Torque-limiting slip clutch system with modular discs

Abstract

This disclosure relates in general to systems and methods for limiting the torque of tools and equipment, and more particularly to low-cost, single-use or disposable slip clutch systems and methods with modular discs for limiting the output torque of manual or power-driven medical drivers.

Description

Technical Field

[0001] (Reference to Related Applications) This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 458,779, filed on April 12, 2023, under the name "TORQUE-LIMITING SLIP-CLUTH SYSTEM WITH MODULAR DISKS", the entire content of which is incorporated herein by reference. The title of this application is the same as that of the said U.S. Provisional Patent Application, except for correcting a minor misspelling in the spelling of the word "clutch".

[0002] The present disclosure generally relates to manual tools and power tools. More specifically, the present disclosure relates to systems and methods for limiting the torque of tools and devices, and particularly to a single-use or disposable, low-cost slip clutch system and method with modular disks for limiting the output torque of manual or power-driven medical drivers.

Background Art

[0003] Drivers integrally equipped with a torque limiting function and drivers connected to torque limiting attachments are commonly used throughout the medical industry. Healthcare workers may use manual or power-driven drivers to secure threaded fasteners to spinal or orthopedic implants. Medical drivers are integrally equipped with a torque limiting function or connected to a torque limiting attachment to apply the correct torque to the threaded fastener, thereby preventing over-torque and under-torque of the threaded fastener.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In surgical procedures, the margin of error is extremely small, and these drivers must apply precise torque. Reusable torque-limiting drivers and attachments require regular recalibration to ensure the drivers apply accurate torque. Reusable drivers, of course, require cleaning and sterilization after each use.

[0005] Disposable or single-use torque limiting drivers and attachments are an alternative to reusable drivers. Disposable torque limiting drivers and attachments are generally used in low-torque applications due to the strength limitations of low-cost engineering materials and manufacturing methods.

[0006] Therefore, it is advantageous to provide a single-use or disposable torque limiting system that can be manufactured at low cost and allows for higher torque thresholds. [Means for solving the problem]

[0007] Some embodiments of the torque-limiting slip clutch system according to this disclosure include an upper clutch disc and an opposing lower clutch disc, each configured to have a plurality of lobes, an elastic member, and a clutch carrier configured to receive the elastic member, the clutch carrier being configured to engage with the upper clutch disc.

[0008] This outlines the features and technical advantages of the disclosure to make the detailed description of the disclosure easier to understand. Additional features and advantages are described below. Those skilled in the art should understand that the disclosure can be readily used as a basis for modifying or designing other structures that accomplish the same objectives of the invention. Those skilled in the art should also understand that equivalent configurations are possible without departing from the teachings of the disclosure described later in the specification.

[0009] The features of this disclosure are considered distinctive in terms of both their configuration and operation, and additional features and advantages will be better understood by referring to the following description along with the accompanying drawings. However, it should be clearly understood that each drawing is provided for illustrative and illustrative purposes only and is not intended to limit the scope of this disclosure. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows a front view of a torque limiting attachment according to an embodiment of a slip clutch system having the features of the present disclosure, with the clutch carrier shown as transparent. [Figure 2] Figure 2 shows an exploded view of the torque limiting module of a torque limiting attachment according to an embodiment of a slip clutch system having the features of the present disclosure. [Figure 3A] Figure 3A shows a top perspective view of one embodiment of a clutch disc having the features of the present disclosure. [Figure 3B] Figure 3B shows a right side view of one embodiment of a clutch disc having the features of the present disclosure. [Figure 3C] Figure 3C shows a bottom perspective view of one embodiment of a clutch disc having the features of the present disclosure. [Figure 4A] Figure 4A shows a top perspective view of another embodiment of a clutch disc having the features of the present disclosure. [Figure 4B] Figure 4B shows a right side view of another embodiment of a clutch disc having the features of the present disclosure. [Figure 4C] Figure 4C shows a bottom perspective view of another embodiment of a clutch disc having the features of the present disclosure. [Figure 5A] Figure 5A shows a top perspective view of another embodiment of a clutch disc having the features of the present disclosure. [Figure 5B] Figure 5B shows a top perspective view of another embodiment of a clutch disc having the features of the present disclosure. [Figure 5C] Figure 5C shows a top perspective view of another embodiment of a clutch disc having the features of the present disclosure. [Figure 6]Figure 6 shows a top perspective view of another embodiment of a clutch disc having the features of the present disclosure. [Figure 7A] Figure 7A shows top perspective views of two embodiments of a conical washer (i.e., a Belleville washer) used in embodiments of the present disclosure. [Figure 7B] Figure 7B shows left side views of two embodiments of a conical washer (i.e., a Belleville washer) used in the embodiments of this disclosure. [Figure 7C] Figure 7C shows top views of two embodiments of a conical washer (i.e., a Belleville washer) used in the embodiments of this disclosure. [Figure 8A] Figure 8A shows a top perspective view of one embodiment of a clutch carrier having the features of the present disclosure. [Figure 8B] Figure 8B shows a bottom view of one embodiment of a clutch carrier having the features of the present disclosure. [Figure 8C] Figure 8C shows a top view of one embodiment of a clutch carrier having the features of the present disclosure. [Figure 8D] Figure 8D shows a right side view of one embodiment of a clutch carrier having the features of the present disclosure. [Figure 8E] Figure 8E shows a bottom perspective side view of one embodiment of a clutch carrier having the features of the present disclosure. [Modes for carrying out the invention]

[0011] This specification describes a low-cost, disposable or single-use torque limiting system and method. The system and method include a modular clutch disk having lobes and a separate clutch carrier that cooperate with an elastic member (e.g., a spring stack) to accurately limit the output torque in applications or devices that require accurate torque limitation. Separating the clutch disk from the clutch carrier facilitates manufacturing (and thus lower cost) and enables it to accommodate higher torque limits. The torque limiting system and method disclosed herein can be used in a medical driver or in other applications or devices where torque limitation is required.

[0012] Slip clutches are used in a variety of applications including torque transmission and torque limiting applications. A clutch typically includes a first and a second member that are relatively movable with respect to each other and means for imparting a selected amount of torsional friction between the two members. Relative movement of the two members occurs only when a torque exceeding a predetermined "slip" torque or "break away" torque associated with the clutch is applied.

[0013] Torsional friction may be imparted by an elastic member and / or a member imparting an elastic load, such as a coil spring or a slightly inclined washer, associated with the two members. The elastic member is attached or connected to one of the two members and is arranged to apply a normal force so as to frictionally engage the other member.

[0014] Embodiments of the present disclosure prevent both excessive torque and insufficient torque. Excessive torque (i.e., excessive force) can cause problems such as galling of threaded fasteners, shear of threaded fasteners or driver heads, and / or cold welding of threads. Insufficient torque can cause joints to become unstable, leading to loosening and failure over time.

[0015] When it is stated that one element is "on top of" another element, that element may be directly positioned on top of the other element, or there may be another element between them. Similarly, when it is stated that one element is "attached" or "connected" to another element, that element may be directly attached / connected, or there may be another element between them. Furthermore, in this specification, relative terms such as "inside," "outside," "upper," "top," "upper," "lower," "bottom," and "below" are used to indicate the relationship between one element and another. Terms such as "high," "low," "wide," and "narrow" are used in this specification to indicate angles and / or relative relationships. These terms are intended to include different orientations of the element or system in addition to the illustrated orientation.

[0016] In this specification, terms such as "first," "second," etc., are used to indicate various elements, members, regions, and / or areas, but the terms are not intended to limit such elements, members, regions, and / or areas. The terms are used solely to distinguish one element, member, region, or area from another. Accordingly, unless otherwise specified, the first element, member, region, or area discussed below may be referred to as the second element, member, region, or area without departing from the teachings of this disclosure.

[0017] Embodiments of the present invention will be described with reference to schematic drawings. Therefore, the thickness of the elements may differ from the actual thickness and may include deformation from the illustrated shape as a result of manufacturing techniques and / or tolerances. Accordingly, the elements illustrated in the drawings are of a schematic nature and their shapes are not intended to represent the exact shape of the area, nor are they intended to limit the scope of the present disclosure.

[0018] Some embodiments incorporating the features of this disclosure are single-use or disposable. An example of such a torque-limiting slip clutch system includes two modular slip clutch discs having an axial lobe design, an elastic member, and a clutch carrier configured to conform to the elastic member.

[0019] Embodiments disclosed herein may be used in specific torque limiting attachments. Torque limiting attachments typically prevent excessive and insufficient torque in medical devices and may include reduction gears, torque limiting systems, and locking mechanisms. This allows manufacturers or users (e.g., surgeons) to set output torque limits for attachments or devices. More specifically, embodiments of torque limiting slip clutch systems disclosed herein may be used in single-use power-driven torque limiting attachments.

[0020] As shown in Figures 1 and 2, one embodiment of the torque-limiting slip clutch system 100 comprises clutch discs 110, 120 and a clutch carrier 130 including an elastic member 132. In the illustrated embodiment, the elastic member is a spring stack formed by a plurality of Belleville washers 132. However, as will be understood by those skilled in the art, the elastic member 132 may include other or additional elements, such as compression springs, rubber springs, corrugated springs, or other well-known solutions.

[0021] Figures 3A-3C and 4A-4C show two embodiments of the clutch discs 110 and 120 disclosed herein. These drawings show modular clutch discs having axial lobe-shaped sections. In particular, each of the clutch discs 110 and 120 has five lobes. However, as can be understood, they may have more or fewer lobes. Similarly, although the embodiment shown in Figure 1 includes two clutch discs 110 and 120, the torque limiting system disclosed herein may include two or more clutch discs.

[0022] The clutch discs 110 and 120 may be formed from a lightweight and durable material such as a polymer resin, a composite-filled resin, a metal, a metal alloy, or other suitable material as understood by those skilled in the art. The clutch discs 110 and 120 may be formed from the same material or from different materials.

[0023] The small size and modular nature of the slip clutch components or discs disclosed herein enable low-cost manufacturing methods such as injection molding, and, for example, polymer injection molding yields better material properties. The simple disc shape reduces the possibility of manufacturing errors or mistakes. These factors result in more consistent material properties and shape of the discs. The highly consistent and strong material properties ultimately facilitate the precise adjustment of higher torque values ​​and torque tolerances. These properties also allow the use of various resins and cast alloys to achieve higher torque thresholds.

[0024] In some embodiments (not shown), needle bearings, thrust washers, or other suitable structures are used to block the effects of axial loads so that the output torque is not affected by axial loads.

[0025] Figures 5A to 5C and 6 illustrate other embodiments of clutch discs that may be used in the torque limiting systems disclosed herein. As shown in Figures 5A to 5C, the clutch discs may have different numbers of lobes. Figures 5A to 5C show clutch discs having 6, 7, and 10 lobes, respectively. Figure 6 illustrates another embodiment of a clutch disc having a conical and three-dimensional shape to increase the contact area of ​​the lobes.

[0026] Figures 7A to 7C show embodiments of a conical disc or cup-shaped spring washer 132, commonly known as a Belleville washer. Because the illustrated disc has a conical shape, it is not flat, and the inner portion is offset axially from the lower portion. Similar to conventional washers, the Belleville washers shown in Figures 7A to 7C may have a central opening for fasteners such as bolts. When stacked with other Belleville washers, the washers form a rigid spring or elastic member.

[0027] In one embodiment of the torque-limiting slip clutch system 100, the elastic member is a spring stack comprising at least two flat washers 134, with at least one Belleville washer 132 positioned between the flat washers. In embodiments featuring the characteristics of this disclosure, the specific number of flat washers 134 or Belleville washers 132 is not required, although in a particular embodiment, the elastic member has at least one Belleville washer 132. As understood, the elastic member may utilize a variety of structures, such as a rigid coil spring, a diaphragm spring, or an elastic member having other suitable structures. The elastic member is housed within the clutch carrier 130 and positioned adjacent to the slip clutch disc, as shown in Figures 1 and 2.

[0028] If the counter-torque from the driver or other device exceeds the torque provided by the two modular slip clutch discs 110, 120 and the spring stack 134, the lobes of the slip clutch discs slide against each other, displacing the spring stack 134, thereby limiting the output torque applied by the driver or device.

[0029] Figures 8A to 8E each illustrate embodiments of the modular clutch carrier 130. The clutch carrier 130 may be formed from a variety of materials, such as polymer resin, composite-filled resin, metal, metal alloy, or other suitable material as understood by those skilled in the art. The clutch carrier 130 may be configured to be a hollow cylinder. The hollow portion of the clutch carrier 130 is molded to fit the elastic members of the system 100. In the embodiments shown in Figures 8A to 8E, the bottom of the clutch carrier 130 is configured to have recesses, protrusions, splines, castellations, and / or other geometric features that engage with corresponding recesses, protrusions, splines, castellations, and / or other geometric features of the clutch discs 110, 120, as understood by those skilled in the art. This is best illustrated in Figure 8E. These recesses, protrusions, splines, castellations, and / or other geometric features cause the clutch carrier 130 to be positioned above the upper clutch disc 120 and to engage with the upper clutch disc 120, and further to engage with the lower clutch disc 110. When the device reaches its torque limit, the upper clutch disc 120 "slips" with the lower clutch disc 110, thereby limiting torque transmission and allowing a predetermined amount of torque to be applied accurately.

[0030] At least one advantage of the systems and methods incorporating the features described herein is that the torque-limiting slip clutch system is modular, with the clutch carrier components separated from the slip clutch disc. The modularization and separability of these components in the slip clutch assembly not only simplifies the design but also allows for better molding and casting of the clutch disc, resulting in more consistent material properties and geometry. The modular design facilitates sterilization in the case of non-single-use designs. Furthermore, another advantage of the systems and methods incorporating the features described herein is that precise adjustment of clockwise and counterclockwise torque is possible by adjusting the shape of the clutch disc lobes (e.g., number, width, height, etc.). The simplicity of the disc itself, and therefore ease of manufacture, allows for the use of various materials to achieve different and / or higher, more precise setpoints and tolerances. The setpoint torque (i.e., maximum torque or output torque) of the torque-limiting slip clutch system 100 disclosed herein is adjustable over a wide range of forces. For example, in system 100 according to this disclosure, the output torque can be set to 14 Newton meters or more, but is not limited to this. In other embodiments, the torque may be set to 15 Newton-meters or more. In yet another embodiment, it may be set to 16 Newton-meters or more. In other systems 100 according to this disclosure, the output torque may be set to less than 14 Newton-meters. Those skilled in the art will understand that any set torque can be selected depending on the design specifications of a particular application.

[0031] It should be understood that the embodiments disclosed herein are illustrative. The embodiments of this disclosure include any combination of adaptable features shown in each figure, and these embodiments are not limited to those expressly illustrated or described. For example, the appended claims may be modified into multiple dependent claims to allow any combination of the claim group or any combination of elements from different claim groups.

[0032] While this disclosure has been described in detail with reference to certain preferred configurations, it is modifiable. Therefore, the spirit and scope of this disclosure should not be limited to the configurations described above.

[0033] Furthermore, it should be understood that the components and concepts of this disclosure may be applied to devices not specifically mentioned herein. For example, but not limited to, these components and concepts may be applied to any machine having rotating parts, such as general processing and manufacturing equipment, conveyors, gearboxes, generators and motors.

[0034] The foregoing description is intended to encompass all modifications and alternative configurations that fall within the spirit and scope of the Disclosure as expressed in the attached claims, and no part of the Disclosure is intended to be placed in the public domain, expressly or implicitly, unless otherwise stated in the claims.

Claims

1. A torque limiting slip clutch system, An upper clutch disc and a lower clutch disc opposite it, each configured to have multiple lobes, Elastic member and A clutch carrier configured to receive the aforementioned elastic member, Equipped with, A torque-limiting slip clutch system characterized in that the clutch carrier is configured to engage with the upper clutch disc.

2. The torque-limiting slip clutch system according to claim 1, wherein the upper clutch disc and the lower clutch disc each have a plurality of lobes.

3. The torque-limiting slip clutch system according to claim 2, wherein the upper clutch disc and the lower clutch disc each have five lobes.

4. The torque-limiting slip clutch system according to claim 2, wherein the upper clutch disc and the lower clutch disc each have six or more lobes.

5. The torque-limiting slip clutch system according to claim 1, wherein the upper clutch disc and the lower clutch disc are modular.

6. The torque-limiting slip clutch system according to claim 1, wherein the upper clutch disc is formed from a metal alloy.

7. The torque-limiting slip clutch system according to claim 1, wherein the lower clutch disc includes a composite material-filled resin material.

8. The torque limiting slip clutch system according to claim 1, wherein the elastic member includes a plurality of flat washers and Belleville washers.

9. The torque limiting slip clutch system according to claim 1, wherein the elastic member includes one or more coil springs.

10. The torque limiting slip clutch system according to claim 8, wherein the washers are configured to be stacked vertically on each other in the clutch carrier.

11. The torque limiting slip clutch system according to claim 1, wherein the clutch carrier defines a cylindrical housing configured to fit the elastic member, the housing having one end as an open end and the other end as a closed end.

12. The torque-limiting slip clutch system according to claim 1, wherein the closed end of the clutch carrier is provided with a projection that follows the lobe shape of the upper clutch, and the clutch carrier is configured to apply torque to the upper clutch.

13. The torque limiting slip clutch system according to claim 1, wherein the output torque of the system is set to 14 Newton meters.

14. The torque limiting slip clutch system according to claim 1, wherein the output torque of the system is set to more than 14 Newton meters.

15. The torque limiting slip clutch system according to claim 1, wherein the system is disposable.

16. Torque limiting driver, An upper clutch disc and a lower clutch disc opposite it, each configured to have multiple lobes, Elastic member and A clutch carrier configured to receive the aforementioned elastic member, A slip clutch equipped with, A main body having an attachment mechanism configured to be attached to the slip clutch, Equipped with, A torque limiting driver characterized in that the upper clutch disc is configured to slip relative to the lower clutch disc when a predetermined torque threshold is applied.

17. The torque limiting driver according to claim 16, wherein the predetermined torque threshold is set based on the elastic member.

18. The torque limiting driver according to claim 16, wherein the elastic member comprises one or more Belleville washers.

19. The torque limiting driver according to claim 16, wherein the upper clutch disc is conical.

20. The torque limiting driver according to claim 19, wherein the lower clutch disc is conical.

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