GB2498340A - A latch operating device comprising a push button and helical cam - Google Patents

Abstract

A latch operating device comprising a worm bushing 1 (button) confined for axial sliding having an internal helical groove 13 and worm shaft 2 confined for rotary movement having a helical thread 6. Linear movement of bushing 1 is converted into rotary movement of shaft and a spring 7 biases the bushing to return to a neutral position. Shaft 2 may have a recess 15 for inserting spindle of a latch mechanism. Preferably (see fig.3, 4) a push button (8) with teeth (19) cooperates with rotor (9) having teeth (25) and splines (18) to sequentially index the position of the bushing to hold the latch in a retracted position and an extended position. The push button latch can be used on toilet doors where hygiene is of a concern.

Description

Description

The position of swing doors are controlled by hinges. The majority of other doors will be closed, opened, locked and unlocked applied by a door locking mechanism, where the jamb prevents the door from swinging to both sides and a locking and blocking mechanism fitted in the end face of the door, like a latch, controls the engagement and disengagement between the door and the jamb of the door.

These door latches (example no 16 in figure 1) fitted in the end face of the door, usually are driven by radial rotation sliding in and out a piece of material (20 and 21) to block and lock the door in position, and connected to handles through a mutual axle. For this axle the latch has provisions (22, 23), and a common axle is a square bar of 8 mm, fitted through the latch and connected to a handle, either on one side or ha ndles on both sides of the door, to operate the latch, like door handles, toilet lockers, but also emergency bars or handles.

It is common that the internal mechanism of the latch provides a return spring for the door handle, so loosening the door handle after applying, the handle returns in genuine position.

For the toilet locker or door locker the latch doesn't provide an automatic return as the locker needs to stay in closed mode, and a specific manual action is required to unlock the latch.

These handles are designed to be operated by bare hand and bare fingers. Especially the toilet lockers are usually small handles the required torque for the radial movement is sometimes hard for those who are less capable or disabled. These handles are applied by bare fingers and hand, and it is well known, that specific in public area's bacteria and infections are easily passed and spread.

The invention This invention provides a device, that drives and controls a mechanism, like a door latch, by applying and small axial load on the device to open, close, lock, unlock and secure, a door, a window or a panel, a door-locker, a toilet locker, but also for emergency exits, caravans, motor homes, windows, panels, just closing and locking mechanisms in general. The small load in axial direction by meaning a small push on a knob, instead of the usual rotation ration of a handle, is operating the mechanism.

The axial load to operate the device -as a push action is required -can be done with the fingers, hand, hand palm, elbow, basically anything or any tool or instrument. The benefit is that the sometimes difficult rotation, and the actual use of the fingers and hand can be avoided. For the return action back to genuine position a spring takes over, so loosening the device is enough. So basically the only manual action to open, close, lock, unlock or secure is a push on the device.

Door blocking/locking/releasing.

The device contains at least a worm bushing (1) with a worm grove (13) to accommodate the start or starts of worms (6) of a worm shaft (2) in the same mutual axial direction (14), so the worm shaft (2) can be screwed into the worm bushing. The relative axial and radial moves of the worm bushing and worm shaft fitted, are restricted, as the worm bushing (1) is restricted to rotate radial but free to move axial, and the worm shaft (2) is restricted to move axial, but free to move radial.

One favourable configuration is to have splines (3) on the outer side of the worm bushing (1), matting the splines (4) of a body (5), so the worm bushing (1) can slide axial, and is prevented to move radial, relative to the body(s).

The worm shaft (2) has preferable more than one start of a worm (6). One of the favourable configurations of the device having 3 starts of a worm, as the forces in a triangle is recognised as more stable to spread the forces.

We appoint a genuine position (see figure 4) , where the worm bushing (1) is positioned and blocked from further axial movement away relative to the worm shaft (2), but connected to the worm shaft (2) by the worms (6) and the spring (7).

As soon as the worm bushing (1) is forced further over the worm shaft (2), and the worm grove (13) of the worm bushing (1) is forced over the worms (6) of the worm shaft (2), and the spring (7) compresses. This results in a radial rotation of the worm shaft (2). This radial rotation drives the axle connected to the blocking and locking mechanism, like a latch. One of the favourable alternatives is that the worm shaft (2) has a provision (15) to accommodate the mutual connection, like an axle.

Pending on the latch (16) mechanism this rotation drives the mechanism and either engage or disengages the locking or blocking mechanism.

Reducing the manual force on the worm bushing (1), the return action is guided by the decompression of the spring (7) resulting in forcing away of the worm bushing (1) in axial direction and making the worm shaft (2) rotate in the opposite direction back into genuine position.

The benefit is that any pull action of the fingers and hand is no longer required. Operating the device is limited to a pushing action.

One of the favourable springs is a compression spring (7) fitted in the centre of the worm bushing (1) and the worm shaft (2) as in figure 2. Here the worm shaft has a provision (24) to guide the spring and limit the movement in radial direction of the spring (7) during compressing and decompressing. This position of the spring has the benefit to create a relative stable movement and balance force between the worm bushing (1) and the worm shaft (2).

Genuine position (figure 4).

The spring (7) putts a load on the worm bushing (1) and as the rotor (9) and the pusher (8) are connected in axial direction, the splines (18) of the rotor (9) and the teeth of the pusher (8) are positioned in the top position of the deep splines (17) of the body (5). The splines (3) worm bushing (1) are slide in the bushing splines (4) of the body (5). This is the genuine position.

As the rotor (9) is prevented to move further in axial position the worm bushing (1) is now held in genuine position Position locker.

An immediate reverse action of the worm bushing (1) after reducing manual axial pressure back to genuine position is not always preferred, such as in a in the function as a locker or toilet locker, as the latch and the jamb of the door should stay in engaged mode -closed and locked.

One of the favourable configurations is to add a position-locker. This alternative creates the possibility to block the worm bushing (2) in a position relative to the worm shaft, preventing the worm bushing (1) to return back into genuine position (figure 4), and therefore preventing the worm shaft (2) to rotate in reverse. This locking position is shown in figure 5.

The position locker mechanism provides, that the blocking position can be released by a small push to the worm bushing (1) relative to the worm shaft (1). The position locker is no longer preventing the spring (7)to decompressing and now decompresses. It moves the worm bushing (1) back into genuine position (figure 4), and drives the worm shaft (2) to rotate, the axle rotates and the latch locking mechanism is driven in reverse.

Into blockade.

As soon as the pusher (8) is forced in axial direction towards the worm shaft (2) the teeth (19) are sliding axial within the splines (17) of the body (5). These teeth are pushing the splines (18) of the rotor (9), and the rotor(9) forces the worm bushing (3) into axial movement.

The signal to reduce the manual force is either the circumstance that the pusher(S) is bottomed out, and can't be pushed further in axial direction, or the sudden reduction of back pressure, as the surface (25) of the splines of the rotor, slides along the teeth (19) of the pusher and the rotor (9) moves (11) radial and in axial towards genuine position (figure 7B en 7C), forced by the decompressed spring (7) lifting the worm bushing (1) and the connected rotor (9) towards genuine position.

Releasing the manual force further on the pusher(S) the spring (7) decompresses further, and pushes the worm bushing (1) and the connected rotor (9) in axial direction towards genuine position. As the rotor (9) has rotated, the surface (25) of the splines of the rotor (9) meet the surface (27) of the splines of the body (5) in axial direction, and drives the splines of the rotor(9) into further axial and radial movement (11) into the blocking splines (28) resulting is a blockade of the rotor (9) and the connected worm bushing (1).

Releasing for blockade back to genuine position.

To release from this mode, a small manual force on the pusher (8) in axial direction is required.

The signal to reduce the manual force is either the circumstance that the pusher(S) is bottomed out, and can't be pushed further in axial direction, or the sudden reduction of back pressure, as the surface (25) of the splines of the rotor, slides along the teeth (19) of the pusher and the rotor (9) moves (11) radial and in axial towards genuine position, forced by the decompressed spring (7) lifting the worm bushing (1) and the connected rotor (9) towards genuine position.

Releasing the manual force further on the pusher (8) the spring (7) decompresses further, and pushes the worm bushing (1) and the connected rotor (9) in axial direction towards genuine position. As the rotor (9) has rotated, the surface (25) of the splines of the rotor (9) meet the surface (27) of the splines of the body (5) in axial direction (figure 9), and drives the splines of the rotor (9) into further axial and radial movement (11) against the surface (27) into the deep splines (17) back into genuine position (figure 4).

The complete return in axial direction of the worm bushing (1) drives the worm shaft (2) in reverse.

Unlock from the outside! Starting in the blocking position / back to genuine position A common toilet locker can be operated from the outside, specific in case of calamities It is common to have a provision to make a rotation to an extended part, fitted to the mutual axle. This extended part such as an indicator, provides to rotate the axle by a grove or similar to be applied for example by a screwdriver or a coin, Forcing the axle to rotate, the reverse action of the toilet locker can be achieved, and so disengagement between latch and jamb of the door.

One of the favourable configurations of the device provides this un-locking from the blocked position (figure 5), by adding a constant connection in axial direction (14) to create a small load between the surfaces of the teeth (19) of the pusher and the surfaces (25) of the splines of the rotor. The favourable configuration is a spring (10) positioned between the pusher (8) and the worm bushing (1).

From the other side of the door the axle is forced to rotate manually, using the mutual axle connected to the locking mechanism, like the latch, and connected to the worm shaft (2).

The small angle of rotation of the worm shaft (2) results in a pulling action of the worm shaft (2) relative to the worm bushing (1) as the worms (6) slide and so the worm bushing (1) moves axial towards the worm shaft (2). As the worm bushing (1) is connected to the pusher by the additional connection (10), the teeth (19) of the pusher are forcing the splines (18) of the rotor out of the blocking splines (28) of the body, and so out of the blocking position.

Releasing the manual force further on the axle the spring (7) decompresses further, and pushes the worm bushing (1) and the connected rotor (9) in axial direction towards genuine position. As the rotor (9) has rotated, the surface (25) of the splines of the rotor (9) meet the surface (27) of the splines of the body (5) in axial direction (figure 9), and drives the splines of the rotor (9) into further axial and radial movement (11) against the surface (27) into the deep splines (17) back into genuine position (figure 4). The blockade is released and so is he locking position of the mechanism.

Figure 1.

The figure shows a common door latch (16) mend to be fitted in the end face of a door, that operates by a rotation axle connected to number 22, sliding in and out the door pin (21). The latch has also a toilet locker, operated by an axle connected to number 23, locking the jamb of the door with lock pin (20).

Figure 2 This figure shows the worm bushing (1) with worm grove (13) matching the worm (6) of the worm shaft (2). The spring (7) is positioned in between. The hole (15)-here a square -in the worm shaft (2) is to accommodate an axle. Number 14 is indicating the mutual axial direction. Number 3 are the splines of the worm bushing (1).

Figure 3.

The parts are positioned in the axial line (14). The splines (3) of the worm bushing (1) are designed to slide in the splines (4) of the body (5) and an end -stop (12) is shown. Rotor (9) is matting the worm bushing (1) and is free of relative rotation and the surface (25) of the splines (18) are touching the teeth (19) of the pusher(s).

Figure 4.

This figure shows a cross cut of the device in genuine position, as the worm bushing (1) is positioned in the maximum top position. The splines (3) of the worm bushing (1) are slide within the splines (4) of the body (5). The spring (7) is clearly positioned between the worm bushing (1) and worm shaft (2) and has decompressed, and the worm shaft (2) has a provision (24) for the spring (7). Number 15 is the square hole in the worm shaft (2) to fit an axle. The worm bushing (1), the rotor (9) and the pusher(S) are relative positioned in axial direction. The figure shows that the worm (6) of the worm shaft (2) is fitted in the worm grove (13) of the worm bushing (1).

FigureS.

This figure shows a side cross cut of the device in blocked position, where the worm bushing (1) is blocked by the rotor (9), as the surface (25) of the spline (18) is blocked by the blocking splines of the body (5).

Figure 6.

This figure shows a side cross cut where the parts rotor (9) and body (5) are shown separate, indicating the genuine position. The splines(18) of the rotor (9) are slide into the deep splines (17) of the body (5).

Figure 7 This figure Is demonstrating 2 parts exclusive, and the relative position of the rotor (9) and the pusher (8).

Figure 7a. The teeth (19) of the pusher (8) and the splines (18) of the rotor(9) are positioned in axial line, as the teeth (19) and the splines (18) are both sliding within the deep splines (17) of the body(S) 9not shown. The width of the deep splines (17) limit parts 19 and 18 to move radial.

Figure 7b. This figure demonstrates the next stage as the pusher the rotor (9) is forced out of the splines (17) of the body (5) and the teeth (19) of the pusher is still within these splines (17). As the rotor (9) is no longer limited to move radial and/or axial, the matting surface (25) of the splines of the rotor and the teeth (19) of the pusher (8), are directing the rotor to move radial and axial (11). This figure shows a clockwise direction to the right.

Figure 7c Demonstrates the movement (11) of the rotor (9), containing radial movement (29) and axial movement (30), as described in 7B, with arrows.

FigureS. A crosscut is shown Further movement in axial direction towards genuine position for the rotor (9) and the body (5).

The figure demonstrating the nearly achieved blocking position of the rotor (9), after further rotating and axial movement. As the surface (25) of the splines of the rotor (9) slides along the surface of the splines (27) of the body (5), towards the blocking splines (28). The rotor will be held into blocking position and prevented for further axial movement.

Figure 9.

After held in position the stages 7A and 7B are indicating the loosening push out of the blocking position.

A side crosscut of the body and the rotor after the splines (18) of the rotor (5) after being pushed in axial direction out of the blocking splines (28) by the teeth (19) of the pusher (8), and the followed movement (11) in radial and axial direction of the rotor. The next stage is that the rotor is forced into axial direction towards genuine position as the spring (7) decompresses, and the surface (25) of the splines will meet the surface (27) of the splines, and forces the rotor to rotate further in axial and radial direction (11) , into the deep splines (17) of the body (5) back into genuine position.