Wrench with torque indicator

Abstract

The present invention relates to a monolithic wrench (1) for indicating whether an applied torque is within a predetermined range, the monolithic wrench (1) comprising: a handle (30) formed in a single piece; a head (20) for receiving an element to be tightened or loosened by said wrench; an outer contour defining a maximum dimension of the wrench; and a torque range indicator (10) received in an inner opening contained entirely within said outer contour, said torque range indicator comprising an amplification mechanism (10A) for amplifying deformation of the head relative to the handle when the wrench is actuated, and a display element (10B) on said amplification mechanism for indicating a range of torque based on the relative displacement of the head relative to the handle. The present disclosure further relates to the use of the monolithic wrench described above.

Description

[Technical field]

[0001] The present invention relates to a wrench configured to indicate a range of applied torque. [Background technology]

[0002] Wrench tools with torque indicators are widely known in the art. The torque indicators may be mechanical or digital and can achieve highly accurate torque measurements.

[0003] In certain fields and situations, it may be more important for the user to know that the applied torque does not exceed a certain threshold or is within a certain range, rather than knowing the exact magnitude. For example, some cutting devices used for surgical purposes have a cutting tool that can be screwed into a handpiece. If the tool is not tightened enough, it may come loose and prevent proper use of the device. If it is tightened too tightly, stresses in the material may damage the cutting tool or the device. This may lead to breakage of the cutting tool or stripping of the threads of the device, which may be potentially dangerous for the patient undergoing surgery. To prevent these cases, the cutting tool must be tightened to a specific torque range.

[0004] Existing designs of torque wrenches that can be used in such situations are often complex and expensive: in fact, they are usually made of several components that require assembly leading to a number of drawbacks, such as complex manufacturing, complex maintenance (e.g. sterilization or cleaning), the need for lubrication, a high risk of contact corrosion, etc.

[0005] JP 2016-43448 A discloses a wrench having a notched handle that can indicate the range of applied torque. The wrench is made from several assembled components.

[0006] An example of a monolithic torque wrench is disclosed in U.S. Pat. No. 7,597,032. The torque wrench of this disclosure is actually a ratchet wrench with a two-part handle that acts as a torque range indicator. When torque is applied in a first rotational direction, the first part of the handle moves away from the second part of the handle. A display element fixed to one of the two parts indicates the range of applied torque. When torque is applied in the opposite rotational direction, the first part of the handle presses against the second part, which acts as a locking mechanism. This two-part design of the handle can be bulky when the first part of the handle moves away from the second part. Furthermore, this design can prevent an operator from gripping the handle securely because the operator must not be prevented from moving the first part away from the second part.

[0007] JP 2016-43448 A discloses a wrench having a notched handle that can indicate the range of applied torque. The wrench is made from several assembled components. Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE PRESENT EMBODIMENT It is an object of the present invention to provide a wrench with a torque indicator that overcomes the shortcomings and limitations of the state of the art.

[0009] Another object of the present invention is to provide a wrench with a torque indicator which is more ergonomic and in particular allows the user to easily read the torque indication while operating the wrench. [Means for solving the problem]

[0010] These objects are achieved by the subject matter of the claims, which in particular provide a monolithic wrench for indicating whether an applied torque is within a given range, Handle and a head for accommodating an element to be tightened or loosened by said wrench; an outer contour defining a maximum dimension of the wrench; a torque range indicator housed in an inner opening contained entirely within said outer contour; Equipped with The torque range indicator is accomplished by a monolithic wrench that includes an amplification mechanism for amplifying deformation of the head relative to the handle when the wrench is actuated, and a display element on the amplification mechanism for indicating a range of torque based on the relative displacement of the head relative to the handle.

[0011] The monolithic design makes the wrench simple and easy to manufacture, especially since no assembly is required. It also makes the wrench easier to maintain (e.g., clean, sterilize, lubrication-free, etc.).

[0012] The handle may be formed from a single rigid piece which allows for easier gripping of the wrench during actuation and prevents actuation from being disturbed by movement of the torque range indicator.

[0013] An additional benefit of this single, solidly formed handle is that the torque indication can be easily read by the user since the torque indicator is not localized under the user's hand, and the torque range indicator is not obscured by the user's hand.

[0014] The relative displacement of the head with respect to the handle due to elastic deformation of the material used can be further increased by connecting the head to the handle via at least one flexible beam.

[0015] The amplification mechanism can include at least two flexible arms connected via a connecting element, the at least two flexible arms configured to move away from the connecting element when a first torque is applied to the contact area in one rotational direction and to move towards the connecting element when a second torque is applied to the contact area in an opposite rotational direction.

[0016] The at least one flexible beam and connecting element allow for further deformation of the amplification mechanism, increasing the range of torque indication.

[0017] The wrench may include torque range markings, the position of the display element relative to the torque range markings representing a corresponding torque.

[0018] The torque range markings may be located on a handle and the display element may face towards the handle.

[0019] The wrench may be made of a metal alloy, preferably a steel-, aluminum-, or titanium-based alloy, or ceramic, polymer, silicon, or wood.

[0020] The torque range may be comprised between 0.2 Nm and 200 Nm. The wrench may be manufactured by subtractive or additive manufacturing.

[0021] The head of the wrench can be configured to accommodate at least two sizes of elements to be tightened or loosened therein.

[0022] According to one embodiment, the head may comprise two branched branches defining a gap space therebetween for accommodating an element to be tightened or loosened, the gap space comprising a first portion of a first width for accommodating an element having a corresponding width to be tightened / loosened, and a second portion of a second width for accommodating an element having a corresponding width to be tightened / loosened.

[0023] The first width is typically greater than the second width. Wrenches can be used to tighten and / or loosen elements of medical tools, the torque range being comprised between 0.2 Nm and 10 Nm.

[0024] The medical tool may be a surgical cutting tool. Exemplary embodiments of the invention are disclosed herein and illustrated in the drawings. [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 shows a perspective view of a wrench with a torque indicator. [Diagram 2] FIG. 2 shows a side view of a torque indicator wrench. [Diagram 3] FIG. 1 illustrates a side view of a torque range indicator when no torque is applied. [Figure 4] 13 shows a side view of the torque range indicator when torque is applied to tighten an element. [Diagram 5] 13 shows a side view of the torque range indicator when torque is applied to loosen an element. [Figure 6] 1 shows a perspective view of a wrench with a torque indicator with the indicator element facing towards the head of the wrench. [Figure 7] FIG. 2 shows a side view of a torque indicator wrench with a display element facing toward the head of the wrench. [Figure 8] 1 shows a side view of a wrench having a head configured for two different sized elements to be tightened and loosened. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] A monolithic wrench 1 according to the present invention is shown in Figure 1. Wrench 1 comprises a head 20, a handle 30 and a torque range indicator 10. Head 20 can accommodate an element to be tightened or loosened by the application of torque. Handle 30 allows an operator to apply force to the wrench to generate torque. Torque range indicator 10 is a mechanical indicator configured to indicate a range of applied torque so that an operator can know if the applied torque is within a predetermined range.

[0027] In the context of the present disclosure, the expression "monolithic wrench" means that the wrench is made from a single piece of material and does not require any assembly, particularly during manufacture. This monolithic design can be obtained by traditional machining (i.e. subtractive manufacturing) or by additive manufacturing (i.e. 3D printing).

[0028] This monolithic design allows for easy and simple maintenance of the wrench, since it is not necessary to disassemble the tool to clean or lubricate each part. Furthermore, since a single material is used, the risk of corrosion is reduced and contact corrosion is avoided. As shown in FIG. 2, the torque range indicator 10 is located in the inner opening of the wrench 1, which is completely contained in the outer contour of the wrench, which determines the maximum dimension of the wrench. The inner opening may be a through opening or may be a blind opening.

[0029] Advantageously, the handle 30 is made from a single rigid piece, meaning that it is formed as one piece and does not have arms that can move relative to each other when the wrench is actuated, this allows the user to have a better grip on the wrench as the entire handle can be held.

[0030] In the context of this disclosure, the term "handle" refers to the portion of the wrench opposite the head 20 and does not include the torque range indicator 10. The purpose of the handle 30 is to enable actuation of the wrench.

[0031] The torque range indicator, and more specifically the amplification mechanism, is entirely contained within the outer contour of the wrench, allowing for a single rigid piece handle 30. In particular, the torque range indicator is not dependent on relative movement of sub-parts of the handle 30.

[0032] When a torque is applied to the handle 30 by an operator to tighten or loosen an element housed in the head 20, the contact area 201 connecting the head to the handle undergoes an elastic deformation that may vary depending on the material used to manufacture the wrench. This deformation results in a movement of the head 20 relative to the handle 30 and is proportional to the applied torque. Quantification of this deformation therefore results in a quantification of the applied torque.

[0033] The torque range indicator 10 includes an amplification mechanism 10A for amplifying deformation of the handle 30 relative to the head 20, and includes a display element 10B for providing information regarding the range of applied torque. The display element is capable of moving in response to the deformation, thereby providing an operator operating the wrench with information regarding the magnitude of the applied torque.

[0034] In one embodiment, the amplification mechanism 10A comprises at least two flexible arms connected via a rigid connecting element 101 that stabilizes the flexible arms. The flexible arms are arranged to move away from the connecting element when a first torque is applied to the contact area 201 in one rotational direction and to move towards the connecting element when a second torque is applied to the contact area in an opposite rotational direction.

[0035] As shown in FIG. 3, the amplification mechanism 10A can comprise a first flexible arm and a second flexible arm 100″. The first flexible arm 100′ is disposed between the contact area 201 and the connecting element 101, while the second flexible arm 100″ is disposed between the connecting element and the handle 30. The first flexible arm 100′ is attached at one of its ends to the handle 30 and at the other end to a first end of the connecting element 101. The second flexible arm 100″ is attached at one of its ends to the contact area 201 and at the other end to a second end of the connecting element 201. When no torque is applied to the wrench, both flexible arms are essentially parallel to the connecting element 101.

[0036] In another embodiment, not shown, the flexible arm and the connecting element are not parallel in the rest position, i.e. in the position where no torque is applied.

[0037] The display element 10B is typically fixed to the amplifier mechanism 10A such that the movement of the amplifier mechanism is transferred to the display element, and thus the magnitude of the movement of the display element represents the applied torque.

[0038] A torque range marking 300 may be disposed on the wrench such that the relative position of the display element 10B with respect to the marking corresponds to the applied torque. Such torque range markings may be, for example, a graduated scale, a nonius marking, one or more zones corresponding to a particular range, etc.

[0039] Advantageously, the torque range markings are located on a portion of the wrench that is not covered by the user's hand actuating the wrench so that the user can easily obtain information about the range of applied torque while using the wrench.

[0040] In one embodiment, the display element 10B comprises a needle having an end attached to the connecting element 101. The other end of the needle is used as a pointer towards a particular zone of the wrench 1. A torque range marking 300 representing the range of torque to be applied to the wrench can be added to this particular zone so that the needle points to the marking and the user can get information regarding the applied torque by looking at the marking.

[0041] 2, torque range markings 300 may be located on the handle 30. The markings may be made up of several zones, for example three zones, each corresponding to a range of torque.

[0042] 3, the needle of the display element 10B may, for example, point towards the handle 30. In another embodiment, shown in FIG.

[0043] When considering a torque, the relative displacement of the needle with respect to the handle will be greater if the needle is pointing towards the handle because the handle moves relative to the head and moves in the opposite direction relative to the needle, however, for design reasons it may be advantageous to have the needle pointing towards the head.

[0044] Alternatively, or in addition, display element 10B may indicate the torque range by obscuring a designated portion of the wrench or torque range markings.

[0045] In another embodiment, the torque range markings include one or more notches or slots into which the display element 10B can fit depending on a corresponding torque, with each notch or slot representing a value of applied torque.

[0046] To increase the deformation of the head 20 relative to the handle 30, the wrench 1 may comprise at least one flexible beam connecting the head to the handle. These flexible beams make it possible to increase the elastic deformation. The flexible beams may extend radially from the head 20 so as to be aligned with the theoretical pivot point of the element to be fastened.

[0047] In the particular embodiment shown in Fig. 2, two flexible beams 200 are arranged symmetrically around the longitudinal axis of the wrench. The contact area 201 is fixed to the head via the neck and is able to move within an inner opening partially defined by the flexible beam. This movement of the contact area results in a significant amplification of the deformation of the wrench to be quantified, thus allowing a precise measurement of this torque.

[0048] FIG. 4 shows the torque range indicator 10 in a configuration obtained when a first torque is applied to the contact area 201 in a first rotational direction, for example to tighten an element housed in the head 20. The two flexible beams 200 deform and the contact area 201 moves relative to the handle 30. The movement of the contact area causes the first flexible arm 100' to move gradually away from the connection element 101. While the end of the first arm attached to the handle moves away from the connection element, the end of the first arm attached to the connection element does not move away from the connection element. Similarly, the second flexible arm 100'' moves gradually away from the connection element. The movement of the two flexible arms causes the connection element to rotate in a direction opposite to the first rotational direction. Thus, the display element 10B attached to the connection element 101 moves essentially in a direction opposite to the first rotational direction.

[0049] FIG. 5 shows the opposite configuration, where torque is applied in a second rotational direction opposite to the first rotational direction, for example to loosen an element housed in the head 20. In this situation, both the first and second flexible arms 100′, 100″ move towards the connecting element 101, causing it to rotate in a direction opposite to the second rotational direction. As a result, the indicator element 10B moves in a direction essentially opposite to the second rotational direction. The indicator element 10B may contact the inner surface of the wrench (i.e. the boundary of the inner opening) and act as a locking stop to stop further deformation of the amplification mechanism. Alternatively or additionally, the flexible arms may also act as a locking stop mechanism when they contact the connecting element.

[0050] To be reusable, the wrench must be manufactured from a material that can handle high stresses without undergoing plastic deformation. Furthermore, other external factors such as heat resistance (sterility) or biocompatibility may be important for the choice of material. In fact, the wrench of the present invention is suitable for use in the medical field, and in particular in the surgical field, for fixing certain surgical tools (such as cutting tools) to handpieces (or for removing these tools from handpieces). Such use requires sterilization of the wrench.

[0051] Alternatively, a material with certain plastic deformation properties can be used, for example to obtain a disposable wrench that remains deformed after use.

[0052] Several different materials can be used to manufacture the monolithic wrench. Such materials include several types of metal alloys, such as steel-based alloys, for example chromium-nickel-copper steel, as well as aluminum-based or titanium-based alloys. Alternatively, materials such as ceramics, various types of polymers, silicon, or wood can be considered, depending on the intended application of the wrench. The choice of material can strongly affect the mechanical properties of the wrench. It can therefore be used to increase or decrease the total deformation of the wrench, i.e., the plastic and elastic deformation.

[0053] As mentioned above, the wrench 1 can be manufactured by traditional machining. Different cutting techniques such as water jet, EDM (electrical discharge machining), laser cutting, etc. can be used to define the contour and the inner opening of the wrench. Hardening, etching and engraving processes can be applied. In particular, the series number and torque range markings can be engraved on the handle by laser.

[0054] The dimensions of the wrench, i.e. the plate thickness, also strongly influence the range of torque that can be applied. The thickness of the wrench of the invention can advantageously vary between 1 mm and 10 mm, depending on the range of torque that needs to be achieved. This thickness can be changed depending on the desired torque, without the need to change other parameters of the wrench design.

[0055] The head 20 can be configured to accommodate at least two different sizes of elements to be tightened or loosened, meaning that the same wrench can be used to tighten or loosen elements of at least two different sizes, i.e. having at least two different widths.

[0056] 8, the head 20 comprises two branches 202, defining a void space between the two branches, which void space is intended to accommodate an element to be tightened or loosened.

[0057] The inner distance between the two branches 202 is variable along the length of the branch to accommodate different sized elements to be tightened or loosened. As a result, the void space defined by the branch 202 is of variable width since its width corresponds to the inner distance between the two branches.

[0058] In a particular embodiment, the gap space comprises a first portion having a first width d1, i.e. the two branched branches comprise a first portion spaced apart from each other by a distance corresponding to the first width d1. This first portion of the gap space can accommodate a fastening or loosening element having a size corresponding to the first width d1. The gap space further comprises a second portion having a second width d2, i.e. the two branched branches comprise a second portion spaced apart from the first by a distance corresponding to the second width d2. This second portion of the gap space can accommodate a fastening or loosening element having a size corresponding to the second width d2.

[0059] In embodiments not shown, the void space comprises three or more portions having different widths to allow for tightening or loosening of elements having three or more sizes (ie, widths).

[0060] As shown in FIG. 8, the first width d1 can be greater than the second width d2. [Explanation of symbols]

[0061] 1 wrench 10 Torque Range Indicator 10A Amplification mechanism 100' First Flexible Arm 100'' Second Flexible Arm 101 Connection elements 10B display element 20 Head 200 flexible beam 201 Contact area 202 Branch 30 Handle 300 Torque range marking d1 First width d2 Second width

Claims

1. A monolithic wrench (1) for indicating whether an applied torque is within a predetermined range, a handle (30); a head (20) for accommodating an element to be tightened or loosened by said wrench; an outer contour defining the maximum dimension of the wrench; a torque range indicator (10) housed in an inner opening contained entirely inside said outer contour; It is equipped with The torque range indicator is a monolithic wrench (1) comprising an amplification mechanism (10A) for amplifying deformation of the head relative to the handle when the wrench is actuated, and a display element (10B) on the amplification mechanism for indicating a range of torque based on the relative displacement of the head relative to the handle.

2. 2. The wrench (1) according to claim 1, wherein the handle (30) is made from a single rigid piece.

3. 2. The wrench (1) of claim 1, wherein the head (20) is connected to the handle (30) via at least one flexible beam (200).

4. 2. The wrench of claim 1, wherein the amplification mechanism comprises at least two flexible arms connected via a connecting element, the at least two flexible arms being configured to move away from the connecting element when a first torque is applied to a contact area in one rotational direction and to move towards the connecting element when a second torque is applied to the contact area in an opposite rotational direction.

5. Torque range marking (300) Furthermore, 2. The wrench (1) of claim 1, wherein the position of the display element (10B) relative to the torque range markings represents a corresponding torque.

6. 6. The wrench (1) of claim 5, wherein the torque range markings are located on the handle (30) and the display element (10B) faces towards the handle (30).

7. 2. The wrench (1) according to claim 1, made of a metal alloy, preferably a steel-based, aluminum-based or titanium-based alloy, or ceramic, polymer, silicon or wood.

8. The wrench (1) according to claim 1, wherein the torque range is comprised between 0.2 Nm and 200 Nm.

9. 10. The wrench (1) according to claim 1, which is manufactured by subtractive manufacturing or by additive manufacturing.

10. 2. The wrench (1) of claim 1, wherein the head (20) is configured to accommodate at least two different sized elements to be tightened or loosened.

11. 11. The wrench (1) of claim 10, wherein the head (20) comprises two branches (202) defining a gap space therebetween, the gap space comprising a first portion with a first width (d1) for accommodating a first element to be tightened or loosened, and a second portion with a second width (d2) for accommodating a second element to be tightened or loosened.

12. 12. The wrench (1) according to claim 11, wherein the first width (d1) is greater than the second width (d2).

13. Use of a monolithic wrench (1) according to any one of claims 1 to 12 for tightening and / or loosening elements of a medical tool, comprising: The torque range is comprised between 0.2 Nm and 10 Nm.

14. Use of a monolithic wrench (1) according to claim 13, wherein said medical tool is a surgical cutting tool.

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