It is a well-known principle that every action has is an equal and opposite reaction (Newton's Third Law). Thus, for a hammer, when the impact surface of the hammerhead impacts a target, the hammer is jolted backwards due to the reaction caused by the hammerhead striking its target. This opposite reaction is commonly referred to as hammer recoil.
For minimizing or eliminating hammer recoils, which cause vibrations and injuries to the user, numerous hammers were invented. Broadly speaking, these hammers utilize some form of inserts placed in a hollow chamber within the hammerhead, or within a separate hollow body having a hollow chamber attached to the hammerhead. The inserts are configured to move from a rear surface of the hollow chamber to a front surface of the hollow chamber. Accordingly, when the hammer moves in a first direction to impact its target, the inserts are pushed by the rear surface of the hollow chamber to move in the same first direction.
As the impact surface of the hammerhead impacts a target and starts its recoil in a second direction, the inserts still move in the first direction within the hollow chamber and impact the front surface of the hollow chamber, in the first direction. The inserts impacting against the front surface of the hollow chamber thus cancel the recoil in total or substantially. The amount of cancellation depends, in part, on the weight percentage of the inserts compared to the weight of the hammerhead. Without being restricted to any particular theory, the deadblow impact or feel to the user also depends on the distance the insert travels before it impacts the front surface, which will influence how far the hammer recoils before the insert impacts the front surface to cancel out the effect.
U.S. Pat. No. 6,234,048 to Carmien discloses a non-recoil hammer, with a hammerhead that has an open socket for receiving a separate hollow canister. The hollow canister connects to a tool handle and contains a relatively high mass moveable filler material in a hollow chamber, such as steel shot pellets. The hollow canister is received within the open socket to form a completed hammer. Due to the two-piece design, the hammer is more complicated and costly to manufacture.
U.S. Pat. No. 5,916,338 to Bergkvist et al. discloses a hammer having a hammerhead with an impact element and a cavity at least partially filled with particulate material, such as steel shot, so as to dampen the recoil of the hammer. The impact element is forged with the head as a single piece or may be formed as a separate part that is connected to the head by welding. However, since the cavity extends the full length of the hammerhead, the handle cannot attach to the hammerhead by passing through central portion of the hammerhead, but is attached via partial through hole at the central portion of the hammerhead. This makes the handle more susceptible to slippage or separation from the hammerhead. Furthermore, because of the cavity, a conventional handle with a split end for wedging the handle with a wedge is not useable with the disclosed hammerhead.
U.S. Pat. No. 4,039,012 to Cook discloses a non-rebound hammer having a hammerhead portion with forwardly and rearwardly facing metallic impact surfaces. The head portion contains a hollow cylindrical core for receiving a quantity of pellets, such as small lead shots. The hammerhead also contains a core hole for receiving a handle rod. The handle rod and the hammerhead are then co-molded with an encasement. Due to the co-molded configuration, the entire hammer must be discarded when damage is done to the handle.
U.S. Pat. No. 2,604,914 to Kahlen discloses a hammerhead having a rebound-preventing means. The hammerhead has a body with a striking head at each end of the body. Each striking head is formed integrally with the body, or alternatively it may be secured to the body as a separate piece. A chamber is formed in the body immediately behind the striking heads. The chamber contains irregularly shaped particles 26, as shown in
There is therefore a need for a non-recoil hammer or deadblow hammer that minimizes or negates the effects of hammer recoils and that do so without the shortcomings of prior art deadblow hammers. Additionally, there is also a need for a method of making the desired deadblow hammer.
The present invention specifically addresses and alleviates the above-mentioned deficiencies associated with the prior art anti-recoil hammers. More particularly, the present invention comprises a deadblow hammer comprising a hammerhead having a body, an anti-recoil chamber for receiving a plurality of insert elements located within a section of the body, and an open socket defined by a handle chamber which passes through the body for receiving a handle. The anti-recoil chamber comprises a first opening that is in communication with the open socket and that provides a first passage into the anti-recoil chamber, the first opening allows the plurality of insert elements to be placed into the anti-recoil chamber by way of the open socket; and wherein insertion of the handle into the handle chamber seals off the first opening and occupies the open socket. Together, these features define a deadblow hammer that is more economical to make and that has an anti-recoil chamber that is easy to access.
The present invention also involves a deadblow hammer comprising a hammerhead having a body, two anti-recoil chambers, each having a plurality of insert elements situated therein and an impact surface attached adjacent thereto, and an open socket defined by a handle chamber that passes through the body for receiving a handle. This hammer is commonly known in the art as a sledge hammer.
The two anti-recoil chambers in the sledge hammer each comprising a first opening that is in communication with the open socket and that provides a first passage into the anti-recoil chamber from the open socket; the first opening allows the plurality of insert elements to be placed into the anti-recoil chamber by way of the open socket; and wherein an insertion of the handle into the handle chamber seals off the first opening of each of the anti-recoil chamber and causes the open socket to be occupied.
The present invention also involves a golf club head comprising a club face, a hosel for attaching the club head to a shaft, and a hollow chamber disposed within the club head; and wherein the hollow chamber includes insert elements for negating and dampening recoils when the golf club head impacts a solid surface.
These and other features, aspects and advantages of the present invention will be more fully understood when considered with respect to the following detailed description, appended claims and accompanying drawings, wherein:
a is a semi-schematic cross-sectional side view of the hammer of
The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of the deadblow hammer in accordance with the present invention and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the features and the steps for constructing and using the deadblow hammer of the present invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and structures may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. Also, as denoted elsewhere herein, like element numbers are intended to indicate like or similar elements or features.
Referring now to
The hammerhead 10 is preferably cast from a steel material but alternatively may be forged from a steel block. The handle 22 may be any number of conventional handles, including handles made from wood, plastic, and fiberglass.
Referring now to
A separate impact plate 17 is shown attached to the body 14 of the hammerhead 12 and covers the hollow chamber's second opening 42. The second opening 42 is shown larger than the first opening 40. However, the arrangement is merely a designer's choice as the relative dimensions between the first opening 40 and the second opening 42 may be reversed. The impact plate 17 may be attached to the body 14 by conventional welding methods, by threads, or by inertia welding. In inertia welding, the body 14 is held in a lath and spins at relatively high speed. The lath used for inertia welding can be a vertical standing lath or a horizontal lath. The impact plate 17, which is not spinning, is then pushed against the spinning end surface 44 of the second opening 42. The friction generated by the contact causes the impact plate 17 and the end surface 44 to partially melt, which results in their fusion. As a by-product of their impact, a protruding section 46 is formed on the impact plate 17, which protrudes into the hollow chamber 32. Alternatively, the impact plate 17 can be rotated in the lath and the body 14 held stationary.
A plurality of insert elements 48 are shown placed in the hollow chamber 32. The insert elements 48 can be any number of weighted materials such as spherical pellets, small metal scraps, lead shots, or their equivalence. In one embodiment, steel pellets 50 are used for the insert elements 48. The quantity of steel pellets 50 used is approximately equal to 25% to 70% of the weight of the hammerhead 12 with 30% to 60% being more preferred. In another embodiment, tungsten shots are used for their relatively heavier density than steel. Consequently, less space or volume is required for the same weight percentage when tungsten shots are used.
The insert elements 48 are added to the hollow chamber 32 by individually depositing the steel pellets 50 in through the first opening 40, before attaching the handle 22 into the open socket 26 and after attaching the impact plate 17 to the end surface 44. Alternatively, the steel pellets 50 may be added to the hollow chamber by first magnetizing the pellets or gluing the pellets so that they form a single large mass. The single large mass can then be added to the hollow chamber via the second opening 42, before attaching the impact plate 17 to the end surface 44. Subsequently, the impact plate 17 may be attached to the end surface 44 by inertia welding, using a vertical standing lath, or by conventional welding. Due to the size of the single large mass, it will not fall out of or fall through the first opening 40 when the welding is taking place. It is understood that if conventional welding is utilized to attach the impact plate 17 to the end surface 44, the surfaces to be welded should be chamfered to provide a v-groove 35 for welding, See, e.g.,
Turning now to
Turning now to
Turning now to
a shows still yet another alternative hammerhead 12d provided in accordance with practice of the present invention. Similar to the other embodiments (i.e.,
Although the hammerhead 64 is shown with integrally formed impact surfaces 72, separate impact plates may be used and thereafter welded to the body 66, as previously discussed with reference to
Next, melted wax is pour into the die to create a wax replica of the hammerhead 86. The wax is then dipped into a slurry bath comprising silica flour and a chemical binder to form an “investment” 88. After the investment hardens, the wax is removed from the investment by heating the investment and the wax in an oven or a steam chamber 90 to melt the wax. Once the wax is removed, the investment is baked or fired in a heater 92 to cure. Molten metal is then poured into the cured investment 94 to form the cast hammerhead.
Once the cast hammerhead sufficiently cools, the investment is removed 96 by impacting the hammerhead to break up the investment. The hammerhead is now ready to receive the insert elements 98. As discussed above with reference to
Although the preferred embodiments of the invention have been described with some specificity, the description and drawings set forth herein are not intended to be delimiting, and persons of ordinary skill in the art will understand that various modifications may be made to the embodiments discussed herein without departing from the scope of the invention, and all such changes and modifications are intended to be encompassed within the appended claims. Various changes to the hammerhead and golf club head may be made including changing the contour, the weight, the hollow chamber configuration, and the overall dimensions, etc. Accordingly, many alterations and modifications may be made by those having ordinary skill in the art without deviating from the spirit and scope of the invention.
This is a continuation application of Ser. No. 10/246,867, filed Sep. 17, 2002, entitled Deadblow Hammer, the contents of which are expressly incorporated herein by reference. Deadblow hammers capable of minimizing or eliminating recoils when the hammers impact their targets are discussed herein. These hammers incorporate filler materials, which function to negate the effects of the hammer recoils, with improved filling port(s) for filling the filler materials.
Number | Date | Country | |
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Parent | 10246867 | Sep 2002 | US |
Child | 11106126 | Apr 2005 | US |