Adjustable clamp for holding objects securely in position

An adjustable clamp for holding objects securely in position comprising at least one arm (1) which exhibits one articulated arrangement (4, 5) arranged at each of the two ends of the arm. The articulated arrangement exhibits two pivot pins (6, 8, 7, 9) arranged at an angle to each other. The object (36) is held securely by a clamping arrangement attached to the articulated arrangement. Each articulated device (4, 5) exhibits, free to move in relation to the arm (1), an articulated body (15) with a curved articulated surface (16) which is in contact with and is so arranged as to move relative to a corresponding curved articulated surface (17) in an articulated component (12) attached to the ends (2, 3) of the arm. The articulated body also exhibits a flat articulated surface (18) which is contact with and may be turned relative to a corresponding flat surface. One of the pivot pins (8) in each articulated arrangement (4, 5) extends through the articulated component and the articulated body and forms a releasable locking arrangement for the arm and for the clamping arrangement. The locking arrangement is capable of adjustment between a locked position in which the articulated surfaces are tightly clamped to each other in a pre-set position by said pivot pin and a released position in which the articulated surfaces are capable of moving relative to each other. The articulated components (12) of the arm (1) are executed in the form of hook-like components, each of which is open to the side in its own particular direction relative to the longitudinal direction of the arm.

TECHNICAL FIELD 
The present invention relates to an adjustable clamp for holding objects 
securely in position comprising at least one arm which exhibits one 
articulated arrangement arranged at each of the two ends of the arm, said 
articulated arrangement exhibiting two pivot pins arranged at an angle to 
each other, whereby said object is so arranged as to be held securely by 
means of a clamping arrangement attached to the articulated arrangement. 
TECHNICAL PROBLEM 
The purpose of the present invention is to propose an adjustable clamp by 
means of which objects may be set in a large number of different positions 
and may be aligned in different directions. Examples of such objects 
include so-called stops which are intended to hold workpieces in position 
during machining operations, for example when drilling at a pre-determined 
point. For this purpose, the clamp is adjusted in conjunction with the 
stop after the first workpiece has been placed in the desired position, 
whereupon the stop is tightened against a suitable edge or surface. Once 
this has been done, a series of identical workpieces can be located in 
identical positions enabling a repeatable machining operation to be 
performed. 
SOLUTION 
The aforementioned purpose is achieved by means of a clamp which is 
characterized in that each articulated device exhibits, free to move in 
relation to the arm, an articulated body with a curved articulated surface 
which is in contact with and is so arranged as to move relative to a 
corresponding curved articulated surface in an articulated component 
attached to the ends of the arm and with a flat articulated surface which 
is in contact with and is so arranged as to be capable of being turned 
relative to a corresponding flat surface, in that one of the pivot pins in 
each articulated arrangement extends through the articulated component and 
the articulated body and forms a releasable locking arrangement for the 
arm and for the clamping arrangement by being adjusted between a locked 
position in which the articulated surfaces are tightly clamped to each 
other in a pre-set position between said pivot pins and a released 
position in which the articulated surfaces are capable of moving relative 
to each other, and in that the articulated components of the arm are 
executed in the form of hook-like components, each of which is open to the 
side in its own particular direction relative to the longitudinal 
direction of the arm.

BEST MOST OF CARRYING OUT THE INVENTION 
The clamp in accordance with the first embodiment illustrated in FIGS. 1-5 
consists of an arm 1, each of the ends 2, 3 of which is provided with its 
own articulated arrangement 4, 5. Each and every one of the articulated 
arrangements 4, 5 exhibits a first pivot pin 6, 7 which is horizontal in 
the typical embodiment shown, and a second pivot pin 8, 9 which is 
vertical in the typical embodiment shown with regard to one of the 
articulated arrangements 4 but which is capable of being set to various 
angles along various vertical planes with regard to the second articulated 
arrangement 5. The first pivot pin 6, 7 in the two articulated 
arrangements 4, 5 is executed in the form of a cylindrical body, whereas 
the second pivot pin 8, 9 is executed in the form of a screw which in the 
typical embodiment shown in one of the articulated arrangements 4 is an 
Allen screw which extends through a transcurrent bore 10 in the pivot pin 
6, 7. The first pivot pin 6, 7 thus exhibits an articulated surface 11 in 
the form of a cylinder jacket. The arm 1 exhibits at either end an 
articulated component 12 forming part of the articulated arrangement 4, 5, 
said articulated component when viewed from the side having a hook-like 
appearance and exhibiting a similarly curved, concave articulated surface 
13 in the form of a cylinder jacket which is designed to make contact with 
the articulated surface 11 of the ivot pin 6, 7. In the articulated 
component 12 is arranged a long groove 14, as may best be appreciated from 
FIG. 3 and FIG. 4, through which the pivot pin 6, 7 extends. 
In each and every one of the articulated arrangements 4, 5 is also 
incorporated an articulated body 15 which exhibits a concave articulated 
surface 16 in the form of a cylinder jacket, designed to make contact with 
a convex articulated surface 17 in the form of a cylinder jacket on the 
articulated component 12 of the arm in each and every one of the 
articulated arrangements 4, 5. These two articulated surfaces 16, 17 
exhibit essentially the same radius of curvature in each and every one of 
the articulated arrangements, whilst the articulated surfaces 11, 13 
exhibit essentially the same mutual radius of curvature. All the curved 
articulated surfaces 11, 13, 16, 17 are coaxial with the pivot pin 6, 7. 
The articulated bodies 15 also exhibit a flat articulated surface 18 
intended to slide against a second flat surface 19, 20 so as to permit 
articulated movement about the pivot pins 8, 9. The articulated surfaces 
11, 13, 16, 17 in the form of a cylinder jacket are intended to slide in 
pairs against one another in order to permit articulated movement about 
the pivot pins 6, 7. The articulated bodies 15 exhibit a transcurrent bore 
21 for the pivot pins 8, 9. 
The lower articulated arrangement 4 in accordance with the first typical 
embodiment is executed in the form of an articulated holder which is 
capable of being moved along a guide arrangement 22, such as is found, for 
instance, on machine tools such as boring machines for the purpose of 
permitting the attachment of, for instance, clamping arrangements such as 
collet jaws or similar arrangements for holding the workpiece securely in 
position. The guide arrangement 22 is executed with a channel 23, for 
instance of T-shaped cross-section and with a narrower part which exhibits 
a groove 24 open towards the top, through which the vertical pivot pin 8 
in the articulated arrangement 4 extends and which with its lower end is 
in threaded engagement with a suitable square nut 25 which is able by 
means of its upward-facing guide surface 26 to slide against, and by 
tightening up the Allen screw 8 to be clamped against a downward-facing 
guide surface 27 in the guide arrangement 22. The shape of the nut 25 
prevents it from turning at the same time as a turning motion is imparted 
to the Allen screw 8. 
By means of the articulated arrangement 4 which serves as an articulated 
holder the clamp may be moved to any desired position along the guide 
arrangement 22 with the Allen screw 8 which serves as a pivot pin 
slackened off slightly. With the screw in that position, the arm 1 may be 
set to any desired angle of articulation about both the vertical pivot pin 
8 and the horizontal pivot pin 6 that is to say it may be articulated to 
any desired angle in the vertical plane and to any desired angle in the 
horizontal plane. Articulation about the vertical pivot pin 8 may take 
place through a full 360 degrees, whereas articulation about the 
horizontal pivot pin 6 takes place within a certain given angular 
interval, in respect of which FIG. 1 shows the two end positions in the 
typical embodiment in question. The solid line shows the lower end 
position with the arm 1 in contact with the guide arrangement, and the 
dotted and dashed lines show the upper end position with the head 28 of 
the screw forming a stop against a flat contact surface 29 on the arm 1. 
The head 28 of the screw is in this instance slightly recessed into the 
horizontal pivot pin 6, but is intentionally not entirely recessed so as 
to enable it to serve as a stop permitting the Allen screw to be tightened 
and slackened by means of a hexagon key. The stop will also prevent any 
unintentional articulation of the arm 1 to the point at which the 
articulated joint will fall apart. 
By activating one and the same element, that is to say the vertical pivot 
pin 8, it is possible for locking to take place in the articulated clamp 
on the guide arrangement 22 and in addition for the arm 1 to be locked 
relative both to the horizontal pivot pin 6 and to the vertical pivot pin 
8, thereby achieving the very effective and stable locking of the arm 1 in 
its desired position. 
The second articulated arrangement 5 has its hook-like articulated 
component 12 facing in the opposite direction in relation to the 
articulated component 12 in the articulated arrangement 4. In this way the 
convex articulated surface 17 of the articulated component faces 
essentially upwards, with the articulated body 15 resting on the 
articulated component 12 and in turn supporting a clamping arrangement 30 
which exhibits said flat surface 20, which is in contact with the flat 
articulated surface 18 of the articulated body 15. The pivot pin 9 extends 
through a transcurrent bore 31 in the articulated body 30 through the 
transcurrent bore 21 in the articulated body 15 and the groove 14 in the 
articulated component 12 and is screwed into the horizontal pivot pin 7 by 
its end which is provided with a screw thread. The pivot pin 7 thus 
exhibits a bore provided with a screw thread which may, for example, be 
transcurrent. The other bores need not be provided with a screw thread. In 
this embodiment, the pivot pin 9 in the articulated arangement 5 is not an 
Allen screw, but is a slotted-head screw or a threaded pin which, at its 
upper end, exhibits an operating lever 32, by means of which the pivot pin 
9 may be turned for the purpose of being tightened and slackened. The 
operating lever 30 is capable in a previously disclosed fashion by 
imparting a movement in the longitudinal direction of the pivot pin 9 of 
being moved between different articulated positions without the need to 
cause the pivot pin 9 to turn with it, enabling the operating lever 32 to 
be set to various positions of engagement enabling the pivot pin to be 
brought into an appropriate position depending on the space available. 
The clamping arrangement 30 is essentially cylindrical in form in the 
embodiment shown and is also provided with a transcurrent bore 33, as may 
best be appreciated from FIG. 2, which extends at right angles to the 
pivot pin 9 and eccentrically from it. Through this bore 33 extends 
transversely across the pivot pin 9 a slot 34 which is so dimensioned as 
to permit the bore 33 to be restricted to a certain extent by a head 33 of 
the pivot pin 9, which is forced into a depression in the clamping 
arrangement 30. 
The clamp in accordance with the invention is so arranged so to be capable 
in a number of different positions of supporting an object which, in the 
embodiment shown, is in the form of a rod-shaped clamping arm 36 extending 
through the bore 33, said arm being of circular cross-section in the 
embodiment shown. This clamping arm is so arranged as to be tightly 
secured to the clamping arrangement 30 in the desired position and 
represents, for example, the object which is intended to be supported by 
the clamp in accordance with the invention in the desired position and in 
the desired direction. The clamping arm 36 in the embodiment shown is 
executed in the form of an extendable arm intended to serve as a stop when 
machining the workpiece. The extendable arm 36 accordingly exhibits at 
either end a stop organ 37, 38. The first stop organ exhibits a flat front 
contact surface 39 and a flat rear contact surface 40 and also a contact 
edge 41. The second stop organ 38 is in the form of a spherically rounded 
end part to the extendable arm 36. The extendable arm 36 is capable of 
being turned through its ability to be removed from the bore 33, turned, 
and inserted into the bore from the opposite direction. At the same time 
the clamping arrangement 30 is capable of being turned through 360 degrees 
about the pivot pin 9 enabling the bore 33 to be positioned in any desired 
direction, and even in one and the same direction but on either side of 
the pivot pin 9. The extendable arm 36 can thus be turned in such a way 
that the stop organ 37 or 38 may be selected depending on the nature of 
the surface or the edge of the workpiece against which the stop organ is 
to make contact. 
The articulated arrangement 5 thus permits the adjustment of the clamping 
arm 36 to any desired angular position in both the horizontal plane and 
the vertical plane by means of the operating lever 32 after having 
slackened off the articulated arrangement, that is to say by screwing out 
slightly the pivot pin 9 from the bore 10 in the pivot pin 7, by causing 
the clamping arrangement 30 to turn about the pivot pin 9 by sliding the 
flat articulated surfaces 20, 38 against each other and by sliding the 
articulated surfaces 11 and 13 and 16 and 17 in the form of cylinder 
jackets against each other. With the articulated arrangement 5 released, 
the clamping arm 36 will also be released so that it may be moved in its 
longitudinal direction to any desired position. For the purpose of placing 
the articulated arrangement 5 in the locked position, the operating lever 
32 is turned in a sense which will cause it to be screwed further into the 
bore 10 in the pivot pin 7, when the pivot pin will be clamped against the 
articulated component 12, thereby creating such friction both in the 
articulated surfaces 11, 13 and 16, 17 in the form of cylinder jackets and 
in the flat articulated surfaces 20, 38 that locking will take place, that 
is to say that the pivot pin 9 will be held securely in the desired 
position and that the clamping arm 36 will be held in the desired angular 
position. In the case of the upper articulated arrangement, the ability to 
articulate in the vertical plane will be limited by the contact of the 
pivot pin 9 with the stop at either end of the groove 14. At the outer end 
of the groove, the stop 42 is formed by a pin extending transversely 
across the groove, said pin extending through a bore in the articulated 
component 12 of the arm 1, whilst the second stop 43 (see FIG. 3) is 
formed by the inner end of the groove 14. 
Locking by means of the operating lever 32 takes place in two locking 
stages, however. The first locking stage occurs in accordance with the 
above in conjunction with the first tightening operation by means of the 
operating lever, when the angular positions in accordance with the above 
are fixed, whilst the clamping arm 36 is still capable of being moved in 
its longitudinal direction. After further tightening by means of the 
operating lever 32, the clamping arm 36 will also be held securely by the 
slight compression of the components of the clamping arrangement 30, which 
are separated by the slot 34. The depth of the slot is, in fact, 
calculated in relation to the flexibility characteristics of the material 
used in the clamping organ, which may be made from a light alloy, for 
instance, so that locking will first occur in the sliding surfaces of the 
articulated arrangement 5, followed by locking of the arm in the bore. 
FIG. 3 and FIG. 4 show the appearance of the arm 1 and the sliding surfaces 
of the articulated arrangements 4, 5, which provide exceptionally stable 
and effective locking due to the great width of the articulated surfaces. 
FIG. 5 shows an application in which use is made of the clamp in accordance 
with the invention as a stop by means of which to determine the position 
of a workpiece 44 during the machining of said workpiece, in this case 
drilling by means of a drilling machine 45. The purpose of the stop is to 
permit a machining operation, in this case drilling, to be performed at 
one and the same point on all the workpieces when drilling a large number 
of workpieces 44 which are identical with each other. For this purpose, 
the first workpiece 44 is placed in the desired position so that the 
machining operation may be performed at the correct point, with the 
clamping arrangement in accordance with the invention initially being 
retracted from the position indicated in FIG. 5. The workpiece 44 is 
raised to the desired height by means of packing pieces 46 and is 
prevented from moving in directions across the transverse plane of the 
paper by means of a vice (not shown) or by means of an adjustable stop in 
the form of an adjustable supporting surface which is brought into contact 
with workpiece. The clamp and the stop in accordance with the invention 
are then advanced with the two articulated arrangements 4, 5 in the 
released, i.e unlocked, position in which the clamp may be moved along the 
guide 22 into the appropriate position in relation to the workpiece 44. 
For this purpose, the lower articulated arrangement 4 is tightened up 
slightly so as to give it a certain degree of location, yet still to 
permit articulated movement should this be necessary during the adjustment 
of the clamp. The upper articulated arrangement 5 is left in the released 
state so that the clamping arm 36 may be set to the desired angular 
position by turning it about both the horizontal pivot pin 7 and the pivot 
pin 9. Use is made of the rounded stop organ 38 in this case, although the 
second stop organ 37 could also be used in this instance. In the workpiece 
44 shown, the position of the bore which is to be executed is dependent on 
the position of a recess 47, which in this case is cylindrical, for which 
reason the stop organ 38 is brought into contact with an internal corner 
of said recess 47, that is to say with both the edge surface 48 and the 
bottom surface 49. The necessary adjustment is best made in this case with 
the clamping arm 36 being both adjusted in the angular sense and advanced 
in a longitudinal sense, whereupon locking of the clamping arm takes place 
against both angular movement and longitudinal movement. When adjustment 
is to be made directly towards a surface, it is preferable for the 
aforementioned locking operation to take place in two stages, with the 
angular positions being adjusted initially, followed by the advancement of 
the clamping arm to the point at which the contact organ 37 or 38 comes 
into contact with the surface in question. The rounded contact surface 37 
or the rounded stop organ 38 may also be used, for example, in bores to 
permit the introduction of the clamping arm 36 into bores and to determine 
the position against any of the surfaces of the bores. The aforementioned 
rearward-facing contact surface 40 may be used in the event of the surface 
of the workpiece facing away from the clamp being most suitable for 
holding the workpiece in position. Once the clamp and the stop organ have 
been adjusted, the position of the workpiece 44 can be reproduced for all 
subsequent workpieces, which will require to be advanced up to the stop 
organ, in so doing assuming the same position as the first workpiece. In 
this way the machining operations will take place at one and the same 
point on each workpiece. Thus, in the case illustrated here, the recess 47 
exhibits a sideways-facing opening which enables the workpiece to be 
removed without the need to move the clamp or the stop organ. 
FIGS. 6, 7 and 8 show a second embodiment of the clamp in accordance with 
the invention. In accordance with this embodiment, the clamp is provided 
with a further arm 50, which is identical with the first arm and similarly 
exhibits two articulated arrangements 51, 52 which function in principle 
in an identical fashion to the articulated arrangements 4, 5 of the first 
arm. For this purpose, the square nut 25 is transferred from the pivot pin 
8 of the first arm to the pivot pin 53 of the second arm, whilst the pivot 
pin of the first arm extends through the articulated body 54 of the second 
arm in the articulated arrangement 52 and is screwed into the horizontal 
pivot pin 55 of the second arm 50. Between the two articulated bodies 15, 
54 which face each other is thus formed the flat point of articulation 
between the flat articulated surface 18 of the upper articulated body 5 
and the flat articulated surface 56 of the lower articulated body 54. In 
this way, a double articulation is thus achieved between the two arms 1, 
50 with a common pivot pin 8 and each of the horizontal pivot pins 6, 55. 
The double articulation thus provides for angular adjustment between the 
two arms 1, 50 in the vertical plane and also for angular adjustment in 
the horizontal plane. In addition, parallel movement is also provided 
between the two arms through the ability of the common pivot pin 8 to be 
adjusted to a variety of angular positions. 
The embodiment with two inter-connected arms 1, 50 illustrated in FIG. 6, 
FIG. 7 and FIG. 8 offers a greater reach and a greater range of adjustment 
for the object which is to be supported. Dotted and dashed lines are used 
to indicate the end position for the angular adjustment between the two 
arms in the vertical plane. Thus, in FIG. 6, the object shown is in the 
form of a stop, as in the previous embodiment, whereas FIG. 7 and FIG. 8 
show a more general view of a clamping arm 57 which can be used to secure 
in position any other object. Typical objects are measuring instruments 
which must be held securely in a precisely determined position, which may 
vary from case to case. Examples of such instruments are a dial gauge for 
measuring changes in level or irregularities in the surface of a material. 
Other examples are lamps for photography, for instance, which must be 
adjusted to various positions which may vary from case to case. 
In a corresponding fashion, the number of arms may be increased further 
depending on the need for adjustment and reach associated with the clamp. 
The material used for the arms and the articulated bodies may be a light 
metal alloy or some other metal, whereas the pivot pins and the 
articulated bodies are best executed in steel. The operating lever may be 
executed in plastic, for instance, which may also be used for certain 
other component parts. It is important, however, for the material used not 
to be excessively flexible, but to be selected in such a way that the 
object in question can be held in the desired position without excessive 
changes in position. 
The invention is not restricted to the typical embodiments specified above 
and illustrated in the drawings, but may be modified within the context of 
the following Patent Claims. For instance, it is conceivable for the arms 
1, 50 and the articulated bodies to be designed with a different 
appearance. It is also conceivable for the surfaces in the form of a 
cylinder jacket to be replaced by double-curvature surfaces or other 
rotationally symmetrical generated surfaces. Also, the articulated clamp 
on the guide arrangement may be executed in a different fashion depending 
on the particular application. The clamp may be replaced by a clamping 
arrangement for clamping to a table top or similar. More than two arms may 
be connected together in a modular system in which the number of arms is 
selected to suit each individual case. Additional clamp organs may be 
inserted between two arms, tht is to say between two articulated bodies 
15, for the purpose of supporting several objects simultaneously in 
different positions. In the above embodiment the clamping arms 36 have 
been assumed to be the object which is supported and whose position is 
determined. In the event of other objects being intended, the clamp should 
also be fitted with a rod-like component which is held in place in the 
same way as the clamping arm 36 and to which the objects in question are 
attached. Alternatively, the object may be fitted with a rod-like shaft.