US2417598A - Wrench for shielded spark plugs - Google Patents

Description

March 18, 1947. J, P, JONES WRENCH FOR SHIELDED SPARK PLUGS Filed Sept. 25, 1944' INVENTOR. Q John Paul Jnes.

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Patented Mar. 18,1947

UNIT ED STAT E S O F F lC E 2,417,598 WRENCH FOR SHIELDED SPARK PLUGS John PaulJ ones, Brownsville, Tex; Applicationseptember 23, 1944; Serial No. 555,561.

This invention relates to socket wrenches for shielded sparkplugs of the type used in airplane engines and, among. other objects, aims to provide a greatly improvedsocket member adapted to be positively engagedwith. and gripped on a non-circular head or nut of a shielded spark plug. by means of a screw threaded nut engaging the shield member. or shell to prevent damage to thelplug when. it is tightened or removed.

Another aim is to provide a simplified form of cylindrical socket. member and wrench handies adaptedto engage the. holding nut and the socket member. The main idea is to provide an improvedsocket wrench of thistypewhich great- 1y facilitates the insertionand removal of shielded spark plugs used in larg airplane engines.

Other aims and advantages of the invention will appear in the specificationwhen considered in connectionwith the accompanying drawings, wherein:

Fig. 1 is asectional view,partly in elevation, showing one form of the, wrench applied to a shieldedspark plug;

Fig. 2 is a vertical sectional'view taken on the line 2-2 of Eigfilg, showing, parts oithe socket member;

Fig. 3is a sectional view taken on the line 3-3 ofFig. 11.

Fig. 4 is an upper end view ofthe socket shown in Fig. 2;

Fig. 5 is a sectional view taken on the line 5-5 of F g; 2;

Fig. 6 isalongitudinal view, partly in section, of a handle for manipulating the socket member; and

Fig. 7 is a fragmentary view, similar to Fig. 4', showing the handle applied to the upper end of a socket member.

Referring more particularly to the drawing, the special type of socket wrench there shown, is designed to be used on a shielded spark plug l0, wherein an insulating shield is protected by a shield member or tubular shell H having screw threads l2 at its upper end to which a conductor fitting or elbow (not shown) is adapted to be engaged. Champion spark plugs are commonly used in airplane engines. They have a narrow nut section l3 which has to be engaged by a socket wrench to remove and replace them. Experience has demonstrated that ordinary socket wrenches soon damage the hexagon or non-circular heads to such an extent that the spark plugs have to be discarded. This is especially true when the plugs become frozen in an engine and require considerable turning effort to 5 Claims. (01. 81-125) remove them. In accordance withthls invention, the screw threads in the shield member orshell ar utilized, for the purpose of positively grip- ,ping and holdinga socket member on theplug,

thereby preventing accidental disengagement from. the plugand consequent damage to the non-circular head.

Referring to Figs. 1 and 2; the socket wrench portion, is shown as comprising an elongated tube l4 having a non-circular socket IE3 at its lower end and. presenting an internal sleeve it tel'escoped within the tube. The lower socket member is preferably, although not necessarily, formed" of a separate piece; and welded in the lower endof the tube; so thatit presentsa should'er 'llontheinside of the tube at a height substantially equal to the height of the plain shank ll of the protecting sleeve member or shell H2 Thetube is shown. as having an elongatedsight opening, IS on one. side and a tubular, floating nut I!) is. slipped into the tube so that it can rotate with respect? to the tube. It is shown as having, a screw threaded, internal thimble 20 adapted to be screwed on the screw threaded portion l2'of theshell or sleeve member Ii. Its lower end engages the shoulder. H to clamp the socket l5 on the nutportion l3 of the plug, with the lower end of the socket engaging the usual flange '2 l of the plugbelow the nut portion.

The floating nut is shown as having a squared socket portion 22 at its upper end adapted to be engaged by the shank of a small wrench handle 23; inserted in.the.upper end of the tube: l4, as shown in Fig. 1'. When the floating nut is screwed home on the screw threads l2 oi the sleeve portion l l, the spark plug is positively engaged by the socket and the wrench handle 23 is then removed.

The upper end of the sleeve 14 has a square socket member 24 adapted to be engaged by an ordinary socket wrench handle. In this instance, there is shown a handle 25 having a square shank 26 at its upper end and a pivoted shank 21 at its lower end adapted to be turned at a right angle, as shown'in Fig. 7, to engage the socket 24 and afford ample leverage to turn the wrench socket. Of course, other male and/or female handles can be employed to extend the effective length of the socket wrench in case the spark plugs are relatively inaccessible. For example, a second plug socket member M can be employed to engage the pivoted shank 21, when turned at a right angle, while the straight shank 26 is engaged in the upper socket 24. Moreover, the pivoted shank 21, when in the position shown in Fig. 6,

can be engaged in the socket 24 and an ordinary straight handle (not shown) inserted in an opening 28 near the upper end of the handle. The handle 25 is shown as being knurled to facilitate gripping. Likewise, the barrel or outer surface of the tube l4 may be knurled to facilitate turning by hand when the spark plug is loose in its screw threaded opening.

From the foregoing description. it will be seen that the wrench is designed to protect spark plugs and prevent damage to the non-circular heads. Also, it prevents accidental disengagement of the spark plugs from the sockets when the spark plugs are removed. Experience has demonstrated that a wrench of this type is greatly in demand. It has served the purpose of removing spark plugs many times without any noticeable damage. In fact, it is contemplated that it will displace other socket wrenches for removing and replacing shielded spark plugs.

Obviously, the invention is not restricted to the particular embodiment herein shown and described.

Having thus described the invention what is claimed is:

1. A spark plug wrench of the character described comprising in combination, a tubular member having a plug engaging socket at its lower end; a floating nut rotatably mounted within the tube adapted to engage a screw threaded shield member on the upper end of the spark plug; a stop shoulder for the nut in the tube, so arranged that the nut will clamp the socket on the spark plug; a removable wrench handle for the floating nut adapted to be inserted in the tube; a wrench socket in the upper end of the tube; and a handle having a shank adapted to engage said upper socket.

2. A socket wrench for spark plugs having a screw threaded shield member comprising an elongated tube having a wrench socket to engage the spark plug; a shoulder within the tube around the shank of the shield member; a nut confined to rotate and slide up and down in the tube and adapted to be screwed on the shield member into engagement with said shoulder to clamp the wrench socket on the spark plug; a wrench handle removably engageable with the floating nut adapted to be inserted in and removed from the tube; and a non-circular wrench socket in the upper end of the tube adapted to be engaged by the shank of a wrench handle.

3. A spark plug wrench of the character described comprising in combination, a tubular 4. member having a plug engaging socket at its lower end; a shoulder portion above the spark plug engaging socket within the tube; a floating nut rotatably mounted within the tube adapted to be screwed on a screw threaded shield member on the upper end of the spark plug and into engagement with said shoulder to clamp the socket on the spark plug; a removable wrench handle for the floating nut adapted to be inserted in the tube; a wrench socket in the upper end of the tube; and a handle having a shank adapted to engage said upper socket.

4. A socket wrench for spark plugs having a screw threaded shield member, comprising in combination, an elongated tube having a wrench socket to engage and rest on the head of a spark plug; a shoulder within the tube around the shank of the shield member; a nut confined to rotate and slide up and down in the tube and adapted to be screwed on the shield member into engagement with the shoulder to clamp the wrench socket on the spark plug; a wrench handle removably engageable with the floating nut adapted to be inserted in and removed from the tube; and a non-circular wrench socket within the upper end of the tube and confining the floating nut therein.

5. A wrench for spark plugs having a screw threaded shield member, comprising a tubular section having a plug socket in one end to rest on the head of a spark plug; an annular shoulder above the plug socket; a floating nut confined in the tubular section adapted to be screwed on the shield member into engagement with said shoulder to clamp the plug in the socket; a nut operating member insertable through the other end of the tubular member and removably engageable with said nut; and handle receiving means in said other end of the tubular member. JOHN PAUL JONES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,235,572 Culbertson Mar. 18, 1941 2,358,249 Portuondo Sept. 12, 1944 FOREIGN PATENTS Number Country Date 418,760 British Oct. 31, 1934 233,875 British May 21, 1925

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