Patent Description:
Door handle systems are used almost in every door. In the simplest form they comprise a movable bolt and a lock in which the bolt can engage. Depending on the needs, door handle systems may also comprise various electronic components which can be used to control different devices. Such door handle systems can therefore be used as safety doors and shut down devices, like robots, if the door is opened to avoid injuries.

A door handle system also has lot of user interaction. Current door handles in the market requires the user to manually rotate when opening, to retract the bolt, and when closing, to extend the bolt. Also, the handle orientation is different when the bolt is in its extended and retracted position. In addition, there are additional adjustments needed when the user needs to mount the handle from left to right door hinged installations, and vice versa. Other products also have dedicated door handle variants for left and right door hinged installations.

<CIT> describes a door handle system. The door handle system can be operated by a handle from one side of the door and by a key from the other side of the door. The bolt of the door handle system is also configured to automatically extend and lock the door as it closes. This is facilitated by a spring-pressed lever mechanism designed to retain the bolt in a retracted position when the door is open. As the door closes, the lever interacts with a fixed part on the door frame, which releases the bolt. Consequently, the bolt is pushed forward by springs into the locked position as soon as the door reaches the closed position.

<CIT> outlines a bolt retaining device configured to prevent the extension of a door's bolt into its locking position when the door is open, safeguarding against damage to both the doorframe and the bolt mechanism. The bolt retaining device features a bolt blocking plate maneuvered by a hinge operator and a biasing spring, ensuring the bolt remains retracted while the door is open. Upon closing, the bolt extends into its locking position automatically.

<CIT> describes a deadbolt lock system designed for enhancing security in areas requiring controlled access. The system includes a housing with a deadbolt capable of moving between extended and retracted positions, controlled by slider and lock mechanisms that facilitate or prevent bolt movement based on security requirements. The system also integrates an escape lever allowing bolt retraction from inside, regardless of other lock states, and includes a deadbolt hold back mechanism to prevent extension when the door is open, automatically extending the deadbolt when the door is closed.

<CIT> describes a lock system that features a unique bolt that remains retracted while the door is open and automatically unlocks as the door is fully closed.

<CIT> describes a door lock system which comprises a bolt that extends automatically when the door is closed. This automatic extension is triggered by the door's movement against a striker-plate, which slightly retracts the bolt, allowing the catch to move and release the bolt fully into engagement under the force of a spring.

<CIT> describes a lock designed for situations where the retracted latch automatically locks in an inactive position and is released only when a part of the release mechanism encounters the door's strike plate as the door closes.

The object of the present invention therefore is to improve the current door handle design in such a way that it overcomes the known problems and that it is more durable compared to current installations.

The object is solved by the door handle system according to the independent claim <NUM>. The dependent claims show preferred embodiments of the door handle system.

The door handle system according to the present invention can be used for a safety door, especially for a sliding door or swing door. The door handle system comprises a bolt unit. The bolt unit comprises a housing with a bolt opening. The bolt unit also comprises a handle. The handle is arranged (attached to) at the housing. The bolt unit also comprises a bolt module with a bolt. The bolt is movable respective to the housing. The bolt can be moved (pushed) out of the bolt opening for engaging with a corresponding lock opening of a lock unit. The bolt unit also comprises a restraining device with a bolt stopper. The bolt stopper is configured to be switched (i.e. moved) between a blocking position in which it engages with the bolt and a release position in which it releases the bolt thereby allowing the bolt to move out of the bolt opening. Preferably, the bolt is fully or predominantly arranged within the housing if the bolt stopper is in the blocking position. The door handle system also comprises an activation means, wherein the bolt stopper is configured to get in contact with the activation means in a closed state of the safety door thereby switching (i.e. moving the bolt stopper) to the release position.

It is very beneficial that the bolt only moves out of the bolt opening if the bolt stopper is in the release position. As such, the bolt is protected and cannot be damaged by closing the (swing) door. Furthermore, the use of the activation means is also very beneficial, because the only thing the user has to do is closing the door in order to make sure that the bolt is being pushed out of the bolt opening and engages with the lock unit.

In a preferred embodiment of the invention, the bolt stopper is configured to prevent the bolt from moving out of the bolt opening if the bolt stopper is in the blocking position. This is preferably done by blocking a part or most of the bolt opening of the housing while the bolt is retracted (located in) into the housing.

In a preferred embodiment of the invention, the door handle system comprises a lock unit, wherein the lock unit comprises a lock housing with the lock opening and wherein the lock unit comprises the activation means.

In a preferred embodiment of the invention, the lock unit is configured to be arranged stationary and the bolt unit is configured to be arranged on the movable safety door. Alternatively, the bolt unit is configured to be arranged stationary and the lock unit is configured to be arranged on the movable safety door.

In a preferred embodiment of the invention, the lock housing and the activation means are made of a single piece. They could comprise or consist of metal or plastic.

In a preferred embodiment of the invention, the activation means comprises a protrusion configured to get into contact with the bolt stopper if the safety door is in a closed position, thereby displacing (moving) the bolt stopper so that the bolt stopper switches to the release position.

In a preferred embodiment of the invention, the bolt stopper is a frame surrounding an opening, wherein the opening of the frame aligns with the bolt opening of the housing if the bolt stopper is the release position, thereby allowing the bolt to move through the opening of the frame and out of the bolt opening of the housing.

In a preferred embodiment of the invention, the frame has a cross section in form of a rectangle or a square. The cross section can also be oval or circular.

In a preferred embodiment of the invention, the frame is fully closed, except for the opening, thereby surrounding bolt in the release position. However, the frame could also comprise interruptions in its frame structure.

In a preferred embodiment of the invention, the bolt stopper rests on the front side of the bolt or on a shoulder of the bolt if the bolt stopper is in the blocking position. If it rests on the front site of the bolt, then the bolt is protected by the bolt stopper while the bolt stopper is in the blocking position.

In a preferred embodiment of the invention, the bolt stopper is in the blocking position while the safety door is opened. Contrary to that, the bolt stopper is in the release position while the safety door is closed.

In a preferred embodiment of the invention, the bolt is invisible during operation of the safety door. If the safety door is opened, the bolt is arranged inside the housing of the bolt unit and shielded by the bolt stopper. If the safety door is closed, the bolt is arranged within the lock opening of the lock unit and shielded by the lock housing. Therefore, damages to the bolt are unlikely.

In a preferred embodiment of the invention, the restraining device comprises a restraining spring, wherein the restraining spring is configured to engage with the bolt stopper in such a way that the bolt stopper rests in the blocking position until it gets in contact with the activation means. Therefore, vibrations applied to the safety door, for example from moving the safety door, would not result in the bolt stopper switching from the blocking position to the release position before the safety door is in its closed position. In addition, the restraining spring is configured to engage with the bolt stopper in such a way that the bolt stopper switches from the release position into the blocking position after the bolt is retracted back into the bolt opening of the housing of the bolt unit and especially behind the bolt stopper. Normally, the bolt is retracted back upon opening the safety door, for example by pressing the handle downwards or upwards. It is very beneficial that the restraining spring permanently applies a closing force on the bolt stopper so that the bolt stopper closes the bolt opening of the housing as soon as the bolt is behind the bolt stopper or as soon as the shoulder of the bolt is behind the bolt stopper. Therefore, the time the bolt is exposed to the surrounding is kept to a minimum. In addition, the activation means must apply a force greater than the closing force of the restraining spring to the bolt stopper in order to switch it from the blocking position into the release position. This force can easily be applied upon closing the safety door.

In a preferred embodiment of the invention, the bolt stopper is configured to seal the housing of the bolt unit. Preferably, the bolt stopper comprises a sealing element like a rubber sealing or a brush-like sealing. Using a sealing, impurities like water droplets or dust particles can be kept outside the housing of the bolt unit.

According to the invention, the bolt module comprises a body portion, wherein the bolt is forming a first end of the body portion. The bolt unit further comprises a spring, wherein the spring is configured to apply a force on the body portion in the direction of the bolt opening of the housing. Depending on the arrangement of the spring, the spring pulls or pushes the body portion towards the bolt opening. If the bolt stopper is in the release position, then the force of the spring pushes the bolt out of the bolt opening. The bolt and the body portion can be made of a single piece or of separate pieces. The body portion can also be made of separate pieces.

In a preferred embodiment of the invention, a first end of the spring is attached at the body portion of the bolt module and a second end of the spring is attached at the housing of the bolt unit in a region of the bolt opening or at the restraining device. In these cases, the spring is configured to pull the body portion of the bolt module towards the bolt opening of the housing. Of course, more than one spring can be used for that purpose.

In a preferred embodiment of the invention, the spring is a spiral spring. More preferably, the spring is made of steel, especially stainless steel.

According to the invention, the housing of the bolt unit comprises a fastening opening opposite to the bolt opening. The body portion comprises a fastening part forming a second end of the body portion opposite to the first end. The fastening part is configured to protrude out of the fastening opening of the housing if the bolt stopper is in the blocking position. In addition, the fastening part is arranged within the housing if the bolt stopper is in the release position. The fastening part is configured to engage with a fastening mean thereby limiting the movement of the bolt respective to the housing. It is very beneficial that an additional fastening part is present. An operator who wants to go into a sealed environment (for example a cage in which a robot operates) can indicate his presents in the sealed environment by attaching a personal lock (for example a U-Bolt lock) to the fastening part. In return, the bolt will not move out of the bolt opening, because the movement is limited by the fastening mean attached by the operator since the fastening mean cannot be moved into the housing through the fastening opening. As such, even if the bolt stopper engages with the activation mean, the bolt stopper cannot switch from the blocking position into the release position. Therefore, the door handle system would not be able to transmit a status signal indicating that the safety door is successfully closed thereby allowing a machinery inside the sealed environment to start up.

In a preferred embodiment of the invention, the housing of the bolt unit comprises a second opening which is arranged opposite to the bolt opening. The bolt module is arrangeable within the housing such that the bolt can be moved out of the second opening instead of the bolt opening which allows the door handle system to be applied to a safety door that opens to the right as well as to a safety door that opens to the left. The second opening can of course be the fastening opening as described in the previous paragraph. Having two similar openings, the installation of the door handle system is simplified.

In a preferred embodiment of the invention, the handle comprises at least one cam or one finger which is configured to get into contact with the bolt module if the handle is pressed. By pressing the handle upwards or downwards, it therefore moves from a first position which can also be called neutral position into a second position. The at least on cam or the at least one finger also rotates as the handle does. By this rotation, the at least one cam or the at least one finger is configured to push the bolt module away from the bolt opening of the housing so that the bolt is moved back into the bolt opening of the housing. As a result, the bolt stopper switches from the release position into the blocking position as soon as the handle is rotated into the second position.

In a preferred embodiment of the invention, the bolt body and therefore the bolt is configured to move along one axis only.

In a preferred embodiment of the invention, a return spring is provided and attached to the handle and the housing. The return spring is configured to move the handle back from second position into the first position. Of course, this is only done if the handle is not pressed (for example upwards or downwards) anymore. In that case, the at least one cam or the at least one finger does not engage with the bolt module anymore. If the activation means engages with the bolt stopper (when closing the safety door), then the bolt stopper immediately switches into the release position. The spring attached to the bolt module therefore pulls the bolt module towards to bolt opening.

In a preferred embodiment of the invention, the return spring is only arranged within the housing of the bolt unit and therefore preferably invisible from the outside of the housing.

In a preferred embodiment of the invention, the restraining spring of the restraining device comprises a first end and a second end, wherein the first end engages with the bolt stopper and the second end engages with the housing of the bolt unit.

In a preferred embodiment of the invention, the activation means is configured to move the bolt stopper against the force of the restraining spring from the blocking position into the release position upon closing of the safety door.

In a preferred embodiment of the invention, the bolt stopper is configured to be moved along one axis.

In a preferred embodiment of the invention, the axis along which the bolt stopper is moveable is arranged perpendicular to the axis along which the bolt is moveable.

In a preferred embodiment of the invention, the bolt stopper is configured to be moved towards a side of the housing of the bolt unit at which the handle is arranged. Alternatively, the bolt stopper is configured to be moved towards a side of the housing of the bolt unit which is opposite to the side of the housing of the bolt unit at which the handle is arranged.

In a preferred embodiment of the invention, the bolt stopper is arranged within the housing of the bolt unit or within a housing module of the restraining device.

In a preferred embodiment of the invention, the bolt stopper is movable with regard to the housing of the bolt unit. However, the bolt stopper is preferably only moveable in one axis with regards to the housing of the bolt unit.

In a preferred embodiment of the invention, the bolt stopper is arranged within a recess of the housing of the bolt unit.

Different embodiments of the invention will be described in the following, by way of example and with reference to the drawings. The same elements are provided with the same reference signs. The figures show in detail:.

<FIG> shows a door handle system <NUM> for a safety door <NUM>, especially for a sliding door 2a or swing door 2b. Furthermore, a cage <NUM> is shown enclosing a sealed environment <NUM> in which a machine, for example in form of a robot, is operating. Upon opening the safety door <NUM>, the door handle system <NUM> is preferably configured to transmit a status update so that the machine within the sealed environment <NUM> stops. This status update could be transmitted directly to the machine or indirectly via a central processing unit (not shown), which in turn turns off the machine. Upon closing the safety door <NUM>, the door handle system <NUM> is preferably configured to transmit another status update so that the machine arranged within the sealed environment <NUM> resumes operation.

<FIG> show an embodiment of the door handle system <NUM> arranged on a door <NUM> in form of a sliding door 2a. In <FIG> the sliding door 2a is at least partly open, wherein in <FIG> the sliding door 2a is closed.

As can be seen, the door handle system <NUM> comprises two units. A bolt unit <NUM> and a lock unit <NUM>. The bolt unit <NUM> comprises a housing <NUM> with a bolt opening <NUM>, and a handle <NUM>. The handle <NUM> is arranged at the housing <NUM>. The bolt unit <NUM> comprises a bolt module <NUM> with a bolt <NUM>. The bolt <NUM> is moveable respective to the housing <NUM>. The bolt <NUM> can be moved out of the bolt opening <NUM> of the housing <NUM> for engaging with a corresponding lock opening <NUM> of the lock unit <NUM>. The bolt unit <NUM> comprises a restraining device <NUM> with a bolt stopper <NUM> (see <FIG> for example). The bolt stopper <NUM> is configured to be switched between a blocking position in which it engages with the bolt <NUM> and a release position in which it releases the bolt <NUM> thereby allowing the bolt <NUM> to move out of the bolt opening <NUM>.

In the blocking position, the bolt stopper <NUM> is configured to prevent the bolt <NUM> from moving out of the bolt opening <NUM>. Preferably, the bolt stopper <NUM> only limits the movement of the bolt <NUM> in one direction, namely out of the bolt opening <NUM>. The bolt <NUM> can still be able to move in the opposite direction, namely further into the housing <NUM> of the bolt unit <NUM>.

The lock unit <NUM> comprises an activation means <NUM> and a lock housing <NUM>. The bolt stopper <NUM> is configured to get in contact with the activation means <NUM> in a closed state of the safety door <NUM> thereby switching to the release position.

The lock housing <NUM> and the activation means <NUM> are preferably made of a single piece. However, the activation means <NUM> could also be attached to the lock housing <NUM>, for example by a screwing connection or clipping connection.

The activation means <NUM> preferably protrudes from the lock housing <NUM>.

The activation means <NUM> preferably comprises a protrusion configured to get into contact with the bolt stopper <NUM> if the safety door <NUM> is in a closed position, thereby displacing the bolt stopper <NUM> so that the bolt stopper <NUM> switches to the release position.

Within <FIG>, the lock unit <NUM> is configured to be arranged stationary and the bolt unit <NUM> is configured to be arranged on the movable safety door <NUM>. In general, the bolt unit <NUM> could also arranged stationary and the lock unit <NUM> could be arranged on the movable safety door <NUM>.

<FIG> and <FIG> show a detailed view on the bolt unit <NUM>, wherein one half of the housing <NUM> is opened so that the internal of the housing <NUM> is visible. In addition, the restraining device <NUM> is shown in detail.

<FIG> shows the bolt stopper <NUM> in the blocking position and <FIG> shows the bolt stopper <NUM> in the release position.

The bolt module <NUM> comprises a body portion <NUM>, wherein the bolt <NUM> forms a first end 18a of the body portion <NUM> and wherein the bolt unit <NUM> comprises a spring <NUM>. The spring <NUM> is configured to apply a force on the body portion <NUM> in the direction of the bolt opening <NUM> of the housing <NUM>. If the bolt stopper <NUM> is in the release position, the force of the spring <NUM> would push the bolt <NUM> out of the bolt opening <NUM> of the housing <NUM>. Between the blocking position and the release position of the bolt stopper <NUM>, the bolt module <NUM> moves relative to the housing <NUM> of the bolt unit <NUM> (inside that housing <NUM>).

The restraining device <NUM> comprises a housing module <NUM> attached to the housing <NUM> of the bolt unit <NUM>. In that case, the restraining device <NUM> is screwed to the housing <NUM> of the bolt unit <NUM> through its housing module <NUM>. The bolt opening <NUM> is therefore part of the housing <NUM> as well as part of the housing module <NUM> of the restraining device <NUM>. The restraining device <NUM> elongates the housing <NUM> of the bolt unit <NUM> in the direction of the moving bolt <NUM>. The housing module <NUM> is stationary connected to the housing <NUM> of the bolt unit <NUM>. Only the bolt stopper <NUM> is arranged moveably towards the housing <NUM> of the bolt unit <NUM>. In addition, the bolt stopper <NUM> is also arranged moveably towards the housing module <NUM> of the restraining device <NUM>.

Preferably, most parts of the bolt stopper <NUM> are covered by the housing module <NUM>. In that case, only the part of the bolt stopper <NUM> that is supposed to get into contact with the activation means <NUM> is not covered by the housing module <NUM> of the restraining device <NUM>.

A first end 19a of the spring <NUM> is attached at the body portion <NUM> of the bolt module <NUM>. A second end 19b of the spring <NUM> is attached at the restraining device <NUM>. The second end 19b of the spring <NUM> could also be attached at the housing <NUM> of the bolt unit <NUM> in a region of the bolt opening <NUM> or at the housing module <NUM> of the restraining device <NUM>.

The body portion <NUM> of the bolt module <NUM> comprises a spring attachment <NUM>. The spring <NUM> is attached with its first end 19a to the spring attachment <NUM> and therefore to the body portion <NUM>. Preferably, the spring attachment <NUM> is arranged closer to a side wall of the housing <NUM> than the body portion <NUM>, thereby providing some space to the spring <NUM>. In this embodiment, the spring attachment <NUM> and the body portion <NUM> are separate elements which are preferably screwed together. However, the spring attachment <NUM> and the body portion <NUM> could also be formed by one element, wherein the spring attachment <NUM> is for example bent towards the side of the housing <NUM>.

In the blocking position of the bolt stopper <NUM>, the spring attachment <NUM> is preferably arranged further away from the bolt opening <NUM> than the axis of rotation of the handle <NUM>.

In <FIG> and <FIG>, two springs <NUM> are used which are arranged in parallel. Between the two springs <NUM> the bolt <NUM> is moved. If the door handle system <NUM> is mounted, one spring <NUM> is arranged closer to the floor than the other spring <NUM>. Using two springs <NUM> with the bolt <NUM> arranged in between, comes with the benefit that a force can be applied to the body portion <NUM> which is oriented parallel to the movement of the bolt, thereby avoiding that the bolt <NUM> might get misaligned or rubbing against the housing <NUM> or the housing module <NUM>.

The bolt opening <NUM> extends through the housing <NUM> of the bolt unit <NUM> and through the housing module <NUM> of the restraining device <NUM>. However, the housing module <NUM> of the restraining device <NUM> is optional, because the housing <NUM> of the bolt unit <NUM> could also serve as housing of the restraining device13.

<FIG> and <FIG> explain the restraining device <NUM> in more detail. Within <FIG> the bolt stopper <NUM> is in its blocking position, thereby limiting the movement of the bolt <NUM>. Contrary to that, <FIG> shows the bolt stopper <NUM> in its release position, thereby allowing the bolt <NUM> to move out of the bolt opening <NUM>.

Within <FIG>, the bolt stopper <NUM> rests on a shoulder of the bolt <NUM>. Therefore, the movement of the bolt <NUM> is restraint in one direction, namely out of the bolt opening <NUM>. Of course, the bolt stopper <NUM> could also rest on the front side of the bolt <NUM>.

In order to assure that the bolt stopper <NUM> can switch from the release position into the blocking position thereby engaging with the bolt <NUM>, the restraining device <NUM> comprises a restraining spring <NUM>. The restraining spring <NUM> is configured to apply a (constant) force onto the bolt stopper <NUM>, thereby displacing the bolt stopper <NUM> in such a way that the bolt stopper <NUM> closes the bolt opening <NUM> at least partly if the bolt <NUM> is retracted into the housing <NUM> of the bolt unit <NUM>. Therefore, a first end of the restraining spring <NUM> rests against the housing module <NUM> of the restraining device <NUM> or against the housing <NUM> of the bolt unit <NUM>. A second end of the restraining spring <NUM> rests against the bolt stopper <NUM>. The restraining spring <NUM> is preferably arranged within the housing module <NUM> or the housing <NUM>.

The bolt stopper <NUM> is in form of a frame enclosing an opening, wherein the opening of the frame aligns with the bolt opening <NUM> of the housing <NUM> if the bolt stopper <NUM> is the release position, thereby allowing the bolt <NUM> to move through the opening of the frame and out of the bolt opening <NUM> of the housing <NUM>. This position is shown in <FIG>. However, if the bolt stopper <NUM> is displaced by the restraining spring <NUM>, then the bolt stopper <NUM> is in the blocking position as shown in <FIG>. If the bolt stopper <NUM> rests on a shoulder of the bolt <NUM>, then the bolt <NUM> at least partly extends though the opening of the frame of the bolt stopper <NUM> both in the blocking position an in the release position. However, in the release position, also the shoulder of the bolt <NUM> can pass through the opening of the frame of the bolt stopper <NUM>.

In order for the bolt stopper <NUM> to switch from the blocking position (<FIG>) to the release position (<FIG>), the activation means <NUM> comes into contact with the bolt stopper <NUM> thereby displacing the bolt stopper <NUM> against the force of the restraining spring <NUM>, so that the opening of the frame of the bolt stopper <NUM> aligns with the bolt opening <NUM>. Then the bolt <NUM>, including its shoulder, passes through the opening of the frame of the bolt stopper <NUM>.

<FIG> shows how the bolt stopper <NUM> is switched back from the release position to the blocking position. To do so, the bolt <NUM> needs to be retracted. This is achieved by pressing the handle <NUM>. The handle <NUM> comprises at least one cam or finger <NUM> which is configured to get into contact with the bolt module <NUM> if the handle <NUM> is pressed. The cam or finger <NUM> therefore moves from a first position into a second position thereby moving the bolt module <NUM> away from the bolt opening <NUM> of the housing <NUM> so that the bolt <NUM> is retracted back into the bolt opening <NUM> of the housing <NUM>. In other words, the handle <NUM> is a first (neutral) position if not pressed and in a second position if pressed. This allows the bolt stopper <NUM> to switch from the release position into the blocking position by the use of the restraining spring <NUM>. The cam or finger <NUM> is fixedly attached to the handle <NUM>. If the handle <NUM> is rotated by <NUM>°, then the cam or finger <NUM> is also rotated by <NUM>°. The bolt module <NUM> comprises contact means <NUM>. The contact means <NUM> is connected (for example screwed) to the body portion <NUM> or is an integral part of the body portion. So, if the cam or finger <NUM> comes into contact with the contact means <NUM> upon pressing the handle <NUM> (upwards or downwards), then the contact means <NUM> and therefore the body portion <NUM> gets shifted which in turn results in the bolt <NUM> to be retracted into the bolt opening <NUM>. The contact means <NUM> is preferably in a different layer compared to the spring attachment <NUM>, so that the spring <NUM> is always arranged in a contact free manner with regard to the contact means. This means that the distance between the contact means <NUM> and the spring attachment <NUM> to the side wall of the housing <NUM> is different.

Within <FIG>, the handle comprises two cams or fingers <NUM> which are spaced apart by approximately <NUM>°. This allows the handle <NUM> to be pressed downwards as shown in <FIG> or to be pressed upwards in order to retract the bolt <NUM> and to open the safety door <NUM>. If the handle <NUM> is pressed downwards, then the first cam or finger <NUM> comes into contact with the contact means <NUM>. If the handle <NUM> is pressed upwards, then the second cam or finger <NUM> comes into contact with the contact means <NUM>.

Preferably, the cam or finger <NUM> elongates for a certain length, wherein the contact area between the cam or finger <NUM> and the contact means <NUM> is at an end region of the cam or finger <NUM> and therefore spaced apart from the axis of rotation of the handle <NUM>.

Upon pressing the handle <NUM>, the handle <NUM> stays in place and is always arranged stationary with respect to the housing <NUM> of the bolt unit <NUM>. However, the bolt module <NUM> moves with respect to the handle <NUM>. For doing so, the body portion <NUM> preferably comprises a recess <NUM> (see <FIG>). The recess <NUM> allows that the body portion <NUM> slides around a part of the handle <NUM>.

Within <FIG> and <FIG>, a return spring <NUM> is shown. The return spring <NUM> is attached to the handle <NUM> (for example through the cam or finger <NUM>) and the housing <NUM> of the bolt unit <NUM>. The return spring <NUM> is configured to move the handle <NUM> back from second position into the first position. The bolt module <NUM> stays in position, because the bolt stopper <NUM> engages with the bolt <NUM> (because of the restraining spring <NUM>) after the bolt <NUM> was pulled back after pressing the handle <NUM>.

<FIG>, <FIG>, <FIG> and <FIG> also show that the housing <NUM> of the bolt unit <NUM> comprises a fastening opening <NUM> opposite to the bolt opening <NUM>. The body portion <NUM> comprises a fastening part <NUM> forming a second end 18b of the body portion <NUM> opposite to the first end 18a. The fastening part <NUM> is configured to protrude out of the fastening opening <NUM> of the housing <NUM> if the bolt stopper <NUM> is in the blocking position. Contrary to that, the fastening part <NUM> is arranged within the housing <NUM> if the bolt stopper <NUM> is in the release position. The fastening part <NUM> is configured to engage with a fastening mean (not shown), like a U-Bolt lock, thereby limiting the movement of the bolt <NUM> respective to the housing <NUM> of the bolt unit <NUM>. For doing so, the fastening part <NUM> comprises a fastening opening <NUM>.

The fastening part <NUM> and the body portion <NUM> can be an integral part or made of separate pieces.

The bolt module <NUM> can comprise of one part which is a bent, pressed, punched and/or lasered part. If the bolt <NUM>, the body portion <NUM>, the spring attachment <NUM>, the contact means <NUM> and the fastening part <NUM> are fully or in part separate elements which are for example screwed together, each of the parts can be bent, pressed, punched and/or lasered part. In that case, they are preferably made of metal or comprise metal. However, they could also be made of plastic. The cam or finger <NUM> could also be a bent, pressed, punched and/or lasered part. The cam or finger <NUM> is preferably made of metal or comprises metal.

<FIG> shows that the door handle system <NUM> can applied to both safety doors <NUM>, namely to safety doors <NUM> that open to the left as well as to safety doors <NUM> that open to the right. For doing so, the handle <NUM> can for example mounted to the other side of the housing <NUM> of the bolt unit. Preferably and as shown in <FIG> and <FIG>, the restraining device <NUM> can easily be mounted on the other end of the housing <NUM>. In that case, the bolt opening <NUM> and the fastening opening <NUM> switch sides.

The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention, which is defined by the appended claims. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

Claim 1:
A door handle system (<NUM>) for a safety door (<NUM>), especially for a sliding door (2a) or swing door (2b), comprising the following features:
- a bolt unit (<NUM>) is provided, wherein the bolt unit (<NUM>) comprises a housing (<NUM>) with a bolt opening (<NUM>), and a handle (<NUM>), wherein the handle (<NUM>) is arranged at the housing (<NUM>);
- the bolt unit (<NUM>) comprises a bolt module (<NUM>) with a bolt (<NUM>);
- the bolt (<NUM>) is moveable respective to the housing (<NUM>), wherein the bolt (<NUM>) can be moved out of the bolt opening (<NUM>) of the housing (<NUM>) for engaging with a corresponding lock opening (<NUM>) of a lock unit (<NUM>);
- the bolt unit (<NUM>) comprises a restraining device (<NUM>) with a bolt stopper (<NUM>);
- the bolt stopper (<NUM>) is configured to be switched between a blocking position in which it engages with the bolt (<NUM>) and a release position in which it releases the bolt (<NUM>) thereby allowing the bolt (<NUM>) to move out of the bolt opening (<NUM>);
- an activation means (<NUM>) is provided, wherein the bolt stopper (<NUM>) is configured to get in contact with the activation means (<NUM>) in a closed state of the safety door (<NUM>) thereby switching to the release position;
- the bolt module (<NUM>) comprises a body portion (<NUM>), wherein the bolt (<NUM>) forms a first end (18a) of the body portion (<NUM>) and wherein the bolt unit (<NUM>) comprises a spring (<NUM>), wherein the spring (<NUM>) is configured to apply a force on the body portion (<NUM>) in the direction of the bolt opening (<NUM>) of the housing (<NUM>);
characterized in that
- the housing (<NUM>) of the bolt unit (<NUM>) comprises a fastening opening (<NUM>) opposite to the bolt opening (<NUM>), wherein the body portion (<NUM>) comprises a fastening part (<NUM>) forming a second end (18b) of the body portion (<NUM>) opposite to the first end (18a) and wherein the fastening part (<NUM>) is configured to protrude out of the fastening opening (<NUM>) of the housing (<NUM>) if the bolt stopper (<NUM>) is in the blocking position and wherein the fastening part (<NUM>) is arranged within the housing (<NUM>) if the bolt stopper (<NUM>) is in the release position and wherein the fastening part (<NUM>) is configured to engage with a fastening mean thereby limiting the movement of the bolt (<NUM>) respective to the housing (<NUM>).