Patent Description:
A vertical conveyor developed and offered by the Applicant is the Prorunner MK5. This is a continuous vertical conveyor, which is specifically suitable for average to high capacity applications. It comprises carriers that are moveable in an endless track, wherein said carriers are configured to transport products between a supply conveyor and a discharge conveyor that are arranged a different height levels. The carrier thus picks up products from the supply conveyor and sets the products down on a discharge conveyor, thereby bridging a height difference.

During use, products may sometimes fall off a carrier and get trapped, possibly causing damage to either one of the assembly as a whole, i.e. to the vertical conveyor, the supply conveyor and/or the discharge conveyor, or to the product.

<CIT>, which is considered the closest prior art, discloses a paternoster elevator having a safety.

The Japanese patent application <CIT> also discloses a vertical conveyor having a safety. <CIT> is acknowledged as further prior art.

An objective of the present invention is to provide an assembly, that is improved relative to the prior art and wherein at least one of the above stated problems is obviated.

The invention proposes a solution of a mechanical nature to the problem of how to prevent damage to either one of the assembly as a whole, i.e. to the vertical conveyor, the supply conveyor and/or the discharge conveyor, or to the product. An alternative solution of an electrical! electronic nature, which is not part of the invention, is also described.

Said objective is achieved with the assembly according to claim <NUM> comprising:.

The assembly according to the invention comprises a mechanical safety that comprises a pivot that is configured to allow a displacement of at least one of the carrier or of the transfer section to mitigate damage to the assembly and/or to the blocking product. In this way, the carrier is incorporated as part of safety means used for detecting a product that would block and thereby impede the operation of the assembly, and that would consequently possibly cause damage to said assembly. The mechanical safety according to the invention provides a simple, reliable and robust safety.

By stopping the assembly as soon as a product blocking the carrier is detected, unnecessary damage to the assembly and/or to the product may be prevented.

Said objective is also achieved with the assembly according to the alternative solution of an electrical/electronic nature, which is not part of the present invention, comprising:.

By applying a processor and/or motor drive that is configured to reverse the motor relative to a movement thereof before the block, stop or slow-down is detected, the assembly according to the alternative solution of an electrical/electronic nature allows a blocking product to be liberated and thereafter manually removed.

The invention is also related to a vertical conveyor for such an assembly according to claim <NUM>, comprising a carrier having a safety configured to detect a product blocking a carrier of the vertical conveyor and stop the assembly.

Furthermore, the invention is related to a conveyor for such an assembly according to claim <NUM>, comprising a transfer section that comprises a safety configured to detect a product blocking a carrier of the vertical conveyor and stop the assembly.

Preferred embodiments are the subject of the dependent claims.

In the following description preferred embodiments of the present invention are further elucidated with reference to the drawing, in which:.

The assembly <NUM> comprises a vertical conveyor <NUM> configured to at least one of pick up products <NUM> from and place products <NUM> on a transfer section <NUM> of a further conveyor <NUM>, and a safety <NUM> configured to detect a product <NUM>, <NUM>-b blocking a carrier <NUM> of the vertical conveyor <NUM> and stop the assembly <NUM> (<FIG>). By stopping the assembly <NUM> as soon as a product <NUM>, <NUM>-b blocking the carrier <NUM> is detected, unnecessary damage to the assembly <NUM>, and possibly also to the product <NUM>, <NUM>-b, may be prevented.

The carrier <NUM> may comprise a fork shape, wherein the teeth <NUM> of the fork shaped carrier <NUM> are configured to pass through spaces between adjacent rollers <NUM> of the further conveyor <NUM>, which may be a roller track but is not limited thereto. In this way, the carrier <NUM> may place a product <NUM> when the carrier <NUM> moves downward and passes the transfer section <NUM> of the further conveyor <NUM>. Conversely, the carrier <NUM> may pick up a product <NUM> from the transfer section <NUM> of the further conveyor <NUM> if a product <NUM> is present on said transfer section <NUM> and the carrier <NUM> moves upward and passes the transfer section <NUM>.

A product <NUM>, <NUM>-b blocking a carrier <NUM> of the vertical conveyor <NUM> may occur in a variety of situations as shown in <FIG>.

In a first blocking situation as shown in <FIG>, the carrier <NUM> carries a product <NUM> and moves downward to place the product <NUM> on the transfer section <NUM>. However, a further product <NUM>, <NUM>-b that is still present on the transfer section <NUM> may be blocking the downward travel of the carrier <NUM>.

In a second blocking situation as shown in <FIG>, the carrier <NUM> moves upward towards the transfer section <NUM> of the further conveyor <NUM> to pick up a product <NUM>. It may occur that the carrier <NUM> still inadvertently carries a further product <NUM>, <NUM>-b. For example, said further product <NUM>, <NUM>-b may accidentally not have been placed down, or said further product <NUM>, <NUM>-b may even have fallen onto the carrier <NUM>. In all cases, said further product <NUM>, <NUM>-b that is inadvertently carried by carrier <NUM> will block the carrier <NUM> when said further product <NUM>, <NUM>-b is trapped between the upward moving carrier <NUM> and the transfer section <NUM> of the further conveyor <NUM>.

In order to deal with blocking situations of the first and second type described above and shown in <FIG> respectively, the safety <NUM> may be configured to detect a product <NUM>, <NUM>-b blocking between the carrier <NUM> of the vertical conveyor <NUM> and the transfer section <NUM> of the further conveyor <NUM>.

In a third blocking situation as shown in <FIG>, the carrier <NUM> may carry a product <NUM>, <NUM>-b that extends sideways beyond the carrier <NUM> to such an extent that it interferes with a travel path of a further carrier <NUM>' that travels in an opposite direction as carrier <NUM>. The product <NUM>, <NUM>-b may get trapped between the two approaching carriers <NUM>, <NUM>'.

In order to deal with this third type of blocking situation shown in <FIG>, the safety <NUM> may be configured to detect a product <NUM> blocking between the carrier <NUM> of the vertical conveyor <NUM> and a further carrier <NUM>' of the vertical conveyor <NUM>.

Although it is conceivable that the safety <NUM> comprises contactless sensor, e.g. based on vision, a far more simple, reliable and robust safety <NUM> may be obtained if the safety is a mechanical safety.

At least one of the carrier <NUM> of the vertical conveyor <NUM> and the transfer section <NUM> of the further conveyor <NUM> comprises the safety <NUM>.

The safety <NUM> comprises a pivot <NUM> that is configured to allow a displacement of at least one of the carrier <NUM> or of the transfer section <NUM> to mitigate damage to the assembly <NUM> and/or to the blocking product <NUM>, <NUM>-b.

The pivot <NUM> of the safety <NUM> may be configured to allow a displacement Du, Dd around pivot axis P if a blocking causes a force above a predetermined threshold. If the force of the predetermined threshold is set at a level that is higher than a downward gravity force caused by the mass of a product <NUM>, a single safety may be used to detect a blocking in the three types of blocking situations shown in <FIG>.

In a more preferred embodiment, the pivot <NUM> of the safety <NUM> is configured to only allow an upward displacement Du. If a downward displacement Dd is prevented by the mechanical nature of the pivot <NUM>, the predetermined threshold may set to a significantly lower value than if the threshold needs to be high enough to at least counteract the weight of the heaviest type of product <NUM> the carrier <NUM> should be able to carry. Thus, if the pivot <NUM> only allows an upward displacement Du, the safety <NUM> may be set to a more sensitive setting. The sooner the safety <NUM> detects a product <NUM>, <NUM>-b blocking the carrier <NUM> and stops the assembly <NUM>, the less damage to the assembly <NUM> and/or to the blocking product <NUM>, <NUM>-b is likely to occur. This is a benefit for a pivot <NUM> of both the transfer section <NUM> and of the carrier <NUM>. A further advantage of the pivot <NUM> being configured to only allow an upward displacement Du is of particular importance to carrier <NUM>, because a too far downward displacement Dd could result in a product <NUM> sliding and falling off of the carrier <NUM>. Such a falling product <NUM> may damage, may cause further blocking situations similar to <FIG>, and may possibly even cause unsafe situation for human operators.

If both the carrier <NUM> of the vertical conveyor <NUM> and the transfer section <NUM> of the further conveyor <NUM> comprise the safety <NUM>, all blocking situations shown in <FIG> may be effectively blocked with pivots <NUM> that are configured to only allow an upward displacement Du. After all, in the <FIG> situation the carrier <NUM> may displace upwardly, whereas the transfer section <NUM> of the further conveyor <NUM> may displace, i.e. pivot, upward in the <FIG> situation. In the blocking situation of <FIG>, the further carrier <NUM>, which is identical to carrier <NUM>, may displace, i.e. pivot, upward. Thus, in a preferred embodiment, each of the carrier <NUM> (and possibly further carriers <NUM>') and the transfer section <NUM> comprises a pivot <NUM> that only allows an upward displacement Du.

A very simple, reliable and robust assembly <NUM> is obtained if the safety <NUM> comprises a switch <NUM>. The switch <NUM> may be configured to stop the assembly <NUM> by breaking an electrical circuit or providing an electrical signal if the safety <NUM> detects a product <NUM>, <NUM>-b blocking a carrier <NUM>, <NUM>' of the vertical conveyor <NUM>.

In <FIG> a motor control <NUM> is shown, for controlling a motor <NUM> having an output shaft <NUM>. Output shaft <NUM> of motor <NUM> has a tooth wheel <NUM> at an end thereof to rotationally propel a drive belt <NUM>, connected to the assembly in any of the foregoing figures. Alternatively, a chain or direct drive may be implemented, instead of belt <NUM>.

Control <NUM> comprises an encoder <NUM>, which is associated with motor shaft <NUM>. Encoder <NUM> measures rotation of shaft <NUM>. Preferably, encoder <NUM> is a high resolution encoder, which may, for example, generate <NUM> pulses for a full <NUM>° rotation, but lower resolution encoders, or other measurement equipment may be employed instead of encoder <NUM>. A measurement signal is provided by encoder <NUM> to a processor <NUM>, which may be configured to detect, from the measurement signals, whether the device is blocked or excessively loaded, causing slow down or stop of the assembly.

When a block, stop or slow down is detected by processor <NUM> from measurement signals from encoder <NUM>, it generates appropriate control signals for a motor drive <NUM>, to stop the motor <NUM>.

In a preferred embodiment, processor <NUM> and/or motor drive <NUM> is configured to reverse motor <NUM>, wherein the reversal is relative to the movement of said motor <NUM> before the block, stop or slow-down is detected. Thus, blocking product <NUM>, <NUM>-b may be liberated and thereafter manually removed.

The processor <NUM> may be formed by a CPU of a computer (not shown), or any appropriately programmed PLC (not shown).

However, in the embodiment of <FIG>, processor <NUM> is embodied as a hard wired or discrete electronics based configuration, comprising connections <NUM> for connecting to encoder <NUM>, and connections <NUM> for connecting to the motor drive <NUM>. A hard wired or discrete electronic configuration may have, as an advantage, of functioning very quickly, without being dependent on software and errors therein and/or delays caused thereby.

Encoder signals on pins <NUM>, <NUM>, of input connections <NUM> from encoder <NUM> are adjustable distributed via component block <NUM> and output via component block <NUM> through connections <NUM>. A detected movement direction is determined by component block <NUM> and output on pins <NUM>, <NUM> for "up" and "down".

A mono-stable multi-vibrator <NUM>, which may be retriggered, generates output signals on pin <NUM> for "active" of connections <NUM>, during round going movement. Contrary to the indicated fixed resistance R23 <NUM> therein, the pulse duration should be adjustable, and for this resistance R23 <NUM> may be replaced by a variable resistance, and the pulse is output at pin <NUM> "pulse" of output connections <NUM>. Check of proper round going movement is activated by a first flip-flop stage <NUM>, after the movement active signal is generated and after allowing a lag time, input on pin <NUM> of the connections <NUM>. A control signal, indicative of slowing down of blockage of the assembly, is generated by second flip-flop stage <NUM>, if the movement active signal falls away in a state of the processor monitoring the proper round going movement. Since the assembly is meant to stop at specific positions, not all control signals from the second flip-flop stage indicate a blockage or unwanted slow down, and the processor may again be set to a monitoring state through a signal on pin <NUM> for "reset" of connections <NUM>.

The motor drive <NUM> and the processor <NUM> may be combined into a single component or assembly of components.

Claim 1:
Assembly (<NUM>), comprising:
- a vertical conveyor (<NUM>) and a further conveyor (<NUM>) wherein the vertical conveyor is configured to at least one of pick up products (<NUM>) from and place products (<NUM>) on a transfer section (<NUM>) of the further conveyor (<NUM>); and
- wherein at least one of a carrier (<NUM>) of the vertical conveyor (<NUM>) and the transfer section (<NUM>) of the further conveyor (<NUM>) comprises a safety (<NUM>) that is configured to detect a product (<NUM>, <NUM>-b) blocking the carrier (<NUM>) of the vertical conveyor (<NUM>) and stop the assembly (<NUM>),
characterized in that the safety (<NUM>) comprises a pivot (<NUM>) that is configured to allow a displacement of at least one of the carrier (<NUM>) or of the transfer section (<NUM>) to mitigate damage to the assembly (<NUM>) and/or to the blocking product (<NUM>, <NUM>-b).