Apparatus for building tools

The present invention is directed generally to tools that are made, at least in part, more durable, particularly one or more working surface(s) of the tools. For example, various tools such as trowels, knives, and scrappers may be made having at least a portion of their blades heat treated to make at least their working edges more durable and extend their useful lives. For example, in one embodiment, a trowel blade may have at least one texturing edge that has been at least partially heat treated.

FIELD OF THE INVENTION

The present invention pertains to methods and various apparatus for building tools. For example, the invention involves methods and various apparatus for high quality durable building tools.

BACKGROUND

Various building tools have been known in the past for applying, molding, smoothing, and/or texturing material of a working surface with, for example, cement, adhesive, etc. to build, for example, a building. One particular type of building tool for applying, molding, smoothing and/or texturing materials is known as the trowel. Some types of trowels include, for example, a finishing trowel, a swimming pool trowel, and notched trowels of various kinds. These trowels are typically comprised of a blade that contacts the working surface and a handle attached to the blade for a person to grab and move the blade around on a working surface. The trowel blades have various different shapes that are designed for various applications (type of work). During use, the trowel may be used or moved at an angle relative to the working surface so that the outer edges of the trowel experiences friction and wear, such that the trowel edge may become worn out and no longer retain its original shape. Further, if the trowel is dropped the outer edges of the trowel blade may be bent so that in use the trowel does not make the desired working surface shape or result. Therefore, trowel blade durability is an important characteristic for determining the useful life of a trowel, and the durability of the outer edges of the trowel is particularly important.

SUMMARY

The present invention is directed generally to building tools that are high quality, durable, and strong. For example, various tools that have blades made of a material such as metal that wear through use may have the blades, or portions thereof, that are manufactured to be more durable and have a longer lasting useful life. For example, portions of the blades may be heat treated and cooled so as to harden or strengthen them for improved quality, durability, and strength performance. The invention is particularly useful for building more durable tools that have thin or flat blades. Such tools may include, for example, tools for the building trades including trowels, knives, and scrappers. In one embodiment, a texturing trowel may have one or more portions of its blade heat treated to improve the quality, durability, and strength performance. In one variation, the texturing trowel may have at least a first texturing edge or side of trowel blade heat treated to reduce blade wear or damage so that the quality, durability, and strength of the texturing edge is increased. In another variation, the texturing trowel may have at least a first texturing edge and a second texturing edge that are heat treated for reduced blade wear or damage, the first texturing edge and second texturing edge may be locate on opposite sides of the blade. The texturing edge may be in the shape of, for example, a square notch (or square tooth), a V notch (or triangle tooth), a rounded tooth with a semi-circle or square notch (semi-circle tooth), etc. In one variation, the blade may have various texturing edges of different shapes so that one texturing edge is a different shape than another texturing edge. In another variation, the entire blade may be heat treated and cooled.

In another embodiment, the tool may be, for example, a finishing trowel having one or more portions of the blade heat treated and cooled to harden or strengthen it. For example, the working edges of the finishing trowel blade may be flat, smooth and/or non-texturing edges that are heat treated and cooled to harden or strengthen the edge(s) so as to reduce blade wear or damage so that the quality, durability, and strength of the working edge is increased. In a still further embodiment, the tool may be, for example, a swimming pool trowel having one or more portions of the blade heat treated and cooled to harden or strengthen the blade where desired. For example, the working edges, that may include rounded ends of the trowel blade, may be heat treated and cooled to harden or strengthen the edge(s) so as to reduce blade wear or damage so that the quality, durability, and strength of the working edge is increased. In variations, the working edges of the swimming pool trowel may include texturing, may be rounded, and may be heat treated and cooled. Of course, the heating and cooling process of the present invention for hardening or strengthening blades may also be applied to other tools, for example, putty knifes, paint scrappers, notched margin trowels (V and/or square notches), notched taping knifes, brick trowels, pointing trowels, margin trowels, etc.

DETAILED DESCRIPTION

The present invention is directed generally to tools that are high quality, stronger, and more durable. As such, the present invention includes various embodiments showing methods and apparatus for building tools that may be, at least in part, made of a material that is heat treated and cooled so as to make its working surface more durable and longer lasting. For example, various tools that have blades made of a material such as metal that wear through use may have the blades, or portions thereof, that are heat treated and cooled so as to harden or strengthen them for improved quality, durability, and strength performance. The invention is particularly useful for building tools with thin or flat blades with edges that will wear through use. The invention is also particularly beneficial to building tools having a texturing surface that is more likely to wear out and lose its original shape.

Referring toFIGS. 1-3, a texturing trowel100according to one embodiment of the invention is presented. The texturing trowel100may be a V notch trowel used to apply, for example, a cement or adhesive, to a building surface. The V notch trowel may include a blade105that may be made of a metal, for example, high carbon steel or other material suitable for acting as a blade105of the V notch trowel. The high carbon steel may be of a type ranging between, for example, AISI 1060 high carbon steel and AISI 1095 high carbon steel, which may be a rolled steel sheet that may be cut, punched, or machined to the size of the blade105. The AISI 1060 Steel may be an alloy including by weight percentage; C of 0.55-0.66, Fe of 98.35-98.85, Mn of 0.6-0.9, P of a maximum 0.04, and S of a maximum 0.05. The AISI 1095 steel may be an alloy including by weight percentage; C of 0.9-1.03, Fe of 98.35-98.8, Mn of 0.3-0.5, P of a maximum 0.04, and S of a maximum 0.05. The blade105may be relatively thin, having a thickness140that may be, for example, in the range of 1/16 to 1/64 an inch. The V notch trowel100may have a tang110made of a metal, for example aluminum, that is coupled to the blade105by, for example, welding, brazing, etc. A handle115made of, for example, wood, plastic, and/or rubber, may be couple to the tang using, for example a threaded nut145, bolt, etc. In this case, the trowel is a V notch trowel100and thus may have teeth, for example, teeth120, along one or more of its blade edges. In this case, the V notch trowel blade has teeth120along three of its four sides. There may be many different notch sizes that may result in many different total numbers of teeth on one or more sides of the trowel.

In use, the V notch trowel100may be placed at an angle, for example, a 45 degree angle relative to the working surface so that the teeth120may contact the working surface only at their points or apex. Used in this manner for spreading, for example, cement or adhesive, the working surface and the cement or adhesive have a textured material shaped in the shape of the V notch or grooves of the trowel. However, due to the friction of the teeth on the working surface or materials being spread on the working surface, the teeth, especially the points of the teeth may be worn down over time resulting in a thinner texturing than desired. As a result, the trowel100would need to be reworked or replaced by a new trowel. To overcome this problem, at least a portion of the outer edges of the V notch trowel, e.g. the outer portion130including the teeth120may be heat treated and cooled so as to produce a hardened portion of the blade that is more resistant to wear during extensive use. Although the entire blade105may be heat treated and cooled to increase the hardness, strength and durability of the outer portion of the teeth120, testing has shown that in some cases heat treating the entire blade may result in a blade that is too brittle and breaks more easily if dropped, during the assembly process, for example, when attaching the tang110or handle115to the blade105, or under the pressure applied during repeated use. However, proper selection of the material used to make the blade105and the method used in heat treating the blade105may help to reduce or solve this problem. In any case, the teeth120are harder, stronger and more durable and may last longer within the desired height tolerance, for example up to 3 to 5 times longer.

In this embodiment, the heat treatment may be performed on, for example, the two longest sides so as to heat treat and harden only the two primary working edges of the trowel100. As shown more clearly inFIG. 2, the heat treatment may be performed on narrow areas, for example, areas130aand130c(width distance from the tip of the tooth120to the solid line) running along the length of the trowel blade105. Selecting to heat treat only two edge areas130aand130cmay help to protect the most often used edges of the trowel and minimize the setup time and complexity for heat treating the desired portions of the trowel. Although in this case the distance130aand130cis shown to be greater than the height of the teeth120, the distance130aand130cmay be less than the height of the teeth120as will be illustrated more clearly in a later described embodiment. The distances from the tip of the teeth120to the dotted lines125aand125cindicate areas where the trowel blade105may be cleaned prior to the heat treating process as described in more detail below. In one variation, the front edge (the b side) and/or the back flat edge (the d side) of the blade105may be cleaned (e.g., area125b) and the heat treated130b(not shown).

Referring toFIG. 4, a flow chart of a process for making a heated treated tool according to at least one embodiment of the invention is provided. First, at405a blade with or without notches or teeth is formed from a sheet of material, for example, a metal sheet. As mentioned above, the metal may be a high carbon steel such as AISI 1060 steel or AISI 1095 steel to name a few. The shape of the blade may be formed by, for example, stamping, cutting, forming, grinding, etc. Next, at410, at least an outer portion of the blade may be cleaned with a degreasing cleanser. The degreasing cleanser may be an alcohol base cleanser that removes dirt and grease to improve the possibility that the heat treating process may be capable of achieving a consistently higher hardness and strength of the material. Although the entire blade105may be cleaner at this step, for greater efficiency and lower cost, the area cleaned may be, for example, up to ½ an inch further into the blade than the area to be heat treated, e.g., the distance125to be degreased may be greater than the distance130to be heat treated. In any case, at least the area to be heat treated should be cleaned, i.e., at least a portion of the outer edge or working edge of the trowel. Next, at415, the blade105may be placed in a blade transporting and/or blade holding equipment and secured in an orientation desired for heating the targeted portion of the blade105. For example, the blade105may be held with a pneumatic clamp or other clamping device that allows the area130aand130cto be heat treated to remain exposed and may shield the rest of the blade105from the heat treatment. The blade105may be held in, for example, a parallel orientation to the heat treatment equipment that is located along either side (a and c) of the blade105so that both sides of the blade105may be treated simultaneously.

Next, at420, at least a portion of the blade105, for example, areas130aand130b, are heated to a desired temperature to harden and strengthen the edge portions and/or teeth120. The heat treatment equipment may be, for example, an electric induction heating machine, a furnace, etc, that can heat at least a portion of the blade105up to the desired temperature. In the case of an electric induction heating hardening is done by heating the metal with a high frequency alternating magnetic field. Heat is generated by high frequency eddy currents and hysteresis currents on the outer surfaces to be hardened. The primary current may be carried by a water cooled copper electrode. The part to be hardened typically serves as the second electrode in the circuit. Induction heat treating is very fast. Induction hardening of trowel teeth may be accomplished by having the blade105stationary and activating the heat treatment equipment for a short period of time or by moving the blade105at the appropriate speed on, for example, a conveyor belt through the location where the heat treatment equipment is located. It is understood that those skilled in the art of induction heat treating will know that the range of operating frequency, heating temperature achieved, exposure time at temperature, and cooling rate will vary based on the type of material used to make the blade105(e.g., high carbon steel ranging from 1060-1095 steel), the original hardness of the material, the desired final hardness, and the specific geometry for the portions of the blade105that are being heat treated, e.g., the edges of the blade. Then at425, the blade105may be cooled to, for example, room temperature and/or ambient temperature rapidly as through, for example, water cooling. Room temperature may vary in a range of, for example, approximately 5 degrees C. to 36 C, depending on the season and/or conditions in the heat treating facility. Alternatively, the blade could be cooled to ambient or room temperature in a controlled temperature chamber to achieve different hardness and/or strength. Further, the blade may be exposed to a second heating and cooling cycle to temper the heat treated portion of the blade. Then at430, a confirmatory test may be performed on the edge, or teeth to ensure that the proper hardness has been achieved by the heat treatment. For example, the target hardness may be in a range of approximately 57 to 61 HRC when using, for example, a heat treated blade105made of high carbon steel 1095. An untreated blade105made of high carbon steel 1095 may have a hardness target or, for example, 44-47 HRC. Other materials may result in different pre and post heat treating target hardness. The result is a blade that is harder, stronger and more durable, having a longer expected life.

After testing, as illustrated inFIG. 3, the tang110and handle115may be attached to the blade105by, for example, welding, brazing, screws, or any other attachment means that is available. Of course, the heat treating may be performed with the tang110and handle115already attached to the blade105. Although, this may complicate the manufacturing process or adversely affect the coupling between the blade105and tang110. In general, it is simpler and easier to heat treat the blade105prior to assembly with the tang110and handle115. This process may be applicable regardless of the type or style of blade105that is used. Although the process has been described as being applied to an example where two edges of the blade105are heat treated, one, two, three, four, or any number of edges, portions or the entire blade105may be heat treated to increase its hardness, strength and durability of the desired areas.

Referring toFIGS. 5 and 6, a perspective view and a top view (without the tang and handle) of a second texturing trowel500is provided. The second texturing trowel500may have a trowel blade505made of a material, for example, a metal. The metal may be, for example, a high carbon steel ranging between AISI 1060 steel and AISI 1095 steel to name a few. In this example, the texturing edge may be in the shape of, for example, a square notch or square teeth520. Further, the square notch or teeth520may be partially heat treated as shown by distance530a, or completely heat treated similar to the embodiments shown inFIGS. 1-3. In this case, the heat treatment530ais shown along only one side or edge of the trowel blade505, side a. However, it is understood that the heat treatment may be applied to any and all areas of the trowel blade505. The heat treatment may be performed using, for example, the process described with respect toFIG. 4or a similar process for hardening the blade505material so that it is more durable, strong, and long lasting. As such, the blade505may be cleaned along one or more sides to be heat treated as indicated shown by the dotted line area, for example areas525aand/or525b, etc., prior to being heat treated.

FIG. 7illustrates a side view of the blade705and a handle715for a third trowel, according to at least one embodiment of the invention. In this embodiment, the handle715is of a different design having two separate attachment points750and760. The handle715may be made of, for example, wood, metal, plastic, rubber, etc. and may be attached to the blade705using, for example, screws, molding, adhesive, welding, brazing, etc. The blade705may be made of the materials described herein, may have the shape and design as described elsewhere herein, and may be heat treated according to the methods described elsewhere herein.

Referring toFIG. 8, a top view (without the handle and/or tang) of another texturing trowel blade805is provided. This texturing trowel blade may be couple to one of a number of handle designs (not shown attached thereto). The trowel blade805made of a material, for example, a metal. The metal may be, for example, a high carbon steel ranging between AISI 1060 steel and AISI 1095 steel. In this example, all four texturing edges, a, b, c, and d, may be in the shape of, for example, a V notch or teeth820. Further, the V notch or teeth820may be partially heat treated as shown by, for example, distance830a, a distance more or less than distance830a, or completely heat treated, similar to the embodiments shown and described above. In this case, the heat treatment830a,830b,830cand830dare shown along each of the four sides or edges (a, b, c and d) of the trowel blade805, side a. However, it is understood that the heat treatment may be applied to any and all of these or other areas of the trowel blade805. The heat treatment may be performed using, for example, the process described with respect toFIG. 4or a similar process for hardening the blade805material so that it is more durable, strong, and long lasting. As such, the blade805may be cleaned along one or more sides to be heat treated as indicated shown by the dotted line area, for example areas825a,825b,825cand/or825d, etc., prior to being heat treated.

Referring toFIG. 9, a top view (without the handle and/or tang) of another texturing trowel blade905is provided. This texturing trowel blade may be couple to one of a number of handle designs (not shown attached thereto). The trowel blade905made of a material, for example, a metal. The metal may be, for example, a high carbon steel such as AISI 1060 steel or AISI 1095 steel, to name a few. In this example, all four texturing edges, a, b, c, and d, may be in the shape of, for example, a square notch or teeth920. Of course a rectangular shape may also be used. Further, the square notch or teeth920may be partially heat treated as shown by, for example, distance930a, a distance more or less than distance930a, or completely heat treated, similar to the embodiments shown and described above. In this case, the heat treatment930a,930b,930cand930dare shown along each of the four sides or edges (a, b, c and d) of the trowel blade905. However, it is understood that the heat treatment may be applied to any and all of these or other areas of the trowel blade905. The heat treatment may be performed using, for example, the process described with respect toFIG. 4or a similar process for hardening the blade905material so that it is more durable, strong, and long lasting. As such, the blade905may be cleaned along one or more sides to be heat treated as indicated shown by the dotted line area, for example areas925a,925b,925cand/or925d, etc., prior to being heat treated.

Referring toFIG. 10, a top view (without the handle and/or tang) of another texturing trowel blade1005is provided. This texturing trowel blade may be couple to one of a number of handle designs (not shown attached thereto). The trowel blade1005made of a material, for example, a metal. The metal may be, for example, a high carbon steel such as AISI 1060 steel or AISI 1095 steel, to name a few. In this example, all four texturing edges, a, b, c, and d, may be in the shape of, for example, a square notch or teeth1020aand1020band a V notch or teeth1020cand1020d. Of course a rectangular shape may also be used. Further, the square notch or teeth1020aand1020band/or the V notch or teeth1020cand1020d, may be partially heat treated as shown by, for example, distances1030a,1030b,1030c, or1030d, or a distance more or less than distance any of these distances, or completely heat treated, similar to the various embodiments shown and described above. In this case, the heat treatment area(s)1030a,1030b,1030cand1030dare shown along each of the four sides or edges (a, b, c and d) of the trowel blade1005, side a. However, it is understood that the heat treatment may be applied to any and all of these or other areas of the trowel blade1005. The heat treatment may be performed using, for example, the process described with respect toFIG. 4or a similar process for hardening the blade1005material so that it is more durable, strong, and long lasting. As such, the blade1005may be cleaned along one or more sides to be heat treated as indicated shown by the dotted line area, for example areas1025a,1025b,1025cand/or1025d, etc., prior to being heat treated.

Referring toFIG. 11, a top view (without the handle and/or tang) of another trowel blade1105is provided. This trowel blade1105is for a straight edge trowel and that does not typically texture a working surface. Rather, it is meant for smoothing surfaces. However, its straight edges may be heat treated to make them last longer with extensive use on, for example, abrasive work surfaces, and be more durable if dropped so that the straight edge remains straight longer. In any case, the blade1105may be couple to one of a number of handle designs (not shown attached thereto). The trowel blade1105made of a material, for example, a metal. The metal may be, for example, a high carbon steel such as AISI 1060 steel or AISI 1095 steel, to name a few. In this example, all four of the edges, a, b, c, and d, may be straight and a portion thereof heat treated, as shown by solid lines with a distance of1130a,1130b,1130c, and/or1130d. One or more of these edges may be partially heat treated as shown by, for example, distance1130a, a distance more or less than distance1130a, or completely heat treated, similar to the embodiments shown and described above. In this case, the heat treatment area(s)1130a,1130b,1130cand1130dare shown along each of the four sides or edges (a, b, c and d) of the trowel blade1105. However, it is understood that the heat treatment may be applied to any and all of these or other areas of the trowel blade1105, as desired. The heat treatment may be performed using, for example, the process described with respect toFIG. 4or a similar process for hardening the blade1105material so that it is more durable, strong, and long lasting. As such, the blade1105may be cleaned along one or more sides to be heat treated as indicated shown by the dotted line area, for example areas1125a,1125b,1125cand/or1125d, etc., prior to being heat treated.

Referring toFIG. 12, a top view (without the handle and/or tang) of another texturing trowel blade905is provided. This texturing trowel blade may be couple to one of a number of handle designs (not shown attached thereto). The trowel blade1205made of a material, for example, a metal. The metal may be, for example, a high carbon steel such as AISI 1060 steel or AISI 1095 steel, to name a few. In this example, all four texturing edges, a, b, c, and d, may be in the shape of, for example, a square notch and rounded teeth1220. Of course a rounded shape notch may also be used. Further, the square notch and rounded teeth1220may be partially heat treated as shown by, for example, distance1230a, a distance more or less than distance1230a, or completely heat treated, similar to the embodiments shown and described above. In this case, the heat treatment1230a,1230b,1230cand1230dare shown along each of the four sides or edges (a, b, c and d) of the trowel blade1205. However, it is understood that the heat treatment may be applied to any and all of these or other areas of the trowel blade1205. The heat treatment may be performed using, for example, the process described with respect toFIG. 4or a similar process for hardening the blade1205material so that it is more durable, strong, and long lasting. As such, the blade1205may be cleaned along one or more sides to be heat treated as indicated shown by the dotted line area, for example areas1225a,1225b,1225cand/or1225d, etc., prior to being heat treated.

Referring toFIG. 13, a top view (without the handle and/or tang) of another trowel blade1305is provided. This trowel blade1305is for a swimming pool trowel having straight edge sides a and c and rounded sides b and d, that does not typically texture a working surface. Rather, it is meant for producing smooth surfaces in, for example, a swimming pool. However, its straight edges (a and c) and rounded edges (b and d) may be heat treated to make them last longer with extensive use on, for example, abrasive work surfaces such as cement, and be more durable if dropped so that the straight edges (a and c) and rounded edges (b and d) remains straight longer. In any case, the blade1305may be couple to one of a number of handle designs (not shown attached thereto). The trowel blade1305made of a material, for example, a metal. The metal may be, for example, a high carbon steel such as AISI 1060 steel or AISI 1095 steel, to name a few. In this example, all four of the edges, a, b, c, and d, may be straight and a portion thereof heat treated, as shown by solid lines with a distance of1330a,1330b,1330c, and/or1330d. One or more of these edges may be partially heat treated as shown by, for example, distance1330a, a distance more or less than distance1330a, or completely heat treated, similar to the embodiments shown and described above. In this case, the heat treatment area(s)1330a,1330b,1330cand1330dare shown along each of the four sides or edges (a, b, c and d) of the trowel blade1305. However, it is understood that the heat treatment may be applied to any and all of these or other areas of the trowel blade1305, as desired. In this case it may be particularly desirable to hear treat edges b and d since they are rounded. The heat treatment may be performed using, for example, the process described with respect toFIG. 4or a similar process for hardening the blade1305material so that it is more durable, strong, and long lasting. As such, the blade1305may be cleaned along one or more sides to be heat treated as indicated shown by the dotted line area, for example areas1325a,1325b,1325cand/or1325d, etc., prior to being heat treated.

Referring toFIG. 14, a top view (without the handle and/or tang) of another trowel blade1405is provided. This trowel blade1405may be a multi-shaped tooth trowel having straight edge sides a and b and textured sides b and d. The textured sides b and d may have a plurality of different shaped teeth,1440c,1441c,1442c,1443c, that may texture a working surface. This texturing trowel1405may have a trowel blade505made of a material, for example, a metal. The metal may be, for example, a high carbon steel such as AISI 1060 steel or AISI 1095 steel to name a few. In this example, the texturing edge may be in the shape of, for example, a repeating pattern of teeth, for example, four different shaped teeth in series that repeat to form a complete side of texturing teeth, for example sides c and d. Of course the repeating pattern may be of 2, 3, 4, etc. number of teeth. Further, the multi-shaped notches or teeth along side c may be partially heat treated or completely heat treated as shown by distance1430c. In this case, the heat treatment1430cis shown along only one side or edge of the trowel blade1405, side c. However, it is understood that the heat treatment may be applied to any and all areas of the trowel blade1405. The heat treatment may be performed using, for example, any of the processes described above, or a similar process, for hardening the blade1405material so that it is more durable, strong, and long lasting. As such, the blade1405may be cleaned along one or more sides to be heat treated as indicated shown by the dotted line area, for example areas1425aand/or1425c, etc., prior to being heat treated. Although, it would be understood by one skilled in the art that the invention may be applicable to trowels with blades and teeth having any of a number of shapes and combination thereof.

Although a particular embodiment(s) of the present invention has been shown and described, it will be understood that it is not intended to limit the invention to the preferred embodiment(s) and it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. For example, the heating and cooling process of the present invention for hardening or strengthening blades may also be applied to other tools, for example, putty knifes, paint scrappers, notched margin trowels (V and/or square notches), notched taping knifes, brick trowels, pointing trowels, margin trowels, trowels with non-rectangular shaped blades, etc, where long term abrasive use may disadvantageously alter the original shape of the tool and/or tool blade. Further, other methods may be used for increasing the durability of the tools working edges (e.g., teeth, etc.), such as attaching (e.g., welding, adhesive, etc.) a more durable material to the tool blade as the work surface. Thus, the invention is intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the invention as defined by the claims.