US2807177A - Drop hammer - Google Patents

Description

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sept. 24, 1957 Filed Feb. 18, 1955 H. TERHUNE DROP HAMMER 2 Sheets-Sheet 1 Sept. 24, 1957 H. TERHUNE DROP HAMMER 2 Sheets-Sheet 2 Filed Feb. 18, 1955 United States Patent O DROP HAMMER Howard Terhune, Alliance, Ohio, assignor, by mcsne assignments, to Baldwin-Lima-Hamilton Corporation, Philadelphia, Pa., a corporation of Pennsylvania Application February 18, 1955, Serial No. 489,228

1 Claim. (Cl. 78-25) This invention relates to drop hammers wherein a ram carrying the upper die is dropped toward an anvil which supports the lower die. In order to prevent sub-v stantial wear of the anvil, the lower die is supported in an anvil cap or die holder which in conventional hammers is fitted into the anvil. Normally, the die holders are mounted in the anvil by dowels and locked in position by keys which are driven into place, for example, by large battering rams, under high pressure. Heavy stresses are thus set up between the die holder and the anvil, and these stresses are further increased during operation of the hammer due to the fact that the die holder heats up faster than the anvil and tends to expand against the latter. The total stresses thus created have been sufiicient to cause frequent anvil failure. It constitutes one of the most serious problems in the upkeep of drop hammers.

It is therefore one of the principal objects of this invention to provide an arrangement of anvil cap or die holder on an anvil which will effectively secure the die holder relative to the anvil without creating large stresses, and which will permit the die holder to expand relative to the anvil in response to temperature rise without creating increased stress between the die holder and the anvil.

Further objects and advantages of this invention will become apparent in the following detailed description thereof.

In the accompanying drawings,

Fig. 1 is a front elevation of a part of a hammer, partly sectioned vertically, and with parts broken away, embodying one form of this invention.

Fig. 2 is a section taken substantially on the line 2-2 of Fig. l.

Fig. 3 is a section taken on the line 33 of Fig. 2.

Referring to the drawings, it will be seen that the drop hammer as illustrated comprises a fixed structure which includes an anvil or base yand a stand fixed to the base and comprising frame members 11 and 12. In Fig. 1 the upper ends of the frame members have been broken away. The upper ends support a steam cylinder (not shown) which is controlled in the usual manner by a Valve. A ram 20 is guided within the stand for movement along a longitudinal operating axis and is operated in the conventional manner by the steam in the steam cylinder. The ram 20 carries the upper die 21 to move it toward and away from the lower die 22 which is carried by the anvil cap or die holder 23 supported on anvil or base 10.

Heretofore, as stated in the introduction hereto, the die holder 23 was fixed in position relative to the anvil by dowels and keys which set up severe stresses in the anvil, and such stresses were greatly amplified by excess temperature of the die holder relative to the temperature of the anvil. To avoid this condition which sometimes resulted in failure of the anvil, the following .arrangement is employed which will (l) maintain the axial relationship of the die holder with respect to the operating axis of the hammer and vertical axis of the anvil, and (2) which V47 in the anvil.

2,807,177 Patented Sept. 24, 1957 ICC will permit the die holder to expand in response to the rising temperature during operation of the hammer without subjecting the anvil to increasing stress and likewise to contract upon a decrease in temperature.

To accomplish the foregoing results, the die holder is formed with a plurality of bearing surfaces 35 which are substantially radial with respect to the vertical operating axis O. Four bearing surfaces are shown symmetrically arranged, two on each side of each coordinate axis. Each bearing surface 35 engages and may slide upon, a cooperating bearing surface 36 of a guide member 37 adjustably mounted on the respective frame member 11, 12, the surfaces 36 also being substantially radially disposed. Any expansion or contraction of the die holder relative to the anvil will result in sliding movement between each set of cooperating surfaces 35, 36. Thus any increase of temperature in the die holder relative to the temperature of the anvil during operation will cause no increase in stress in the anvil. This major cause of anvil failure is thereby eliminated.

To damp any tendency to vertical movement or oscillation of the die holder, each guide member 37 may be provided with an inwardly extending vertical taper as shown at 50 in Fig. 3, the die holder having a cooperating machined face.

The surfaces 38 of the guide members 37 are not radially disposed with respect to the vertical operating axis O but converge to a predetermined degree so that as wear between surfaces 35, 36 occurs, the guide members may be moved inwardly to take up such wear. Keys 41 may be provided for determining the position of the guide members, said keys being vertically `adjustable on the frame members by means of adjusting nuts 43. For locking the parts in their adjusted positions, bolts 39 and nuts 40 cooperate with horizontal slots 44 in the guide members 37, and bolts 42 and nuts 48 cooperate with Vertical slots 45 in the keys 41.

As shown in Figs. l and 2, die holder 23 may be provided with a round projection 46 on its lower surface adapted to engage in a corresponding machined opening This will additionally locate the die holder with respect to the vertical axis of operation. In this case, the substantially radial surfaces 35 will prevent rotation of the die holder about the vertical axis of operation, while still permitting expansion of the die holder in response to increase in temperature, without increasing the stress.

Having described my invention, what I claim and desire to secure by Letters Patent is:

A drop hammer comprising a xed structure including an anvil and a frame fixed relative thereto, a die holder supported on the anvil, a lower die supported by said die holder, a ram, van upper die carried by said ram, said ram and said upper die being movable in said frame along a longitudinal operating axis toward and away from said lower die, and means for preventing displacement of the axis of the die holder While permitting radial expansion and contraction of the die holder relative to the fixed anvil, said last-named means comprising a plurality of fixed, substantially radial bearing surfaces formed on said fixed structure, and a plurality of bearing surfaces formed on said die holder and adapted to engage the bearing surfaces on the fixed structure.

References Cited in the le of this patent UNITED STATES PATENTS 940,005 Gorton Nov. 16, 1909 2,116,804 Swanson May 10, 1938 2,449,647 Fitzgerald Sept. 2l, 1948 2,703,024 Albers et al. Mar. l, 1955

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