Fastening tools instant torque metering accessory

Abstract

The invention pertains to the field of manual fastening tools The invention is an accessory to most fastening tools, of any length and size: when coupled to the handle of the fastening tool of choice by means of a quick adaptive coupling system, the device's electronics will show on a digital display the instant torque resulting from the sensed applied force and its measured specific arm. The display's touch screen allows entry of Calibration data, target torque values, force arm length alternate entry, and selection of measuring unit.

Description

FASTENING TOOLS INSTANT TORQUE METERING ACCESSORY Technical field: Manual tools In the field of manual mechanical tools, torque wrenches are tools used to apply a specific torque to a rotary fastener. 5 Background art: Manual torque wrenches are usable within a torque range of a few tens of Nm; these tools are made of a tubular metal body showing at the two ends, respectively, a handle and the connection fitting for various socket types and sizes. When operated, a torque wrench will give a visual indication, an aural indication, or a combination thereof when the preset torque is reached; tools equipped with a digital display will permanently show the current applied torque value. 10 Below is a partial list of the limits of existing torque wrenches. - In order to withstand the mechanical stress it is subject to, when operated close to the upper end of its torque range, a torque wrench is obviously oversized with regard to the lower end of said range. - A torque range of only a few tens of Nm does not meet the requirements of any automotive 15 workshop, where application of torque ranging anywhere from 10 to 350 Nm is frequent; therefore at least two different torque wrenches are required. 20 - The shape and size of existing torque wrenches are often incompatible with narrow spaces, such as the engine compartment of a car. - Click torque wrenches do not provide indication of the current torque value but only provide a click signal when the preset torque value is reached. Furthermore, a noisy environment might hide the click signal, which could result in excessive mechanical stress on the fastener. This overtightening condition does not happen with electronic torque wrenches, provided that the wrench's sensorial alerts are effective or that the digital screen is always visible to the operator. 25 - Manual torque wrenches' internal mechanism never allows torque to exceed the torque range; consequently, the application of a cheater bar only reduces the operator's effort. - Proper storage of mechanical wrenches requires that load is relieved from internal spring. - Calibration of torque wrenches require complex procedures and / or expensive equipment. Disclosure of invention 30 Note 1: in the following text the terms "spanner'', "wrench", "fastening tool" are considered to have the same meaning with respect to the explanation of the function of the invention. Also, the term "Device" with a capital D refers to the invention, to avoid confusion with other devices. Note 2: Force, Force Arm, Torque are entities described in Physics and each is represented as a vector, defined by a point of application, a magnitude, a line of action and a sense. It's understood that the 1 Date Re9ue / Date Received 2024-05-01 35 Force, described as acting on a tool, or its value (magnitude), as shown on a display, describe the same concept with no need for further explanation. Similarly, the terms "force arm", "lever", "lever length", "distance between the point of application and the fulcrum" represent the same concept. The primary purpose of the invention is to provide a removable physical accessory to simple fastening tools, from time to time coupled with a different tool, so that, when firmly connected to the handle 40 of such fastening tool, switched on and correctly operated, said accessory measures the applied torque and shows its value on a digital display. Correct operation is achieved when the user pushes on the Device as if it were the handle of the fastening tool, to which the Device has been coupled, so that all the force applied by the operator is entirely transferred to the tool. Another purpose of the invention is to calculate the applied torque by electronically and individually 45 measuring both its components: the force and its lever arm. Another purpose of the invention is a versatile coupling system which allows the same Device to be quickly joined either to a small and short fastening tool or to a large and long one. Another purpose of the invention are the Device's extremely small dimensions which, not significantly altering the hosting tool overall dimensions, does not preclude its use in restricted spaces. 50 Another purpose of the invention is that the user may continuously keep in sight the digital display, during operation, as this is not rigidly connected to the Device. Another purpose of the invention is a torque measuring instrument which is simple, light and small so that production and transport costs are significantly lower than what the market currently offers. Another purpose of the invention is the simplicity of the calibration procedures that do not require 55 special equipment and / or specific skills. All these and other objects which will result from the following description are reached with this invention. Description of drawings: Fig 1 shows the Force Sensing Assembly; Fig 2 shows the exploded view of the same assembly; Fig 3 shows a view of the coupling system; Fig 4 shows an exploded view of the 60 same; Fig 5 shows a two schematic views of the PCB (12), of the Li-Ion battery (13), and of the Enclosure (14). Fig 6 shows parts from (1) to (10). Scale is shown on each drawing. Parts are identified with corresponding numbers in the text that follows. Best mode for carrying out the invention: The present invention is hereafter further clarified, with reference to the attached drawings, in a preferred embodiment thereof, given purely by way of non- 65 limiting example. The Device, in the appearance of an oblong handle, conveniently combined to a fastening tool: -measures the force being exerted on said tool to fasten a fastener; -measures the arm of said force; 2 Date Re9ue / Date Received 2024-05-01 -calculates the torque, which is the result of the multiplication of the force by its arm, and displays its 70 value. The device main components are: - the Force Sensing Assembly. It comprises: a force sensor, i. e. a full bridge electronic load cell (4), conveniently placed between two steel barrettes (2) (5), each connected by a pair of screws (1) to the opposite ends and faces of the load cell; between each barrette (2) (5) and the load cell (4) a steel 75 spacer (3) is placed. Four screws (1) pass through holes conveniently drilled in the barrettes and spacers. Four electric wires, not shown in the drawings, connect the load cell to a PCB (12); when compressed between the two barrettes, the electrically powered load cell generates an electric signal proportional to the magnitude of the compression (1. e.: the force). - the Quick Adaptive Coupling System. It enables coupling and uncoupling the Device and a fastening 80 tool in only a few seconds; it comprises: a carbon steel spring clip (7), shaped to be joined firmly to the shorter barrette (5); a carbon steel spring clip (9), shaped to be joined firmly to the fastening tool handle; a steel spacer (8) between the two clips (7) and (9); a domed head hex screw (6), passing through drilled holes in the spring clips and the spacer, and screwed into a rectangular nut (10) to hold clips and spacers together. The screw's domed head fits in a conveniently shaped hole in the barrette 85 (5), so that joining the barrette and the quick connection assembly in the correct relative position is easily done. Furthermore, the nut (10) being the only contact point between the force sensing unit and the fastening tool, the position of the point of application of the force is identified, a necessary condition to precisely measure the force arm. The "adaptive" feature of the system relates to the availability of different size and shape clips (like (9) and (11)), that allow coupling the device to tool 90 handles of different size and shape. An Electronic Processing Unit, or Electronic Processor (12), also referred to as the PCB, that carries, besides all necessary electronic components, a BLE module (Bluetooth Low Energy), connectors to the load cell and to the Li-Ion cell; and that hosts the electronic distance measuring subsystem comprising a laser diode sensor to measure the force arm; 95 -it controls the electric power to the system, and recharges the Li-Ion cell when connected to an external power source via the USB connector (used also as a communication port for system upgrade and electronic component calibration); -it gathers and processes the signals received from the load cell to define the magnitude of the force acting on the fastening tool; 100 -it receives the signals from the laser diode sensor, which is conveniently positioned to measure the magnitude of the force arm; -it computes the resulting torque by multiplying the force and the force arm; 3 Date Re9ue / Date Received 2024-05-01 -it feeds all processed information to a dedicated smartphone application via the Bluetooth module. A Li-Ion rechargeable cell (13). It's a battery connected via two wires (not shown in the drawings) to 105 the PCB (12); -it supplies electrical power to the Device. An Input device. It allows selection of the appropriate operating mode: -system upgrading and / or software updating; -calibration of the device, if required; 110 -torque measure; and -to enter the torque value recommended for a specific bolt (this information is generally found on workshop manuals); in the text that follows this value is referred to as the target torque; -to enter the force arm, if known, whenever the distance measuring subsystem is inoperable; 115 -to select the preferred measuring units (lbs, kg, meters, inches, Newton, etc.) A Digital Display. It shows: -the value in digits of the instant torque. In this embodiment both the Input device and the Digital Display are integrated in a smartphone which, by means of a dedicated proprietary application, becomes the user interface required to 120 operate the Device; connection between the smartphone and the Device can be either wireless or via a cable. The Input device is typically a touchscreen. An Enclosure. The Force Sensing Assembly, the PCB and the Li-Ion cell are housed together in a plastic enclosure (14). A "window" in the Enclosure allows the quick connection assembly to be coupled to the Force sensing assembly. 4 Date Re9ue / Date Received 2024-05-01

Claims

125 CLAIMS 130 135 140 1. A torque metering device for any fastening tool, said device comprising: a force sensing assembly for detecting a force exerted on the fastening tool to produce a torque, said force sensing assembly comprising a load cell force sensor (4) placed between two steel barrettes (2, 5) each connected, by means of a pair of screws (1) and with the interposition of steel spacers (3), to the opposite ends of the load cell (4); an electronic distance measuring system having a laser diode that measures the actual lever arm of the force; said force sensing assembly and said electronic distance measuring system connected to an electronic processing unit, wherein the electronic processor unit receives and processes information from the force sensing assembly and the distance measuring system for the computation of the instant torque; a digital display on which the value of the instant torque is displayed; a user interface and an input device that allows the operator to select an operating mode to enter known and target values and to select measuring units; a battery (13); an enclosure (14) in the shape of an oblong handle; and a coupling system comprising spring clips (7) of appropriate size and shape (9, 11) for allowing the device to be temporarily and firmly attached to any fastening tool.

2. The device as claimed in claim 1, wherein the connection between said digital screen and said device is wireless or through a cable.

3. The device as claimed in claim 1, whose electronic processing unit is equipped with a communication port for system upgrade and electronic component calibration. 5 Date Re9ue / Date Received 2024-05-01