Year: 1897

page_text: fig. 4 is a similar section with the shank of the movable jaw out of contact with the
thumb screw.
In a
casing H which also forms the handle of the wrench is placed the shank C of
the movable jaw B of the instrument, the fixed jaw being made in one piece with the
handle H.
The inner side H¹ H2 H³ of the casing forms a broken line, the parts H H and
and H2 H3 meeting in an obtuse angle; the opposite inner edge of the handle forms
a somewhat similar line; the part HHs is parallel to the lower part H¹ H³ and the
part H He is curved parallel to the outer edge of the handle so that there is a
sufficiently large hollow space left between the side H H of the handle casing
and the shank C of the movable claw to lodge a spring F, which presses the shank Č
against the side H1 H2 at the other inner edge of the handle. Now at this side the
shank is provided with teeth C², which by preference are so that they do not reach,
close up to line H₁ H³, a projection C₁ at the end of the shank limits the approach of
the shank towards the side H¹ H². The lateral distance from the corner H² to the
opposite side H* H³ is exactly of the width of the shank C.
From this construction of the handle casing it will be understood that the shank C
of the jaw B, can swing upon the point H like the beam of a pair of scales and that,
because H H is parallel to H H³ when the shank is pressed by the spring F against
the side H H the upper opposite part of the shank will meet closely the side H* H*
and consequently the shank C will be guided parallel between those two sides.
Now opposite, to the spring F, I place a screw D in a recess D¹ worked into the
solid metal at this part of the handle H. The pins E of the screw are carried in small
recesses E¹ in which they can be turned round, and which protect A from falling
out. The shape of the thread of the screw D, as well as that of the teeth C of the
shank C resembles that of teeth of a saw as best seen from figure 1.
The screw D
projects at both sides out of the handle so that it can be turned by the fingers and
therefore, when the shank is pressed against it by the spring F the shank C and the
jaw B can be moved forwards and backwards; the mouth of the screw wrench can be
opened and closed very finely. The quik opening however is done, as explained
above, by pressing with the thumb of the hand against the back side of the jaw B,

page_text: thereby making it to oscillate round the corner H2 and release the teeth C from the
thread of the screw D and pushing the jaw forwards or backwards, as the case may
be, in order to set it approximately and temporarely to a nut or bolt-head and then
adjust it exactly by means of the screw D.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed I declare that what I claim is :
In a screw wrench the combination of a handle H, having a fixed head A, inner
sides H¹ H2, H* H³ forming an obtuse angle at the point H2, opposite sides H* H³
parallel to H H and H He forming a widened recess with a movable head B fixed to
a shank having teeth C at the lower part, a thumb screw D lodged in the lower part
of the handle and engaging with the teeth C² of the shank, a spring F fixed to the
widened part He of the handle and pressing the shank C against the screw D, the
whole as described and illustrated and for the purpose set forth.
Dated this oth
1005
EMANUEL SCHMIDT
Per Karl J. Mayer
Agent