Patent Application
20230364767
The present invention is directed to hammers commonly used in the construction industry. More precisely, the present invention is directed to a two-piece titanium hammer.
Hammers are typically manufactured using two different methods of construction: a two-piece design where the metal head and non-metal handle are made separately then assembled together, versus a one-piece design where the head and handle are formed from one piece of metal.
A two-piece hammer consists of a metallic head with a through-hole or eyelet to receive either a wood or composite handle. In a wood handled hammer the handle is inserted through the hole in the head and secured using mechanical fasteners. In a composite-handled hammer the handle is typically constructed from a durable, pultruded fiberglass core that is over-molded with durable plastic and rubber. The rubber is used in the grip area for comfort, dampening vibration, and a secure grip with the remainder of the fiberglass core being covered in plastic. The non-gripping end of the handle is stepped down allowing it to be press fit into the lower portion of the through hole in the head while a smaller section protrudes into but not through the hole with a void space around it. The void space is filled with a chemically activated epoxy resin that secures the hammer head to the handle when cured. The aforementioned press fit between the handle and the lower portion of the through hole acts as a gasket to prevent the epoxy from leaking out the bottom of the hole during assembly before it cures.
In a one-piece design the hammer handle and head are made from the same material and are formed at the same time during the manufacturing process. Since they are made from the same piece, there is no mechanical interface needed between the handle and head. To make the hammer more comfortable to use, a grip is installed over the lower portion of the metallic handle.
In the last several years a few manufacturers have released hybrid style designs which deviate from the most common manufacturing methods mentioned above. Most notably U.S. Pat. No. 9,718,179 (Martinez) utilizes a two-piece design where the head and handle are both metallic and bolted together with a fastener.
In U.S. Pat. No. 9,168,648 (Lombardi), this two-piece hammer consists of a handle with a steel core (versus fiberglass) surrounded by plastic in an effort to reduce the overall weight and allow for slight compliance between the handle and the hammer head to reduce vibration felt by the user after impact. In this design, the handle is permanently affixed to the head.
The present invention in a preferred embodiment is directed to a handheld hammering tool. The tool, such as a household, carpenter, or camping hammer, includes a hammer head having a preferably hardened impact face at one end, wherein the hammer head further includes a flange having a nub at its periphery, an intermediate portion including a stepped-down, recessed bed and an angled profile, and a claw at an opposite end. The tool further includes a handle optionally made from a material including titanium or the like, wherein the handle includes an elongated shaft with a grip at one end and a cylindrical hoop at an opposite end that is disposed at a right angle to the elongated shaft, and wherein the hoop includes a front-facing edge with a notch for receiving the nub therein, and wherein the hoop further includes a flattened wall section. The hammer head is preferably inserted front the front of the hoop during assembly at the factory.
The tool also includes a locking means for securing the hammer head to the handle, wherein the locking means includes a wedge with an angular surface abutting the angled profile of the intermediate portion inside the hoop. The wedge, when inserted from the back end of the hoop, pushes the recessed bed of the hammer head into and capturing the flattened wall section of the hoop therein. The hammer further includes a fastener holding the wedge and the intermediate portion together.
The wedging action pushes the recessed bed section into the flattened wall section capturing or trapping it therein. This prevents any axial movement of the hammer head relative to the hoop/handle even after many repeated hammer head strikes as the tool is used. To prevent rotational movement of the hammer head relative to the hoop/handle, the nub of the flange engages notch at the front-facing edge of the hoop, which captures or locks the nub therein.
In various alternative embodiments, the handle may be fashioned from steel, titanium, aluminum, fiberglass, wood, plastic, iron, or any combination thereof. The hammer head may be fashioned from hardened steel, titanium, aluminum, iron, lead, metal cladding, or any combination thereof.
The present invention in various preferred embodiments contemplates a titanium hammer assembled from multiple components. What is loosely referred to as “two-piece” hammers are of interest, because the two key components such as the hammer head and the handle shaft can be made from different materials. For instance, the handle shaft may be constructed from lightweight titanium or like alloy, while the head is made from hardened steel or like strong material. If the head is also made from titanium, there may be wear or durability concerns because titanium is a softer material as compared to steel. Of course, a titanium hammer head may be clad with a tougher material to protect the softer titanium.
Making a hammer from, say, two pieces allows the handle shaft to be made from a less expensive material such as wood, plastic, or fiberglass. Fabricating the complex shape of a hammer using a single piece of base material for the hammer head and shaft may increase the cost of fabrication for molds and finish machining. Fabricating a head from the shaft in discrete pieces reduces the manufacturing costs.
An important consideration is safety for the user in having the hammer head and shaft staying tightly assembled while undergoing many, many impact blows when used for many years. Because of the many impact blows to the head transmit shock and vibration to the locking mechanism, the hammer design and locking mechanism are important considerations for safety of the user and those working around the user. The locking mechanism should not fracture or become loosened throughout the life of the hammer. And even in the unlikely event of the locking mechanism’s failure, the head and shaft should stay together sufficiently so that the user can recognize such failure has occurred and immediately stop using the hammer.
Disclosed below are two preferred embodiments of a two-piece hammer. Although loosely described as two pieces referring to the hammer head and shaft, it is contemplated that the present invention hammer may be fashioned from more than two pieces, such as adding a rubber grip covering the handle, cladding to the hammer head, multiple component pieces assembled together for the shaft or hammer head, etc. The preferred embodiment hammer has a titanium shaft, but other materials and combination of materials are contemplated.
The first preferred embodiment is shown in
As seen in
As best seen in
Other locking means are contemplated, such as rivets, mechanical interlocking pieces, cement or bonding agents, a hook and eyelet, brazing, welding, latch locks, rack and pinion gears, multiple wedges, interference friction fits, and the like.
Optionally, the intermediate portion 32 includes a recessed bed 36 with a stepped-down profile as best seen in
Moreover, the intermediate portion 32 and wedge 20 are preferably contained within the hoop 26. As the hammer 10 is swung swiftly in an arc during use, the centrifugal/inertial force from the accelerated mass of the hammer head 12 and wedge 20 assembly urges the assembly to separate from the shaft 18, if not constrained inside the hoop 26. Therefore, the hoop 26 holds the hammer head components together and inside, even if the parts become loose or fail. When swung by the user even after failure, the pieces will not be sent flying, because the hoop holds those pieces therein, at least momentarily. After the swing, the user will immediately recognize from sight, sound, or feel of the loosened or broken parts that the hammer has failed and will stop using it. Therefore, when the discrete components are contained inside the hoop 26, this feature provides another safety measure enjoyed by the preferred embodiment.
At the front end the recessed bed 36 just behind the impact surface 14 of the hammer head is an optional flange 40. As best seen in
In the preferred embodiment, the flange 40 is spaced apart from the weighted section 48 of the hammer head containing the impact face 14. First, this allows the weighted section 48 to be made from a high strength, hardened or tough steel to minimize wear from repeated impact blows, or a more dense material to increase inertia for the hammer when it is swung. Second, spacing apart the weighted section 48 away from the flange 52 (and the handle 18) improves the balance of the hammer, and gives access of the impact face 14 in tight quarters where the handle might otherwise get in the way. Third, the gap between the flange 40 and weighted section 48 may be used as a tool for receiving therein and bending the shaft of a wire or long nail. In an alternative embodiment, the flange and the weighted section are formed integrally with no gap.
In both exemplary embodiments, the linear forward and backward head motion relative to the handle as well as the rotational movement of the head relative to the handle are eliminated. There is thus a solid mating of these components which is achieved by the wedge locking mechanism engaging the assembly and forcing the assembly against the inside wall of the hoop of the handle.
While the particular preferred embodiments of the invention have been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. It is contemplated that elements from one embodiment may be combined or substituted with elements from another embodiment.
This non-provisional patent application claims benefit of priority from U.S. Provisional Application No. 63/341,853, filed on May 13, 2022, the contents of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63341853 | May 2022 | US |
