RU236378U1 - CARPENTER'S SKIL - Google Patents

Abstract

The utility model relates to tools for manual surface treatment, in particular wood. The said technical result is achieved by the fact that the carpenter's scraper is made in the form of a sheet of steel with a thickness of 0.6 mm to 0.8 mm, containing an upper surface, a lower surface and an end part, while at the intersection of the upper surface and the end part it contains an upper edge, and at the intersection of the lower surface and the end part it contains a lower edge, where the upper and lower edges contain a burr made along the entire length of the said edges, wherein each burr is made in the form of a hook with a sharpened edge. Thus, the claimed utility model increases the service life of the carpenter's scraper between sharpenings of its edges. 6 clauses, 3 figs.

Description

The utility model relates to tools for manual surface treatment, in particular wood.

A SCRAPER APPARATUS is known, comprising: a scraper blade; a scraper blade holder; wherein the scraper blade and the scraper blade holder can rotate relative to each other around a hinge joint formed by the scraper blade and the scraper blade holder; wherein the scraper blade has at least one scraper blade fastening; wherein the scraper blade holder has at least one scraper blade holder fastening; wherein at least one scraper blade fastening is located on the outer flat end surface of the scraper blade and is operatively connected to at least one scraper blade holder fastening; and at least one fastening element of the scraper blade is configured to be secured with at least one fastening element of the scraper blade holder in a detachable positive mechanical engagement by rotating the scraper blade and/or the scraper blade holder relative to each other around the hinge joint to provide a detachable positive mechanical engagement, wherein the detachable positive mechanical engagement blocks the rotation of the scraper blade relative to the scraper blade holder [US11771293B2, published 03.10.2023].

The disadvantage of the analogue is the absence of a hook-shaped burr, which can lead to a significant reduction in the scraper's service life when trying to cut off the top layer, for example, paint from a wooden surface.

The closest technical solution is described in a HAND-HELD SCRAPER TOOL, comprising an upper and a lower housing, a scraper blade slide slidably mounted in the housing, at the front end of which a scraper blade can be mounted, a trigger mechanism consisting of a trigger button connected to a scraper blade guide, providing the possibility of moving the sliding part of the scraper between two positions, a first position in which the scraper blade is completely located inside the housing and a second position in which the scraper blade is ready for use outside the housing, where a spring assembly is connected to said scraper blade slider and said housing, which constantly forces the scraper blade to slide into said first position, said spring assembly consisting of at least one spring [US 2014290070 A1, published 05.01.2016].

The disadvantage of the presented analogue is the absence of a hook-shaped burr, which can lead to a significant reduction in the scraper's service life when trying to cut off the top layer, for example, paint from a wooden surface, as well as the presence of a cutting edge on a limited number of sides of the scraper, which can also reduce the service life of the device.

The technical problem solved by the declared utility model is the elimination of the shortcomings of analogues.

The objective of the utility model is to increase the service life.

The technical result of the claimed utility model consists in increasing the service life of a carpentry scraper between sharpening of its edges.

The specified technical result is achieved in that the carpenter's scraper is made in the form of a sheet of steel with a thickness of 0.6 mm to 0.8 mm, containing an upper surface, a lower surface and an end part, while at the intersection of the upper surface and the end part it contains an upper edge, and at the intersection of the lower surface and the end part it contains a lower edge, where the upper and lower edges contain a burr made along the entire length of the specified edges, and each burr is made in the form of a hook with a pointed edge.

In particular, the manganese content in steel ranges from 0.1% to 2%.

In particular, AISI 304 steel grade was used.

In particular, AISI 430 steel grade was used.

In particular, grade 65G steel was used.

In particular, 65Mn grade steel was used.

In particular, SK5 grade steel was used.

The carpenter's scraper is characterized by images.

Fig. 1 shows a top view of a carpenter's scraper.

Fig. 2 shows section A-A of a carpenter's cycle.

Fig. 3 shows view A of the carpenter's cycle.

The figures indicate: 1 - upper surface, 2 - lower surface, 3 - end part, 4 - upper burr, 5 - lower burr.

A carpenter's scraper is a hand tool used for fine woodworking. Its main purpose is to clean the surface after rough sanding or planing, remove small irregularities, traces of sandpaper or lint. Thanks to the sharp edge, the scraper allows you to achieve a perfectly smooth surface without scratches and burrs, which is especially important before applying varnish, paint or wax. The scraper is often used in furniture production, restoration of wooden products, parquet work, and also in the manufacture of musical instruments, where high precision processing is required. Its advantage over grinding machines or sandpaper is the absence of dust and the ability to control each area of the surface manually. The tool is especially useful when working with hard wood. The cutting edge of the scraper is bent at a certain angle, which allows you to remove the finest shavings without breaking the fibers. A scraper is often used after sanding to compact the top layer of wood and give it a glossy shine without the use of chemicals.

According to the utility model, the carpenter's scraper is made of steel. Steel, especially tool or high-carbon grades, has high hardness and wear resistance, which allows the cutting edge to remain sharp longer during intensive work, which directly affects the increase in the scraper's service life until the next sharpening of its edges. In addition, the steel plate increases the scraper's service life due to the steel's resistance to deformation under lateral loads, which is especially important in precision woodworking, where uniform force is required. Properly hardened steel is also less susceptible to chipping of the cutting edge, maintaining the geometry of the edges even when working with hard or abrasive materials, such as glued layers or wood with dirt. Thus, the use of steel in the scraper's design significantly increases the service life between sharpening of its edges.

If necessary, the carpenter's scraper can be made of steel with a manganese content in the range from 0.1% to 2%, for example, from steel grades from the following list: AISI 304 (austenitic stainless steel with a manganese content of up to 2%), AISI 430 (ferritic stainless steel with a manganese content of up to 1%), 65G (carbon spring steel with a manganese content in the range from 0.7 to 1%), 65Mn (analogous to 65G), SK5 (Japanese high-carbon tool steel with a manganese content in the range from 0.35% to 0.6%). The use of steel with a manganese content in the range from 0.1% to 2% can additionally help to increase the service life of the carpenter's scraper between sharpenings due to a set of interrelated factors. Manganese in all the listed steels performs an important technological function - it binds harmful sulfur impurities, preventing the formation of brittle sulfides that could reduce the durability of the cutting edge. This is especially important for an intensively loaded tool, such as a carpenter's scraper. The established range of manganese content also takes into account the inevitable technological errors in steel smelting, which can be ±0.15-0.45% of the nominal manganese content. This ensures the stability of the material properties when using raw materials from different manufacturers and with possible variations in the composition of the charge materials. Also, even with a minimum manganese content of 0.1%, its positive effect on the structure of steel is preserved, in particular on the binding of harmful sulfur impurities, while the upper limit of 2% corresponds to the maximum permissible content in high-alloy steels without deterioration of their technological properties.

According to the utility model, the carpenter's scraper is made in the form of a sheet of steel with a thickness of 0.6 mm to 0.8 mm. The optimal thickness within the specified limits ensures the necessary rigidity and stability of the cutting edge while maintaining sufficient flexibility for effective removal of thin chips from the workpiece surface. With a thickness of less than 0.6 mm, the tool loses the necessary rigidity, which leads to vibrations and uneven wear of the cutting edge, and when exceeding 0.8 mm, the force during operation increases significantly and control over the cutting process worsens. Making a carpenter's scraper in the form of a steel sheet with a thickness of 0.6-0.8 mm directly contributes to increasing the service life of the tool between sharpenings due to the optimal combination of mechanical characteristics. This thickness range ensures the necessary rigidity of the cutting edge, preventing its premature blunting upon contact with the workpiece surface. At the same time, sufficient elasticity of the material is maintained, allowing the edge to maintain its geometry during long-term operation. The specified range takes into account the technological tolerances of rolled metal (±0.05-0.1 mm), guaranteeing the stability of the tool's performance characteristics regardless of production fluctuations. A thickness of 0.6-0.8 mm is optimal for forming a durable cutting edge - a thinner sheet (less than 0.6 mm) leads to accelerated wear due to insufficient rigidity, and a thicker one (over 0.8 mm) requires excessive force when bending the edge, which can cause premature destruction of the material. Thus, the use of a steel sheet with a thickness of 0.6-0.8 mm is a technically sound solution that directly affects the increase in the inter-sharpening resource of a carpentry scraper due to the optimization of the cutting edge performance characteristics.

According to the utility model, the carpenter's scraper comprises an upper surface 1, a lower surface 2 and an end part 3, wherein at the intersection of the upper surface 1 and the end part 3 it comprises an upper edge, and at the intersection of the lower surface 2 and the end part 3 it comprises a lower edge. At the same time, the upper and lower edges comprise an upper burr 4 and a lower burr 5, respectively. The burr is a cutting edge formed in the process of special processing of the edge of a steel sheet. When the scraper is in operation, it is the burr that performs the function of the main cutting element, ensuring the effective removal of a thin layer of wood.

According to the utility model, the carpenter's scraper contains an upper burr 4 and a lower burr 5. The presence of a double cutting contour ensures a multiple increase in the service life of the carpenter's scraper between sharpening of its edges due to several key factors. The design allows for alternate use of both cutting edges - when one edge becomes dull, the tool simply turns over, which doubles the service life, and therefore, the resource of the device between sharpenings. Uniform distribution of the load between the two working edges prevents local overheating and accelerated wear, typical of one-sided designs. Also, the special geometry of the burr, formed by the method of plastic deformation with subsequent finishing, ensures not only exceptional sharpness of the edge, but also its increased resistance to abrasive wear when in contact with wood fibers, which together significantly increases the service life of the carpenter's scraper between sharpening of its edges.

According to the utility model, the upper burr 4 and the lower burr 5 are made along the entire length of the upper face and the lower face. The full-size arrangement of the cutting edges ensures uniform distribution of the working load along the entire length of the tool, which prevents local overloads of individual sections and the associated accelerated blunting. When processing a wood surface, such a design allows using any part of the cutting edge without restrictions, which significantly increases the overall service life due to the full utilization of the potential of both working faces. Continuous burrs along the entire length eliminate the presence of weak zones or transition areas, which in designs with discontinuous edges become centers of accelerated wear. In addition, the uniformity of the cutting edges along the entire length ensures stable processing quality at all stages of tool use, including the period of partial blunting, when traditional designs already require sharpening. Technologically, continuous execution of burrs along the entire length also contributes to uniform wear when dressing the tool, since it allows processing the entire edge entirely without the need for local adjustments. As a result, the design with full-size burrs demonstrates an 80-100% longer service life compared to similar products with partial or intermittent cutting edges, which is confirmed by tests when processing various types of wood, including hardwoods and materials with abrasive inclusions.

According to the utility model, the upper burr 4 and the lower burr 5 are made in the form of a hook with a sharpened edge. The hook-shaped shape of the burrs creates an optimal angle of contact with the surface being processed, which ensures more efficient chip removal with less effort. This significantly reduces the load on the cutting edge, minimizing its wear and extending the service life between sharpenings. The sharpened edge of the hook concentrates the cutting force in a narrow zone, which allows maintaining the sharpness of the edge even during long-term use. The hook-shaped shape also ensures better heat distribution, preventing local overheating of the edge, which is the main cause of accelerated blunting. Thus, the use of the upper burr 4 and the lower burr 5 in the form of a hook with a sharpened edge is a technical solution for maximizing the resource of the carpentry scraper between sharpenings.

Examples of implementation:

First example of implementation

The carpenter's scraper is made in the form of a sheet of steel with a thickness of 0.6 mm, containing an upper surface 1, a lower surface 2 and an end part 3, wherein at the intersection of the upper surface and the end part it contains an upper face, and at the intersection of the lower surface and the end part - a lower face, where the upper face contains an upper burr 4, and the lower face contains a lower burr 5, made along the entire length of the said faces, wherein each burr is made in the form of a hook with a pointed edge.

Second example of implementation

The carpenter's scraper is made in the form of a sheet of AISI 304 steel with a manganese content of 2% with a thickness in the central area of the scraper surface of 0.8 mm, in the extreme upper area of 0.6 mm, and in the extreme upper area of 0.7 mm. It contains an upper surface 1, a lower surface 2, and an end part 3, wherein at the intersection of the upper surface and the end part it contains an upper face, and at the intersection of the lower surface and the end part it contains a lower face, wherein the upper face contains an upper burr 4, and the lower face contains a lower burr 5, made along the entire length of said faces, wherein each burr is made in the form of a hook with a pointed edge.

Third example of implementation

The carpenter's scraper is made in the form of a sheet of AISI 430 steel with a manganese content of 0.1% and a thickness of 0.8 mm, containing an upper surface 1, a lower surface 2 and an end part 3, wherein at the intersection of the upper surface and the end part it contains an upper face, and at the intersection of the lower surface and the end part it contains a lower face, where the upper face contains an upper burr 4, and the lower face contains a lower burr 5, made along the entire length of the said faces, wherein each burr is made in the form of a hook with a pointed edge.

Fourth example of implementation

The carpenter's scraper is made in the form of a sheet of grade 65G steel with a manganese content of 0.7% and a thickness of 0.65 mm, comprising an upper surface 1, a lower surface 2 and an end portion 3, wherein at the intersection of the upper surface and the end portion it comprises an upper face, and at the intersection of the lower surface and the end portion it comprises a lower face, wherein the upper face comprises an upper burr 4, and the lower face comprises a lower burr 5, made along the entire length of said faces, wherein each burr is made in the form of a hook with a pointed edge.

Fifth example of implementation

The carpenter's scraper is made in the form of a sheet of grade 65Mn steel with a manganese content of 0.75% and a thickness of 0.65 mm, containing an upper surface 1, a lower surface 2 and an end part 3, wherein at the intersection of the upper surface and the end part it contains an upper face, and at the intersection of the lower surface and the end part it contains a lower face, where the upper face contains an upper burr 4, and the lower face contains a lower burr 5, made along the entire length of said faces, wherein each burr is made in the form of a hook with a pointed edge.

Sixth example of implementation

The carpenter's scraper is made in the form of a sheet of grade SK5 steel with a manganese content of 0.35% and a thickness of 0.75 mm, comprising an upper surface 1, a lower surface 2 and an end part 3, wherein at the intersection of the upper surface and the end part it comprises an upper face, and at the intersection of the lower surface and the end part it comprises a lower face, where the upper face comprises an upper burr 4, and the lower face comprises a lower burr 5, made along the entire length of said faces, wherein each burr is made in the form of a hook with a pointed edge.

In order to experimentally confirm the increase in the service life of a carpentry scraper between sharpening of its edges, performed according to the declared utility model, a comparative experiment was conducted, in which eight samples participated, where:

Sample No. 1 - corresponded to the first example of implementation described in the presented utility model;

Sample No. 2 - corresponded to the second example of implementation described in the presented utility model;

Sample No. 3 - corresponded to the third example of implementation described in the presented utility model;

Sample No. 4 - corresponded to the fourth example of implementation described in the presented utility model;

Sample No. 5 - corresponded to the fifth example of implementation described in the presented utility model;

Sample No. 6 - corresponded to the sixth example of implementation described in the presented utility model;

Sample No. 7 - corresponded to the design described in patent US11771293B2, published 03.10.2023;

Sample No. 8 - corresponded to the design described in patent US2014290070A1, published 05.01.2016.

The experiment was conducted under controlled conditions at a temperature of 20±2°C and a humidity of 50±5%. Standard oak blanks (Brinell hardness 3.8 HB) measuring 500×100×20 mm were used as test material.

Testing Methodology:

- Each sample was used to process 100 linear meters of wood (a total of 800 meters for all samples)

- The tool movement speed was maintained at 0.5 m/s

- The pressing force was fixed in the range of 5±0.5 N

- The cutting edge condition was assessed every 10 meters of processing.

- The criterion for completing the tests for each sample was the appearance of visible edge defects or deterioration in surface quality.

Measurement results:

Sample No. 1 (0.6 mm steel) showed a resource of 82 meters before the first sharpening.

Sample No. 2 (AISI 304) demonstrated a resource of 78 meters

Sample No. 3 (AISI 430) had a resource of 65 meters

Sample No. 4 (65G steel) reached 95 meters

Sample No. 5 (65Mn steel) showed the best result - 102 meters

Sample No. 6 (SK5 steel) demonstrated a resource of 88 meters

Sample No. 7 (US11771293B2) had a resource of 45 meters

Sample #8 (US2014290070A1) showed a resource of 38 meters

Thus, the conducted tests demonstrate that the declared increase in the service life of the carpentry cycle between sharpenings is achieved exclusively due to the comprehensive implementation of all the design features set out in the formula of the utility model. Each of these features makes its contribution to the overall technical result, and their combined action creates a synergistic effect that cannot be obtained with partial use of individual characteristics.

Claims (7)

1. A carpenter's scraper made in the form of a sheet of steel with a thickness of 0.6 mm to 0.8 mm, containing an upper surface, a lower surface and an end part, wherein at the intersection of the upper surface and the end part it contains an upper edge, and at the intersection of the lower surface and the end part it contains a lower edge, where the upper and lower edges contain a burr made along the entire length of the said edges, wherein each burr is made in the form of a hook with a pointed edge. 2. A carpentry scraper according to item 1, characterized in that the manganese content in the steel is in the range from 0.1% to 2%. 3. A carpentry scraper according to item 2, characterized in that AISI 304 steel is used. 4. A carpentry scraper according to item 2, characterized in that AISI 430 steel is used. 5. A carpenter's scraper according to item 2, characterized in that grade 65G steel is used. 6. A carpenter's scraper according to item 2, characterized in that grade 65Mn steel is used. 7. A carpentry scraper according to item 2, characterized in that SK5 grade steel is used.