US2142112A - Drop hammer lifting means - Google Patents

Description

Jan. 3, 1939.

w w. CRILEY DROP HAMMER LIF'TING MEANS Filed April 9, 1956 5 Sheets-Sheet 1 INVENTOR.

' ATTORNEY.

Jams, 1939.- w w cmLEY' 2,142,112

DROP HAMMER LIFTING MEANS' Filed April 9, 1936 5 Sheets-Sheet 2 INVENTOR. g 4 MAM/4M 14/ CR/Lz-Y 0 1 #AMQW M ATTORNEY.

Jan. 3, 1939. w. w. CRILEY 2,142,112

DROP HAMMER LIFTING MEANS Filed April 9, 1936 5 Sheets-Sheet 3 INVENTOR. Fig. 10 MAL/AM W CR/AEK ATTORNEY.

Jan. 3, 1939. w. w. CRILEY DROP HAMMER LIFTING MEANS 5 Sheets-Shee t 4 Filed April 9, 1956 INVENTOR. lA/ILLIAM l L/ CR/LEY ATTORNEY.

Jan. 3, 1939. w. w. CRILEY DROP HAMMER LIFTING MEANS Filed April e, 1956 5 Sheets-Sheet 5 INVENTOR. W/LZ/AM WCR/LEV ATTORNEY.

Patented Jan. 3, 1939 UNITED STATES PATENT OFFICE 8 Claims.

This invention relates to an improvement in drop hammers and more specifically is directed to a unique construction and arrangement for lifting the ram which will overcome many of the difficulties now experienced, as well as avoiding dangers inherent in such machines.

The usual fiat rectangular wood boards used in most drop hammers are undesirable for several reasons. The relatively soft surface of any wood board thus employed wears more rapidly at the zone where the rolls first engage the board to lift the ram from its lowermost position. This results in the formation of deep depressions in the engaging faces of the board at that zone which gradually taper to full board thickness toward the opposite end thereof. Thus these rolls must be capable of wide separation so as to clear the board when idling or when the ram is in elevated position. If the rolls are allowed to engage the board while idling, suilicient heat may be generated by friction to glaze the board surfaces and consequently reduce the coefficient of friction so that the ram cannot be lifted. This friction, if continued, may even scorch or char the board.

Furthermore, difficulty is encountered in providing a method for positively anchoring the board to the ram and which may also afford convenient detachment therefrom.

Other objections to the use of boards for drop hammers include the constant source of danger from flying splinters of considerable size, the increasing difficulty and expense of obtaining such boards which will meet the exacting specifications of characteristics of the wood, and the duration of the shut-down time required for their frequent replacement.

An object of the present invention lies in the provision of a means for elevating the ram of a drop hammer which will at all times insure a smooth and uniform surface engagement between a hard metallic lift rod and a relatively soft, resilient friction facing n the rolls, capable of withstanding relatively high temperatures without glazing or charring.

A further object is to provide for convenient renewal or reconditioning of roll surfaces and of very durable character capable of much longer life after such renewal, than the present Wood boards, there being no appreciable wear on the metal lift rod.

A still further object is to so design the engaging surfaces of the lift rod and the rolls as to obtain a high contacting pressure between the rolls and the rod.

Another object is to provide a drop hammer with an effective and inexpensive means for securing the ram lifting rod to the ram, and which is capable of very simple and convenient disconnection of the rod from the ram.

Still further objects are to provide an improved ram elevating mechanism for drop hammers which is made safer by the arrangement of parts so as not to overhang the operators head, is more effective, more dependable and less expensive to maintain than the conventional mechanism employing metallic rolls and Wood boards.

A still further object is to provide an arrangement for distributing and dissipating heat which may be generated by slipping during the acceleration of the same or at the time of first engagement of the rolls with the lifting rod when the ram is being raised.

It is further desirable to provide a ram lifting rod of sufficient rigidity so that it may act as a guide during the blow of the ram and prevent cocking on work eccentrically located on the lower die.

Further objects may become apparent from the following description and the accompanying drawings.

In the drawings:

Fig. 1 shows a schematic View in the nature of a front elevation of a drop hammer embodying one form of the present invention.

Fig. 2 is a fragmentary sectional elevation of a lifting rod and one pair of rolls.

Fig. 3 is an enlarged partially sectional plan view of a preferred form of lifting roll.

Fig. 4 is a perspective view of a preferred form of friction facing material for the rolls.

Fig. 5 is a plan view of a ram for use with a pair of rods.

Fig. 6 is a horizontal sectional elevation of a pair of lift rods and coacting rolls.

Fig. '7 is a fragmentary vertical sectional view showing the rolls positioned in tandem with respect to the rod.

Fig. 8 is a perspective view of a modified form of friction facing material.

Fig. 9 is a View showing an assembled arrangement of segmental friction facing blocks.

Fig. 10 is a radial section through a form of block for the arrangement of Fig. 9.

Fig. 11 is a radial section of another form of block or facing ring which may be a complete unitary ring of molded material.

Fig. 12 is a partially sectional plan view of a modification of the friction lifting rolls.

The present invention constitutes primarily the use of a rigid metallic lift rod preferably presenting diagonal or V-shaped surfaces to the lifting rolls, which have fitting or co-acting surfaces constructed in a novel manner, and so that the friction material on the rolls may most effectively engage the lift rod. Further economies are effected in that a unique arrangement of friction material may be carried out on the disks and which allows for economical and convenient renewal of the surfaces thereof.

As above indicated in the statement of objects,

the present difficulties of the frequent renewal of the wood boards for the lifting of the ram are greatly reduced, particularly in that the frequency and length of time of shut-down, between the times of renewal of the lifting wheel surfaces, is greatly increased over the normal life of the lifting board. The convenience of attaching the lifting rod to the ram or hammer, and convenience of change effected by the change of the lifting wheels for renewal of the friction surfaces instead of the change of the board, compares favorably in the shut-down time of the drop hammer machine.

In carrying out the foregoing and other objects, I prefer the construction and arrangement hereinafter first described. However, various modifications may be made without departing from the scope of the invention as set forth in the appended claims. Certain illustrative modifications are shown in the drawings hereinafter described.

Referring to Fig. l of the drawings, I represents the anvil or base of a drop hammer which supports a pair of laterally spaced and upwardly extending columns 3. Between these columns is the usual ram 5 which is constrained to move vertically between guides 8 on the inner faces of the columns. Secured to the ram 5 is a top die 6 which is adapted to strike a bottom die 9 rigidly fixed to the anvil I in any well known manner.

Mounted on the upper end of the columns is shown a suitable lifter frame 12 in which is carried a pair of lifter rolls I5, hereinafter more fully described. These rolls may be mounted on roll driving shafts 16 which are journaled in roll eccentric bearing housings IT. The eccentric housings are adapted to effect relative movement of the rolls in the frame I2, to cause simultaneous engagement and disengagement of the peripheries thereof with the lift rod l8. This tangential engagement of the rod between said rolls effects the lifting of the ram.

The lower end of the rod I8 is preferably machined to produce a round and gradually tapering surface 20 as shown in Fig. 2, which is driven into a complementary tapering opening 22 suitably formed or machined in the ram 5. Thus the ram is firmly secured to the rod It! by the friction and wedging action of the tapering surface 20 in the opening 22. In use, each blow of the ram tends to drive the rod more firmly into tight engagement.

In Fig. 1 it will be noted that the opening 22 passes vertically through the ram 5 so! as to facilitate removal of the rod therefrom. The rod may be driven out of the ram by removing the top die 6 and placing a drift pin on the lower die in vertical alignment with the opening 22 and allowing the ram to drop on the pin which, upon striking the lower die block 9, will push the rod l8 out of the opening 22.

A preferred form of construction for the lifting rolls is shown in Fig. 3. A suitable hub member 25 has a cylindrical faced wheel portion 21 onto which is shown as fitted a flange sleeve member 30, the flanged portion 3| of which embraces the periphery of the member 21, and an inwardly extending flange portion 32 fits against the side of the hub member 21 and may be secured as by screws 34.

An outwardly extending flange 33 taken with a collar 39 forms a channel shaped carrying member for friction disk members which are built up to comprise a somewhat resilient but highly effective friction gripping surface for engaging the lift rod. A screw as shown at 40 may pass through the flange 33 and the co-acting flangelike collar 39 and through the friction disk members 36. 'These members are preferably of progressively smaller diameter toward the center, and. a middle disk 42 may be of still smaller external diameter as shown. The surfaces 43 are cut or dressed to fit the surface angle of the sides of the lift rod.

In this form of constructing the friction members of the lift wheels, the disks as illustrated in Fig. 4 are preferably of suitable clutch plate or brake shoe facing material, or any material of like character, having characteristics of proper hardness, durability and resistance to high temperatures and pressures while affording the effective friction gripping action on the rod. These disks have openings as at 31 adapted to fit over the flange 3| in the arrangement shown.

When the parts are assembled as described and the hub 25 is keyed to the shaft IS, a pair of these wheels acting to grip the rod from opposite sides as shown in Fig. 2 affords a very effective lifting action, and. upon slight separation the hammer may be allowed to drop while the lift rod is guided between the surfaces 43.

The rod shown is substantially square. Although approximately similar effective results may be accomplished with a round rod, it is not quite as satisfactory nor efficient, and does not afford equal convenience in preparing the gripping surfaces corresponding to the surfaces 43.

Even though such material as I prefer to use for the friction elements is quite costly, the use of diagonal surfaces 43 compensates for this expense. To recondition the worn friction surfaces of such a roll is a relatively inexpensive operation both as to material and maintenance costs. For example, two or more of the central disks 36 may be easily and quickly removed and the same number of new disks placed on the outer sides adjacent the flange 33 and the disk retaining ring member 39 and then the surfaces of the groove are again machined as before.

Modified forms of the friction facing may be effectively employed. One such modification is illustrated in Fig. 8, in which material such as heretofore described instead of being made of separate disks is made in a spiral 42 of sufficient number of turns to fill the space between the gripping flanges of the lift wheel. When in position, the proper facing or grooving of the surface of the wheel may be effected by cutting as before.

Figs. 9 and 10 illustrate a further modification of building up of an annulus of wood blocks 44 which may be arranged in double rows or a pair of unitary complementary rings having beveled surfaces facing inwardly to form the surfaces 43a, (Fig. 10).

In Fig. 11 is shown a still further modified form in which an annulus 45 may be formed or molded of composition of suitable friction material, and which may be carried on the friction Wheels by an arrangement shown in Fig. 3.

Another form of roll which may be employed is shown in Fig. 12 and comprises a wheel having a hub 50, a web portion 52 and a rim 54 with outwardly diverging flanges as at 55 and 56 around the periphery. The flange 56 may be a portion of a ring member 58 separable from the wheel and secured thereto as by bolts 60. In such a roll, these diverging flanges are faced with similarly flanged rings of friction material as at 62, which as before statedfare designed to with- 75 stand severe wear as well as relatively high pressures and temperatures; These rings may be pressed or molded from blanks of the general shape of the disks illustrated in Fig. 4.

The outer portions of the friction facing 62 may be secured to the flanges 55 and 56 by rivets 65, while the inner portions are held in compression between annular parallel surfaces on the ring 58 and the web 52 by the bolts 60. A ring 66 interposed between the facings 62 provides clearance for the corner of the rod [8 as the facing becomes worn. The ring separator 66 is preferably made of metal.

From the foregoing description of the operation of my invention, it will be apparent'that by reason of the diverging surfaces of the groove, the total normal pressure between the outer edges of the friction disks 36 and the flat surface of the rod i8 is definitely greater than the engaging pressure applied to the driving shafts of the rolls.

Applicant is aware that grooved rolls having hard surfaces have been used before in conjunction with square wood rods, the surface of which is definitely softer than the roll surface. In such a mechanism, however, the surface of the wood rod or board Wears more rapidly at the location where the rolls first engage the board to elevate the ram, thus causing an irregular engaging surface, as explained above. He also realizes that fiat rolls have been provided with friction facing, such as rubber, vulcanized to the surface for engaging the board. The boards used withsuch rolls are still not free from localized wear by the rolls and shattering from impact blows. The cost of manufacture and maintenance of such rolls is so far out of proportion to the advantage obtained as to be of little practical value.

In the present invention, however,- the wear is confined to and uniformly distributed around the circumference of the relatively soft friction facing on the rolls while the surface of the hard rod remains substantially unaffected by wear. Thus a smooth and uniform surface is always maintained on the roll as well as on the rod. Obviously my friction facing which is capable of withstanding high temperatures and pressures, is far superior in wearing qualities and effectiveness than rubber vulcanized to the surface of a roll. This lining may be molded or pressed to the desired size and shape ready for assembly or replacement at a relatively small cost.

It will be noted from Fig. 1 that by reason of the relatively large diameter rolls used in the present invention, the area of contact of these rolls on the rod is considerably greater than can be obtained from the usual size rolls. By reason of this larger area of contact, theseirolls offergreater traction on the rod. When used in conjunction with a single rod, the liftrolls may be mounted in the frame I2 in a position so as not to overhang the head of the operator.

With very heavy rams, however, when two or more rods are used, it may be more convenient to mount the lift rolls at right angles to the plane of the guides 8, primarily because of the inherent narrow construction of the upper portion of the ram 5a. In such instances smaller diameterrolls to avoid excessive overhang may be used, which, coupled with the added area of contact obtained by employing two or more rods, more than compensate for the inherent area of contact of small rolls. This will be apparent from examination of Fig. 5 and Fig. 6.

The arrangement of two or more lift rods operating between rolls I5 as shown in Fig. 6, and

the positioning of two or more pairs of rolls as at l5 which are engageable with a single rod I8 as in Fig. 7, illustrate practical constructions which may be employed for elevating heavy rams.

In'Fig. 2 the rod I8 is shown as having a substantially square cross section, although as stated, it is contemplated that bars having other sections may be effectively employed.

The rod I8 may be solid as indicated in Fig. 1. As shown at [8 in Fig. 2, it is made hollow as by a drilled opening I9. It may be made of tubing as at l8 which is plugged at the lower end, as at 2i in Fig. v7, and then drawn to provide a solid portion for fitting the tapered socket of the ram.

An advantage of the hollow rod is to decrease its weight. It also distributes and dissipates the heat generated by the slipping action of the rolls on the rod while the ram is being raised. The opening l9 may'contain a suitable cooling medium for absorbing and distributing the heat throughout the length of the bar. By such cooling action, the hard surface of the rod is further assured.

From the foregoing description, it will be seen that I have provided a novel co-acting lift rod and friction lift wheel construction by which the objects hereinbefore set forth are attained, and difficulties heretofore encountered are avoided Having thus described my invention, what I claim is:

1. In a power operated drop hammer, a device for raising the ram comprising a plurality of driven synchronized rolls having V-shaped grooves of essentially non-metallic, heat resistant, friction material provided in the peripheries thereof, and a rigid metal ram lifting rod of substantially square cross section located tangentially between said rolls and disposed diagonally within the grooves, and the surfaces of the rod which are engageable by the V-shaped grooves being hardened and Wear resistant.

2. In a drop hammer having a frame, upright guides, a ram guided by the guides for vertical travel, a lift member connected to the ram and extending longitudinally of the path of travel of the ram, driven friction lift rolls spaced above the ram, and accommodating the lift member between their peripher-al surfaces in all positions of the ram, said rolls being mounted for limited relative movement toward each other for frictionally engaging the lift member for lifting the ram and away from each other for disengaging the lift member to release the ram, and to assist in guiding the ram when the ram is released, said lift member comprising a rigid metal rod of substantially square cross-section and having hardened fiat longitudinal outer Working faces, the rod being disposed with its diagonal plane normal to the axes of the rolls, and each of said rolls having peripheral working surfaces of tough, essentially non-metallic, heat resistant material angularly disposed to each other and substantially complementary to and fitting adjacent outer faces of the rod.

3. In a drop hammer having a frame, upright guides, a ram guided by the guides for vertical travel, a lift member connected to the ram and extending longitudinally of the path of travel of the ram, friction lift rolls spaced above the ram, and accommodating the lift member between their peripheral surfaces in all positions of the ram, said rolls being mounted for limited relative movement toward each other for frictionally engaging the lift member for lifting the ram and away from each other for releasing the ram, said lift member comprising a metal rod having hardened flat longitudinal working faces arranged in pairs, the faces of each pair being angularly disposed with respect to each other, and each of said rolls comprising axially spaced, radial flanges, coaxial discs of different diameters and comprised of tough, essentially non metallic, heat resistant material, said discs being clamped between the flanges with their peripheral edges defining the said working faces of the roll, said working faces of each roll being angularly disposed to each other and complementary to and fitting the adjacent pair of working faces of the rod.

4. In a drop hammer having a frame, upright guides, a ram guide by the guides for vertical travel, a lift member connected to the ram and extending longitudinally of the path of travel of the ram, driven friction lift rolls spaced above the ram, and accommodating the lift member between their peripheral surfaces in all positions of the ram, said rolls being mounted for limited relative movement toward each other for frictionally engaging the lift member for lifting the ram and away from each other for disengaging the lift member to release the ram, and to assist in guiding the ram when the ram is released, said lift member comprising a rigid metal rod having hardened flat longitudinal working faces arranged in opposite pairs, the faces of each pair being equal in size and angularly disposed with respect to each other, and the intersections of the faces of the respective pairs lying in a common plane normal to the axes of the rolls, and said rolls having peripheral'working surfaces of tough, essentially non-metallic, heat resistant material angularly disposed to each other and complementary to and fitting the pairs of working faces of the rod respectively, and means for effecting relative balanced wedging action between the working surfaces of each roll and the associated working faces of the rod'for rendering the contact pressure therebetween greater than the pressure applied to the rolls.

5. In a drop hammer having a frame, upright guides, a ram guided by the guides for vertical travel, a lift member connected to the ram and extending longitudinally of the path of travel of the ram, driven friction lift rolls spaced above the ram and accommodating the lift member between their peripheral surfaces in all positions of the ram, said rolls being mounted for limited relative movement toward each otherfor frictionally engaging the lift member for lifting the ram and away from each other for disengaging the lift member to release the ram and to assist in guiding the ram when the ram is released, said lift member comprising a rigid metal rod having hardened flat, longitudinal working faces arranged in pairs, the faces of each pair being angularly disposed with respect to each other, each of said rolls having peripheral working surfaces of tough, essentially non-metallic, heat resistant material and being angularly disposed to each other and complementary to and fitting the pairs of working faces of the rod respectively.

6. In a drop hammer having a frame, upright guides, a ram guided by the guides for vertical travel, a lift member connected to the ram and extending longitudinally of the path of travel of the ram, driven friction lift rolls spaced above the ram and accommodating the lift member between their peripheral surfaces in all positions of the ram, said rolls being mounted for limited relative movement toward each other for frictionally engaging the lift member for lifting the ram and away from each other for disengaging the lift member to release the ram and to assist in guiding the ram when the ram is released, said lift member comprising a rigid metal rod having hardened flat, longitudinal working faces arranged in pairs, the faces of each pair being angularly disposed with respect to each other, each of said rolls having peripheral working surfaces of tough, essentially non-metallic, heat resistant material and being angularly disposed to each other and complementary to and fitting the pairs of working faces of the rod respectively, and each pair of roll working faces and associated working faces of the rod being configured with respect to each other to eliminate relative contact at the zone of their respective intersections when the rolls and rod are frictionally engaged.

'7. In a drop hammer having a frame, upright guides, a ram guided by the guides for vertical travel, a lift member connected to the ram and extending longitudinally of the path of travel of the ram, driven friction lift rolls spaced above the ram, and accommodating the lift member between their peripheral surfaces in all positions of the ram, said rolls being mounted for limited relative movement toward each other for frictionally engaging the lift member for lifting the ram and away from each other for disengaging the lift member to release the ram, and to assist in guiding the ram when the ram is released, said lift member comprising a rigid metal rod having hardened longitudinal working surfaces, said rolls having-peripheral working surfaces of tough, essentially non-metallic, heat resistant, friction material, said roll working surfaces being in embracing relation to rod surfaces and said rod and roll working surfaces being configured-relative to each other to effect uniformly distributed contact pressure therebetween throughout the width of said surfaces and with a total contact pressure greater than the total pressure applied on the rolls.

8. In a drop hammer having a frame, upright guides, a ram guided by the guides for vertical travel, a lift rod connected to the ram and extending vertically upwardly therefrom, driven friction lift rolls having circumferentially grooved peripheral surfaces and carried by the frame and spaced above the ram, and accommodating the lift rod between their peripheral surfaces in all positions of the ram and rolls, said rolls being mounted on the frame for limited relative movement toward each other for frictionally engaging the lift rod between their peripheral surfaces for lifting the ram, and away from each other for disengaging the lift rod to release the ram, said lift rod comprising a hard, wear resistant material and being rigid for resisting bending and fi'exure in all directions, the peripheral surfaces of the rolls being configured to fit substantially the cross section of the rod and to limit the disalignment of the rod to a sufficient degree to prevent whipping of the rod during operation of the ram, and the rod engaging peripheral surfaces of the rolls being comprised of hard, tough, heat and wear resistant, essentially non-metallic, friction material.

1 WILLIAM W. CRILEY.

Images