Modular rake shaft assembly

A modular rake shaft assembly is provided for attachment to and use the support frame of a bowling pin setting machine which includes three components namely, two rake arms interconnected by a tubular member. Each arm has a transversely extending stub shaft at one end. Each stub shaft has an opening on its outer end and a flange on its inner end. The tubular member has flanges at each end for connection to the respective stub shaft flanges. Each arm is tubular, but is deformed by a longitudinal groove along one side to increase the strength of the arms against bending. An angle member is also mounted on each arm to serve as a stop during movement of the arms and to further minimize the likelihood of breaking due to repeated striking of the arms against the stops. The flanges each have spaced lobes spaced unequally to accommodate swinging movement of the rake shaft assembly with respect to the support frame.

DESCRIPTION 
1. Technical Field 
This invention relates to a rake shaft assembly for an automatic bowling 
pin setting apparatus and more particularly to a modular rake shaft 
assembly which can be installed and/or replaced without the necessity of 
disassembling portions of the pin setting apparatus. 
2. Background Art 
In order to meet the needs of the bowling public, it has become necessary 
to devise bowling pin setting devices which can reset pins and return the 
bowling balls quickly and which are reliable in operation. Furthermore, 
the pin setting devices must be capable of rapid, inexpensive repair when 
they break down so as not to disrupt the bowling activity for a prolonged 
period of time. 
Unfortunately, the bowling pin setting devices have become so complex that 
when a breakdown occurs, it is often necessary to disassemble significant 
portions of the machine in order to repair or replace the broken 
component. In particular, it is often necessary to disassemble the support 
structure for the turret assembly which arrange the pins prior to setting 
them. This results in extended down time and high labor costs. 
An example of a component which is subject to relatively frequent failure, 
which can result in extended down time for the automatic pin setting 
apparatus, is the rake shaft assembly which pivots the rake to clear the 
pins from the alley after a bowling ball has been thrown. This component 
is typically made in one piece comprising a horizontal tubular member 
about which the component pivots and a pair of depending rake sweep arms 
on each side whose lower ends are connected indirectly to the rake. 
Typically, the arms swing against a pair of stops on the frame of the pin 
setting apparatus at the end of each cycle. As a result, the arms become 
fatigued after a period of use and break. In order to replace the rake 
shaft assembly, it is necessary to dismantle substantial portions of the 
pin setting machine. In particular, the turret support rods and the turret 
which holds the bowling pins must be disassembled. Furthermore, if the 
replacement rake shaft assembly is not exactly the same length as the one 
it replaces, the adjustments required in order to make it fit and work 
properly are considerable. The cost of replacement is not only the cost of 
the rake shaft assembly itself, but the considerable labor involved in 
removing the broken component and installing the new one. Furthermore, the 
rake shaft assembly is a relatively large component which is difficult to 
ship, requiring a large carton and is expensive to ship. 
In order to avoid these costly repairs, the broken arms are repaired by 
welding. However, the metal in the arms is fatigued and new breaks occur 
at successively lower points along the arm after each weld. Eventually a 
new rake shaft assembly is required. 
DISCLOSURE OF THE INVENTION 
In accordance with this invention, a modular rake shaft assembly for 
pivotal attachment to the frame of an automatic bowling pin setting 
apparatus is provided. The assembly includes three components, namely a 
pair of spaced parallel elongated rake sweep arms and an interconnecting 
pivot shaft. Each arm has a first and second end, with a yoke at the first 
end of each arm for pivotal attachment to a rake board. A transverse stub 
shaft is mounted on the second end of each arm along an axis transverse to 
the axis of the arms, the stub shafts each being rotationally supported on 
the frame of the apparatus. A removable tubular section extends between 
the respective stub shafts and means are provided for removably connecting 
the tubular section to the stub shafts to facilitate disassembly. 
More specifically, the rake shaft assembly includes a pair of parallel 
spaced elongated sweep arms wherein each arm includes a tubular member 
having a generally circular cross section with a score along one side 
thereof to deform one side to increase the strength of the member against 
bending. An angle member also can be provided along a portion of each arm 
to further strengthen each rake shaft arm against breakage due to striking 
a stop on the frame of the apparatus during each cycle of the apparatus. 
Additionally, each arm includes a U-shaped bracket at a first distal end 
of the arm for attachment to a rake board. A stub shaft is connected to 
and extends transversely across a second end of the arm and includes a 
bearing at the outer end of the stub shaft for pivoting the arm on the 
frame of the bowling pin setting apparatus about a transverse axis. 
An inwardly facing flange is attached to the inner end of each stub shaft. 
A tubular section extends between the stub shafts and has first and second 
ends, each having a flange corresponding in size and shape to the inwardly 
facing flanges. Means, such as bolts, are provided for removably 
connecting the respective stub shaft flanges to the respective tubular 
member flanges to facilitate assembly and disassembly of the rake shaft 
assembly. The flanges of both the stub shaft and the tubular section may 
be provided with angularly disposed lobes with openings therethrough for 
receiving the bolts. With three lobes on each flange, the spacing between 
lobes can be on the order of 105 degrees which leaves the two lobes on the 
outer sides of a center lobe spaced at an angle of 150 degrees. This 
arrangement provides space to clear the cross rods to which support rods 
for the turret assembly is connected. Conveniently, connections are 
provided along each arm for connection to suitable drive means to pivot 
the arms. 
With the rake shaft assembly described, it is possible to install and 
remove the same with virtually no disassembly of the automatic pin setting 
mechanism, which was previously impossible. Furthermore, the inner 
connecting flanges can be provided with shims to vary the length of the 
shaft to accommodate slight variations in the length of the shaft being 
replaced on different automatic pin setting devices. 
An additional advantage of the rake arm assembly described is that it can 
be broken down into the three components for shipping. This results in a 
package of sufficiently small size which can be shipped in a smaller 
carton more economically than in the larger carton required by the prior 
art one piece construction. 
Additional advantages of this invention will become apparent from the 
description which follows, taken in conjunction with the accompanying 
drawings.

BEST MODE FOR CARRYING OUT THE INVENTION 
In accordance with this invention, a modular rake shaft assembly A is 
provided on a bowling pin setting apparatus S for moving rake board 10 
from the raised position shown in FIG. 1 along an arcuate pass so as to 
sweep any pins on alley 12 into the pit 14 at the end of the alley. 
Conveniently, there are gutters 16 on each side of the alley bounded by 
side boards 18 to which a support frame assembly F is mounted, as shown. A 
turret assembly T is suspended above the alley, as by a pair of support 
rods 20 which extend forwardly over the rake shaft assembly A, as shown in 
FIGS. 1 and 2. The turret assembly is used to collect the pins and 
position them for lowering them onto the alley after the completion of 
each frame of bowling. 
The modular rake shaft assembly A of this invention is intended to replace 
the original equipment rake shaft assembly which is a single unitary 
generally U-shaped assembly having a transverse pivot rod with two 
depending arms for connection to the rake board 10. The difficulty 
encountered with the original equipment rake shaft assembly is that 
through repeated use wherein the arms strike stops 22 during each cycle, 
the depending arms ultimately fatigue and break at this point. Repairs are 
usually undertaken wherein the arms are welded but the result is that they 
ultimately break again at a lower point. They can be rewelded but the 
breaking continues to occur, always toward the distal end. Ultimately, the 
assembly must be replaced and since it is made in one piece, substantial 
disassembly of the pin setting apparatus S must be undertaken. In 
particular, supports 20 must be removed and turret T dropped down. In 
addition, the frame F must be at least partially disassembled in order to 
get the broken sweep arm assembly out. This is extremely time consuming, 
resulting in extensive down time of the bowling alley and very high labor 
costs in replacing the rake shaft assembly. Furthermore, since the 
assembly is rather large and bulky, it is expensive to ship. 
As best seen in FIG. 3, the modular rake shaft assembly A of this invention 
comprises three components, namely a right rake sweep arm 24 and a left 
rake sweep arm 26 interconnected at their upper ends by a tubular member 
28. As can best be seen in FIG. 3, each end of tubular member 28 
terminates in a flange 30. One flange 30 is connected to a flange 32 on 
stub shaft 34 of sweep arm 24 whereas the other flange 30 is connected to 
a flange 36 on stub shaft 38 of sweep arm 26. 
A detail of flange 30 is shown in FIG. 5 and all of the other flanges have 
the identical configuration. Conveniently, flange 30 has three lobes 40, 
42, and 44, each having a central opening through which bolts 46 pass to 
interconnect the flanges. Conveniently, lobes 40 and 44 are at an angle of 
approximately 150 to each other and at an angle of 105 respectively with 
respect to center lobe 42. This greater spacing between lobes 40 and 44 
allows the rake arm assembly to pivot without the flanges striking a cross 
bar 48 of frame F, as well as rod 50 to which the upper ends of support 
rods 20 are attached, as best seen in FIGS. 1 and 2. Center lobe 42 
extends between parallel arms 24 and 26 but at an angle to a plane formed 
by the arms. 
Right sweep arm 24 in addition to flange 32 and stub shaft 34 includes an 
arm member 52 which depends from stub shaft 34 and has a yoke 54 at the 
distal end thereof. An angle member 56 is attached to arm member 52, as by 
welding, and extends along a substantial length of arm member 52, as 
shown. Conveniently, the forward surface of angle 56 strikes stop 22 near 
the upper end of the angle member at the end of each swinging cycle of the 
rake arm. Because of the strengthening provided by the angle member, the 
likelihood of arm member 52 being broken or bent is minimized. 
An offset flange 58 is connected, as by welding, to the inner upper portion 
of angle member 56 for connection to a portion of the activating mechanism 
for the rake arms, such as piston 60 shown in FIG. 7. A second flange 62 
is connected to the side of arm member 52 above angle member 56 and is 
laterally spaced from the upper end of orrset flange 58. This flange, 
conveniently, serves as a point of connection for a spring 64 which is 
also part of the activation mechanism for the sweep arms. A third flange 
66 is provided at the bottom and generally opposite flange 62 for 
attachment to a piston rod 68 of activation piston 70, as shown. 
Advantageously, both flanges 62 and 66 can be provided on opposite sides 
of a plate 72 attached to the inner side of arm member 52 at the upper end 
thereof. A portion of this plate can extend around stub shaft 34, as seen 
in FIG. 7. 
The left rake sweep arm 26 is substantially the same as right rake sweep 
arm 24. It includes an arm member 74 having a yoke 76 connected at the 
distal end and including a longitudinal groove 78 extending substantially 
the full length of the inner side of arm 74, as best seen in FIG. 6. The 
arm is further strengthened by angle member 80 whose upper end is 
positioned to strike against stop 22 during the cycling of the apparatus. 
A plate 82 extends upwardly as an integral part of angle member 80 and 
includes an upper flange 84 for connection to a suitable spring (not 
shown) and a lower flange 86 which connects to piston arm 88 of piston 90. 
It will be understood that pistons 90 and 70 work in concert to swing the 
modular rake shaft assembly duing each cycling of the pin setting 
apparatus S. At the upper end of arm 74 is a stub shaft 92 which is 
substantially longer than stub shaft 34 and includes a pair of spaced 
flanges 94 and 96 which are connected to a latch mechanism 98 which forms 
a part of the activation mechanism for the pin setting apparatus. 
The way in which the modular rake arm assembly is pivotably mounted on the 
frame assembly can best be seen by viewing FIG. 9. The upper end of frame 
arm 49 has a flattened upper end portion 100 and a cylindrical pivot block 
102 is connected to the inside thereof, as by bolts 104. Conveniently, 
block 102 has a bearing sleeve 106 thereon about which the open end of 
stub shaft 32 pivots. A similar arrangement is provided at the upper end 
of the other side of the arm so that stub shaft 92 can pivot thereon. 
From the foregoing, the advantages of this invention are readily apparent. 
A modular rake shaft assembly has been devised which can be assembled and 
disassembled without disassembly of the frame of the automatic bowling pin 
setting apparatus. Furthermore, the sweep arms of the modular unit each 
have grooved sides to deform the tubular shape thereof to increase the 
strength of the arms against bending and are further provided with 
longitudinally extending angles, the upper end of which serves as an 
abuttment against a stop on the frame and further strengthen the arms 
against bending or breaking. Conveniently, the upper end of each arm is 
provided with a stub shaft having a hollow end serving as a bearing for 
pivoting the arms about a pivot block attached to the frame. Additionally, 
the stub shafts are provided with suitable flanges for connection to the 
operative mechanism of the pin setting apparatus to swing the sweep arms 
during each cycle of the pin setting machine. Finally, the connection 
between the modular units are flanges having three spaced lobes through 
which fastening means, such as bolts, extend to connect the flanges. The 
lobes are spaced around the periphery of the flanges so that the end lobes 
are spaced on the order of 105 degrees from the center load but on the 
order of 150 degrees from each other to accommodate the structural 
elements of the frame when the sweep arm assembly swings. 
The invention has been described in detail with particular reference to a 
preferred embodiment thereof, but it will be understood that variations 
and modifications can be effected within the spirit and scope of this 
invention.