Scraper assembly for a conveyor with discrete scraper force settings
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- LAITRAM LLC
- Filing Date
- 2024-07-31
- Publication Date
- 2026-06-10
AI Technical Summary
Existing conveyor systems face challenges in maintaining hygiene due to the accumulation of dirt, debris, bacteria, and other contaminants, which are not effectively addressed by current scraper assemblies.
A scraper assembly for a conveyor that includes opposing scraper mounting plates, a flat spring for biasing a scraper blade into an operating position, and an adjustable tensioning stop to adjust the force applied to the spring, allowing for discrete scraper force settings.
The scraper assembly effectively removes debris from the conveyor belt while allowing for adjustable force settings, enhancing hygiene and operational flexibility by ensuring consistent and customizable scraper engagement.
Smart Images
Figure US2024040303_13022025_PF_FP_ABST
Abstract
Description
[0001]Scraper Assembly for a Conveyor with Discrete Scraper Force Settings Related Applications The present invention claims priority to US Provisional Patent Application No. 63 / 530,749, filed August 4, 2023 and entitled “Scraper Assembly for a Conveyor with Discrete Scraper Force Settings”, the contents of which are herein incorporated by reference. Field of the Invention The present invention relates to power‐driven conveyors. More particularly, the invention relates to scraper assemblies at an outfeed end of a conveyor. Background of the Invention Power‐driven conveyors are used to convey items. Infeed assemblies are used to transition items onto the conveyor as the conveyor belt moves from a returnway to a carryway above the returnway. Outfeed assemblies are used to transition items off of the conveyor as the belt moves from the carryway to the returnway. A drive moves the conveyor belt through the conveying circuit. For example, drive sprockets mounted on a rotatable shaft may engage and drive the conveyor belt along the conveying circuit. Drive sprockets can be located at the outfeed of the conveyor or within the returnway of the circuit. Scrapers can be mounted at the outfeed to remove debris from the conveyor belt before it enters the returnway. Hygiene can pose a problem with conveyors, as dirt, debris, bacteria and other contaminants can become trapped in the different components. Summary of the Invention A scraper assembly for a conveyor comprises opposing scraper mounting plates for mounting the scraper assembly to a conveyor frame. The scraper assembly includes a flat spring, shown as a leaf spring or cantilever spring, for selectively biasing a scraper blade into an operating position when the scraper assembly is mounted between the opposing end plates. An adjustable device allows for the force of the spring to be adjusted. According to one aspect, a scraper assembly for a conveyor belt comprises a pair of opposing scraper mounting plates, a base extending laterally between the pair of opposing scraper mounting plates for mounting a scraper blade, a flat spring mounted to a mounting portion on a first end of the base and extending inwards from the base for selectively biasing the scraper blade into a scraping position relative to the conveyor belt, a tensioning stop for applying a force to the flat spring to bias the scraper blade into the scraping position and an adjustment mechanism for adjusting the amount of force applied to the flat spring. According to another aspect, an adjustable tensioning stop for applying an adjustable force to a flat spring biasing a scraper blade into a scraping position with a conveyor belt in a conveyor comprises a wheel seated in a recess of a scraper mounting plate, a shaped boss extending laterally inwards from the wheel along a central axis, the shaped boss configured to be received in a shaped opening connected to the recess, and an external protrusion extending outwards from the wheel and offset from the central axis for pressing against the flat spring. According to another aspect, an assembly for a conveyor comprises a scraper mounting plate having a front saddle at a front end, a shaped recess at a second end and a shaped opening formed in a body of the plate connected to the shaped recess and an adjustable tensioning stop mounted to the scraper mounting plate. The adjustable tensioning stop has a wheel seated in the shaped recess, a shaped boss extending from the wheel into the shaped opening along a central axis of the wheel and an external protrusion extending outwards from the wheel and offset from the central axis for pressing against a flat spring. Brief Description of the Figures FIG. 1 is an isometric view of a drive assembly for a conveyor according to an embodiment of the invention; FIG. 2 is a close‐up view of a first side of the drive assembly of FIG. 1; FIG. 3 is a side view of the drive assembly of FIG. 1 in a first setting, applying minimal force to a tensioning device; FIG. 4 is a side view of the drive assembly of FIG. 1 in a first setting, applying medium force to a tensioning device; FIG. 5 is a side view of the drive assembly of FIG. 1 in a first setting, applying maximum force to a tensioning device; FIG. 6 is an exploded view of an outside of the scraper mounting plate and adjustable tensioning stop of the drive assembly of FIG. 1; FIG. 7 is another exploded view of the scraper mounting plate and adjustable tensioning stop of the drive assembly of FIG. 1; FIG. 8 is an exploded view of an inside of the scraper mounting plate and adjustable tensioning stop of the drive assembly of FIG. 1; FIG. 9 is an isometric view of a drive assembly for a conveyor according to another embodiment. Detailed Description of the Invention The present invention provides a sanitary scraper system at an outfeed end of a conveyor that can be easily installed, adjusted, and—or removed. The present invention will be described below relative to an illustrative embodiment. Those skilled in the art will appreciate that the present invention may be implemented in a number of different applications and embodiments and is not specifically limited in its application to the particular embodiments depicted herein. FIGS. 1 and 2 show a scraper assembly 10 at an outfeed end of a conveyor. The illustrative outfeed end is a drive end, including a drive, but the outfeed end can omit the drive, which can be placed in another location in the conveyor. The scraper assembly 10 includes bearing mounts 20 for mounting a drive axle 42 of a sprocket 44 or other reversing element for a conveyor belt 40 at an outfeed end of a carryway. The illustrative conveyor belt 40 is a modular plastic conveyor belt formed by hingedly connected conveyor belt modules, but the invention is not so limited. The scraper assembly 10 further includes a pair of opposing scraper mounting plates 50 mounted to the bearing mounts 20. Each scraper mounting plate 50 includes a pair of mounting openings 52 for receiving fasteners 54, shown as bolts, to mount the scraper mounting plate 50 to an associated bearing mount 20, which may be a standard bearing mount. The same fasteners 54 that mount the scraper mounting plate 50 to the bearing mounts 20 can extend into and attach both components to a frame of the conveyor. A top edge of the scraper mounting plate 50 is curved to accommodate the bearing mount 20. A front end of the scraper mounting plate 50 includes a saddle 56 for mounting a scraper assembly 80. The illustrative saddle 56 is an open seat comprising a curved protrusion, but the invention is not so limited. For example, the saddle can be a closed hole of any suitable shape, and can be mounted inboard of the bearing housing, rather than outboard. A back end of the scraper mounting plate 50 includes an adjustable tensioning stop 70 for selectively adjusting the tension applied to the scraper assembly 80, as described below. The scraper assembly 80 comprises a substantially cylindrical base 81 extending between the scraper mounting plates 50. A scraper blade 83, which can be removable, extends up from the base 81. The base 81 includes a reduced‐diameter neck portion 86 configured to be received in the saddle 56. A handle 87 may extend from the neck portion 86. One or both ends of the scraper assembly form tension mounts 88 for mounting a tensioning device, shown as a flat, cantilever spring 90 or leaf spring. The tensioning device biases the scraper blade 83 into contact with the conveyor belt 40 to remove debris therefrom. Each tension mount 88 extends from the neck portion 86 and includes a first protrusion 91 extending laterally outwards for attaching the flat spring 90 to the scraper assembly using a fastener, such as a bolt 92, keyhole feature or other suitable mounting means. A second protrusion 93 extending laterally outwards from the neck portion and spaced rearward from the first protrusion 91 forms a pivot point for the spring 90. The protrusions 91, 92 can be combined into a unitary structure or comprise two regions on the same protrusion. The flat spring may alternatively be mounted using a fastenless connection, such as a keyhole opening that rotationally locks the flat spring to the scraper assembly. The spring 90 extends rearward to the adjustable tensioning stop 70, which pushes down on the spring 90 to bias the scraper blade 83 into engagement with the conveyor belt 40. The tensioning stop 70 can be adjusted to change the amount of spring deflection, thereby modifying the force on the spring. FIG. 3 shows a scraper assembly 10 with the tensioning stop 70 in a first position, providing minimal force. FIG. 4 shows the tensioning stop 70 in a second position, providing medium force. FIG. 5 shows the tensioning stop 70 in a third position, providing maximum force on the spring 90. The illustrative scraper assembly 10 thus allows for changing the amount of spring deflection without changing springs by adjusting the tensioning stop 70. Springs of different widths and thicknesses can be swapped to provide different scraper forces. Referring to FIGS. 6—8, the illustrative tensioning stop 70 comprises a rotatable wheel 71 mounted to the scraper mounting plate, though the invention is not limited to a circular structure. The wheel 71 includes an external protrusion 72 for contacting and pressing against the spring 90. The wheel 71 fits into a recess 59 in the scraper mounting plate 50 and can rotate within the recess 59. The tensioning step 70 includes a shaped boss 73 extending inwards from the wheel 71 opposite the external protrusion 72. As shown, the shaped boss 73 extends along a central axis of the wheel 71, while the external protrusion 72 is offset from the central axis. The scraper mounting plate 50 includes a shaped opening 58 extending inwards from the recess 59 for receiving the shaped boss 73. The shaped opening 58 includes a bottom through hole 57 for receiving a fastener 78, shown as a bolt, that is received in an opening 79 in the shaped boss 73. The wheel 71 can have other shapes suitable for discretely positioning the external protrusion 72. The illustrative external protrusion 72 is rod‐shaped, but the invention is not so limited. For example, the external protrusion for applying pressure to the spring 90 can be a hook, flat protrusion, planar protrusion, or other form and be formed of bent sheet metal or other material. The shaped boss 73 has a polygonal shape corresponding to a selected number of tension settings, and may be rotationally symmetric. The illustrative shaped boss 73 is a decagon, with ten flat sides, but the invention is not so limited. Each tension setting corresponding to a rotational position of the shaped boss 73 is indicated by indicia on the wheel 71. The illustrative shaped opening 58 is shaped to selectively lock the wheel 71 in one of multiple discrete orientations using a shape‐lock feature. For example, the illustrative shaped opening 58 comprises a curved surface and a smaller flat surface for each flat surface of the shaped boss. The shaped opening 58 holds the wheel in a selected position, while the fastener 78 locks the components in the selected setting. The fastener 78 can be removed and the wheel 71 rotated manually or with a tool to adjust the amount of force applied to the spring 90. The illustrative invention is not limited to the illustrative means for adjusting the tension applied to the tensioning device. For example, in another embodiment, an adjustable tensioning mechanism may be located in a different location, for example at an attachment or pivot point of a flat spring. As shown in FIG. 9, a scraper mounting plate 150 in a conveyor scraper assembly 100 can comprise bent sheet metal forming a hook 172 for latching a leaf spring 190 extending from an attachment point 192 over a pivot point 193. A saddle 156 seats a neck of a scraper mounting bar 181 mounting a scraper 183. The illustrative saddle 156 is closed, but can be open. A top recess 160 accommodates a bearing 162 of a drive shaft 142 driving a sprocket 144, but the assembly need not be a drive assembly. Openings 164 receive connectors to mount the plate 150 to the bearing 172 or other conveyor frame component. The attachment point 192 and pivot point 193 extend from the end of the scraper mounting bar 181. The leaf spring 190 biases a scraper blade 183 into contact with a conveyor belt 140 driven by the sprocket 144. The attachment point 192 and—or pivot point 193 can be adjustable to change the natural extension of the spring 190. The hook 172, which can be fixed in position, applies a variable pressure depending on the natural position of the spring 190, which can be adjusted using an adjustment mechanism 120 in the end cap 188 of the scraper mounting bar 181. When the natural position of the spring is higher (ending at 190a), a higher pressure is applied. In an intermediate position (190b), an intermediate pressure is applied. In a lower natural position (190c), a lower pressure is applied. The adjustment mechanism 120 can be rotatable to raise and—or lower the attachment point 192 or pivot point 193, or can use any suitable means to adjust the natural position of the spring 190. The illustrative scraper mounting plate 150 can be customized for a wide range of bearing mounts and locations. A mirror‐image mounting plate 151 is located on the other side of the drive assembly. The scope of the claims is not meant to be limited to the details of the described exemplary embodiments.
Claims
What is claimed is:
1. A scraper assembly for a conveyor belt, comprising: a pair of opposing scraper mounting plates; a base extending laterally between the pair of opposing scraper mounting plates for mounting a scraper blade; a flat spring mounted to a mounting portion on a first end of the base and extending inwards from the base for selectively biasing the scraper blade into a scraping position relative to the conveyor belt; a stop for applying a force to the flat spring to bias the scraper blade into the scraping position; and an adjustment mechanism for adjusting the amount of force applied to the flat spring.
2. The scraper assembly of claim 1, wherein each scraper mounting plate includes a saddle at a front end and the base includes a reduced‐diameter neck portion at each end configured to be received in a corresponding saddle.
3. The scraper assembly of claim 2, wherein the mounting portion includes a first protrusion extending laterally outwards for attaching the flat spring to the scraper assembly using a fastener.
4. The scraper assembly of claim 3, wherein the mounting portion includes a second protrusion extending laterally outwards and spaced rearward from the first protrusion to form a pivot point for the flat spring.
5. The scraper assembly of claim 1, wherein the adjustable tensioning stop comprises: a wheel seated in a recess of a scraper mounting plate, a shaped boss extending laterally inwards from the wheel along a central axis, the shaped boss received in a shaped opening connected to the recess; and an external protrusion extending outwards from the wheel and offset from the central axis for pressing against the flat spring.
6. The scraper assembly of claim 5, wherein the shaped boss is a decagon.
7. The scraper assembly of claim 5, further comprising a fastener extending through a through hole of the scraper mounting plate into the shaped opening and received in the shaped boss for locking the tensioning stop in a selected orientation.
8. The scraper assembly of claim 1, wherein the adjustment mechanism is located in the mounting portion of the flat spring.
9. In a conveyor, an adjustable tensioning stop for applying an adjustable force to a flat spring biasing a scraper blade into a scraping position with a conveyor belt, comprising: a wheel seated in a recess of a scraper mounting plate, a shaped boss extending laterally inwards from the wheel along a central axis, the shaped boss configured to be received in a shaped opening connected to the recess; and an external protrusion extending outwards from the wheel and offset from the central axis for pressing against the flat spring.
10. The adjustable tensioning stop of claim 9, wherein the shaped boss further includes an opening in an end face for receiving a fastener.
11. The adjustable tensioning stop of claim 9, wherein the shaped boss is a decagon.
12. The adjustable tensioning stop of claim 1, further comprising indicia on the wheel indicating different tension settings corresponding to each rotational position of the shaped boss.
13. An assembly for a conveyor comprising: a scraper mounting plate having a front saddle at a front end, a shaped recess at a second end and a shaped opening formed in a body of the plate connected to the shaped recess; and an adjustable tensioning stop mounted to the scraper mounting plate, the adjustable tensioning stop having a wheel seated in the shaped recess, a shaped boss extending from the wheel into the shaped opening along a central axis of the wheel and an external protrusion extending outwards from the wheel and offset from the central axis for pressing against a flat spring.
14. The assembly of claim 13, wherein the shaped boss further includes an opening in an end face for receiving a fastener.
15. The assembly of claim13 , wherein the shaped boss is a decagon.
16. The assembly of claim 13, further comprising indicia on the wheel indicating different tension settings corresponding to each rotational position of the shaped boss.
17. The assembly of claim 13, wherein the external protrusion is a hook.