Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D1/00—Hand hammers; Hammer heads of special shape or materials
  • B25D1/12—Hand hammers; Hammer heads of special shape or materials having shock-absorbing means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25G—HANDLES FOR HAND IMPLEMENTS
  • B25G1/00—Handle constructions
  • B25G1/01—Shock-absorbing means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25G—HANDLES FOR HAND IMPLEMENTS
  • B25G3/00—Attaching handles to the implements
  • B25G3/02—Socket, tang, or like fixings
  • B25G3/10—Socket, tang, or like fixings with elastic, taper, or other self-grip socket or tang
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25G—HANDLES FOR HAND IMPLEMENTS
  • B25G3/00—Attaching handles to the implements
  • B25G3/34—Attaching handles to the implements by pressing the handle on the implements; using cement or molten metal, e.g. casting, moulding, by welding or the like

Definitions

• the present invention concerns a shock absorbing hammer, comprising a shaft and a hammer head being provided with a shock absorbing material, e.g. in the form of a rubber material, a hydraulic cushioning material or the like, the purpose being to dampen the rebound force and vibrations imparted to the shaft when the hammer head hits an object during a swinging motion of the hammer.
• a shock absorbing material e.g. in the form of a rubber material, a hydraulic cushioning material or the like
• hammers of this general kind see e.g. US 2,451,217, US 3,172,438, US 4,085,784 and SE-B-462,616.
• the last-mentioned document discloses a hammer, wherein an end portion of the shaft is mounted in a recess in the hammer head so as to permit a limited pivotal movement, being damped by a shock absorbing material, in one angular direction from a rest position when the hammer head strikes an object during a swinging motion of the hammer, whereas mutual movement in the opposite angular direction from said rest position is inhibited.
• the hammer can either be used in the normal way for striking an object, e.g. a nail, with the hammer head or, alternatively, for withdrawing a fastener, e.g. a nail, by means of a claw portion at the back of the hammer head.
• this known hammer is relatively complicated in its structure, namely with radially projecting lugs formed at the shaft end portion in order to ensure a direct surface contact between the shaft and the hammer head inside the recess, the latter being substantially parallel to but wider than the shaft end portion.
• a primary object of the present invention is to accomplish a shock absorbing hammer of the kind defined in the preamble of claim 1 which has a simple structure and is inexpensive to manufacture and which provides an effective shock absorbtion.
• the shaft end portion and the recess in the hammer head are both cylindrical, the cylindrical recess in the hammer head being obliquely inclined in relation to the cylindrical shaft end portion, so as to provide wedge ⁇ like upper and lower recess portions, which accommodate the shock absorbing material and permit a limited pivotal movement in one angular direction, and in that, in the rest position, the shaft end portion is in surface contact with the inside wall of the obliquely inclined cylindrical recess at diagonally opposite locations directly, i.e., without the intermediary of said shock absorbing material, whereby mutual movement in the opposite angular direction is inhibited.
• the manufacture of a hammer according to the invention is simple. Thus, it is sufficient to make a downwardly inclined bore hole in the hammer head, as seen from the side of the shaft, and to insert the cylindrical shaft end portion, which has a smaller diameter, into the bore horisontally, so that the shaft end portion makes direct contact with the walls of the bore adjacent to the front end of the shaft, normally near the bottom of the hole, and adjacent to the opening of the bore, whereby the shaft end portion, and the central axis thereof, will extend at an angle, normally 3°-10°, preferably about 4°, relative to the bore axis.
• the cylindrical bore in the hammer head is lined internally by a cylindrical sleeve, fitted tightly in the bore, so that the interior of the sleeve constitutes the recess into which the shaft end portion is inserted.
• the sleeve is made of metal and is provided with deformed portions near its ends, at the upper side near the bottom of the bore and at the lower side near the opening of the bore, these deformed portions extending radially inwards so as to provide the desired surface contact between the recess and the shaft end portion.
• Fig. 1 is a sectional view of the hammer head and the shaft end portion of a hammer according to the invention
• Fig. 2 shows a sleeve separately in longitudinal section along the line A-A in fig. 3, the sleeve forming a part of the connection between the shaft and the hammer head;
• Fig. 3 shows an end view of the sleeve of fig. 2.
• the illustrated hammer comprises a conventional hammer head 1 which is resiliently connected to an end portion 2a of a tubular shaft 2, e.g. made of metal or a reinforced plastic material.
• the other end of the shaft (not shown in fig. 1) is provided with a gripping handle, as is well-known in the art of hand tools of this kind.
• the hammer head has a lower striking surface 3 and an upper claw portion 4, the latter being used for withdrawing nails or the like.
• a mid-portion of the hammer head 1 includes a substantially cylindrical portion 5 projecting backwards in parallel to the axis S of the shaft 2, to the right in fig. 1, to provide a secure connection with the shaft 2.
• a cylindrical bore 6, the diameter of which is somewhat larger than the external diameter of the tubular shaft 2, is made at a small angle ⁇ , about 4° in the illustrated embodiment, so that the bore axis B is slightly inclined downwards towards the front end, to the left in Fig. 1, relative to the horisontal axis S of the shaf 2 and the hammer head portion 5.
• a bushing or sleeve 7 (compare figs. 2 and 3), made of a metal material, preferably steel, is press-fitted into the bore 6, so that the interior of the sleeve constitutes a cylindrical recess firmly integrated with the hammer head 1.
• the shaft 2 is inserted with its end portion 2a into this recess, the axis S thereof being oriented horisontally or in parallel to the cylindrical, backwardly projecting portion 5 of the hammer head 1. Consequently, the forward, upper end of the shaft end portion 2a makes direct contact with the innermost end 7a of the sleeve 7 and the rear, lower end of the shaft end portion 2a makes direct contact with the outer end 7b of the sleeve.
• This contact is well-defined and distributed over a surface area by means of inwardly deformed material portions 8 and 9, respectively, at each location.
• the recess portions 10 and 11 are filled with a shock absorbing material, e.g. of rubber, foam, an elastically resilient plastic material or the like, which secures a permanent connection between the hammer head 1 and the shaft 2, on one hand, and provides the desired shock absorbing effect therebetween, on the other hand.
• a shock absorbing material e.g. of rubber, foam, an elastically resilient plastic material or the like
• the structure of the hammer according to the invention may be modified by those skilled in the art within the scope of the appended claims.
• the "cylindrical" shape of the hammer head recess and the shaft end portion includes also non- circular cross-sectional configurations, e.g. a rectangular cross-section.
• the crucial feature is the obliquely inclined orientation of the shaft end portion within the hammer head recess.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Percussive Tools And Related Accessories (AREA)
• Vibration Dampers (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=20399428

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (1)

• 1995
  • 1995-09-11 SE SE9503124A patent/SE505352C2/sv not_active IP Right Cessation
• 1996
  • 1996-09-06 EP EP96931321A patent/EP0850125A1/en not_active Withdrawn
  • 1996-09-06 WO PCT/SE1996/001115 patent/WO1997010075A1/en not_active Application Discontinuation
• 1998
  • 1998-03-09 NO NO981023A patent/NO304463B1/no not_active IP Right Cessation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events