US3289813A

US3289813A - Holmes etal bumpers

Info

Publication number: US3289813A
Authority: US
Publication date: 1966-12-06
Anticipated expiration: 1983-12-06

Description

Dec. 6, 1966 G. D. HOLMES ETAL 3,289,813

BUMPERS 5 Sheets-Sheet 1 Filed March 1.2, 1965 FIG].

Iruvznrroes GORDON D4 HOLMES & BY WILLIAM J. RICHMOND j 2 VA on Dec. 6, 1966 G. D. HOLMES ETAL 3,289,813

BUMPERS Filed March 12. 1965 5 Sheets-Sheet 2 INVENTOES GORDON D. HOLMES 8- By WILLIAM J. RICHMOND T BR ATToeuEv 1966 G. D. HOLMES ETAL 3,

BUMPERS Filed March 12. 1965 5 Sheets-Sheet 4 INVENTOES GORDON D HOLMES & By WILLIAM JRICHMOND THEIR A'Y-rocausv Dec. 6, 1966 Filed March 12, 1965 G. D. HOLMES ETAL.

BUMPERS 5 Sheets-Sheet 5 Imvam'osas GORDON D HOLMES & WILLIAM J RICHMOND THEjR ATTQRNEN United States Patent 3,289,813 BUMPERS Gordon David Holmes, Worksop, and WIIham James Richmond, Shetfield, England, assignors to Davy and United Engineering Company Limited, Sheffield, England Filed Mar. 12, 1965, Ser. No. 439,321 Claims priority, application Great Britain, Mar. 16, 1964, 11,078/64 7 Claims. (Cl. 198-427) This invention relates to bumpers; for example, when a steel slab is discharged from a re-heating furnace it slides down a ramp onto a roller table and its travel across the table is arrested by a bumper.

The conventional furnace bumper is usually an expensive mechanism, combining castings and fabrications, and incorporating spring or hydraulic shock absorbers. Such a structure is unable to withstand repeated impact and associated shock waves and as a result it invariably breaks down after limited service, involving lengthy and expensive renovations.

According to the present invention a bumper comprises an impact receiving member suspended from a suspension member and having a mass connected thereto by connecting means such that movement of the impact member from its rest position moves the mass upwards.

In a preferred form the mass is arranged to move up and down and inclined plane, so that friction between the mass and the inclined surface produces a damping effect. The connecting means preferably provide a mechanical advantage.

In one form the impact member is secured to intermediate points of a plurality of suspension members, in the form of ropes, chains or wires, one end of each suspension member being fixed and the other end being connected to the mass through a pulley system. In another form the connecting means comprise a bell crank system.

The impact member is preferably a horizontal elongate plate with its length normal to the axes of the rolls of a roller table and its lower edge scalloped to suit the table rollers and allow a part of the impact member to be below the top of the rollers. This obviates any possibility of an impacting slab getting underneath the impact member. Preferably the masses are located behind the table drive box to give freedom from scale and easy access.

Two embodiments of furnace bumper in accordance with the invention will now be described by way of example only, with reference to the accompanying drawings of which:

FIGURE 1 is a front elevation of a first furnace bumper,

FIGURE 2 is a section on the line II-II of FIGURE 1,

FIGURE 3 is a plan view of an alternative embodiment of a furnace bumper,

FIGURE 4 is a section on the line IVIV of FIG URE 3, and

FIGURE 5 is a section on the line V-V of FIG- URE 4.

Referring to FIGURES 1 and 2, a roller table 12 having rollers 13, is arranged to receive from a furnace (not shown) slabs 14 travelling in the direction of arrow V. A bumper 15 is arranged to arrest the slabs on the roller table.

The bumper 15 comprises an elongate rigid impact receiving member in the form of a plate 16, adjacent to the edge of the roller table, and having its length normal to the axes 17 of the rolls 13. The lower edge 18 of the impact plate 16 is scalloped to suit the table rollers and allow a part of the plate to be below the top of the rollers.

Patented Dec. 6, 1966 The impact plate 16 is suspended from four

flexible suspension members

20, 21, 22 and 23, in the form of wire ropes. These may alternatively be chains or the like. The upper end of each rope is pivotally attached at 24 to a support structure, an intermediate point 25 of each rope is secured to the back of the impact plate, that is the side remote from the impacting face 26, and the lower end 27 of each rope is pivotally secured at 28 to a pulley block 30.

Between the impact plate and its pulley block, each rope passes betwen the table rollers and through a pair of guide pulleys 31, 32, pulley 31 being ambushed between fianges 33 of pulley 32.

Other ropes 34 pass over pulley wheels 35 of each of the pulley blocks 30, one end of each rope 34 being pivotally secured to the foundations 36, and the other end being attached to a mass 37. In the system shown there are two masses 37a, 3712, the weight of mass 370 being carried by

ropes

20 and 21, and the weight of mass 37b being carried by

ropes

22 and 23.

Air cylinders (not shown) may be mounted on the supporting framework or on the table drive box behind the impact plate to restore the plate to its neutral position in the event of a slab sticking on the roller table after striking the plate.

In operation a hot slab is ejected from a furnace, slides across the roller table in the direction of arrow V, and strikes the plate 16. The plate is displaced horizontally, thus inclining the suspension ropes and lifting the pulley block 30 through a distance proportional to that horizontal displacement. Because of the pulleys 30 the masses are lifted twice as far as the pulley blocks to obtain a mechanical advantage. The effect of this is to transform the kinetic energy of the slab (minus any impact slab deformation or friction losses) into potential energy in the masses 37. The masses then fall again returning the plate to its neutral position and pushing the slab back to the central position on the table. This last phase is assisted, if necessary, by air cylinders which (though not connected to the plate), can push on the back of the plate. The pulleys 31, 32 guide the ropes and serve to control the masses.

The bumper shown in FIGURES 3, 4 and 5 has a similar impact plate 16 arranged at one side of a furnace delivery roller table 12 having rollers 13. The back of the impact bar is secured as in the embodiment of FIG- URES 1 and 2 to intermediate points of six wire ropes 38 the upper ends of which are pivotally secured at 39 to an overhead support 40 and the lower ends of which are pivotally secured at 41 to one arm 42 of a bell crank mechanism 43. An intermediate part 44 of the bell crank mechanism is pivotally mounted on the support 45 and the other arm 46 of the bell crank mechanism is pivotally secured to a horizontal connecting link 47. The other end of the connecting link is pivotally secured at 48 to one arm 50 of a second bell crank mechanism 51. An intermediate part 52 of the bell crank mechanism 51 is pivotally mounted on the support 45 and the other arm 53 of the mechanism 51 extends into a pocket 56 in a mass 57, and has two arcuate bearing surfaces 58, 59 bearing against the upper and lower sides of the pocket respectively. As best seen in FIGURE 3 there are three:

large masses

57a, 57b and 570 each of which has two pockets 56 into which an arm 53 of a bell crank lever associated with a different rope 38 extends. Each mass 57 is arranged to slide up and down inclined plane surfaces 60 of a pair of supports 61, mounted on a foundation 62. The friction between the mass and surfaces 60 increases the effectiveness of the bumper both by reducing the stroke of the impact plate, and introducing a damping effect which reduces the amount by which the slab is thrown back.

The roller table drive box is shown at 63 and it will be seen that the horizontal link 47 passes under this drive box so that the masses 57 and slides 61 are behind the table drive box giving freedom from scale and easy access.

In operation when a slab hits the impact plate 16 driving it from its rest position shown, with the ropes 38 vertical, the movement of the plate 16 acts through the bell crank mechanism and link to drive the masses 57 up the surfaces 60, thus converting the kinetic energy of the slab to potential energy of the masses and frictional losses at the slides. The relative lengths of the arms of the bell cranks are designed to give a mechanical advantage as in the pulley block arrangement. The masses then fall gradually to their original position pulling the slab back to the centre of the table.

The advantages of these designs are that there are no welds directly subjected to impact; the bumper is cheaper to manufacture and maintain than conventional bumpers; spare suspension ropes cost little and are quickly changed; little expensive machining is required, and shock loads are confined to a robust impact member. The loads in the other parts of the device are gradually applied.

In accordance with the provisions of the patent statutes, we have explained the principle and operation of our invention and have illustrated and described what we consider to represent the best embodiment thereof. However, we desire to have it understood that within the scope of the appended claims, the invention may be prac ticed otherwise than as specifically illustrated and described.

We claim:

1. A bumper comprising a support, a plurality of flexible suspension members, an impact receiving plate secured to said flexible suspension members intermediate their ends, the upper ends of said flexible suspension members being secured to said support, a mass, connecting means for connecting the mass to the lower ends of said flexible suspension members such that movement of the impact receiving plate from a rest position moves the mass upward.

2. A bumper according to claim 1 in which the connecting means includes a device having a mechanical advantage to increase the effective weight of the mass.

3. A bumper according to claim 1 in which the lower ends of the suspension members carry pulleys and the mass is connected to ropes or the like passing over the pulleys.

4. A bumper according to claim 3 including guide means associated with each suspension member located below the impact plate for guiding it in its movement.

5. A bumper according to claim 1 in which the connecting means between each suspension member and the mass comprises a first pivotally mounted bell crank mechanism having one arm pivotally connected to the suspension member and the other arm pivotally connected to one end of a link, a second pivotally mounted bell crank mechanism having one arm pivotally connected to the other end of the link and a second arm in contact with the mass.

6. A bumper according to claim 5 in which the second arm of each second bell crank mechanism extends into a pocket in the mass and has bearing surfaces pivotally contacting the upper and lower walls of the bore.

7. In combination with a slab furnace delivery table having rolls adapted to support workpieces and drive means for at least some of the rolls arranged on one side of said table, a bumper comprising a support, a plurality of flexible suspension members having one end connected to said support, an impact receiving plate extending normal to the axes of the rolls and above the level of the rolls arranged to be engaged by workpieces supported by said rolls and being connected to said flexible suspension members intermediate their ends, a weighted member connected to said flexible suspension members and arranged below the rolls, said flexible suspension members extending through the table having their upper ends secured to said support above the table and their lower ends eifectively connected to said Weighted member located behind said drive.

References Cited by the Examiner UNITED STATES PATENTS 829,580 8/1906 Folsom 273-55 2,258,802 10/1941 Pearlman 73-12 X 2,803,463 8/1957 Congelli 198-29 X 3,085,659 4/1963 Ashmead 10425O X FOREIGN PATENTS 32,217 2/ 1934 Germany.

EVON C. BLUNK, Primary Examiner.

SAMUEL F. COLEMAN, Examiner. A. L. LEVINE, E. A. SROKA, Assirtrmt Examiners.

Claims

1. A BUMPER COMPRISING A SUPPORT, A PLURALITY OF FLEXIBLE SUSPENSION MEMBERS, AN IMPACT RECEIVING PLATE SECURED TO SAID FLEXIBLE SUSPENSION MEMBERS INTERMEDIATE THEIR ENDS, THE UPPER ENDS OF SAID FLEXIBLE SUSPENSION MEMBERS BEING SECURED TO SAID SUPPORT, A MASS, CONNECTING MEANS FOR CONNECTING THE MASS TO THE LOWER ENDS OF SAID FLEXIBLE SUSPENSION MEMBERS SUCH THAT MOVEMENT OF THE IMPACT RECIEVING PLATE FROM A REST POSITION MOVES THE MASS UPWARD.