US449121A - Road-cart - Google Patents

Description

(No Model.) 2 sheetssheet 1 s. B. IRWIN.

ROAD CART.

'No. 449,121 Patented Mar. 31', 1891.

. flyentor (No Model.) 2 Sheets-Sheet 2.. S. B. IRWIN.

. ROAD OART. No. 449,121. Patented Mar. 31,1891.

' ja adv? MM @W MK 1 5 "cam Finns-0a., mwnrumm, wunmn'ron n c UNTTED STATES PATENT @FFICE.

SAMUEL B. IRWIN, OF \VES" HEBRON, NElV YORK.

ROAD-CART.

SPECIFICATION forming part of Letters Patent No. 449,121, dated March 31, 1891.

Application filed July 24, 1890. $erial No. 359,820. (No model.) A

To all whom it may concern.-

Be it known that I, SAMUEL B. IRWIN, a citizen of the United States, residing at West Hebron, in the countyof Washington and State of New York, have invented certain new and useful Improvements in Road-Carts; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improvement in road-carts, the object thereof being to simplify, perfect, and greatly improve the construction of carts or vehicles of this kind; and the invention consists in the construction, arrangement, and combination of parts, substantially as will be hereinafter described and claimed.

In the accompanying drawings, illustrating my invention, Figure 1 is a sectional side elevation on the line so a; of Fig. 2. Fig. 2 is a top plan View of my improved road-cart. Fig. 3 is a detailed side view showingcertain features of construction. Fig. 4 is an enlarged view of the clip which holds the spring beneath the cross-bar, said spring and cross bar being shown in section. Fig. 5 is an enlarged detail view of one of the devices that are attached to the vehicle-frame and connected to the inner ends of the springs. Fig. 6 is an enlarged section on the line y y of Fig. 1. Fig; 7 isa detail plan and edge view of one of the plates that are used with the elliptical springs.

Like letters of reference designate corresponding parts throughout all the different figures of the drawings.

B B denote the wheels, B the axle, O the seat, D the forward portion of the body or foot rest, and b Z; the thills or shafts, of a twowheeled vehicle or road-cart, and c the crossbar connecting these thills, and (Z the whiffletree pivoted on the cross-bar, these parts being shown here for the purpose of illustration, in order to indicate how my improvements are applied thereto and operatively arranged in connection therewith for the purpose of perfecting, completing, bettering, and making more efficient the entire structure of the ve hicle.

Of course my improvements are applicable to road-carts of many and various kinds, and the special form of cart which is shown here is given by way of example merely.

A A designate two spiral springs located alongside of the thills b 1) between the same and underthe cross-bar 0 near the ends thereof.

This is the preferable position of these springs,

although this exact location may be changed, if desired. The springs A A are simple spirals having their ends preferably somewhat conical or of less diameter than the central portions of the springs, and the extreme ends of the wire which forms the springs are provided with loops or eyelets a a of a suitable size to admit of the passage therethrough of a suitably-sized bolt. The front end loops a a of the two springs are connected by bolts to the small angle-irons G G, which are fastened to the under sides of the thills b I), respectively, as shown, said angle-irons being preferably slotted for the passage through them of fastening-screws, by means of which said irons are secured to the thills. The slots permit the adjustment of said irons. These springs are held up against the under side of the cross-bar c by means of clips 6. This arrangement is shown in the enlarged view of Fig. 4. The ends of the clip pass up through the bar a and are secured by nuts on the top of the bar. act easily, these clips 6 0 should loosely encir cle the springs, each of which lies in its respective clip as on a bed, the clip serving simply to support the spring, but not binding itorhinderingitsaction If the spring yields too easily, it is obvious that the clip can be tightened by adjusting the nuts on the ends of the clip, and thus throwing the springs firmly against the cross-bar and lessening its flexibility of action. By increasing or diminishing the length of that portion of the spring lying on the side of the clip next to the cartbody, and to which the front end of the cartbody is attached, any desired degree of flexibility of the spring maybe attained, and this adjustment can be very easily made by moving the aforesaid iron G, to which the front end of the spring is connected, the movement being either backward or forward beneath the thill. If only a small portion of the coil is allowed to reach beyond the clip--that is, in front thereof-the spring will be compara- In order that the springs may tively stiff, while it a larger portion lies on that side the spring will be proportionately limber. The front end D of the vehicleframe is connected to these springs by irons F F, which are shown very clearly in the detail view in Fig. 5. These irons are angle: irons of suitable form, and they are secured to the sides of the body 13. The outer ends of the irons are fastened to the springs A A by means of bolts ff, which pass through perforations in the irons and through the rear eyes a. All this is clearly shown in Fig. This connection provides a pivotal joint, so that the parts may move easily with relation to each other. Thus it will be seen that the forward end of the cart-body is pivotally con nected to springs which are supported beneath the cross-bar and whose forward ends are connected to irons on the thill. ward end of the cart-body has therefore a yielding support.

It may be here remarked that a coiled or spiral spring has a double action-that is, it has one action by which it yields to a straight or direct pull, and this action maybe termed its direct action, and it has another action by which it bends upon itself, and this action may be termed its lateral action. It is the lateral action which mainly comes into play when the spring is used in the manner that I use it in connection with the front end of the road-cart, although the lateral and the direct actions of the supporting-springs are combined in a constantly-varying degree, according to the amount of strain.

\Vhen a cart or similar vehicle is properly balanced,the center of gravity will fall sufficiently far behind the axle to aliowthe thills to be carried at the level which they occupy when in the shaft-tugs. The axle is the center upon which the body turns when said body is secured in place by means of clips and springs, as in the case in the example of vehicle we are now considering. Now if we suppose that the center of gravity is behind the axle, the back part of the body, in moving backward and downward, will describe an arc of a circle of which the axle is the center, and at the same time the front end of the body will move upward and backward, describing an arc of a greater circle of which the axle is also the center. From this it will be evident that while the first action in the coil is mainly lateral the direct action comes more and more into play as the traction is increased. The flexibility of the coil readily admits of this action, which may be said to take place in a varying oblique manner. The advantage of the coiled springs consists in the fact that when they are used in this way a short and very effective spring device is obtained, and one that readily adapts itself to the ever-varying movement of the front end of the body, which movement, as has been already exu plained, is constantly taking place in an arc of a circle of which the cart-axle is the center. The point aimed at in the construction of ve- The forhiclcs of this kind is to secure an extremely sensitive and yielding spring, so that the law of inertia may be availed of in the construction of a road-cart, so as to limit to the least; possible degree the unpleasant horse motion, as it is called, which is constantly tak ing place during the progress of the cart. Obviously if two bodies have a solid connection between them one cannot be moved without a corresponding movement of the other; but if they are connected by a yielding and extremely sensitive spring one of the parts, particularly if it be lighter in weight than the other, may be moved through a limited space without moving the other at all. Therefore the body of a cart with one or more persons therein may be considered to be the heavy body and the thills as the lighter body, the cart and thills being united by a very flexi ble coil. These thills are secured to the axle by a common buggy shackle, so that any horse motion that is communicated to the body must take place through the coils already described. \Vhen the horse stops, the thills descend or drop to a certain extent. If the body is united or joined to the thills or cross-bar by a solid or a pivotal joint, it must of necessity move correspondiu gly. The front end of the body must move downward and forward, and the seat moving in the part of a circle of which the axle is the center will move almost directly forward. When the horse starts or goes forward, the movements are reversed, for the thills rise, the front end of the body of the cart moving upward and slightly backward in the are of a circle already mentioned, and the seat moves almost directly backward. This back and forth movement constitutes what is referred to in speaking of the unpleasant horse motion. \Vhen the body and the thills are connected by means of an extremely sensitive or yielding coil, it will be seen that when the horse steps the thills descends as before and the strain of moving the body comes upon the yielding spring, which yields to the strain. If the lowered position of the thills should be kept up for any length of time, the springs by virtue of their elasticity would draw the body forward and downward and the former relation of the body and thills would be restored; but before the elastic action of the springs has time to come into play the horse will move forward, thus rising and taking another step, and the thills are raised above the mean level, and any movement of the body is arrested or prevented. Of course every succeeding step and the movements accompanying it are but a repetition of what I have just described. It may be estimated that a horse moving at a moderate rate when trotting takes one hundred and fifty steps per minute. The thills make of course the same number of movements, but only through a very limited space, and as their connection with the body is by a very yielding spring the spring yields and the movements are so rapid that theyare lost in the spring and not communicated to the body. Thus united the thills move too fast for the body, and by taking advantage of the law of inertia the un pleasant horse motion is gotten rid of.

The location of the spring, as I have already once intimated hereinabove, may be changed. They maybe placed under the thill under the cross-bar, in which case they reach from the [O thills toward the body, or they may reach from the thills alone toward the body; but in any of these positions the action is the same. The form of coil may also vary and the attachments at each end thereof may he changed without departing from the invention.

lVhenever the front end of the body of a cart is connected to the cross-bar or thills by means of any kind of springs, there is a tendency in the cart-body to move or lurch 2o slightly forward just at the time when the movement of descent on the supportingsprings is completed. This movement is very similar initsresults to thehorse motion whichI have above described as being com municated z 5 to the cart-body from the thills. In order to effectually overcome this trouble, I provide straps g g. These straps connect to the front end of the cart-body D, near each side thereof, and also to the cross-bare. The straps buckle 3 at the middle, so that their length maybe adjusted as maybe desired. The straps should be loose enough, so that they will not interfere with the descent of the body upon the springs, but not long enough to allow of motion beyond this. Thus these straps prevent or arrest the lurching motion. Experience will dictate as to the adjustment of the length of the straps. If they are too tight, the result will be to communicate the thill motion to the 4 body, and if too loose they will permit of the unpleasant lurching motion.

hen the body of a cart or similar vehicle is supported by means of a pair of elliptical springs placed crosswise upon the axle, if the seat is placed evenly upon the springs the center of gravity will fall in front of the axle and too great weight will fall upon the back of the horse. To obviate this trouble, the spring-bars must be lengthened posteriorly and the seat moved back upon them, so as in a measure to overhang the springs behind; but when this is done it causes the weight of the person or persons occupying the seat to come mainly upon the springs just at thepoint Where the spring-bars at the rearcome in contact with the springs. This unequal distribution of the weight upon the. springs causes an unequal action, for the back parts of the springs yield greatly and constantly, while the forward portions thereof yield very little.

This causes what maybe termed a rolling motion of the seat. The back partthereof describes an arc of a circle which has its center somewhere in the ellipse formed by the springs. This motion is as unpleasant as the horse motion and is hardly distinguishable therefrom. To obviate this I arrange and construct the spring-bars so that when they are placed upon the springs they come in contact with them rearwardly only as far back as the center of the springthat is to say, they are placed upon the spring forward of a line drawn perpendicularly through the middle portion of said spring. This is shown in Fig. By this arrangement the weight must of necessity come upon the centerof the spring, and the descent of the same is practically vertical. When this is done, however, nearlyall of the weight comes upon that point of the spring which has been weakened by having therein the hole for the bolt which holds the leaves of the springs together, and in practical use I have found that the spring kept constantly breaking at this point. In order to obviate this, I provide a plate of iron II, made just as wide as the spring and having its extremities made each in the form of a T, as 72, said plate being provided throughout with suitable holes orperforations forthe passage of the bolts for securing the plates upon the spring, the. The plate II will preferably be equal in length to that part of the spring-bar which comes in immediate contact with the spring. Itshould be so placed as to reach backward as far as that part of the spring-bar which is in contact with the spring reaches forward.

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

1. In a road-cart or other vehicle, the combination, with the thills and the body, of springs connecting the thills with the body, said springs being supported by means of clips secu red beneath the cross-bar, and straps attached to the forward end of the body and the cross-bar.

2. In a road-cart, the combination,with the thills or shafts, the cross-bar having clips, and the cart-body, of the springs held within said clips, pivotally connected to the cart-body and also connected to the thills, substantially as described.

3. In a road-cart, the combination of the cart-body and the thills, the springs consisting of longitudinalcoils, the clips surrounding said springs and connected to the crossbar for the purpose of supporting the springs, the irons for connecting the ends of the springs to the thills, and the irons for 0011- necting the opposite ends of the springs to the body, substantially as described.

at. The combination, with the thills and the cart-body, of the intermediate springs supported by the cross-bar, said springs having the wire of which they are composed formed at each end with loops or eyes, the irons on the thills bolted to the eyes on one end of the springs, and the irons secured to the body and pivotally connected to the other ends of the springs.

5. In a road-cart, the combination of the TOO thills, the cart-body, the coiled springs 0on nected at one end to the thills and atthe i the other end to the thiils and having both :1- ili'Oi'tlhitllli direct motion, and the adjustubie strnps fastened to the eart-body at its forward end and also to the crossbar.

In testimony whereof I zti'fiX my signzttu re in In presence of two witnesses.

SAMUEL l3. I'INVIN.

other end to the em't-hody,sztid springs being supported by the Cl'OSS-bfll',tl1(1' the straps secured at one end to the forward part of the body and at the other end to the cross-bar, 5 substantially as described.

6. In a road-cart, the combination of the thills, the cart-body, the CIOSSbZli having clips, the springs supported by said eiips, said springs being pivotally connected at one end is to the cart-body and adjustnhiy connected at Witnesses:

(I. A. BEAlTIE, J. M. WALSH.

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