US767772A - Connecting-rod. - Google Patents

Description

PATBNTED AUG. 16, 1904.

C. M. SPALDING. CONNBGTING ROD.y APPLICATION FILED FEB. 24, 1903.

No MODEL.

Fig.

Chester mpaldng. by M,;

UNITED STATES Patented August 16, 1904.

PATENT OFFICE.

CHESTER M. SPALDING, OF SCHENECTADY, NEV YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ooNNECTlNe-ROD.

SPECIFICATION forming part of Letters Patent No. 767,772, dated August 16, 1904.

Application filed February 24, 1903. Serial No. 144,653. (No model.) Y

To all whom it may concern: Y

Be it known that I, CHESTER M. SPALDING, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and usefulV ularly relates to such connecting-rods as are used in air-compressors or the like.

In the application of electrically-driven aircompressors to railway-work, especially for use in air-brake systems, great diiiiculty and consequent inconvenience has been experienced due to the vibration of the compressor while operating. In air-compressors in which the driving-motor is directly connected by means of a connecting-rod to the plunger or piston of the air-compressor there is considerable strain on' the connections between the crank-pin on the armature-shaft and the connecting-rod, as said rod reciprocates while the compressor is in action. Consequently there is considerable wear in the bearing in the rod in which the said pin operates. This wear soon causes a certain amount of lost motion between the pin and the connectingrod, allowing a free movement of said pin in its bearing at each end or approximately at each end of the stroke of the compressor-piston, thereby causing considerable vibration and noise. .If it is attempted to prevent this lost motion by fitting the crank-pin very tightly in its bearing when the compressor is'first assembled, there will be a gripping and clamping action of the different parts of said bearing after it has been running a short time, due to frictional heating. The same statements apply equally to the other end of the connecting-rod, which carries a bearing in which a pin or shaft which is fastened to the piston of the compressor operates.

The object of my invention is to reduce the vibration due to the causes above enumerated, thereby reducing the noise and increasing the efciency and the smoothness with which the compressor may be run.

In the accompanying drawings, which illustrate the preferred embodiment of my invention, Figure l represents a longitudinal section through a double-acting direct-connected air-compressor driven by an electric m0- tor and to which my improved connectingrod is applied. Fig. 2 is a perspective view of the connecting-rod. Fig. 3 is a section through the said connecting-rod on the line 3 3 of Fig. 2, and Fig. 4 is a detail of the connecting-rod.

Referring now to Fig. l, A represents the casing of a motor of the inclosed type. Fastened to said casing A are two cylinders Cr of the air-compressor, the said cylinders being provided with external circumferential ribs g to radiate the heat of the air compressed in the cylinders. rPhe two cylinders are in line with each other, their axes being at right angles to the axis of the armature-shaft C and intersecting it at a point beyond the end of the journal C about half the length of the crank-pin D. 1n each cylinder is a piston H, the two being connected by upper and lower tie-bars 7L, preferably cast integral with the pistons. One of said pistons H carries the wristpin L, whose axis is transverse to that of said piston and is parallel to the axis of the armature-shaft. The connecting-rod P is pivotally connected at one end to said wrist-pin /L anfv at the other end to the crank-pin D. The heads G' are preferably secured by means of the screw-bolts G2. Each head carries one or more inlet-valve chambers N and one or more outlet-valve chambers N. The air drawn in through the inlet-valves and compressed in the cylinders flows through the outlet-valves into a passage K and thence to a delivery pipe.

The specific form of air-compressor herein shown and described does not constitute any part of my invention, since the same forms the subject-matter of a copending application of Asa F. Batchelder, Serial No. 74,244, filed September 3, 1901.

To take up the wear between the bearings in which the crank-pin D and the wrist-pin /a operate and said pins and at the same time prevent tight bearings due to frictional heating, I have provided the connecting-rod P with self-adjusting and yielding bearings. The said coimecting-rod is made up of the rigid member or strut O and the stirrups or straps It and It. The spceilic construction of the connecting-rod is more clearly shown in Figs. 2 and 3, upon an inspection of which it will be seen that the stirrup It is formed with an extension or loop r, which is inter-linked with the strut or rigid member O. The strap or stirrup R/ is also formed with an extension or loop fr, which in this case is bifurcated in order to receive the extension or loop fr. The said loop r2 is also interlinked with the rigid member O, the three parts R, R, and O being connected together in the same manner in which the links of chain are connected together. The member O is divided longitudinally into two parts, which are riveted together when the connecting-rod is assembled. Located between the inner ends lr and r" of the loops or extensions of the stirrupsR and R, respectively, is a compressible spring' S, which is held in place by centering-pieces formed integral with or otherwise fastened to said stirrups. The centering-piece W, which is mounted on the inner end I/of the extension y' of the stirrup R, is shown in Figs. 3 and 4f. It will thus be seen that the spring S tends to separate the inner ends r and r4, and consequently to draw together the outer ends of the stirrups or straps R and R, respectively, whenever the bearings in which the pins D and L'" operate are worn away by use.

It will be seen that as the air is compressed in the left-hand cylinder Gr, Fig. l, the thrust of the piston H is taken directly on the strut O. New if this connecting-rod is applied to a direct-connected single-acting air-col'npressor a comparatively small amount of pull would be exerted on the spring S during either the forward or return stroke of said piston H. Under such conditions a very small spring is all that is necessary to take up automatically the wear in the bearings. In. applying' the invention to the double-acting air-compressor shown in Fig. l, however, it is necessary to make the spring S heavy and strong enough y to take the direct thrust of the piston H at the right-hand end of the air-compressor when the air is being compressed in the cylinder G at that end of the compressor. rIhe spring S should be made so strong that the distance between the axes of the pins D and /z/, respectively, would not be changed in any part of the forward or return strokes of the piston or pistons.

Although I have shown and described my invention as applied to a specific form of aircompressor, I do not wish to limit the application of said invention to such a device, since the improved connecting-rod is clearly applicable to all kinds of engines or machines in which it is desirable -to reduce the vibration caused by lost motion in the bearings of the connectingrod. Furthermore, many modifications of the construction herein shown may be made without departing from the spirit and scope of my invention, and in the appended claims I aim to cover all such modifications.

Vhat I claim as new, and desire to secure by Letters Patent of the United States, is-

y 1. A connectingred comprising a rigid member, relatively adjustable members adapted to coact with the said rigid member to form bearings for shafts or pins at the ends of said rigid member, anda spring connection between said adjustable members.

2. A connecting rod comprising a rigid member, a relatively adjustable member at each end of said rigid member which forms with the end of said rigid member a bearing for a pin or shaft, and a spring between said adjustable members for the purpose of making said bearings yieldingly self-adj usting.

3. A connectingrod comprising a rigid strut, a stirrup or strap at each end of said strut which forms with the end of said strut a bearing for a pin or shaft, and a spring between said stirrups for the purpose of automatically taking up the wear in said bearings.

4. A connecting rod comprising' a rigid strut in the form of a link, two straps er stirrups intel-linked with said strut each of said straps or stirrups forming with the end of said strutv a bearing for a pin or shaft, and yielding means normally tending to draw said straps toward the ends of said strut.

A connectingrod comprising a rigid strut in the form of a link, two straps or stirrups nterlinked with said strut each of said straps or stirrups forming with the end of said struta bearing for a pin or shaft, and a spring located between the inner ends of said interlinked straps or stirrups for the purpose of automatically taking up the wear in said bearings.

In witness whereof I have hereunto set my hand this 20th day of February, 1903.

CHESTER M. SPALDING. WVitnesses:

BENJAMIN B. HULL, HELEN ORFoRD.

ICO

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