US2741020A - Valve spring compressors and clamping devices - Google Patents

Description

April 10, 1956 E. M. ARTHUR VALVE SPRING COMPRESSORS AND CLAMPING DEVICES 2 Sheets-Sheet 1 Filed April 5, 1952 v I flTrORNEYJH April 10, 1956 E. M. ARTHUR VALVE SPRING COMPRESSORS AND CLAMPING DEVICES Filed April 5, 1952 2 Sheets-Sheet 2 Flqz.

INVENTOI? z I J .ATTOKNEYS.

VALVE SPRING COMPRESSORS AND CLAMPING DEVICES Evan Meir-ion Arthur, West Heath, Birmingham, England Application April 3, 1952, Serial No. 280,296

2 Claims. (Cl. 29-215) This invention relates to valve spring compressors and clamping devices and it has for its object compressing or clamping means which are foot operated. A further object is compressing or clamping means particularly adapted for compressing overhead valve springs. A further object is a device in which the clamping means and the force applying means are separate units connected by a flexible force transmitting cable.

Referring to the drawings:

Figure 1 is a side elevation of a valve spring compressor constructed according to this invention.

Figure 2 is a section on line IIII of Figure 1.

Figure 3 is a plan view of the clamping unit.

Figure 4 is an underside view of the clamping unit.

Figure, 5 is a section on line V-V of Figure 1.

Figure 6 is a section on line VIVI of Figure 1.

According to a convenient embodiment of this invention, an overhead valve spring compressor or a clamping device comprises a clamping head formed as an independent unit and comprises two bars 1 and 2 for carrying gripping arms which are slidably mounted on one another by means of two headed screw threaded pins which pass through slots 3 in one bar and engage tapped holes 3b in the other bar. A set of tapped holes 3c are provided in order that the range within which the gripping arms move can be obtained with diiferent distances between the arms. The bars on opposite ends have laterally projecting portions 4 and 5 respectively and gripping arms are fixed thereto. One gripping arm 6 is U-shaped in cross section and the projecting portion 5 fits into the channel and is fixed therein by screwed pins or rivets, and the outer end of this U-shaped arm is fitted with a gripping jaw member which is conveniently in the form of an adjustable set pin 7. The other arm 8 is U-shaped in cross section at the inner end for being similarly fixed to the projecting portion 4 on the other slide bar 1 and the two side walls of the gripping arm are extended and splayed outwardly. A gripping jaw for engaging a valve spring comprises two jaw arms 9 suitably shaped at the outer end and each jaw arm is detachably fitted to the side walls of the gripping arm conveniently by sliding the inner ends into a U-shaped member 10 conveniently pierced and pressed from the side walls of the gripping arm 8. The jaw arms are also anchored to the gripping arm by means of a screwed pin 11 which passes through perforations in the walls of the arm 8 and the two arms 9 of the gripping jaw, so that the pin serves both to fix the arms 9 in position and also to adjust the distance apart of the gripping jaw arms 9. A clip 12 is fixed to each gripping arm and each clip carries an anchor socket 13 for the Bowden cable mechanism. The inner member of the Bowden cable is anchored in the socket by means of a hook 14 on which a head 14a of said inner member bears and which book can be lifted from the socket with the head 14a and removed to allow the inner cable to be detached by passing back through the socket. A helical spring 15 is arranged on the inner wire cable 16 between the two gripping arms and between the slide bars and the outer ends of the clamping arms to normally force the gripping jaws thereon apart. An extra length of cable is provided between the arms 6 and 8 to provide for the adjustment when bolts 3a are fixed in the holes 3c. The cable mechanism is operated by means of a foot lever 17 which is pivotally mounted on a floor or base plate 18 which is conveniently channel shaped in cross section and the foot lever 17 is pivotally mounted between the sides of this channel so that when depressed it enters the channel and the foot pressing the lever is thereby only at a small height above the ground. The base plate thus has the lever 17 pivoted thereto near the ground and the liability of tilting a small base plate 18 is reduced to a minimum. The inner member of the Bowden cable is anchored to the foot lever intermediate its ends, so that a substantial mechanical advantage is obtained and the outer member 16a of the Bowden cable which is formed of close helically coiled wire is anchored to the upper end of an arm 19 pivoted on the base plate and slidably engaged through a slot in the lever 17 in order that anchorage can adjust itself with the movement of the foot lever to automatically keep the inner and outer members at the anchorage in alignment and thereby avoid undue wear and friction. The outer member 16a of the operating cable mechanism is rotatably anchored in the head of the screwed pin 21 slidably engaged in the socket 22 on the arm 19 and the adjustable nut 23 forms an adjustable abutment for adjusting the point of anchorage of the end of the outer member 16a. The device thus constructed enables the valve springs of overhead valves of internal combustion engines to be very conveniently and quickly compressed and both hands of the operator are free. The device is readily adapted to suit varying conditions of application, as the initial distance apart of the jaws can be varied according to the required distance which the gripping arms are required to span, whilst the abutment stud on one arm is also adjustable. The fitting of the Bowden cable mechanism to the gripping arms is also reversible so that the outer member of the cable mechanism can be anchored to either arm according to the varying conditions of use. The device thus constructed can have broken or damaged parts readily replaced.

The appliance can be readily adapted for use as a clamp and the detachable gripping jaws can be constructed according to the shape of the workpiece to be gripped. The device can be readily adapted for compressing the springs of side valves of internal combustion engines. The foot lever may be fitted with a catch to hold it depressed in the clamping position and such catch may be in the form of a pivoted ratchet toothed rack bar normally spring pressed into engagement with the catch member on the foot lever, the rack bar being released by means of a lateral movement of the foot. A spring may be fitted to normally pressthe foot lever in the release direction, and for this purpose the arm 19 is pivotally mounted on an arm 25 pivotally mounted on the pin 24 pivotally connecting the foot lever 17 to the base plate 18. A mouse trap spring is mounted on the pin 24 and one end bears on the arm 25 whilst the other end bears on the foot plate 18.

In a modified form the gripping arms may be pivotally mounted together instead of being slidably mounted to provide the opening and closing movement.-

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

l. A valve spring compressor or clamping device comprising a clamping head formed of two clamping arms mounted to be movable in relation to one another, a spring urging the arms apart, a Bowden force transmitting flexible cable mechanism having the inner member thereof anchored to one said arm and the outer member thereof anchored to the other arm to force the arms towards one another, an operating unit for said force transmitting cable comprising a base member, a foot lever pivotally mounted on the base member and to which the inner member of the force transmitting cable is anchored intermediate the outer foot applying end of the foot lever and the pivoted end, an arm pivotally anchored in relation to the base member, means for anchoring the said outer member of the force transmitting cable to said pivoted arm, guide means on said pivoted arm for guiding the inner member of the force transmitting cable to its anchorage on the foot lever, and means for slidably engaging said pivoted arm with the pivoted foot lever near the point of anchorage of the cable to such lever so that the arm is pivoted with the foot lever, whereby the inner member of the force transmitting cable and said guide means are maintained in alignment when the foot lever is depressed.

2. A valve spring compressor or clamping device comprising two flat plates mounted on one another face to face, two pins detachably fixed in holes in one plate, two aligned slots in the other plate in each of which a said pin engages to slidably fix the plates together, a second set of holes in the first mentioned plate in which the pins can be fixed to adjust the clamp to be effective over two different ranges, such plates being L-shaped and arranged to form lateral projections at opposite ends of the plates,

an arm on each lateral projection to form a U-shaped clamping member with the arms slidably movable in relation to one another to compress a valve spring, a gripping jaw on each of said arms, an anchor clip and a force transmitting flexible cable fixed to each arm between the inner and outer ends of the arms so that the force applied to draw the arms together applies a turning moment opposite the turning of the pressure applied to the gripping jaws, the anchor clips detachably receiving the force transmitting cable to enable the position of the clamping arms to be reversed, a helical spring on the inner member of force transmitting flexible cable extending between the arms for urging the arms apart, and a foot operated unit for actuating the force transmitting cable.

References Cited in the file of this patent UNITED STATES PATENTS 1,384,472 Leahy July 12, 1921 1,620,649 Hartz Mar. 15, 1927 1,621,820 Allen Mar. 22, 1927 1,783,827 Carr Dec. 2, 1930 1,792,567 Blomberg Feb. 17, 1931 2,509,516 Murphy May 30, 1950 FOREIGN PATENTS 390,843 France Aug. 10, 1908

Images