Ergonomic hammer, axe structure

Abstract

An ergonomic hammer and axe structure includes a handle and a striking member, the handle has a first body, a second body and a third body, the first body, the second body and the third body are connected in sequence from front to back, the central axis of the first body is inclined upward relative to the central axis of the second body by a first inclination angle, the central axis of the third body is inclined downward relative to the central axis of the second body by a second inclination angle, the striking member is vertically arranged on the first body, when the user holds the third body and swings the handle downward to make the striking member strike a nail, the striking member can be aligned with the nail and knocked down through the correction of the first inclination angle and the second inclination angle, the hand is kept straight and the palm and the web of the user are prevented from being stretched, and the striking member has a parabolic curved surface design.

Description

Technical Field

[0001] This invention relates to an ergonomic hammer and axe structure, specifically an ergonomic hammer and axe structure that is easy to hold and correct the direction of striking. Background Technology

[0002] In recent years, advancements in science and technology have led to the automation or use of electric machinery replacing many tasks that previously required manual labor and hand tools. However, many tasks in daily life still require manual operation. For example, construction work, plumbing, and home renovation often involve hammering. Traditional hammer designs did not adequately consider ergonomics, forcing users to compromise with the hammer's design, often choosing unsuitable hammers, relying on experience to make inappropriate movements, or overworking due to insufficient safety knowledge, resulting in unnecessary fatigue and workplace injuries. In particular, when hammering nails, ordinary users frequently knock nails askew or bent, often injuring their hands and causing serious injuries. Improvements are indeed necessary.

[0003] According to the existing hammer, by Figure 18 and Figure 19 As shown, there is a hammer (90) with a handle (91) and a hammer head (92) vertically disposed on the handle (91). When the user holds the handle (91) and strikes the nail with the hammer head (92), the hammer head (92) is not directly facing the nail when it strikes downwards because the hammer head (92) is perpendicular to the handle (91) and there is a distance between the hand and the striking point. This may cause the nail to be knocked off course after being struck, and may also cause the hand to be close to the plane and get injured. Therefore, how to correct the striking direction is one of the problems that needs to be solved.

[0004] Construction site workers differ significantly from general DIY hand tool users in their work knowledge and experience. Professional users on construction sites possess better muscle endurance, physical strength, and tool handling skills, and are more adept at balancing work and rest; general users often lack these qualities. When hammering nails into walls, tabletops, or floors, the hammer's angle varies depending on the nail's location. Therefore, it's necessary to design hammers with handles and hammerheads of different angles to accommodate different users and operating conditions, ensuring ergonomic design and minimizing nail misalignment and bending. To improve nail-hammering accuracy, the inventors studied geometric principles to design the optimal striking surface, allowing the nail to be driven in the desired direction even when struck off-center, rather than necessarily at the center of the hammerhead.

[0005] After a long period of research, the inventor explored the problems of traditional hammer design, the anatomical structure of the human upper limb, and the damage caused by improper use of tools, such as myofascitis. Finally, the inventor proposed this invention, which greatly improves the problem that ordinary users cannot accurately hammer nails.

[0006] The operation of a hammer is primarily performed by the hand. Therefore, to study hammer design, one should first gain a basic understanding of the muscles in the human hand related to hammer operation. From a physiological and anatomical perspective, through kinematic analysis, and by studying the swinging motion of the hammer, a hammer that is more suitable for the human body can be designed. The following discussion focuses on the physiological and anatomical structure of the hand, exploring these aspects in detail.

[0007] The upper limb is divided into the upper arm, forearm, and hand. The upper arm is framed by the humerus. The forearm is framed by the radius and ulna, and connects to the hand at the wrist joint; it connects to the humerus of the upper arm at the elbow joint.

[0008] The muscles of the upper arm include the biceps brachii, brachialis, brachioradialis, triceps brachii, anconeus, pronator, and supinator. Contraction of the biceps brachii, brachialis, and brachioradialis produces forearm flexion; the pronator and supinator produce forearm internal and external rotation. However, forearm flexion is primarily driven by the biceps brachii, while the triceps brachii is the main muscle responsible for forearm extension.

[0009] The muscles of the forearm include wrist flexors, wrist extensors, palmaris longus, finger flexors, finger extensors, adductor pollicis longus, abductor pollicis longus, and flexor pollicis longus.

[0010] The wrist is a rather complex joint, connecting the palm to the forearm. The carpal tunnel, located in a hollow in the wrist, connects to many small bones and ligaments. Several important nerves, blood vessels, and tendons pass through this tunnel, allowing the hand to perform various movements. Anatomical studies have shown that the average person's hand can deviate radially by 15-20 degrees; ulnarly by 35-37 degrees; palmar flexion and extension by 85-90 degrees; and dorsiflexion by 75-80 degrees. Because a large number of nerves and blood vessels pass through the carpal tunnel, excessive radial and ulnar deviation, or improper force applied during deflection, can compress and damage these nerves and blood vessels, a condition known as "carpal tunnel syndrome."

[0011] The radial and ulnar deviations of the wrist, as well as palmar and dorsiflexion movements, are mainly controlled by two muscle groups, which can be divided into the wrist extensor group and the wrist flexor group. The wrist extensor group consists of two muscles, the extensor carpi radialis and the extensor carpi ulnaris, which are responsible for the outward extension of the wrist. Each muscle attaches to the humerus of the upper arm at one end and to the bones of the palm at the other end.

[0012] The muscles located on the palmar side of the forearm are mainly responsible for wrist flexion, finger flexion, and pronation (palm turning downwards). The forearm muscles are an important muscle group connecting the elbow and wrist, responsible for the fine movements of the wrist and fingers as well as the rotational function of the forearm. The anterior side of the forearm (flexor muscles) is located on the palmar side of the forearm and is mainly responsible for wrist flexion, finger flexion, and pronation (palm turning downwards). It is further divided into deep muscles and superficial muscles.

[0013] The superficial muscle groups include: (I) Pronator teres, origin: head of humerus, medial epicondyle of humerus (originating from the humerus together with the common flexor tendon), head of ulna, medial border of the coronoid process of ulna (may be absent in some individuals), insertion: middle of the lateral surface of the radius (forming the pronator teres tubercle), function: forearm pronation (turning the palm backward or to the ground), assisting in elbow flexion; (II) flexor carpi radialis, origin: medial epicondyle of humerus, insertion: base of the second metacarpal bone, function: wrist flexion (bending the palm toward the arm), radial deviation (abducting the wrist, tilting the hand toward the thumb). (iii) Palmaris longus (absent in some individuals), origin: medial epicondyle of the humerus, insertion: palmar aponeurosis, function: wrist flexion, tension of the palmar aponeurosis; (iv) Flexor carpi ulnaris, origin: medial epicondyle of the humerus, ulna, insertion: pisiform bone, base of the 5th metacarpal bone, function: wrist flexion (palmar flexion), synergistically with flexor carpi radialis to flex the wrist, ulnar deviation of the hand (bending towards the little finger side, adduction), pulling the hand towards the ulnar side (little finger side), such as in hammer swinging or throwing movements, stabilizing the wrist joint, providing stability when making a fist or grasping. The flexor carpi ulnaris is one of the strongest flexor muscles of the wrist, playing a key role in ulnar deviation. The flexion and adduction of the wrist when using a hammer to strike or playing tennis both depend on this muscle.

[0014] The deep muscle groups include: (i) flexor digitorum superficialis, origin: medial epicondyle of humerus, coronoid process of ulna, anterior border of radius, insertion: middle phalanges of the 2nd to 5th fingers, function: flexion of proximal interphalangeal joint (PIP), metacarpophalangeal joint (MCP) and wrist joint; (ii) flexor digitorum profundus, origin: anterior aspect of proximal ulna and interosseous membrane, insertion: distal phalanges of the 2nd to 5th fingers, function: flexion of distal interphalangeal joint (DIP), assisting in wrist flexion; (iii) flexor pollicis longus, origin: anterior aspect of radius and interosseous membrane, insertion: big phalanx, function: flexion of thumb interphalangeal joint (IP); (iv) pronator quadratus, origin: anterior aspect of distal ulna (approximately the anterior aspect of the lower 1 / 4 of ulna), insertion: anterior aspect of distal radius (approximately the anterior aspect of the lower 1 / 4 of radius), function: pronation of forearm, stabilization of distal radioulnar joint (maintaining wrist joint stability).

[0015] Superficial muscle groups include: Extensor carpi radialis longus, origin: lateral epicondyle of the humerus, insertion: base of the 2nd metacarpal. Function: wrist extension, radial deviation of the hand. Extensor carpi radialis brevis, origin: lateral epicondyle of the humerus, insertion: base of the 3rd metacarpal. Function: wrist extension. Extensor digitorum, origin: lateral epicondyle of the humerus, insertion: distal and middle phalanges of the 2nd-5th fingers. Function: finger extension (extension of metacarpophalangeal and interphalangeal joints). Extensor digiti minimi, origin: lateral epicondyle of the humerus, insertion: dorsal aponeurosis of the little finger. Function: extension of the little finger. Extensor carpi ulnaris, origin: lateral epicondyle of the humerus and posterior border of the ulna, insertion: base of the 5th metacarpal. Function: wrist extension (dorsiflexion), participates in ulnar deviation of the wrist (tilting the hand towards the little finger).

[0016] The deep muscle groups include: (i) supinator, origin: lateral epicondyle of humerus and proximal ulna, insertion: anterior end of proximal radius, function: supination of the forearm; (ii) abductor pollicis longus, origin: posterior aspect of ulna and radius, insertion: base of the first metacarpal bone, function: abduct the thumb (away from the palm); (iii) extensor pollicis brevis, origin: posterior aspect of radius, insertion: proximal phalanx of thumb, function: extension of the metacarpophalangeal joint (MCP) of the thumb; (iv) extensor pollicis longus, origin: posterior aspect of ulna, insertion: greater phalanx, function: extension of the interphalangeal joint (IP) of the thumb; (v) extensor indicis, origin: posterior aspect of ulna, insertion: dorsal aponeurosis of the indicative finger, function: independent extension of the indicative finger.

[0017] Summary of forearm functions: (I) Flexion: The wrist and fingers bend (e.g., making a fist). (II) Extension: The wrist and fingers straighten (e.g., opening the palm). (III) Pronation: The forearm internally rotates (e.g., turning a screw). (IV) Supination: The forearm externally rotates (e.g., turning the palm upward). (V) Radial and ulnar deviation: The wrist tilts towards the thumb or little finger side.

[0018] Hand movements on the horizontal plane, moving towards the thumb side (that is, towards the radius), are called radial deviation; movements towards the little finger side (that is, towards the ulna) are called ulnar deviation.

[0019] When striking nails with a hammer, there are two main types of physical and mechanical movements of the limbs: one is the back-and-forth translational movement at any point on the limb's curvilinearity, called "reciprocating motion"; the other is the back-and-forth rotational movement of the limbs, called "oscillatory motion".

[0020] From a kinesiological perspective, these two movements are shoulder flexion and elbow flexion. The reciprocating movement, shoulder flexion, is controlled by the shoulder muscles, primarily the latissimus dorsi. Elbow flexion, controlled by the upper arm muscles, is mainly due to the contraction of the triceps brachii and biceps brachii. Wrist rotation is primarily controlled by the extensor carpi radialis, flexor carpi radialis, extensor carpi ulnaris, and flexor carpi ulnaris. These movements are controlled by two or more muscle groups. The hammer strikes downwards (downswing), and after the first strike, the hammerhead is raised upwards (upswing) from its highest point. The downward strike constitutes one-third of the cycle, providing the acceleration phase with the necessary force; the upward swing is the deceleration phase, allowing the limb to return to the desired height. This process is repeated to complete the complex hammer striking operation. The muscle activation process during the entire striking operation is shown below.

[0021] The analysis of the hammer striking motion can be seen in the table below:

[0022] Occupational injuries to bones and muscles caused by using a hammer can generally be categorized as follows: Immediate injuries include bruises, lacerations, crush injuries, and sprains. These are mostly caused by improper work methods, lack of experience, poor tool design, and unsuitable working environments, resulting in immediate and noticeable injuries. Because the symptoms are obvious, they are relatively easy to treat immediately and are less likely to leave serious sequelae. In the process of hammering nails, the most common incident is when the hammer accidentally hits the hand holding the nail (when the nail is temporarily fixed to a board before actual hammering).

[0023] Cumulative injuries: Tendinities such as tendinitis and carpal tunnel syndrome. Symptoms at the injured site typically include numbness, paleness (due to poor blood circulation), pain, loss of muscle control, or decreased sensitivity to hot and cold. These injuries often occur insidiously over a long period due to improper posture or the use of poorly designed tools, leading to cumulative damage. Because initial symptoms are often subtle, they are frequently overlooked, resulting in irreparable damage or intractable sequelae over time.

[0024] Regarding the types of cumulative injuries, injuries to the hand and wrist include tendinitis, carpal tunnel syndrome, and white finger syndrome; injuries to the arm and elbow include tennis elbow, radial tunnel complications, and extensor tendon synovitis; and injuries to the shoulder include supraspinatus tendinitis.

[0025] Cumulative work injuries associated with using a hammer: Because hammers are designed to generate significant striking force, their center of gravity is mostly shifted towards the front. During the preparatory motion before striking, the forearm rotates forward, and the wrist joint deviates radially and dorsiflexes, which can easily cause tennis elbow. At the moment of impact, the forearm strongly pronates, and the wrist joint deviates strongly ulnarly, which can easily cause tendinitis.

[0026] Studies of the shape and size of the parts that come into contact with the hand revealed that the center of the palm is the most sensitive area of ​​the hand, meaning it has the lowest tolerance for sustained pressure. This is followed by the base of the thumb near the palm, and then the fingers. The research in this invention found that an ergonomically designed hammer, with correctly angled handle and head, can significantly reduce the wobbling of the handle in the operator's hand when swinging the hammer to strike nails, and reduce vibration to the palm.

[0027] Research on hammer working patterns revealed that professional construction workers primarily use the triceps brachii in their upper arms to drive the swing, resulting in higher efficiency and less fatigue. In contrast, general users experience the greatest strain on the radial and ulnar flexor carpi radialis muscles during hammer swings, and the areas of soreness afterward differ from those experienced by construction workers.

[0028] Analysis of force distribution and movement in the upper arm and forearm during nail driving: From a biomechanical perspective, the muscles used to lift the hammer are the radial extensor carpi radialis in the forearm and the biceps brachii in the upper arm, controlling wrist and forearm movements. When swinging the hammer downwards, the average user exerts the greatest force on the radial and ulnar extensor carpi radialis; while professional users exert the greatest force on the triceps brachii, which strikes the hammer downwards. Besides the difference in the timing of maximum force application, the distribution also differs: professional users exert the greatest force on the upper arm, while average users exert it on the forearm. The difference in muscle size between the forearm and upper arm directly relates to the magnitude of force output and endurance, thus affecting the efficiency and fatigue level of nail driving.

[0029] Studies have shown that during hammer driving, professional users utilize the triceps brachii (approximately 45%), meaning the largest proportion of force is applied during the downward swing. In contrast, for average users, the radial flexor carpi radialis (approximately 47%) contributes the largest percentage of force, primarily in lifting the hammer. This results in lower efficiency and faster fatigue for average users. Professional users leverage their large, powerful triceps to drive the forearm downward, while average users rely on their smaller radial flexor carpi radialis to rotate the wrist downward. Besides less force, the lever arm is also shorter, generating less power and thus lower efficiency. This explains the efficiency difference between average and professional users as stemming from their different work patterns.

[0030] Differences in posture among test subjects. Users less familiar with hammering nails typically have a smaller forearm swing arc than professional users. Their hammer swing is primarily centered on the wrist joint, driven by the palm. Because this movement uses smaller muscle groups that drive wrist movement—the radial flexor and radial extensor wrists—it exerts less force and causes greater fatigue, requiring more swings to drive the nail into the wood. Professional users, on the other hand, swing the hammer with a larger motion. The arm movement primarily involves swinging the upper arm first, then using the elbow and shoulder joints as axes to swing the upper arm and forearm at a larger angle. Therefore, the triceps brachii is the most burdened muscle. Anatomically, this movement also uses larger muscles such as the deltoid and latissimus dorsi, driving a greater forearm rotation arc. This not only generates greater impact force but also reduces fatigue, allowing for the driving of more nails. However, the latissimus dorsi muscle controls complex movements, not only related to the up-and-down swinging of the upper arm during nailing operations, but also controlling the extension, adduction, internal rotation of the upper arm, and even the downward and backward pulling of the scapula. All of these movements are accomplished by the contraction of this muscle.

[0031] When swinging a hammer, the muscles involved in muscle contraction are primarily the radial flexor carpi radialis, radial extensor carpi radialis, biceps brachii, and triceps brachii. In general use, when hammering nails, the radial extensor carpi radialis bears the heaviest workload among these four muscles, contributing to forearm soreness. Therefore, this invention focuses on exploring whether design variations, such as changing the angle of the hammer handle's bend, can reduce the load on the radial extensor carpi radialis, thereby reducing forearm fatigue, improving comfort and efficiency, and even potentially achieving a more expert-like posture.

[0032] In this invention, we studied the bending angles of the hammer handle and the hammer head. The evaluation criteria primarily focused on the degree of radial and ulnar wrist deviation, subjective preference after work, work efficiency during operation, and the accuracy of nail placement. This is because using a hammer typically involves strong radial and ulnar impact forces, creating significant pressure on the palm. Long-term workers frequently suffer from cumulative musculoskeletal injuries related to the wrist. Accurate nail placement (where the nail is attracted to the hammer by a magnet in the nail groove on the hammer head, allowing the hammer to be swung with one hand without holding the nail) eliminates the need for the user to hold the nail while striking it, reducing the risk of accidental hand injuries.

[0033] The effects of handle angle and center of gravity on nail driving operations, and the influence of bent handle on grip strength attenuation and wrist radial-ulnar deviation angle. This study found that straight-handled hammers cause less radial deviation and more ulnar deviation.

[0034] When ordinary users hammer nails, they rarely achieve perfect accuracy. This is because if the hammer doesn't strike the center of the nail head, or if the hammer head isn't centered, or if the angle of the hammer is off, the nail will bend or misalign. This damages the wood being hammered and causes significant frustration. Therefore, an ergonomically designed handle and a corrected hammer head angle to ensure the hammer head is perpendicular to the nail are crucial. Furthermore, utilizing geometric principles, the parabolic striking surface allows for greater flexibility in the hammer's grip angle and the verticality of the strike, giving the operator more control over their technique, reducing the likelihood of hitting the nail off-center, and increasing satisfaction and efficiency.

[0035] In summary, an ergonomically designed hammer should, when used, ensure: 1. a straight wrist to avoid ulnar deviation; 2. prevent tissue compression; 3. reduce the impact of hand vibration; and 4. accurate striking of nails.

[0036] Improper hand flexion can lead to cumulative injuries such as carpal tunnel syndrome, tenosynovitis, and trigger finger. During hammering, the operator's hand is prone to ulnar deviation and is subjected to strong impact forces, resulting in cumulative fatigue and workplace injuries. Therefore, ulnar deviation should be avoided in the grip design.

[0037] To avoid compressing tissues, the hand must exert considerable force when operating hand tools and directly bears the impact of the reaction force. The palm contains important blood vessels and nerves, making it particularly sensitive to pressure. Strong impact and compression can easily obstruct blood flow through the ulnar artery, causing local ischemia or ischemia, leading to numbness and tingling in the fingers. Therefore, when designing hammers, pressure on the palm should be reduced, distributing the force to the finger joints or the thumb's arc to apply force effectively and reduce pressure on the palm.

[0038] The effects of rebound force are most often seen in the vibrations induced in the arm or palm when using hand tools. During hammering, the strong impact can cause a tingling sensation in the palm and fingers. Short-term hammering may not cause discomfort to the operator, but with prolonged use, the hand's vibration sensitivity decreases, and unconscious operation can easily lead to numbness and tingling in the fingers.

[0039] Depend on Figure 18 As shown, when the user holds the hammer handle (91) and strikes down, it is quite close to the flat surface. This is an unnatural phenomenon, and the hand may be injured from striking the flat surface. A person's hand will instinctively move away to avoid striking the flat surface and prevent injury; this is a self-preservation mechanism. Figure 19 As shown, the user will deflect the hammer head (92) inward to correct its downward striking direction, but it still has the problem of not being able to hit the nail directly.

[0040] Furthermore, when the hammer (90) strikes, the rotation of the hammer handle (91) is too large, which may prevent the user's hand from fitting properly with the hammer handle (91), causing the palm and the web of the hand to be spread apart, or the wrist to twist too much, or the hammer handle (91) to be tilted and not covered by the user's palm, causing the vibration during the strike to damage the vulnerable parts of the hand. After a long time of striking, the hand will be quite sore and there is a risk of dropping the hammer (90). Improper tool design can cause physical damage in the long run, such as carpal tunnel syndrome, tenosynovitis and other muscle injury diseases. Many jobs require the frequent use of hand tools, so the incidence of cumulative trauma is very high, which is a kind of occupational injury. In the long run, it will reduce the willingness to work, and improving the tools is equivalent to improving the working environment.

[0041] Therefore, after a long period of research, the inventor explored the problems of traditional hammer design, the reasons for nails being driven crookedly, the anatomical structure of the human upper limb, and the problem of myofascitis and other injuries caused by improper use of tools in the arms, wrists, and palms. Finally, the inventor proposed the invention "Ergonomic Hammer and Axe Structure", which greatly improves the problem that ordinary users cannot accurately drive nails. In view of this, the inventor came up with the idea of ​​invention and designed it based on many years of experience. After extensive discussions, sample tests, and multiple revisions and improvements, the invention was launched. Summary of the Invention

[0042] Technical issues to be addressed: The technical problem to be solved by the present invention is to provide an ergonomic hammer / axe structure that is easy to hold and correct the direction of striking, in order to address the above-mentioned deficiencies in the existing technology.

[0043] The experimental design of this invention involved manufacturing dozens of hammers with different handle and head angles, and having several operators conduct tests on hammering nails. Video recordings were taken using a high-speed camera at 120fps, 240fps, and 7680fps (fps, frames per second) for analysis. The perpendicularity of the nail during hammering was analyzed and recorded, along with the perpendicularity of the hammer head to the board with each hammer strike. The differences in the angles of the palm, wrist, forearm, elbow, upper arm, and shoulder joints when using different hammer angles were also analyzed. Furthermore, the location and degree of arm fatigue in the subjects' arms after dozens of consecutive hammer strikes were recorded to determine the muscle groups used. The subjects' preference for different hammer angles was also analyzed to determine the principles of most ergonomic design. After summarizing the most suitable design, it was repeatedly verified by a variety of unspecified individuals, including professional formwork craftsmen, plumbers, general users, and both men and women, until the optimal design principles were finally determined. It was also discovered that while ergonomics has no fixed rules, people do have certain habits when using tools. By studying these habitual movements, tools that best conform to human usage habits can be designed. This invention is the result of tens of thousands of striking tests.

[0044] Our research revealed a significant correlation between the angle of the hand tool handle and the radial-ulnar deflection of the wrist. A handle design that allows the wrist to remain upright during work not only facilitates force application but also reduces cumulative hand injuries. The head angle is designed to correct the perpendicularity of the hammer head angle. A shock-absorbing spring is installed in the hammer head body for optimal hand protection. A parabolic striking surface is designed to improve the accuracy of nail application.

[0045] Technical characteristics of the problem-solving process: This invention provides an ergonomic hammer / axe structure, comprising a handle and a striking element. The handle has a first body, a second body, and a third body, which are sequentially connected from front to back. The central axis of the first body is inclined upward at a first angle relative to the central axis of the second body, and the central axis of the third body is inclined downward at a second angle relative to the central axis of the second body. The striking element is vertically mounted on the first body. When the user holds the third body and swings the handle downward to strike a nail, the tilt angles between the first, second, and third bodies correct the striking element to strike the nail directly, maintaining a straight hand position and preventing the user's palm and forefinger from being spread open by the third body due to the tilt of the handle. This ensures the handle conforms to an ergonomic design. The striking element is a hammer head or an axe blade, and it has a parabolic striking surface.

[0046] Alternatively, the striking element has a striking element body, a shock-absorbing spring, and a nut. The first body has an assembly hole. One end of the striking element body has a protruding striking head. The other end of the striking element body passes through the assembly hole and is locked with the nut. The shock-absorbing spring abuts against the striking head and the first body to elastically absorb vibration, thereby mounting the striking element on the first body.

[0047] Alternatively, the striking element is integrally connected to the first body.

[0048] The main objective of this invention is that, due to the mutual inclination of the central axes between the first body, the second body, and the second body, as well as between the third body and the striking element, the first and second inclination angles are used to correct the angle between the third body and the striking element. This corrects the striking direction, prevents the nail from tilting, and avoids excessive tilting of the third body, which could cause the palm or forefinger to be stretched open or the wrist to be excessively bent. This improves grip comfort and prevents workplace injuries.

[0049] The design incorporates a parabolic striking surface to improve the accuracy of striking nails.

[0050] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description and the accompanying drawings. Attached Figure Description

[0051] Figure 1 This is a perspective view of the hammer shape of the present invention.

[0052] Figure 2 This is an exploded view of the hammer shape of the present invention.

[0053] Figure 3 This is a front view of the hammer shape of the present invention.

[0054] Figure 4 This is a schematic diagram of the hammer-shaped form of the present invention in use.

[0055] Figure 5 This is a schematic diagram of the user holding the third body in the present invention.

[0056] Figure 6 This is a schematic diagram of the hammer-shaped striking surface of the present invention.

[0057] Figure 7 This is a schematic diagram of the hammer-shaped spring of the present invention.

[0058] Figure 8 This is a schematic diagram of the axe-shaped striking surface of the present invention.

[0059] Figure 9 This is a schematic diagram of the axe-shaped spring of the present invention.

[0060] Figure 10 This is a front view of the axe-shaped part of the present invention.

[0061] Figure 11 This is a front view of another aspect of the axe-shaped form of the present invention.

[0062] Figure 12 This is a front view of the first embodiment of the present invention.

[0063] Figure 13 This is a front view of the second embodiment of the present invention.

[0064] Figure 14 This is a front view of the third embodiment of the present invention.

[0065] Figure 15 This is a front view of another form of the hammer shape of the present invention.

[0066] Figure 16 This is a schematic diagram of another usage state of the hammer form of the present invention.

[0067] Figure 17 This is a front view of another aspect of the axe-shaped form of the present invention.

[0068] Figure 18 This is one of the schematic diagrams showing the current usage of a hammer.

[0069] Figure 19 The second diagram illustrates the current usage of the hammer.

[0070] Symbol explanation: Existing section: Hammer ------(90) Hammer handle ----(91) Hammer head -- (92) This invention includes: Handle ------(10) First Body -----(11) Assembly hole -----(111) Pin removal part -----(112) Second entity --- (12) Third entity --- (13) Striking component -----(20) Striking component body ---(21) Knocking head -----(211) Shock-absorbing spring ----(22) Nut ------(23) Nail body ------(30) Hands ------(40) First tilt angle --- (A) Second dip angle ----(B) Tapping surface -----(X) Detailed Implementation

[0071] To further understand and appreciate the purpose, features, and effects of this invention, the following is a detailed description in conjunction with the accompanying drawings: First, please let Figures 1 to 3 As shown, the present invention provides an ergonomic hammer / axe structure, comprising a handle (10) and a striking element (20). The handle (10) has a first body (11), a second body (12), and a third body (13), which are sequentially connected from front to back. The central axis of the first body (11) is inclined upwards at a first angle (A) relative to the central axis of the second body (12), and the central axis of the third body (13) is inclined downwards at a second angle (B) relative to the central axis of the second body (12). The striking element (20) is vertically disposed on the first body (11). Figure 4 and Figure 5 As shown, when the user holds the third body (13) and swings the handle (10) downward to make the striking element (20) strike a nail (30), the tilt angle between the first body (11), the second body (12), and the third body (13) is corrected so that the striking element (20) can strike the nail (30) directly, keeping the hand upright and preventing the user's palm and thumb from being spread open by the third body (13) due to the tilt of the handle (10). This allows the handle (10) to conform to an ergonomic design and work in conjunction with... Figure 6 and Figure 8 As shown, the striking element (20) is a hammer head or an axe blade.

[0072] Depend on Figure 6 and Figure 8As shown, the present invention provides an ergonomic hammer and axe structure, wherein the striking element (20) has a parabolic striking surface (X).

[0073] The geometric principle behind designing the striking surface as a parabolic surface is as follows: the focus of the parabola is designed at the center of the main force application point. The distance from this focus to the striking surface is designed as the focal length of the parabola, thus shaping the striking surface into a parabola. The force emanating from this focus, applied to the nail head that strikes the parabola, is parallel to the principal axis of the parabola. This means that the nail will strike the parabola without deviation, regardless of whether the impact point is in the center or off-center. Such parabolic surfaces can be precisely manufactured using CNC lathes.

[0074] In a shock-absorbing hammer, the striking surface is designed as a parabolic curve. The focal point of this parabolic surface can be designed at the center point of the junction between the hammerhead and the striking head, specifically at the center of the lower end face of the shock-absorbing spring, which is also the center point of the main force application area. The distance from this focal point to the striking surface is designed as the focal length of this parabolic surface. By designing this point as the center point of the main force application area, the direction of the nail's striking force is the same as the direction of swinging the hammer. Even if the angle of the handle is skewed, as long as the direction of swinging the hammer is correct, the direction of the nail's striking force will be determined, and the nail will not be skewed.

[0075] In a shock-absorbing hammer, the striking surface is designed as a parabolic curve. The focal point of this parabolic surface can also be designed at the center point of the junction between the hammer head and the first body. That is, the center of the upper end face of the shock-absorbing spring is designed as the center point of the main force application part. The distance from this focal point to the striking surface is designed as the focal length of this parabolic surface. With this point designed as the center point of the main force application part, the direction of the nail's striking force is perpendicular to the platform below the first body; that is, the angle at which the user holds the handle determines the direction of the nail's striking force.

[0076] In a hammer without a shock-absorbing spring, the striking surface is designed as a parabolic surface. The focus of this parabolic surface can be designed at the center point where the hammer body and the hammerhead meet. The distance from this focus to the striking surface is designed as the focal length of this parabolic surface.

[0077] In a hammer without a shock-absorbing spring, the striking surface is designed as a parabolic surface. The focus of this parabolic surface can also be designed at the center point where the hammerhead meets the hammer body. The distance from this focus to the striking surface is designed as the focal length of this parabolic surface.

[0078] In a shock-absorbing axe, the blade edge (striking surface) is designed as a parabolic surface. The focal point of this parabolic surface can be designed at the center point of the intersection between the striking part of the axe blade and the uppermost platform of the axe surface, that is, at the center below the shock-absorbing spring. The distance from this focal point to the blade edge is designed as the focal length of this parabolic surface.

[0079] In a shock-absorbing axe, the blade is designed as a parabolic surface. The focal point of this parabolic surface can also be designed at the center point of the junction between the striking part of the axe blade and the first body, i.e., the center point above the shock-absorbing spring. The distance from this focal point to the blade is designed as the focal length of this parabolic surface.

[0080] In axes without shock-absorbing springs, the blade is designed as a parabolic surface. The focal point of this parabolic surface can be designed at the center point where the axe body and the blade meet. The distance from this focal point to the blade is designed as the focal length of this parabolic surface.

[0081] Depend on Figures 1 to 3 and Figure 10 and Figure 11 As shown, the present invention provides an ergonomic hammer and axe structure. Figure 10 It is a shock-absorbing dual-purpose axe, whose nail-pulling part (112) can provide digging function, and its structure generally does not have V-shaped grooves. Figure 11 The hammer (20) is a shock-absorbing axe. The hammer has a hammer body (21), a shock-absorbing spring (22) and a nut (23). The first body (11) has an assembly hole (111) through it. One end of the hammer body (21) is provided with a hammer head (211). The other end of the hammer body (21) passes through the assembly hole (111) and is locked with the nut (23). The shock-absorbing spring (22) abuts against the hammer head (211) and the first body (11) to absorb vibration elastically. The hammer (20) is installed on the first body (11). The hammer (20) has a better shock absorption effect to prevent work injuries.

[0082] Depend on Figure 6 and Figure 7 As shown, the present invention provides an ergonomic hammer and axe structure, wherein the striking element (20) is a hammer head, and the structure at the junction of the striking head (211) and the striking element body (21) has an R-angle to increase its structural strength. The inner structure of the shock-absorbing spring (22) also has an R-angle to cooperate with the R-angle at the junction of the striking head (211) and the striking element body (21).

[0083] Depend on Figure 8 and Figure 9As shown, the present invention provides an ergonomic hammer and axe structure, wherein the striking element (20) is an axe blade, and the structure at the junction of the striking head (211) and the striking element body (21) has an R-angle to increase its structural strength. The inner structure of the shock-absorbing spring (22) also has an R-angle to cooperate with the R-angle at the junction of the striking head (211) and the striking element body (21).

[0084] Depend on Figure 4 and Figure 5 As shown, the user's hand (40) holds the third body (13) of the handle (10). By correcting the tilt angle between the first body (11), the second body (12), and the third body (13), the hand (40) can be further away from the plane to avoid injury during the striking process. The hand (40) can hold the third body (13) tightly without being pried open by the shaking of the hammer handle. The hand (40) can hold the third body (13) tightly without opening it. At the same time, the striking part (20) can strike the nail body (30) directly, improving the quality of construction.

[0085] The present invention provides an ergonomic hammer and axe structure, wherein a nail-pulling part (112) extends from the top of the first body (11) for operating a lever to remove the nail.

[0086] The present invention provides an ergonomic hammer and axe structure, wherein the first tilt angle (A) is between 3 degrees and 10 degrees, and the second tilt angle (B) is between 8 degrees and 17 degrees.

[0087] Depend on Figure 12 As shown, the present invention provides an ergonomic hammer and axe structure, wherein the first tilt angle (A) is 5 degrees and the second tilt angle (B) is 10 degrees, which has better grip comfort and the effect of correcting the striking direction. The second tilt angle (B) is corrected by 10 degrees to better conform to ergonomics. This is derived from observing the habits of people holding the handle (10) and having the striking part (20) strike an object. It allows the user's hand (40) to be farther away from the striking surface, and takes into account the human body's self-defense mechanism, so that the striking part (20) can strike the nail body (30) directly. Therefore, it takes into account both physiological and psychological considerations.

[0088] Depend on Figure 13 As shown, the present invention provides an ergonomic hammer and axe structure, wherein the first tilt angle (A) is 5 degrees and the second tilt angle (B) is 13 degrees.

[0089] Depend on Figure 14 As shown, the present invention provides an ergonomic hammer and axe structure, wherein the first tilt angle (A) is 8 degrees (8 degrees upward) and the second tilt angle (B) is 15 degrees (15 degrees downward).

[0090] Depend on Figures 15 to 17 As shown, this is another aspect of the present invention. The present invention provides an ergonomic hammer and axe structure, wherein the striking element (20) is integrally connected to the first body (11).

[0091] In summary, the ergonomic hammer and axe structure of the present invention has the following advantages: Since the central axes of the first body (11) and the second body (12) and the second body (12) and the third body (13) are inclined to each other, the first tilt angle (A) and the second tilt angle (B) are corrected by the first tilt angle (A) and the second tilt angle (B) to correct the angle between the third body (13) and the striking member (20), thereby correcting the striking direction to prevent the nail body (30) from tilting, and avoiding the third body (13) from tilting too much, which would cause the palm and the tiger's mouth to be stretched open or the wrist to be bent excessively, thereby improving the comfort of holding and preventing the occurrence of work injuries.

[0092] The advantages of the specific combination of the first tilt angle (A) and the second tilt angle (B) can be better understood from the following explanation: In the study of this invention, high-speed photography revealed that when the first tilt angle (A) is 5 degrees and the second tilt angle (B) is 10 degrees, or when the first tilt angle (A) is 5 degrees and the second tilt angle (B) is 13 degrees, or when the first tilt angle (A) is 8 degrees and the second tilt angle (B) is 15 degrees, the striking head (211) is always aligned with the nail body (30) during hammer drop, and the hand remains upright. The wrist joint angle is almost identical, with no radial or ulnar deviation, palmar flexion or dorsiflexion. The slight differences in the angle of the third body (13) are compensated for by the elbow and shoulder joints. Furthermore, when the hammer is dropped, the hand holds the third body (13) with almost no wobbling. Therefore, pressure and vibration damage to the palm can be reduced. The gripping force required for the fingers is also less, making it easier for the user. The ergonomic design reduces the risk of occupational injury with long-term use. Other angle combinations are less ergonomic. In comparison, straight-handled hammers exhibit significant ulnar deviation during impact, leading to considerable hand and handle movement over extended periods. This requires greater grip strength and is more strenuous for the user. Furthermore, the increased vibration to the palm makes them more prone to wrist and hand injuries. This can easily result in trigger finger (stenosing tenosynovitis of the flexor tendons), tendinitis, carpal tunnel syndrome, white finger syndrome, mommy's thumb (stenosing tenosynovitis), and other tendon and joint inflammations such as deltoid cartilage injury.

[0093] In the study of this invention, high-speed photography revealed that when the hammer is raised to its highest point, the combination of a first tilt angle (A) of 5 degrees and a second tilt angle (B) of 10 degrees results in a relatively large radial movement of the wrist joint. The muscles exerting the force are mainly the extensor carpi radialis and extensor carpi ulnaris of the forearm, which are responsible for the outward extension of the wrist to swing the hammer. The combination of a first tilt angle (A) of 5 degrees and a second tilt angle (B) of 13 degrees results in a moderate degree of radial movement of the wrist joint, while the combination of a first tilt angle (A) of 8 degrees and a second tilt angle (B) of 15 degrees results in the minimum degree of radial movement of the wrist joint. When the hammer is swung, the combination of a first tilt angle (A) of 5 degrees and a second tilt angle (B) of 10 degrees results in the maximum wrist joint movement; the combination of a first tilt angle (A) of 5 degrees and a second tilt angle (B) of 13 degrees results in a moderate wrist joint movement; and the combination of a first tilt angle (A) of 8 degrees and a second tilt angle (B) of 15 degrees results in the minimum wrist joint movement. The muscles exerting the force are primarily the triceps brachii of the upper arm. The combination of a first tilt angle (A) of 5 degrees and a second tilt angle (B) of 10 degrees is more suitable for general DIY users or small hammer designs. The combination of a first tilt angle (A) of 8 degrees and a second tilt angle (B) of 15 degrees is suitable for professional users and large hammer designs requiring extremely heavy strikes. The combination of a first tilt angle (A) of 5 degrees and a second tilt angle (B) of 13 degrees is considered a general-purpose design. All three hammer combinations of the first tilt angle (A) and the second tilt angle (B) have excellent ergonomics and hammerhead verticality. When lifting the hammer, the user's radial movement of the wrist joint varies slightly for the three different combinations, but because the hammer is not striking at this time, the joint is not subjected to impact force. The wrist joint can have a large degree of radial deviation tolerance, so none of the three degrees of radial movement will cause tendon joint damage.

[0094] The first tilt angle (A) and the second tilt angle (B) of the handle (10) are designed to be ergonomically sound in combinations such as the first tilt angle (A) being 5 degrees and the second tilt angle (B) being 10 degrees, the first tilt angle (A) being 5 degrees and the second tilt angle (B) being 13 degrees, and the first tilt angle (A) being 8 degrees and the second tilt angle (B) being 15 degrees, reducing the risk of tendinitis caused by long-term use. The hammer head remains directly aligned with the nail body (30) during hammer strikes, preventing the nail body (30) from tilting. Furthermore, the verticality of the single-handed nail-holding mechanism eliminates the need for the user to hold the nail body (30), reducing hand injuries from impacts. The parabolic design of the hammer head's striking surface allows for more precise impacts on the nail body (30), preventing it from tilting or bending. Keeping the hand upright and easy to grip and apply force, the third body (13) will not tilt too much when it is knocked down. It can effectively maintain the user in the correct posture and hold the handle (10) with the flesh of the palm, avoiding injury to the more vulnerable areas of the hand or pressing on blood vessels, and preventing the muscles and tendons of the hand from being damaged in the long term and causing cumulative trauma.

[0095] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention; that is, all equivalent changes and modifications made in accordance with the scope of the patent application of the present invention should still fall within the scope of the patent of the present invention.

Claims

1. An ergonomic hammer, axe structure, characterized by, It includes a handle and a striking element, wherein: The handle has a first body, a second body, and a third body, which are connected sequentially from front to back. The central axis of the first body is inclined upward at a first angle relative to the central axis of the second body, and the central axis of the third body is inclined downward at a second angle relative to the central axis of the second body. The first angle is between 3 and 10 degrees, and the second angle is between 8 and 17 degrees. The striking element is vertically mounted on the first body. When the user holds the third body and swings the handle downward to make the striking element strike a nail, the tilt angles between the first, second, and third bodies are corrected so that the striking element can strike the nail directly, keeping the hand upright and preventing the user's palm and forefinger from being spread open by the third body due to the tilt of the handle. This makes the handle ergonomically designed. The striking element is a hammer head or an axe blade, and the striking element has a parabolic striking surface.

2. The ergonomic hammer, axe structure of claim 1, wherein, The first tilt angle is 5 degrees, and the second tilt angle is 10 degrees.

3. The ergonomic hammer, axe structure of claim 1, wherein, The first tilt angle is 5 degrees, and the second tilt angle is 13 degrees.

4. The ergonomic hammer, axe structure of claim 1, wherein, The first tilt angle is 8 degrees, and the second tilt angle is 15 degrees.

5. The ergonomic hammer, axe structure of any one of claims 1 to 4, wherein, The top of the first body extends a nail-pulling section for operating a lever to remove the nail.

6. The ergonomic hammer, axe structure of any one of claims 1 to 4, wherein, The striking element is integrally connected to the first body.

7. The ergonomic hammer, axe structure of any one of claims 1 to 4, wherein, The striking component has a striking component body, a shock-absorbing spring, and a nut. The first body has an assembly hole. One end of the striking component body has a protruding striking head. The other end of the striking component body passes through the assembly hole and is locked with the nut. The shock-absorbing spring abuts against the striking head and the first body to elastically absorb vibration, thereby installing the striking component on the first body.

8. The ergonomic hammer and axe structure as described in claim 7, characterized in that, The striking element is a hammer head, and the structure at the junction of the striking head and the striking element body has an R-angle. The inner structure of the shock-absorbing spring also has an R-angle to match the R-angle at the junction of the striking head and the striking element body.

9. The ergonomic hammer and axe structure as described in claim 7, characterized in that, The striking element is an axe blade. The structure at the junction of the striking head and the striking element body has an R-angle. The inner structure of the shock-absorbing spring also has an R-angle to match the R-angle at the junction of the striking head and the striking element body.

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