[0001] The invention relates to a connection of a shaft with an element, in particular the
shaft of a rotary setting member with a setting wheel, said connection comprising
a recess provided for seating the shaft in said element and an opening by which said
recess is connected to the outer edge of said element and through which the connection
can be effected by relative movement of the shaft and the element transversely to
the axis of said shaft.
[0002] Connections of this type are as a rule used if lack of space or special spatial or
constructional circumstances render it difficult or impossible to bring the shaft
and the recess forming its seat or bearing into engagement by a relative movement
in the axial direction (relative to the axis of the shaft). If there is not sufficient
space available a given shaft length can prevent the shaft from being inserted by
axial shifting into a recess which serves as a bearing in a bearing block or plate.
If the first element including such a recess is a wheel which is to be brought into
position on a shaft lack of space or special reasons of manufacture or assembly may
also forbid shifting of the wheel onto the shaft from the shaft end.
[0003] It is the object of the invention to provide a connection of the generic type which
is adapted for universal use and particularly advantageous in cases where a setting
wheel has to be connected with the shaft of a rotary setting member.
[0004] According to the invention this object is attained with a connection of the aforementioned
type in that a second element is inserted into the opening in a direction transverse
to the axis of the shaft and in that interlocking means provided on said first and
said second element cooperate to fix the second element in the opening of the first
element.
[0005] Since, in accordance with the invention, a second element is provided which can be
inserted into the opening of the first element, the first element whose outer contour
was initially interrupted by the opening extending up to its edge, can be given a
desired shape, e.g. a closed shape, by the insertion of the second element.
[0006] If the connection is intended for linking a shaft to a wheel the opening in the wheel
portion, which forms the first element and includes the recess for the shaft, and
the insert which forms the second element, can be shaped in a particularly advantageous
manner such that when the connection is completed, the wheel connected with the shaft
has a closed uninterrupted contour and/or exhibits the desired wheel shape.
[0007] If the second element is for example a wheel segment by which a setting wheel is
completed, such wheel segment may be made from a material differing in color from
the rest of the wheel and thus serving at the same time as a colored setting mark
on the circumference of the wheel.
[0008] The invention will be described in further detail with reference to embodiments illustrated
in the drawing in which:
- Fig. 1
- shows a front view of a setting wheel adapted for the connection, with a noncircular
portion of a shaft illustrated in section and the elements not yet connected;
- Fig. 2
- shows a front view corresponding to Fig. 1, with the elements connected;
- Fig. 3
- shows a front view of a circumferential section of the setting wheel according to
Figs. 1 and 2, with parts broken away; and
- Figs. 4 and 5
- show front views, with parts broken away, of an embodiment of the connection , with
a shaft in a bearing illustrated in section and the elements in positions prior to
the completion and after completion of the connection respectively.
[0009] Figs. 1 to 3 show the connection according to the invention with reference to a setting
wheel 1 which is to be mounted on a non-circular portion of a shaft 3. In the embodiment
illustrated shaft 3 is the setting shaft of an adjusting potentiometer (not illustrated)
which serves as a rotary setting member. During the so-called surface mounting the
potentiometer is attached to a printed circuit board (not illustrated) on the upper
surface facing away from the conductors such that shaft 3 extends in parallel with
the circuit board and setting wheel 1 is received with its rim in a slot of said circuit
board. For connecting the circuit board with the potentiometer, the solder pins thereof
are plugged through the circuit board and are then electrically connected with the
conductor paths on the lower side of the circuit board in that said lower part of
the circuit board along with the free ends of the solder pins is moved across a solder
bath. This soldering operation must be carried out before the setting wheel is positioned
on shaft 3 of the potentiometer because otherwise the setting wheel would be immersed
in the solder bath with its rim projecting from the slot of the lower side of the
circuit board. A setting wheel made from plastic for example would thus be damaged
in that the portion immersed would melt.
[0010] If, however, the potentiometer is connected with the circuit board without setting
wheel 1 the setting wheel 1 cannot be axially mounted on shaft 3 if the rim of the
setting wheel is to extend through the slot of the circuit board as in the case of
the embodiment described. In such cases, therefore, a connection of setting wheel
1 with shaft 3 can only be effected by a radial movement of said wheel relative to
the axis of the shaft.
[0011] In the case of the embodiment setting wheel 1 is a center disk wheel molded from
plastic and provided on part of its circumference with projections 5 forming a knurled
surface which facilitates manual rotation. Between its rim featuring the projections
5 and an adjacent inner hub portion 7, the wheel disk has a portion 9 which is thinner
than the rest and extends over the majority of the circumference of the wheel. Hub
portion 7 includes a recess 11 in the central portion of wheel 1, which serves to
seat the noncircular shaft 3. Recess 11 is part of an opening 13 which extends to
the periphery of the wheel so that wheel 1 is open on part of its circumference. With
the exception of recess 11, the entire opening 13 can be closed by a wedge 15 which
is molded from plastic and shaped such that when it is placed in the opening 13 the
circumference of setting wheel 1 is at least substantially completed and a closed
wheel thus formed. Wedge portion 17 which is located close to recess 11 when the wedge
is inserted is shaped like recess 11 such that it fits the noncircular portion of
shaft 3 positioned in recess 11 and, in cooperation with the edge of recess 11, connects
the shaft with setting wheel 3 in a manner preventing rotation.
[0012] In the case of the embodiment illustrated the thickness of wedge 15 corresponds to
that of hub portion 7 of wheel 1. In an end section 19 facing radially outwards with
respect to the axis of shaft 3, wedge 15 forms an arcuate section. In the areas close
to the circumference of the wheel the edges of opening 13 are provided with strips
21 and 23 which are axially offset relative to each other (with respect to the axis
of shaft 3) such that the outer surface of one strip is flush with the outer surface
of hub portion 7 on one side of the wheel and the other strip is flush with the outer
surface of hub portion 7 on the other side of the wheel. The strips 21 and 23 thus
provide facing inner step surfaces for mounting the facing inner surfaces of lateral
wings 25 and 27 respectively integrally formed with wedge 15 in a position complementary
to that of the strips 21, 23 of wheel 1. In order to safely prevent wedge 15 from
being rotated out of the plane of wheel 1 about an axis extending radially with respect
to shaft 3 even if wheel 1 is very thin, the end faces of wheel 1, which in the area
of the strips 21 and 23 face the end faces of wedge 15 and rest against said faces,
may form acute angles with the step surfaces formed by the strips 21 and 23 so that
when the end faces of wedge 15 are inclined accordingly, wedge 15 is locked with wheel
1.
[0013] The strips 21 and 23 have projections 29 and 31 respectively which are brought into
locking engagement with locking noses 33 and 35 respectively of wedge 15 when the
wedge is inserted into opening 13.
[0014] The locking noses 33 and 35 respectively can override the rear sides of the projections
29, 31 in that wedge 15 is resilient in the range of noses 33, 35. The resiliency
is brought about in that wedge 15 has in its central area a cut-out 39 which allows
it to be deformed in the adjacent areas in the manner indicated in Fig. 3 in dash-dotted
lines. This also allows wedge 15 to be removed after insertion by means of a tool
such as a screwdriver blade 41, shown in section in Fig. 3, which is inserted between
locking nose 35 and strip 23 to urge nose 35 out of engagement with projection 31.
[0015] The connection between setting wheel 1 and shaft 3 can be effected in that wheel
1 is moved transversely to the axis of shaft 3 as indicated by the arrow 43 in Fig.
1. When shaft 3 has been positioned by this movement in the recess 11 of hub portion
7 of wheel 1 wedge 15 is inserted by an opposite insertion movement transversely to
the axis of shaft 3 - see arrow 45 in Fig. 1 - into opening 13, with the locking noses
33 and 35 engaging the projections 29 and 31 respectively. This position is shown
in Fig. 2 which depicts the completed connection in which shaft 3 is fixed against
rotation in recess 11 of hub portion 7 of the wheel.
[0016] Setting wheel 1 can be axially fixed on shaft 3 in various manners. In the case of
a setting wheel that is fixed on the shaft of a potentiometer mounted on a printed
circuit board, the edges of the slot of the circuit board in which setting wheel 1
is received, serve as abutments by which axial movement of the wheel is limited. Alternatively,
the shaft section seated in hub portion 7 of wheel 1 could be a tapered section in
the form of an annular groove.
[0017] Rather than connecting shaft 3 and setting wheel 1 in a manner preventing rotation,
a wheel could also be rotatably mounted on the associated shaft. In such a case the
recess in hub portion 7 of wheel 1 and the adjacent portion 17 of wedge 15 would have
to be adapted to the circular shape of the shaft.
[0018] Wedge 15 may consist of a material which differs in color from the material of wheel
1 so that wedge 15 forms a colored section on the circumference of wheel 1, which
may serve as a setting mark or the like.
[0019] In Figs. 4 and 5, those parts whose shapes or functions correspond to those of parts
of the embodiment according to Figs. 1 to 3, have reference numerals to which 100
has been added in each case. They show an embodiment in which a rotary shaft 103 is
to be connected with a stationary bearing block 101. In a manner analogous to that
described with reference to the embodiment in Figs. 1 to 3, the connection is effected
by relative movement of the elements transversely to the axis of shaft 103. The design
of recess 111 of bearing block 101 and portion 117 of wedge 115, which defines recess
111, is adapted to the round shape of shaft 103. Fig. 4 shows the elements prior to
their connection, Fig. 5 shows the completed connection. As can be seen from these
Figs. wedge 115 is shaped at its outside 119 such that it completes the outer contour
of bearing block 101 and a closed body with a straight edge is thus obtained.
[0020] The above description and the drawing are restricted to features which are essential
to the disclosure of an embodiment of the invention. Features not disclosed in the
description and the drawing and not mentioned in the claims also serve if necessary
to define the subject matter of the application.
1. Connection of a shaft (3; 103) with an element (1; 101), in particular the shaft (3)
of a rotary setting element with a setting wheel (1), said connection comprising a
recess (11; 111) provided for seating said shaft in said element and an opening (13;
113) by which said recess is connected with the outer edge of the element and through
which the connection can be effected by relative movement of the shaft and the element
transversely to the axis of said shaft, characterized in that a second element (15; 115) is inserted into the opening (13; 113) in a direction
transversely to the axis of the shaft and that interlocking means provided on the
first element (1; 101) and the second element (15; 115) cooperate to fix the second
element (15; 115) in the opening (13; 113) of the first element (1; 101).
2. Connection according to claim 1, characterized in that shape and dimensions of the
second element (15; 115) are adapted to those of the opening (13; 113) and the outer
contour of the first element (1; 101) such that when the second element (15; 115)
is inserted, the latter is completed at least in the area of its outer edge and given
a substantially closed shape.
3. Connection according to claim 2, characterized in that the first element is designed
as a wheel (1) and the closed shape is the outer contour of the wheel.
4. Connection according to one of claims 1 to 3, characterized in that the interlocking
means consist of locking means (29; 31 and 33; 35 respectively) which are provided
at the edges of the opening (13; 113) of the first element (1; 101) and in associated
edge areas of the second element (15; 115).
5. Connection according to claim 4, characterized in that the second element is designed
as a wedge (15; 115) which can be inserted into the opening (13; 113) of the first
element (1; 101) and in that the locking means comprise resilient locking noses (33,
35) provided on wall portions of the wedge and adapted to cooperate with projections
(29 and 31 respectively) in the opening (13; 113).
6. Connection according to one of claims 1 to 5, characterized in that the first and/or
the second element (1 and 15 respectively) have a cut-out (39) in the range of the
interlocking means, said cut-out allowing the element to be resiliently deformed and
the interlocking means to be unlocked.
7. Connection according to one of claims 1 to 6, characterized in that shaft (3) is noncircular
at least in the area which is to be connected with the first element (1) and that
the shape of recess (11) and/or the adjacent area (17) of the second element (15)
is adapted to said noncircular shape in order to connect said element with shaft (3)
in a manner preventing rotation.