Pipe bending plier

A pipe bending plier, including a planar plate connected with a housing and a pair of spaced stationary anvil members coupled with the plate, a movable presser slidably coupled with the planar plate and movable relative to the housing and the anvil members, a movable handle for moving the movable presser towards the anvil members, a fixed handle coupled with the housing and a spring coupled with the housing for holding the movable handle away from the fixed handle, a pawl-ratchet mechanism housed within the housing and comprising an extension arm on a portion thereof carrying a ratchet, and a pawl connected with the movable handle, the ratchet being coupled with the movable presser and operatively associated with the pawl in one direction of movement of the extension arm for movement by the extension arm in one orientation thereof towards the pair of spaced stationary anvil members and in another orientation of the extension arm, the pawl and the ratchet are disengaged so that the extension arm is movable together with the movable presser towards and away from the pair of spaced stationary anvil members to bend a pipe without kinking it and to provide smooth continuous bends for different angular shapes.

BACKGROUND OF THE INVENTION 
1. Field of the Invention The invention relates to a pipe bending tool or 
plier for use in bending hollow copper pipes. 
2. Description of the Prior Art 
With devices for bending pipes, different tools are required for different 
diameters of hollow copper pipe and, in some instances, it is necessary to 
use the services of more than one individual to bend a single pipe. 
SUMMARY OF THE INVENTION 
The invention is primarily concerned with bending pipes having a bending 
radius of 12 mm to 39 mm, although the tool can be easily adapted for 
different diameters of pipes and radii of bends so that the wall thickness 
will not be damaged. 
For example, pipes from 18 mm to 12 mm or from 3/8" to 1/2" can be bent 
with a bending pliers conforming with the invention so that they will all 
have the same 27 mm bending radius and so that will look tidy and the form 
of the pipe material will remain useful. This is possible because furrows 
in a presser plate are dimensioned according to the pipe so that when the 
pipe is pressed with the moving part against correctly dimensioned anvils, 
the material of the pipe will move because of correctly formed furrows so 
that the pipe wall will maintain its original thickness and its round pipe 
form. Therefore, sharper and stronger turns can be made on pipelines with 
the bending pliers conforming with the invention than can be done with 
heretofore known methods. 
When a tool conforming with the invention is hand-held at a working 
position, with handles downward, the larger furrows are above the body and 
pipe furrows get smaller when coming down. 
To these ends, the present invention consists in a pipe bending plier, 
comprising a pair of stationary anvil members coupled with a planar plate 
connected with a housing, a movable presser slidably coupled with the 
planar plate and movable relative to the housing and the anvil members, 
movement means coupled with the movable presser for movement of the 
movable presser towards and away from the anvil members, a fixed handle 
coupled with the housing and a movable handle pivotally coupled with the 
housing and a spring coupled with the housing for holding the movable 
handle away from the fixed handle, the movement means including a 
pawl-ratchet mechanism housed within the housing and comprising an 
extension arm on a portion thereof carrying a ratchet, and a pawl 
connected with the movable handle, the ratchet being coupled with the 
movable presser and operatively associated with the pawl in one direction 
of movement of the extension arm for movement by the extension arm in one 
orientation thereof towards the pair of spaced stationary anvil members 
and in another orientation of the extension arm, the pawl and the ratchet 
are disengaged and the extension arm is movable together with the movable 
presser towards and away from the pair of spaced stationary anvil members. 
It is an object of the invention to provide pipe bending pliers which have 
furrows in a bending part thereof which are deeper than, e.g., the 
diameter of a 1/2" pipe and narrower than the diameter of the pipe, and 
while bending the pipe the shape of the pipe leads to movement of pipe 
material preventing a change in the outer circumferential form of the pipe 
and preventing the wall from becoming thinner or distorted when the pipe 
is being bent for effectively stretching one portion thereof and bending 
another portion of the pipe.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now more particularly to the drawings, a pipe bending plier 10 is 
shown which includes a housing 12 for housing some of the operating 
mechanisms coupled with a movable handle 14 movable relative to a 
stationary handle 16 coupled with and fixedly attached to housing 12. 
A planar plate 20 in the form of a U-shaped member includes a base 22, a 
pair of legs 24a, 24b each having one end 26a, 26b connected with base 22 
and its free ends 28a, 28b connected with housing 12. A pair of stationary 
anvil members 30, one 30a, 30b for each leg 24, 26 and orthogonally 
related thereto. 
A hollow pipe P shown in phantom is shown positioned on top of planar plate 
20, but could equally well have been positioned below, depending on the 
outer diameter of the hollow pipe P to be bent. Positioned on the other 
side of pipe P is a movable presser member 32 mechanically intercoupled 
with extension rod 34 by a screw connection comprising a female connector 
portion 36 in the presser member 32 and a male screw connection portion 38 
at one end of the extension rod 34. The other end of the extension rod 34 
is provided with a handle portion 40 so that it can be rotated through an 
angle of 180.degree. axially along the longitudinal axis of the extension 
rod 34 to place ratchet teeth 42 into alignment with pawl teeth 44 or pawl 
46, as best seen in FIG. 5. In the position shown in FIG. 5, extension rod 
34 is fixed in position relative to planar plate 20 and held there by the 
pawl-ratchet mechanism formed by ratchet teeth 42 and pawl teeth 44. As 
seen in FIG. 1, handle 40 is rotated through an angle of 180.degree. so 
that the ratchet teeth 42 are out of engagement with the pawl teeth. In 
the FIG. 5 orientation, the extension rod 34 is seen in its operative 
position for moving the movable presser member 32 towards stationary anvil 
members 30. In the FIG. 1 position or orientation, extension arm 34 is 
movable by handle 40 longitudinally towards and away from housing 12. 
Handle 40 is rotated or moved in a counter-clockwise direction, as viewed 
in FIG. 5. Handle 14 is coupled with pawl 46 through spring 52 so that as 
handle 14 is moved towards handle 16 in the direction of arrow 48, spring 
52 moves pawl 46 and extension arm 34 in an opposite direction (towards 
the left side of the drawing) to the movement of handle 14. In the FIG. 6 
showing, pawl 46 is not in engagement with ratchet 42 and handle 14 does 
not move extension arm 34. 
Handle 14 is pivotally connected about pivot connection 18 relative to 
handle 16 and is movable towards handle 16 in the direction of arrow to 
position shown in phantom at 50 to release pawl teeth 44 by moving pawl 46 
in its longitudinal axial direction to cause anvil members 30 and presser 
member 32 to be brought closer together to impart a bending action to pipe 
P. 
Pawl 46 and pawl teeth 44 are held in engagement with ratchet teeth 42 by 
spring 52 bearing on pawl 46 and handle 14. Handle 14 as it is rotated 
towards handle 16 compresses spring 52 and pawl teeth 44 move extension 
rod 34 towards the left direction, as viewed in FIG. 5, and the front 
teeth of pawl 46 move out of engagement with ratchet teeth 42 while the 
rear teeth of pawl 46 impart longitudinal translational movement axially 
of the longitudinal axis of extension rod 34 to extension rod 34, and upon 
release of handle 14 which is then moved to its full outline position 
under pressure from compression spring 54 causes handles 14 and 16 to 
separate from each other and to rotate pawl 46 in a clockwise manner so 
that all of pawl teeth 44 are engaged with ratchet teeth 42 and extension 
rod 34 is moved to cause the gap between the anvil members 30 and presser 
member to narrow and to cause presser member to move axially of the 
longitudinal axis to achieve and impart different angular bends to the 
pipe. 
In the FIG. 6 position, handle 40 is rotated into a position between the 
position shown in FIGS. 1 and 5 to show ratchet teeth 42 out of engagement 
with pawl teeth 44, in a manner similar to FIG. 1, in which handle 40 is 
rotated through an angle of 180.degree.. 
Extension rod clamp member 56 having one end 58 connected with housing 12 
at 60. End 58 and housing connection 60 form a pivot connection for 
clamping member 56 to provide for pivoting thereof relative to housing 12. 
Clamping member 60 is provided with opening 62 through which extension rod 
34 passes. Clamp member 56 at opening 62 is provided with a bearing 
surface member 64 which is held against the outer surface portion of 
extension rod 34 by compression spring 66 which urges clamping member 56 
away from housing 12 about pivot end 58 and prevents extension rod 3 from 
being moved axially thereof. 
Extension rod 34 is provided with handle 40 so that upon release of clamp 
member 56 by exerting pressure thereon to overcome spring action of spring 
54 and compress the spring, the extension rod 34 is rotatable about its 
longitudinal axis through an angle of 180.degree. to move ratchet teeth 42 
and pawl teeth 44 out of engagement with each other. Once ratchet teeth 42 
and pawl teeth 44 are moved out of engagement with each other, movable 
presser member 32 is movable towards and away from anvil members 30. 
In FIG. 7, spring 52 is shown in its position to exert pressure onto pawl 
46 to cause pawl teeth 44 to be engaged with the ratchet teeth 42. In the 
FIG. 7A position of extension rod 34, with pawl teeth rotated out of 
engagement with ratchet teeth 42, the pawl teeth bear onto to outer 
circumferential portion 35 of the extension rod 34 free of the ratchet 
teeth 42. 
Movable presser member 32 is movable along planar plate 20 which is 
provided with a guideway 68 between legs 24a, 24b for guiding movable 
presser member 32. One face 70 of planar plate 20 is provided with indicia 
markings 72 to provide a preselected indication for different pipe bands 
or angles, such as 45.degree., 90.degree., 135.degree., and 180.degree., 
although different angles can be used in accordance with job requirements. 
Movable presser member 32 is a cylindraceous member 74 having a front 
semi-cylindrical surface portion 76 which is approximately 180.degree. in 
circumferential extent and a rear side which is shown as a flat side 78 
and is the portion containing the female connector portion 36. Presser 
member 32 on semi-cylindrical surface portion is shown with three 
partially circumferential undercut portions or furrows 80a, 80b, 80c. 
While three furrows 80a, 80b, 80c of different dimensions are shown for 
pipes with outer diameters of different gradations, it is within the scope 
of the invention to use a presser member having more than three different 
dimensions. 
Anvil members 30a, 30b cooperate with presser member 32, and each of the 
anvil members includes an outer cylindraceous surface 82 which includes a 
partial sector having undercuts or furrows 84a, 84b, 84c, having a 
curvature complementary to the curvature of furrows 80a, 80b, 80c, 
respectively. Indicia marking 72a is selected so that anvil members 30 and 
presser member are aligned to have a hollow pipe P as shown in FIG. 3 
without a bend. The indicia markings 72b, 72c, 72d are selected in 
accordance with tangents to the circumferential portions of furrows 80a, 
80b and 80c so that they are parallel to tangential portions to the 
circumferential portions of furrows 84a, 84b and 84c, respectively. 
DESCRIPTION OF OPERATION 
The pipe bending plier 10 which generally includes a housing 12, a planar 
plate anvil mechanism coupled with the housing comprising a planar plate 
20 connected with the housing and a pair of spaced stationary anvil 
members 30 coupled with the plate; a movable presser 32 is slidable 
coupled with the planar plate and movable relative to the housing means 12 
and the anvil members; the movable presser is associated with a 
pawl-ratchet mechanism or movement mechanism for movement of the movable 
presser towards and away from the anvil members; a fixed handle 16 is 
coupled with the housing, and a movable handle 14 is pivotally coupled at 
18 with the housing and a spring 54 coupled with the housing 12 and handle 
14 holds the movable handle away from the fixed handle 16; the mechanism 
which includes the pawl-ratchet mechanism is housed within the housing and 
comprises an extension arm 34 carrying on a portion thereof a ratchet 42 
and a pawl 46 connected with the movable handle, the ratchet being coupled 
with the presser 32 and is operatively associated with the pawl 46 in one 
direction of movement of the extension arm for movement by the extension 
arm 34 in one orientation thereof towards the pair of spaced stationary 
anvil members 30 and in another orientation of the extension arm, the pawl 
teeth 44 and the ratchet teeth 42 are disengaged so that the extension arm 
is movable together with the movable presser towards and away from the 
pair of spaced stationary anvil members. 
Each of the pair of stationary anvil members includes at least two 
semi-circular undercut surface portions 84 and each is adapted to conform 
partially to an outer circumferential surface portion of the hollow pipe P 
to be bent. The pair of anvil members are aligned by the planar plate 20 
so that the axis of the hollow pipe is aligned with the undercut surface 
portions and is substantially parallel to a plane containing the planar 
plate. Each of the anvil members includes at least one of the undercut 
surface portions 8 above the planar plate 20 and at least preferably two 
of the undercut surface portions below the planar plate for balancing 
purposes of the tool and ease of handling. 
The indicia markings 72 on the planar plate is provided for positioning the 
presser thereon to impart a pre-designated angular bend to a pipe in 
accordance with the outer diameter of the pipe. 
The clamp member or clamp 56 is associated with the extension arm 34 for 
holding the extension arm in the one orientation with the pawl and the 
ratchet engaged. The clamp member is pivotally connected at 58 with the 
housing at 60 and the spring 66 associated with the clamp member and the 
extension arm to hold the clamp member in a braking engagement with the 
extension arm to coact with the pawl and ratchet to hold the pawl and 
ratchet in engagement with each other. The clamp member has a facing 
portion 57 for exerting pressure thereon for pivoting thereof to move the 
ratchet and pawl out of braking engagement with each other, and for 
movement of bearing surface member 64 out of engagement with extension arm 
34. Spring 66 is provided for pressing the clamp member in to braking 
engagement with the extension arm. The clamp member also controls the 
direction of movement of the movable presser member 32, permitting 
movement in one direction and preventing movement in the other direction 
unless its braking effect is released. One spring 52 is coupled between 
the pawl and the movable handle for urging the pawl out of engagement with 
some of the ratchet teeth while leaving the pawl in engagement with one of 
the ratchet teeth to move the extension arm and the movable presser in a 
direction towards the anvil members 30. Another spring 54 is coupled 
between the fixed or stationary handle 16 and the movable handle 14 to 
keep the handles separated from each other and to keep the one spring 52 
compressed to maintain the pawl in engagement with the ratchet in the one 
orientation of the extension arm. 
The movable presser 32 and the extension arm 34 include a connecting 
mechanism 36, 38 for coupling each together and for de-coupling each from 
each other. One is a male coupler 38 on the extension arm and a female 
coupler 36 on the movable presser. 
The movable presser 32 includes a semi-cylindraceous member 74 having one 
outer surface 76 provided with at least one curved undercut portion 80 to 
conform to the outside diameter of a pipe to be bent. The one outer 
surface may preferably be provided with a plurality of different undercut 
portions 80a, 80b, 80c to conform to the outside diameter of preselected 
pipes to be bent. The movable presser provides for one portion of its 
outer surface having the outer cylindraceous configuration with undercuts 
which are un the form of undercut furrows substantially partially 
coextensive with the outer diameter of the pipe to be bent and another 
portion having a planar facial surface perpendicular to the longitudinal 
axis of the extension rod 34, and the stationary anvil members 30 also 
have 
furrows 84a, 84b, 84c complementary to the furrows 80a, 80b, 80c of the 
movable presser and an outer cylindrical surface portion having tangential 
portions parallel to tangential portions of the movable presser. 
The planar plate 20 includes a U-shaped member 21 having each of its legs 
24 coupled with the housing 12 to provide a track-guideway 24a, 24b for 
the movable presser for movement towards and away from the housing and 
towards the base of the U-shaped member. The movable presser means 
includes a pair of oppositely facing face plates 86, 88 in contact with 
the track-guideway 24a, 24b for guiding the movement of the movable 
presser, and a central member 90 (FIG. 2) connecting the oppositely facing 
face plates 86, 88 together and positioned for movement between each of 
the legs 24a, 24b of the U-shaped member and forming the back guideway. 
The plier has a longitudinal axis coaxial with the axis of said extension 
arm, and a major diameter of the movable presser means is transverse to 
the longitudinal axis. 
While there is shown what is considered to be the preferred embodiments of 
the invention, various modifications and changes may be made without 
departing from the scope of the invention.