |
Country Status (1)
| Country | Link |
|---|---|
| AU (1) | AU2017268644B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110593731B (en) * | 2019-10-03 | 2020-10-20 | 泉州市盛发安防发展有限公司 | Two-leaf folio fireproof door capable of being closed sequentially |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4429492A (en) * | 1982-01-26 | 1984-02-07 | Leigh Products, Inc. | Door coordinator |
| US20130200767A1 (en) * | 2012-02-08 | 2013-08-08 | Justrite Manufacturing Company L.L.C. | Safety cabinet with sequential door-closing system |
| CN110593731A (en) * | 2019-10-03 | 2019-12-20 | 陆中艳 | Two-leaf folio fireproof door capable of being closed sequentially |
-
2017
- 2017-11-30 AU AU2017268644A patent/AU2017268644B2/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4429492A (en) * | 1982-01-26 | 1984-02-07 | Leigh Products, Inc. | Door coordinator |
| US20130200767A1 (en) * | 2012-02-08 | 2013-08-08 | Justrite Manufacturing Company L.L.C. | Safety cabinet with sequential door-closing system |
| CN110593731A (en) * | 2019-10-03 | 2019-12-20 | 陆中艳 | Two-leaf folio fireproof door capable of being closed sequentially |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2017268644A1 (en) | 2018-06-21 |
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