ERGONOMIC HOE FOR FORESTRY WORK

Abstract

An ergonomic hoe for forestry work comprising a handle (1) and a blade (3) fixed to one end of the handle, characterized in that: - The handle (1) has a non-circular cross-section and an anatomical knob or stop (2) at its free or end, - The blade (3) forms an angle (4) between the inner face of the blade (3) and the longitudinal axis of the handle that is between 68° and 70°.

Description

ERGONOMIC HOE FOR FORESTRY WORK OBJECT OF THE INVENTION The object of the present invention, as stated in the title of the invention, is an ergonomic hoe for forestry work, which has the following characteristics: an adaptable length handle, a non-circular gripping handle, a knob at the end, and an optimized angular insertion of the blade. The present invention is characterized by the special design and configuration of each and every part of the hoe, including its handle, the blade, and the relative arrangement of both elements. The present invention falls within the sector of manual tools for forestry and agricultural work, and more specifically within the field of hoes used in opening defense lines, clearing and soil removal in forest fires, as well as in work of high prolonged physical demand. BACKGROUND OF THE INVENTION The hoes commonly used by forest firefighters are derived from conventional agricultural models, characterized by straight handles of fixed length, smooth cylindrical sections, and tight angles between the blade and the handle. This design forces the user to adopt working postures with high lumbar dorsiflexion, increased mechanical stress on the L5-S1 vertebrae, and greater muscle activation in the upper extremities, which accelerates the onset of fatigue and increases the risk of musculoskeletal injuries. Furthermore, state-of-the-art hoes do not allow for adapting the tool to users of different heights and body types without compromising its functional efficiency, nor do they allow for a secure grip and control of the tool under adverse conditions (use of gloves, uneven terrain, heat). Moreover, operational efficiency is susceptible to being adapted. Therefore, the object of the present invention is to overcome the drawbacks of prior art hoes, improving conventional hoes with a design that enhances the work done with traditional hoes when used in forestry work, developing a hoe as described below and set out in its essentials in claim one. DESCRIPTION OF THE INVENTION The object of the present invention is set out in its essentials in the independent claim and the different embodiments are set out in the dependent claims. The present invention relates to an ergonomic hoe for forestry work, which has a series of minimum characteristics: On the one hand, the handle has a mostly non-circular section, especially in the grip area, preferably with an oval or rectangular section. In addition, it has a handle with a length between 800 mm and 1500 mm. - Also, the distal end of the handle incorporates an anatomical knob or stop that acts as a retention element and reduces the need for active gripping force. Additionally, it has a blade such that, when inserted into the handle, it presents an angle with respect to the handle between 68º and 70º, an angle that is measured between the lower face of the blade and the longitudinal axis of the handle. Additionally, and as a complement, the hoe blade has a decreasing thickness towards the free end of the blade. Another additional, complementary, non-limiting improvement is the reduction of the hoe's weight, which, in one possible embodiment, could reduce the weight, compared to a traditional hoe, by about 350 grams, that is, approximately 16% less weight for the proposed hoe. Thanks to its flat handle design and prominent knob, this tool offers greater grip stability with less muscle effort. The knob acts as an anatomical stop, which: • Reduces the need for active gripping force. • Limits handle slippage during the cutting motion. • Minimizes hyperextension and ulnar deviation of the wrist. Several studies have shown that tools with shapes that offer distal support, such as pistol grips or handles with stops, reduce muscle activation in the forearm and wrist, improving efficiency in repetitive and prolonged tasks. Furthermore, as previously mentioned, firefighters wear thick gloves as part of their PPE during wildfires, which makes it even more difficult to grip smooth handles. This can cause the tool to slip or even escape, significantly increasing the risk of workplace accidents, especially considering that firefighters work in close proximity to one another when performing maneuvers such as the "defense line." In summary, the rectangular design with a knob not only improves grip from a mechanical and safety standpoint, but also has a direct impact on reducing active muscle load on the forearm and wrist, resulting in less fatigue and a lower risk of overuse injuries, which is especially critical in long-duration tasks such as creating firebreaks in forest fires. The traditional design of hoes used in forest fires, based on agricultural tools, presents substantial ergonomic limitations. One of the most significant is the narrow angle between the blade and the handle axis, which forces the user to excessively bend their torso to effectively apply force to the soil. This position promotes sustained lumbar dorsiflexion, increasing compressive load on the intervertebral discs, especially in the L5-S1 segment, and raising the risk of lumbar injury. The blade-to-handle angle, ranging from 30° to 35° for the upper face relative to the shaft, as proposed by reference studies in hand tool ergonomics (Sankaranarayanan et al., 2014), allows for a more natural and sustainable posture during work, improving the efficiency of the technical movement and reducing muscle fatigue in repetitive tasks such as opening firebreaks. Furthermore, it has been documented that in situations of prolonged work under high ambient heat (as occurs in forest fires), fatigue from awkward postures accumulates more rapidly, with a direct impact on decreased performance and an increased risk of injury (National Institute for Safety and Health at Work [INSST], 2020). Finally, an angle of between 68º and 70º was chosen between the underside of the blade and the longitudinal axis of the handle. This technical adjustment proved to be a key ergonomic improvement: it allowed for more efficient and prolonged cuts without compromising spinal posture, facilitating a more upright and natural working position, especially in tasks such as horizontally cutting logs on the ground. Thanks to the fact that the tools used by forest firefighters adopt a blade-to-handle tilt angle of approximately 68° to 70°, the following technical effects result: • It allows for greater verticality of the user by approaching an inclination of between 30° and 35° with respect to the work plane • It reduces lumbar dorsiflexion and spinal erector fatigue. • Improves joint alignment of shoulders, elbows and wrists. • Reduces the cumulative load on the lumbar region during long-duration tasks. In conclusion, modifying the blade-handle angle not only represents a functional improvement, but should be considered a priority ergonomic intervention to reduce the risk of musculoskeletal injuries in forestry personnel and improve sustained performance in demanding operational contexts. Another significant modification is the lateral tapering of the blade, meaning the progressive thinning of the material from the central body towards the edges. In commercial hoes, the average blade thickness two centimeters from the cutting edge is usually 5 mm, while now it is reduced to approximately 2.5 mm. This structural difference has several functional implications: • Improves penetration into the soil or against obstacles such as roots. • Reduces lateral friction, allowing deeper cuts with less resistance. • Provides a functional edge to the side edges, facilitating clearing, debarking, or adjusting cutting angles without needing to completely reposition the tool. • It optimizes muscle energy consumption by reducing the force required per blow. A well-sharpened, tempered, and properly ground edge allows: • Reduce the number of blows needed to cut a root or penetrate dense vegetation. • Increase the precision of the gesture, avoiding inefficient impacts. • Maintain a high work rate for longer periods without compromising technique. Unless otherwise stated, all technical and scientific terms used herein have the meanings commonly understood by a person skilled in the art to which this invention pertains. Similar or equivalent procedures and materials to those described herein may be used in the practice of the present invention. Throughout the description and claims, the word "comprises" and its variants are not intended to exclude other technical features, additives, components, or steps. For those skilled in the art, other objects, advantages, and features of the invention will become apparent partly from the description and partly from the practice of the invention. EXPLANATION OF THE FIGURES To complement the description being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of its practical embodiment, a set of drawings is included as an integral part of said description, in which the following has been represented for illustrative and non-limiting purposes. In Figure 1, we can observe a perspective representation of the hoe where the blade part is detailed. In Figure 2, we can observe a second perspective representation of the hoe where part of the hoe head and the end of the handle are detailed. Figure 3 shows several perspective views of the handle and a side view of it. Figure 4 shows different constructive aspects of the hoe blade. PREFERRED EMBODIMENT OF THE INVENTION. In view of the figures, a preferred embodiment of the proposed invention is described below. In Figure 1 we can observe that the hoe of the invention comprises a handle (1) which has at its free or end an anatomical knob or stop (2), in addition at the other end of the handle (1) there is a blade (3) which forms an angle (4) between the inner face of the blade (3) and the longitudinal axis of the handle which is between 68º and 70º, while in addition, as a complement the blade (3) has a reduction of the effective section as it approaches the free end of the blade, forming a progressive sharpening (5), which in a possible non-limiting embodiment ends with a thickness of 2.5 mm. Figure 3 shows the handle (1) of the hoe, which, as previously mentioned, can be between 800 mm and 1500 mm long and has an insertion end (1.1) for the blade (3). This insertion end (1.1) has a progressively increasing circular cross-section for insertion into the blade (3) of the hoe. Furthermore, the handle, especially in the gripping area, has a non-circular cross-section, preferably oval or quadrangular, to facilitate a better grip. Figure 4 shows in more detail the angle (4) formed by the blade (3) on its inner face with the longitudinal axis of the handle (1). The progressive sharpening (5) of the sides of the blade can also be seen. Having sufficiently described the nature of the present invention, as well as the manner of putting it into practice, it is stated that, within its essential nature, it may be put into practice in other forms of embodiment that differ in detail from the one indicated as an example, and which will also achieve the protection sought, provided that it does not alter, change or modify its fundamental principle.

Claims

1. An ergonomic hoe for forestry work comprising a handle (1) and a blade (3) fixed to one end of the handle, characterized in that: - The handle (1) has a non-circular cross-section and an anatomical knob or stop (2) at its free or end, - The blade (3) forms an angle (4) between the inner face of the blade (3) and the longitudinal axis of the handle that is between 68° and 70°.

2. An ergonomic hoe for forestry work according to claim 1, characterized in that the handle (1) has a length between 800 mm and 1500 mm.

3. An ergonomic hoe for forestry work according to claim 1 or 2, characterized in that it has an insertion end (1.1) on the blade (3), wherein this insertion end (1.1) has a circular cross-section for insertion into the blade (3).

4. An ergonomic hoe for forestry work according to any of the preceding claims, characterized in that the handle cross-section is oval. 5.An ergonomic hoe for forestry work according to any of claims 1 to 3, characterized in that the handle section is rectangular.

6. An ergonomic hoe for forestry work according to any of the preceding claims, characterized in that the blade (3) exhibits a reduction in effective section as it approaches the free end of the blade, forming a progressively sharpened edge (5).

7. An ergonomic hoe for forestry work according to claim 6, characterized in that the thickness of the free edge of the blade is 2.5 mm.