US2228962A

US2228962A - Claw bar

Info

Publication number: US2228962A
Application number: US311649A
Authority: US
Inventors: Maney Thomas
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-12-29
Filing date: 1939-12-29
Publication date: 1941-01-14
Anticipated expiration: 1958-01-14

Description

T. MAN EY Jan. 14, 1941.

CLAWBAR Filed Dec. 29, 1959 Patented Jan. 14, 1941 UNITED STATES PATENT OFFICE.

6 Claims.

My invention relates to an improvement in clawbars, designe-d toy lift railway spikes vertically.

The object is to provide a bar so designed that it will not offer any disturbing contact with the spike since its design and dimensions have been carefully and precisely engineered to prevent this.

My invention consists of means whereby force is applied to the under side of the spike head at the very beginning of the pull at a predetermined point, at one side of the vertical central axis of the spike, whence it shifts so that at the end of the movement of the bar the force is applied at a point approximately in the center line or longitudinal axis of the spike shaft.

In the accompanying drawing:

Fig. 1 is a top plan View showing the claw beneath the spike head and the shaft of the spike in dotted lines;

Fig. 2 is a View in side elevation showing the position of the claw bar at the start of the pull;

Fig. 3 is a side view showing the position of the claw bar in one of the positions during the raising of the spike, the handle of the claw bar being broken away; and

Fig. 4 is a view from the front with the claw applied beneath the head, and the lower end of the spike broken away.

The numeral I represents the handle of the claw bar, the lower end of which is curved to form a base-arc 2, upon which it is adapted to rest and rock on a support such as a tie-plate 3, as illustrated in Figs. 2 and 3. The upper edge 4 of the claw bar is termed the upper arc.

My improved bar is constructed to lift the spike from semi-circular tips of the claw, throughout, and these tips are so made as to best receive this inevitable burden, thus affording a line instead of just a point of bearing. Since it is the shaft of the spike that must be withdrawn from the timber, and as the head of the spike overlaps the rail and extends inwardly for a distance greater than the total width of the shaft of the spike, it is a matter 0f prime importance as to just where under the head of the spike the power should be exerted. If the power is exerted at the extreme -tip of the head bill, or .anywhere outside of the shaft of the spike, the result necessarily would be an eccentric pull, which would force the shaft to lateral bearing, add to the normal resistance, and bend the spike shaft.

Therefore, it is desirable- First, to form the points or tips of the claws, so that they may approximately t the under slope of the spike head at all stages of the with- (Cl. ZIM-25) drawal, in order that they may oiier the least friction in sliding or rotating, and consequently bear the least subsequent wear or deformation. For these reasons, the tips o-f the claws are made semi-circular in cross-section and conical as to width.

Second, the points or tips must engage the under side of the spike head somewhere between the coniines of the shaft, in order to avoid the objectionable eccentric pull just mentioned, and this is accomplished by a stop or relative position of the rear wall of the slot in the claw of the bar, and the rear of this slot is designed to bear a denite relationship to the length of the claw.

This slot is indicated by the numeral 5, the rear 6 of which is termed a stop, as indicated in full lines in Fig. l, and indotted lines in Figs. 2 and 3. The numeral 1 represents curved and conical surfaces extending from the outer edges 8 of the claws to the side edges of the slots 5, as indicated in Figs. 1 and 4, and constitutes what I term a line of bearing.

The letter A, represents the point ci contact; and the line A extending therebelow, the direct line of pull at the beginning; and the letter B, the point of contact with the spike-head at the end of the operation, which is approximately in direct line with the central longitudinal axis of the spike S.

In operation, the claw is pushed under the spike-head until point C contacts the spike S, it having a rolling contact. The spike is then raised by successive stages with each new position of the bar I. To effect this order of movement, the slot 5 is made in the bottom of the clawhead, to receive or straddle the spike in its vertical position as the bar rotates about the line of y bearing under the spike-head, while rocking on the base arc 2 which forms a fulcrum as indicated in Figs. 2 and 3. The short radius of the base arc 2 gives a very wide difference between the two arms of the lever resulting in a very high multiple power.

The salient'features of my invention are:

(1) The stop C which prevents the points or tips of the claw being inserted under the spike head further than the desired distance.

(2) The elongated slot at the bottom of the claw-edge extending from C to G as shownin dotted lines in Figs. 2 and 3, to aiiord clearance to permit the bar to move freely under the spike head.

(3) The tips of the claw in the form of cone and arcs, which bear againts the under surface of the head H of the spike S.

Prior patentees speak of a seat for the spikehead, between the claws, but it is obvious that as soon as the lift starts, any such seat would be lost by the angular change between bar and spike head, if the spike is to be drawn vertically, which is the desideratum, and that the lifting claws, under the spike head, would then have only a point of engagement. It is in recognition of this fact that my bar is designed and constructed to lift from semi-circular and conical tips of the claws throughout.

I claim:

1. A claw bar designed to lift a spike vertically, it being provided with curved lines of bearing on opposite sides of the spike-head, which lines move from a line of contact and line of pull extending approximately parallel with and at one side of a line extending longitudinally through the center cf the spike.

2. A claw bar designed to lift a spike vertically, it being provided with curved and conical lines of bearing on opposite sides of the spike-head, said lines extending outwardly in opposite directions from the location of the spike-head, which lines move from a line of contact with the spike and a line of pull extending approximately parallel with and at one side of a line extending longitudinally through the center of the spike.

3. A claw bar having a base arc adapted to rock upon a suitable support and divided at its forward end by a slot to provide two claws and a stop, said claws terminating at their tips in curved and rounded lines of bearing, which contact and move against the lower surface of the head of the spike from a point out of its longitudinal center to a point at the longitudinal center of the spike, whereby the main lifting pull is in substantially a direct line through the longitudinal center of 'the spike.

4. A claw bar having a base arc adapted to be rocked on a suitable support and divided at its forward end by a slot to provide two claws and a stop therebetween, the claws terminating at their tips in curved and rounded bearing surfaces which are approximately semicircular in crosssecticn and conical as to width, which bearing surfaces conform to the lower surfaces of the head of the spike, and contact and move against said surfaces from a point initially out of the longitudinal center to a point approximately at the longitudinal center of the spike, whereby the main lifting pull of the spike is in a substantially direct line through the longitudinal center of the spoke.

5. A claw bar having a base arc adapted to be rocked on a suitable support, the operative end of the claw being divided, the back wall of the division forming a pointed and elongated wall, the point and the wall positioned and adapted to successively engage the back of the spike during the different stages of the pulling of the spike.

6. A claw bar having a base arc adapted to be rocked on a suitable support, the operative end of the claw being divided, the back wall of the division forming a pointed and elongated wall, the point and the wall positioned end adapted to successively engage the back of the spike during the diiTerent stages of the pulling of the spike, and the extreme or tip ends of the claw terminating in bearing surfaces which are approximately semi-circular in cross-section and conical widthwise, whereby to present successive straight lines of bearing which contact and approximately t the under side of the spike head as the base arc of the claw is rocked upon its support.

THGMAS MANEY.