Patent Application
20060112789
This application relates generally to impact tools, such as hammers, and, more particularly, relates to hammers of the type designed to minimize rebound, commonly referred to as “dead blow hammers.”
Dead blow hammers are typically provided with a head which is, at least, partially filled with a flowable, rebound-inhibiting material, such as steel pellets or shot. As such, the rebound-inhibiting material absorbs a majority of the impact force when the hammer impacts a work surface and prevents a rebound effect. However, many such hammers have handles which extend into the tubular hammer head, thus impeding the free-flowability of the rebound-inhibiting material.
It is known to provide dead blow hammers formed from a skeleton consisting of a hammer head and handle framework, partially or fully encapsulated or encased within an outer casing or covering which may be overmolded onto the skeleton. However, such prior encapsulated hammers have had complicated or require expensive skeletal structures and/or have been characterized by less than optimal weight distribution between the hammer head and the handle. Further, the hammer head and the handle are typically formed of the same material, thus providing a conduit for the transmission of vibrational forces during use.
U.S. Pat. No. 6,595,087, which is commonly assigned with the present application, optimizes the weight distribution between the hammer head and the handle and avoids penetration of the head with the handle by providing a radially, outwardly projecting neck tube integrally coupled to the hammer head, such as with a weldment, and adapted to receive a working end of the handle, which may be formed of any material. The hammer head and handle are then overmolded with a plastic material.
The present application discloses an improved dead blow hammer, and a method for making the same, having a skeleton consisting of a hammer head, a collar adapted to be disposed substantially about the hammer head, and a handle. The collar includes a neck tube outwardly radially extending therefrom which is adapted to receive a working end of the handle. In an embodiment, the assembled hammer, including the hammer head, the collar and the handle, is substantially encapsulated with a casing.
For the purpose of facilitating an understanding of the subject matter sought to be protected, there is illustrated in the accompanying drawing embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages, should be readily understood and appreciated.
Referring to
In an embodiment, the hammer includes a collar 20 disposed substantially about the periphery 14 and intermediately on the hammer head 11, and a handle 30 having a working end 31 and a distal end 32. The hammer head 11, the collar 20 and the handle 30, when in an assembled condition, may be substantially overmolded or encapsulated with a casing 40. The casing 40 may be formed of an elastomeric material. Casing 40 may include an overmolded or formed resilient grip 41 disposed adjacently to the distal end 32.
In an embodiment, the handle 30 is formed of a fibrous material, such as, for example, fiberglass or carbon fiber.
Referring also to
When the hammer 10 is in an assembled condition, the neck tube 22 is inclined relative to the longitudinal axis. In an embodiment, the neck tube 22 is substantially perpendicular to the longitudinal axis.
In an embodiment, the inner surface 21 of the collar 20 is adapted to form a friction-fit with the periphery 14 of the hammer head 11 when the collar 20 is disposed substantially about the periphery 14 and intermediately on the hammer head 11. The inner surface 21 may include a plurality of inwardly extending ribs 23 that are substantially parallel to the longitudinal axis and are adapted to frictionally engage the periphery 14 when the hammer 10 is in an assembled condition. The ribs 23 may be circumferentially disposed about the inner surface 21 and be substantially equiangularly spaced relative to each other.
Also disclosed herein is a method of making a hammer. The method comprises providing a substantially tubular head having a periphery and a longitudinal axis, frictionally fitting a collar having an inner surface and a neck tube radially outwardly projecting therefrom with the head so that the collar is substantially intermediately disposed on the head and the neck tube is inclined relative to the longitudinal axis, inserting a proximal, working end of a handle in the neck tube, and substantially encapsulating the head, the collar and the handle with an elastomeric casing. The method may further comprise adhesively securing the handle to the neck tube. The method may also comprise overmolding a grip on the casing adjacent to a distal end of the handle or filling the head with a substantially flowable, rebound-inhibiting material.
From the foregoing, it can be seen that there has been described an improved dead blow hammer which is of simple and economical construction, improved weight distribution and force-delivering capacity, and improved vibration resistance and ergonomic design.
The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants' contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
