Automatic sales unit with robot unit and vacuum gripper
Patent Information
- Application Number
- EP2023777141
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-06
- Filing Date
- 2023-09-05
- Publication Date
- 2025-07-16
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Conventional automatic sales units with mechanical robot grippers face limitations in handling large and heavy items due to restricted access and gripping capabilities, as they require direct arm access which is not feasible for all objects.
The integration of a vacuum gripper with a suction unit and a contact element, allowing for flexible gripping by creating negative pressure to secure items, enabling the handling of large and heavy objects by compensating gravitational forces with static friction and utilizing a distance sensor for precise approach.
This solution enhances the flexibility and capability of automatic sales units to handle a wide range of items, including large and heavy ones, by using vacuum grippers that can grip items on side surfaces and lift them with reduced pressure requirements, ensuring stable and efficient item movement.
Smart Images
Figure 1.1
Abstract
Description
[0001] Automatic sales unit with robot unit and vacuum gripping
[0002] The invention relates to a vacuum gripper and an automatic sales unit. Such sales units have recently become increasingly popular. They essentially comprise storage units for storing items offered for sale, user interfaces, and dispensing units for dispensing items requested via the user interface to a user. Typically, at least one robot unit is provided for transferring items from the storage unit to the dispensing unit.
[0003] A generic sales unit is offered by Kirschenhofer Maschinen GmbH under the name "VPS Roberta." This sales unit provides the article and uses a mechanical robot gripper.
[0004] The object of the present invention is to provide an improved automatic sales unit and an improved vacuum gripper.
[0005] This object is achieved by the devices having the features of the independent claims. The subclaims relate to advantageous developments and variants of the invention.
[0006] An automatic sales unit according to the invention comprises at least one storage unit for storing articles offered for sale, as well as at least one user interface and an output unit for dispensing articles requested via the user interface to a user. At least one robot unit is provided for transferring articles from the storage unit to the output unit, which is characterized in that it comprises a vacuum gripper. The use of a vacuum gripper has the advantage over the use of conventional mechanical grippers that it results in considerably improved flexibility with regard to the objects to be gripped. For a vacuum gripper, it is generally sufficient if there is a surface on the article to be gripped that allows suction through a vacuum.In this way, even comparatively large-volume items, which would not allow access by a conventional gripper arm, become accessible to the robot unit.
[0007] Because the vacuum gripper comprises at least one suction unit for sucking an article by means of a negative pressure and at least one contact element for mechanically fixing the article during the suction, an improved fixing of the article to the gripper can be achieved.
[0008] The contact element can be designed as a separate element and / or as a flexible element. This opens up the possibility of designing the contact element in such a way that it exhibits maximum static friction with the outer surface of an article, which can be advantageous during the picking up and subsequent handling of the article.
[0009] The suction unit can, in particular, be a suction gripper. A suction gripper in the sense of the present invention is understood to be a flexible suction cup that reduces its extension toward a suctioned article under the influence of a negative pressure, so that the article is drawn toward the suction gripper, thus moving in the direction of the acting negative pressure. Conversely, in this case, the associated robot arm can also be guided toward the article.
[0010] An article can then be picked up using the vacuum gripper in the manner described below:
[0011] The contact element is arranged adjacent to the suction gripper and the suction gripper projects at least partially beyond the contact element in a first operating state in which no negative pressure is applied to the suction gripper.
[0012] In a first step, the vacuum gripper approaches the article to be gripped in such a way that the suction cup mouths come into contact with an outer surface of the article. The vacuum gripper can approach the article with the assistance of a distance sensor, particularly an optical distance sensor.
[0013] At the latest when the suction cups come into contact with the outer surface of the article, a negative pressure is applied to the suction cups, causing them to suck the article in. As the suction cup reduces its longitudinal extension due to the negative pressure, the article is pulled toward the contact element, and an outer surface of the article is pressed against a contact surface with a contact force F.
[0014] If the vacuum gripper is now aligned, at least temporarily, such that the contact force has a component perpendicular to the direction of the gravitational force, the entire gravitational force of the article no longer needs to be applied through the vacuum. Instead, part of the gravitational force to be compensated is applied by the static friction force between the outer surface of the article and the contact surface of the contact element.
[0015] This effect can be maximized by aligning the vacuum gripper, at least temporarily, so that the contact force acts perpendicular to the direction of the gravitational force. In this case, virtually the entire gravitational force is applied by the static friction force. Depending on the mass distribution of the struck article, a torque will typically still occur around a horizontal axis if it would lead to the article tipping around this axis. This torque can be compensated by the suction grippers located in the upper area of the vacuum gripper.
[0016] In other words, the invention, and in particular the design of the vacuum gripper as described above, allows an article to be gripped by a side surface, lifted, and placed at a predetermined location. This makes it possible to move even comparatively large and heavy articles with the robot arm. For this purpose, it is sufficient if the articles to be moved have at least one outer surface accessible to suction by the suction gripper. Because the contact element is made of an elastic material, in particular containing polyurethane, the properties of the contact element can be further optimized for the desired function.
[0017] It is advantageous if the contact element has cavities in its interior; in an advantageous variant of the invention, the contact element has a rib structure in its interior.
[0018] Adaptation of the device according to the invention to different application scenarios can be achieved by disposing the contact element detachably on a support element; the contact element and the support element can be connected to each other by means of a tongue and groove connection.
[0019] A particularly compact and advantageous design of the vacuum gripper can be realized in that the contact element and the carrier element are designed as mutually corresponding, at least partially hollow cylindrical elements.
[0020] The suction unit can be arranged at least partially in the interior of the contact element and the carrier element.
[0021] Because the vacuum gripper includes a distance sensor, the approach of the vacuum gripper to the article to be gripped can be controlled.
[0022] The distance sensor can be designed as an optical sensor, particularly a blue light sensor. Such sensors have exceptionally advantageous properties with regard to their sensitivity to reflections on a wide variety of surfaces.
[0023] The vacuum gripper described above in the context of automated vending units is not limited to this application. It can be used particularly where a wide variety of items or objects need to be handled reliably.
[0024] In the following, embodiments and variants of the invention are explained in more detail with reference to the drawing. Figure 1 shows an exemplary embodiment of a vacuum gripper, and
[0025] Figure 2 a detail of the invention
[0026] Figure 1 shows an exemplary embodiment of a vacuum gripper for a sales unit according to the invention. The vacuum gripper 1 is designed as part of a gripping unit 11 and is connected via a holding tube 2 to a connecting piece 3 for a robot mount. In the example shown, the vacuum gripper 1 comprises three suction units designed as suction grippers 4, which are connected to a vacuum housing 6 via an intermediate piece 5. In the example shown, three ejector modules 7 are arranged on the vacuum housing 6. These ejector modules serve to generate negative pressure and are connected to an external compressed air source via compressed air lines (not shown) that run through the holding tube 2. The negative pressure side of the ejector modules 7 is connected to channels (not shown in the figure) in the vacuum housing 6, which run through the intermediate piece 5 and are connected to the suction grippers 4.Also visible in the figure are the pressure sensors 8, which are connected to the vacuum housing 6 via lines 9 and are in turn connected to an electronics housing 10 via electrical connections not specifically designated in the figure.
[0027] In the example shown, the suction grippers 4 are arranged in the interior of partially hollow-cylindrical, corresponding support elements 12 and contact elements 13. The figure shows that the support and contact elements 12, 13 comprise an axially extending cutout, so that the associated suction grippers 4 can be arranged relatively close to one another. It is of course also conceivable, if the space allows, to design the support and contact elements 12, 13 as closed hollow-cylindrical elements. Conversely, a design as several, possibly arcuate, sub-segments is also conceivable. In the example shown, the contact elements 13 are attached to the end faces of the support elements 12.Furthermore, the support elements 12 are themselves arranged interchangeably on the intermediate piece 5, so that they can be replaced with other support elements if necessary, for example to adapt the length of the support elements, i.e. their axial extent, to corresponding conditions. During operation of the vacuum gripper 1 according to the invention, it is first approached by means of a robot arm (not shown in the figure) to an article to be gripped until the suction grippers 4 come into contact with an outer surface of the article. The approach is usually assisted by the optical distance sensor 14. The distance sensor 14 can in particular be a blue light sensor which detects blue light reflected from the article by means of a flat receiver area and, based on the detected intensity, allows conclusions to be drawn about the distance of the vacuum gripper 1 from the article.
[0028] Subsequently, the suction grippers 4 are subjected to a negative pressure. This negative pressure is created by applying compressed air to the ejector modules 7 at a pressure of approximately five bar. Due to the design of the suction grippers 4, which is clearly visible in the figure, in the manner of a flexible bellows, the article is pulled towards the vacuum gripper 1, so that its outer surface comes into mechanical contact with the contact elements 13 in some areas and is pressed against them with a specific contact force. The contact force depends, among other things, on the negative pressure created and the elastic properties of the suction grippers 4. If necessary, the picking up of the article and bringing it into contact with the contact elements 13 can be assisted by a corresponding movement of the robot arm.
[0029] The article can now, for example, be lifted and moved to another location using the robot arm. The soft, flexible design of the contact elements 13 is advantageous here. The aforementioned design of the contact elements 13 enables a high level of friction between the contact elements 13 and an outer surface of the article in question. If, for example, the gripped outer surface runs predominantly vertically, the weight of the article is not absorbed by the suction grippers 4, but by the contact elements 13 and, consequently, by the rigid parts of the vacuum gripper 1. In other words, it is sufficient for the article to be picked up if the static friction force between the outer surface of the article and the contact element 13 is greater than the weight of the article.The suction grippers 4 can then only absorb a force resulting from a torque that essentially depends on the lateral extent of the article and its mass distribution. This enables the vacuum gripper 1 according to the invention to pick up and transfer comparatively large loads with comparatively low negative pressures.
[0030] Figure 2 shows a radial section to illustrate the structure of an exemplary contact element 13. In the example shown, the contact element 13 can be manufactured using an additive process, for example, a 3D printing process. The use of an additive process also enables the creation of comparatively complex internal structures of the contact element 13. In the example shown, the internal structure of the contact element 13 comprises a plurality of ribs 15, which are oriented in the manner of a bellows. Of course, other structures, such as foamed structures, are also conceivable.
[0031] List of reference symbols
[0032] 1 vacuum gripper
[0033] 2 holding tube
[0034] 3 connecting piece
[0035] 4 suction cups
[0036] 5 Intermediate piece
[0037] 6 vacuum housings
[0038] 7 Ejector module
[0039] 8 Pressure sensor
[0040] 9 Management
[0041] 10 electronics housings
[0042] 11 Gripping unit
[0043] 12 support element
[0044] 13 Contact element
[0045] 14 Distance sensor
[0046] 15 ribs
Claims
Patent claims 1 . Automatic sales unit, comprising - at least one storage unit for storing items offered for sale - at least one user interface and one output unit for outputting items requested via the user interface to a user - at least one robot unit for transferring articles from the storage unit to the dispensing unit, characterized in that the robot unit comprises a vacuum gripper (1).
2. Automatic sales unit according to claim 1, characterized in that the vacuum gripper (1) comprises at least one suction unit for sucking an article by means of a negative pressure and at least one contact element (13) for mechanically fixing the article during the suction 3. Automatic sales unit according to claim 2, characterized in that the contact element (13) is designed as a separate element.
4. Automatic sales unit according to claim 2 or 3, characterized in that the contact element (13) is designed as a flexible element.
5. Automatic sales unit according to one of claims 2 to 4, characterized in that the suction unit is a suction gripper (4).
6. Automatic sales unit according to claim 5, characterized in that the contact element (13) is arranged adjacent to the suction gripper (4) and the suction gripper (4) projects at least partially beyond the contact element (13) in a first operating state in which no negative pressure is applied to the suction gripper (4). Automatic sales unit according to claim 6, characterized in that in a second operating state, in which a negative pressure is applied to the suction gripper (4) and the suction gripper (4) sucks up an article, an outer surface of the article is pressed against a contact surface with a contact force F. Automatic sales unit according to claim 6 or 7, characterized in that the vacuum gripper (1) is at least temporarily aligned such that the contact force has a component perpendicular to the direction of the gravitational force. Automatic sales unit according to claim 8, characterized in that the vacuum gripper (1) is at least temporarily alignable such that the contact force acts perpendicular to the direction of the gravitational force. Automatic sales unit according to one of claims 2 to 9, characterized in that the contact element (13) is formed from an elastic material.Automatic sales unit according to claim 10, characterized in that the contact element (13) contains polyurethane. Automatic sales unit according to one of claims 10 or 11, characterized in that the contact element (13) has cavities in its interior. Automatic sales unit according to claim 12, characterized in that the contact element (13) has a rib structure in its interior. Automatic sales unit according to one of claims 2 to 13, characterized in that the contact element (13) is detachably arranged on a carrier element (12). Automatic sales unit according to claim 14, characterized in that. the contact element (13) and the carrier element (12) are connected to each other by means of a tongue and groove connection.
16. Automatic sales unit according to claim 14 or 15, characterized in that the contact element (13) and the carrier element (12) are designed as mutually corresponding, at least partially hollow cylindrical elements. 1 / .Automatic sales unit according to claim 16, characterized in that the suction unit is arranged at least partially in the inner region of the contact element (13) and the carrier element (12).
18. Automatic sales unit according to one of the preceding claims, characterized in that the vacuum gripper (1) comprises a distance sensor (14).
19. Automatic sales unit according to claim 18, characterized in that the distance sensor (14) is designed as an optical sensor.
20. Automatic sales unit according to claim 19, characterized in that the optical sensor is designed as a blue light sensor.
21. Vacuum gripper (1) for picking up and handling articles, wherein the vacuum gripper (1) comprises at least one suction unit for sucking up an article by means of a negative pressure, characterized in that the vacuum gripper (1) comprises at least one contact element (13) for mechanically fixing the article during suction.
22. Vacuum gripper (1) according to claim 21, characterized in that the contact element (13) is designed as a separate element.
23. Vacuum gripper (1) according to claim 21 or 22, characterized in that the contact element (13) is designed as a flexible element. Vacuum gripper (1) according to one of claims 21 to 23, characterized in that the suction unit is a suction gripper (4). Vacuum gripper (1) according to claim 24, characterized in that the contact element (13) is arranged adjacent to the suction gripper (4) and the suction gripper (4) projects at least partially beyond the contact element (13) in a first operating state in which no negative pressure is applied to the suction gripper (4). Vacuum gripper (1) according to claim 25, characterized in that in a second operating state in which a negative pressure is applied to the suction gripper (4) and the suction gripper (4) sucks up an article, an outer surface of the article is pressed against a contact surface with a contact force F. Vacuum gripper (1) according to claim 25 or 26, characterized in that the vacuum gripper (1) is at least temporarily aligned such that the contact pressure has a component perpendicular to the direction of the gravitational force.Vacuum gripper (1) according to claim 27, characterized in that the vacuum gripper (1) can be aligned at least temporarily such that the contact force acts perpendicular to the direction of the gravitational force. Vacuum gripper (1) according to one of claims 21 to 28, characterized in that the contact element (13) is formed from an elastic material. Vacuum gripper (1) according to claim 29, characterized in that the contact element (13) has cavities in its interior. Vacuum gripper (1) according to claim 30, characterized in that the contact element (13) has a rib structure in its interior. Vacuum gripper (1) according to one of claims 21 to 31, characterized in that the contact element (13) is detachably arranged on a carrier element (12). Vacuum gripper (1) according to claim 32, characterized in that the contact element (13) and the carrier element (12) are connected to one another by means of a tongue and groove connection. Vacuum gripper (1) according to claim 32 or 33, characterized in that the contact element (13) and the carrier element (12) are designed as mutually corresponding, at least partially hollow-cylindrical elements. Vacuum gripper (1) according to claim 34, characterized in that the suction unit is arranged at least partially in the inner region of the contact element (13) and the carrier element (12).