Method of making a variable molded part

A method for variably making tie bar guides usable to guide tie bars within locking system housings having different inner dimensions, which tie bar guides have a body portion including four sides substantially aligned with an opening through the body portion for slidably receiving a tie bar. A mold block defines an opening for the body portion of the guide and receives material in a substantially flowable state. A cylindrical channel is also provided in the mold block along one side of said body portion opening. A semi-cylindrical pin is secured within the channel, which pin is pivoted to open a selected portion of the channel to the mold block opening and thereby extend the mold block opening and contiguous open channel to a selected outer dimension. Further, at least one slot is provided along a second side of the body portion opening. Prior to flowing material into the mold block, a selected number of substantially uniform slats sufficient to block the slot at the selected outer dimension are inserted into the slot. Finally, material is flowed into the mold block opening for forming the selected tie bar guide, the material is allowed to harden into the shape of the selected tie bar guide, and the tie bar guide is removed from the mold block.

BACKGROUND OF THE INVENTION 
1. Technical Field 
The present invention is directed toward a method of making molded parts 
having variable outer dimension requirements, and more particularly toward 
a method of making lock tie bar guides for assorted window configurations. 
2. Background Art 
Movable windows in general use sashes, which are either sliding, double 
hung or pivotal, with the latter type including awning and casement 
windows. Many different forms of window locks are available for locking a 
movable window. 
Commonly window locks include a handle on the interior side of the window 
frame, which handle can be manipulated to cause a cam member to grasp a 
keeper secured to the window sash. Enhanced security can be provided by 
locks which include two cam members and two keepers spaced apart on one 
side of the window frame and sash. Such locks typically include one cam 
member and one keeper adjacent the handle mechanism, and connect the 
handle to the other cam member by a tie bar. 
It is crucial for proper operation of locks having two spaced cam members 
that the tie bar be mounted to the window frame strongly enough to provide 
the desired security against forced entry. Further, smooth operation of 
the lock requires that the tie bar be mounted in a manner which allows 
easy reciprocation during operation without twisting or bending. Tie bar 
guides, usually molded plastic parts, are typically fixed to the window 
frame to mount the lock tie bar. 
However, locks are commonly used in a variety of different windows which, 
even though similar in appearance to an observer when closed, include 
differently oriented sash and frame insulation surfaces defining the 
opening within which the lock is mounted. Accordingly, though virtually 
identical lock components may be used with such different windows, 
identical tie bar guides cannot be used with all such windows as they will 
not be properly oriented to properly secure the tie bar while at the same 
time ensuring that the tie bar not bind from twisting or bending during 
operation. Providing appropriate tie bar guides for all of the different 
window configurations can be disproportionately costly to the overall cost 
of the lock. Further, in view of the virtually limitless different types 
of configurations possible and the ever increasing proliferation of new 
window configurations, creation of a new tie bar guide for each new window 
configuration can be undesirably time consuming and can thereby hinder 
sales of the entire lock to manufacturers of new windows. 
The present invention is directed toward overcoming one or more of the 
problems set forth above. 
SUMMARY OF THE INVENTION 
In one aspect of the present invention, a method is disclosed for variably 
making tie bar guides usable to guide tie bars within locking system 
housings having different inner dimensions, which tie bar guides have a 
body portion including four sides substantially aligned with an opening 
through the body portion for slidably receiving a tie bar. A mold block 
defines an opening for the body portion of the guide and receives material 
in a substantially flowable state. A cylindrical channel is also provided 
in the mold block along one side of said body portion opening. A 
semi-cylindrical pin is secured within the channel, which pin is pivoted 
to open a selected portion of the channel to the mold block opening and 
thereby extend the mold block opening and contiguous open channel to a 
selected outer dimension. Material is then flowed into the mold block 
opening for forming the selected tie bar guide, the material is allowed to 
harden into the shape of the selected tie bar guide, and the tie bar guide 
is removed from the mold block. 
In another aspect of the present invention, at least one slot is provided 
along a second side of the body portion opening, which second side is 
substantially at right angles to the body portion opening one side having 
the channel therein. Prior to flowing material into the mold block, a 
selected number of substantially uniform slats sufficient to block the 
slot at the selected outer dimension are inserted into the slot. 
It is an object of the invention to provide a method for inexpensively 
making tie bar guides which can be adapted to use in virtually any 
configuration window, which tie bar guides will also properly secure the 
tie bar to ensure smooth operation without undesirable bending or 
twisting. 
It is another object of the present invention to provide a method of making 
tie bar guides which can be quickly and easily adapted to making such 
guides to fit in virtually any window configuration, thereby enhancing the 
sales of the overall lock by providing virtually immediate product for 
customers no matter what the customer's window configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
A window lock 10 with which tie bar guides made according to the present 
invention may be used is shown in FIG. 1. The window has a window frame, 
indicated generally at 12, in which the window sash, generally indicated 
at 14, of a casement window is pivotally mounted. The mounting of such a 
window by hinges is well known in the art as well as use of a window 
operator, indicated generally at 16, for moving the window sash between 
closed and fully open positions or any desired position therebetween. 
Of course, as will be readily recognized, window locks such as shown herein 
can also be used for awning-type windows (in which the window sash pivots 
about a horizontal axis, rather than the vertical axis of the casement 
window). Further, such window locks could also be used with other types of 
movable windows, such as a double hung window. 
Window locks using tie bar guides have particular utility with a vinyl 
window, one embodiment of which is shown fragmentarily in FIG. 2. The 
window frame 12 has vertical wall sections 20, 22 suitably integrally 
interconnected by interconnecting walls and with a pair of interconnected 
vertical walls 24, 26 extending at right angles thereto and with the wall 
26 defining a room-facing surface of the window frame 12. 
Of course, a large variety of window frame configurations are common among 
different window manufacturers. Yet another such configuration is shown in 
FIG. 3, which has vertical wall sections 20', 22' suitably integrally 
interconnected by interconnecting walls and with a pair of interconnected 
vertical walls 24 , 26' extending at right angles thereto and with the 
wall 26' defining a room facing surface of the window frame 12'. 
The window sash 14 has a vertical exterior wall 28 with integrally 
associated walls including a wall 30 extending normal thereto which 
defines one of the walls mounting a vertical face panel 32 which can be 
brought closely adjacent to the vertical frame wall 24 when the window is 
closed and with a suitable weather strip 34 assuring a tight seal. 
One example of a window lock which requires tie bar guides made according 
to the present invention is disclosed in Nolte et al. U.S. Ser. No. 
535,282 (filed June 7, 1990), entitled "Window Lock" and having a common 
assignee with this application. The disclosure of that application is 
hereby incorporated by reference. Such a window lock is shown generally in 
FIG. 4. 
Specifically, that window lock has a slider 40 movable in a path extending 
lengthwise thereof and which mounts a cam member, in the form of a roller 
42. The slider 40 is movable in said path by its mounting on a planar part 
of a bracket 44 which mounts a pair of shouldered guide rivets 46, 48 
which extend through the slider slots 50, 52, respectively, and which 
enable movement of the slider from a window unlocked position to a window 
locked position. 
The bracket 44 has a pair of bracket flanges 54, 56 at right angles to the 
planar part thereof which can receive a pair of fasteners 58, 60, 
respectively, which thread into a pair of alignment bosses 62, 64 
extending inwardly from the lock housing 66 and which fit into a slot 
formed in the walls 24, 26 of the frame 12. The fasteners 58, 60 can draw 
the bracket flanges 54, 56 against the inner face of the frame wall 24 and 
the perimeter of the housing 10 against the wall 26 to capture the window 
frame therebetween. 
The housing 66 rotatably mounts the handle 68 for movement between two 
limit positions. One of these limit positions is the window locked 
positions, as shown in FIG. 4, wherein the handle 68 extends downwardly. 
The slider 40 and handle 68 have coacting means whereby rotation of the 
handle 68 results in linear movement of the slider along the path 
lengthwise of the slider 40. Such operation can be suitably obtained by, 
for example, a drive link (not shown) which rotates with the handle 68 and 
which is secured between tines 74, 76 of a forked section of the slider 
40. Thus, pivoting the handle 68 counterclockwise (as viewed in FIG. 4) to 
the position shown in FIG. 4 moves the lock 10 to the window locked 
position. Similarly, pivoting the handle 68 clockwise from the position 
shown in FIG. 4 moves the lock 10 to the window unlocked position. 
During locking action of the lock 10, the roller 42 on the slider 40 coacts 
with a ramped keeper 80 which is mounted by suitable means to the vertical 
wall 30 of the window sash 14. The ramped keeper 80 has an inclined ramp 
section 82 and a generally planar section 84. The lock 10 is shown in the 
locked position in FIG. 4, which is reached from the unlocked position by 
the slider 40 and roller 42 moving up, whereby the roller 42 first engages 
the inclined ramp section 82 and rolls therealong to draw and maintain the 
window sash fully closed when the roller 42 moves onto the planar section 
82 of the ramped keeper 80. 
In order to achieve multi-point locking, the window sash mounts a second 
ramped keeper 90 similar in construction to the ramped keeper 80 and 
suitably mounted to the sash vertical wall 30 at a distance from the first 
keeper 80. A second roller 92 similarly coacts with the ramped keeper 90, 
said roller 92 being rotatably mounted on a tie bar 94 which is connected 
to an end of the slider 40 for lengthwise movement therewith. An upper end 
of the tie bar 94 is movable within a tie bar guide 100 discussed in 
greater detail below. 
Further, the roller 42, 92 and the planar sections of the keepers 80, 90 
are bevelled to resist separation therebetween in a direction normal to 
the path of the slider 40. Such a feature has particular utility for a 
vinyl window because of the flexibility thereof. 
Multi-point locking is achieved with delayed lock-up of the roller 92 and 
ramped keeper 90 relative to the roller 42 and first ramped keeper 80. 
This is accomplished by spacing the ramped keepers 80, 90 apart a distance 
greater than the distance between the rollers 42, 92. This delayed 
multi-point locking limits the maximum amount of force required at any one 
time to achieve the full locking of the window. 
It is apparent that locks as described above require strong and secure tie 
bar guides 100 for their operation. To provide smooth and reliable 
operation, the tie bar guide 100 must be configured and positioned to 
ensure that the tie bar 94 may easily be moved longitudinally along the 
proper axis during locking and unlocking operation. Further, the tie bar 
guide 100 must also strongly anchor the tie bar 94 to the window frame 12 
to prevent forced entry through the window when locked (entry might be 
accomplished by prying the sash 14 sufficiently so that its ramped keeper 
90 pulls against the tie bar roller 92 sufficiently hard so that the tie 
bar 94 and its guide 100 are ripped from their mounting on the window 
frame 12). Still further, it is important that the tie bar guide 100 be 
manufactured inexpensively while at the same time be usable in a variety 
of different configuration window frames. 
The method of manufacture of the tie bar guides 100 disclosed herein 
readily allow for the inexpensive manufacture of guides providing all of 
these attributes. 
Specifically, as best shown in FIGS. 5, 7, and 8, the tie bar guide 100 
includes a body portion 102 with an opening 104 therethrough for slidably 
receiving the tie bar therein. As previously discussed, it is particularly 
important that this opening 104 be precisely oriented to prevent twisting 
of the tie bar about its axis or bending of the tie bar along its length, 
as either type of distortion prevents smooth operation of the lock 10. 
On one side of the guide 100, a pair of pads or legs 106, 108 are provided, 
which pads 106, 108 abut a frame vertical wall section 20 or 20' (see 
FIGS. 2 and 3) when mounted to the window frame 12. As described in 
greater detail hereafter, the length of these pads 106, 108 may be varied 
(as perhaps best seen from a comparison of FIGS. 2 and 3) in order to 
accommodate different window frame configurations to prevent the guide 
opening 104 from being misoriented so as to cause undesirable twisting of 
the tie bar 94. 
Further, a pair of variable projections 110, 112 are provided on a second 
side of the guide 100, as is also described in greater detail hereafter. 
The size of these projections 110, 112 can also be varied to accommodate 
different window configurations to prevent the guide opening 104 from 
being misoriented to one side or another and thus cause undesirable 
bending of the tie bar 94. Compare, for example, FIGS. 2 and 3, where the 
portions of the tie bar guide 100' in FIG. 3 are comparable to, but have 
different dimensions than, the tie bar guide 100 of FIG. 2, and thus the 
FIG. 3 portions are identified by comparable reference numbers "primed". 
A pair of screw holes 116, 118 are also provided through the guide body 
portion 102, allowing suitable screws 120 (see FIGS. 2 and 3) to be used 
to secure the guide 100 to the window frame 12. 
The tie bar guide 100 can be easily and inexpensively manufactured with a 
selected dimension outer periphery by molding suitable material (such as 
hard plastic) as follows. 
Specifically, a mold block 130 (see FIG. 7) defines an opening 
substantially in the shape of the guide 100 and receives the guide 
material (such as plastic) in a flowable state prior to setting. 
The projections 110, 112 are defined on one side of the guide 100 by two 
cylindrical channels 132 in the mold block 130 which receive a pair of 
pins 134 having a semi-cylindrical portion 136 on one end (see FIG. 6). 
The opposite end of each pin 134 includes a number of flatted portions 137 
which may be engaged by set screws 138 (see FIG. 5) to secure it in a 
desired position. Specifically, as perhaps best shown in FIG. 5 (two pins 
134 being shown in phantom) and FIG. 8, the size of the projections 110, 
112, and thus the length of the guide 100, can be set anywhere from L1 to 
L2 simply by appropriately turning the pins 134 prior to molding the guide 
100. 
The slots or openings 140, 142 can also be varied to provide different 
height pads 106, 108 by insertion of a selected number of slats 144 as 
shown in FIG. 5 (in phantom) and FIG. 7. Thus, for example, pad 106 can be 
molded with a height anywhere from zero to H1 see FIG. 7) by inserting the 
appropriate number of slats 144 prior to molding the guide 100. 
Once the mold block 130 is thus appropriately set up to make guides 100 
having the desired outer dimensions needed for a particular window 
configuration, the flowable plastic material is flowed into the mold block 
opening, the material is allowed to harden into the shape of the selected 
tie bar guide 100, and the tie bar guide 100 is removed from the mold 
block 130. 
As will be apparent to a person of ordinary skill in the art once they have 
obtained an understanding of the present invention, the above described 
method of making tie bar guides will allow for the inexpensive manufacture 
of guides which can be used in virtually any configuration window. 
Further, manufacturing guides according to the present invention will 
ensure that the guides will properly secure the tie bar to ensure smooth 
operation without undesirable bending or twisting. 
Still further, manufacturing tie bar guides according to the present 
invention simplifies changing from manufacturing one guide for one window 
configuration to manufacturing another guide for another window 
configuration. This not only helps to ensure minimal cost in manufacture, 
but also can even enhance the sales of the overall lock by providing 
virtually immediate product for customers no matter what the customer's 
window configuration. 
Still other aspects, objects, and advantages of the present invention can 
be obtained from a study of the specification, the drawings, and the 
appended claims.